EyeLink EEG / fNIRS / TMS Publications
All EyeLink EEG, fNIRS, and TMS research publications (with concurrent eye tracking) up until 2023 (with early 2024s) are listed below by year. You can search the publications using keywords such as P300, Gamma band, NIRS, etc. You can also search for individual author names. If we missed any EyeLink EEG, fNIRS, or TMS articles, please email us!
2020 |
Cristian Morales; Suril Gohel; Mitchell Scheiman; Xiaobo Li; Elio M. Santos; Ayushi Sangoi; Tara L. Alvarez Test-retest of a phoria adaptation stimulus-induced functional MRI experiment Journal Article In: Journal of Vision, vol. 20, no. 8, pp. 1–15, 2020. @article{Morales2020, This study was designed to identify the neural substrates activated during a phoria adaptation task using functional magnetic resonance imaging (MRI) in young adults with normal binocular vision and to test the repeatability of the fMRI measurements for this protocol. The phoria adaptation task consisted of a block protocol of 90 seconds of near visual crossed fixation followed by 90 seconds of far visual uncrossed fixation, repeated three times; the data were collected during two different experimental sessions. Results showed that the oculomotor vermis, cuneus, and primary visual cortex had the greatest functional activity within the regions of interest studied when stimulated by the phoria adaptation task. The oculomotor vermis functional activity had an intraclass correlation coefficient (ICC) of 0.3, whereas the bilateral cuneus and primary visual cortex had good ICC results of greater than 0.6. These results suggest that the sustained visual fixation task described within this study reliably activates the neural substrates of phoria adaptation. This protocol establishes a methodology that can be used in future longitudinal studies investigating therapeutic interventions that may modify phoria adaptation. |
Dillan J. Newbold; Timothy O. Laumann; Catherine R. Hoyt; Jacqueline M. Hampton; David F. Montez; Ryan V. Raut; Mario Ortega; Anish Mitra; Ashley N. Nielsen; Derek B. Miller; Babatunde Adeyemo; Annie L. Nguyen; Kristen M. Scheidter; Aaron B. Tanenbaum; Andrew N. Van; Scott Marek; Bradley L. Schlaggar; Alexandre R. Carter; Deanna J. Greene; Evan M. Gordon; Marcus E. Raichle; Steven E. Petersen; Abraham Z. Snyder; Nico U. F. Dosenbach Plasticity and spontaneous activity pulses in disused human brain circuits Journal Article In: Neuron, vol. 107, no. 3, pp. 580–589.e6, 2020. @article{Newbold2020, To induce brain plasticity in humans, we casted the dominant upper extremity for 2 weeks and tracked changes in functional connectivity using daily 30-min scans of resting-state functional MRI (rs-fMRI). Casting caused cortical and cerebellar regions controlling the disused extremity to functionally disconnect from the rest of the somatomotor system, while internal connectivity within the disused sub-circuit was maintained. Functional disconnection was evident within 48 h, progressed throughout the cast period, and reversed after cast removal. During the cast period, large, spontaneous pulses of activity propagated through the disused somatomotor sub-circuit. The adult brain seems to rely on regular use to maintain its functional architecture. Disuse-driven spontaneous activity pulses may help preserve functionally disconnected sub-circuits. |
Ioannis Agtzidis; Inga Meyhöfer; Michael Dorr; Rebekka Lencer Following Forrest Gump: Smooth pursuit related brain activation during free movie viewing Journal Article In: NeuroImage, vol. 216, pp. 116491, 2020. @article{Agtzidis2020, Most fMRI studies investigating smooth pursuit (SP) related brain activity have used simple synthetic stimuli such as a sinusoidally moving dot. However, real-life situations are much more complex and SP does not occur in isolation but within sequences of saccades and fixations. This raises the question whether the same brain networks for SP that have been identified under laboratory conditions are activated when following moving objects in a movie. Here, we used the publicly available studyforrest data set that provides eye movement recordings along with 3 T fMRI recordings from 15 subjects while watching the Hollywood movie “Forrest Gump”. All three major eye movement events, namely fixations, saccades, and smooth pursuit, were detected with a state-of-the-art algorithm. In our analysis, smooth pursuit (SP) was the eye movement of interest, while saccades were acting as the steady state of viewing behaviour due to their lower variability. For the fMRI analysis we used an event-related design modelling saccades and SP as regressors initially. Because of the interdependency of SP and content motion, we then added a new low-level content motion regressor to separate brain activations from these two sources. We identified higher BOLD-responses during SP than saccades bilaterally in MT+/V5, in middle cingulate extending to precuneus, and in the right temporoparietal junction. When the motion regressor was added, SP showed higher BOLD-response relative to saccades bilaterally in the cortex lining the superior temporal sulcus, precuneus, and supplementary eye field, presumably due to a confounding effect of background motion. Only parts of V2 showed higher activation during saccades in comparison to SP. Taken together, our approach should be regarded as proof of principle for deciphering brain activity related to SP, which is one of the most prominent eye movements besides saccades, in complex dynamic naturalistic situations. |
Sara Ajina; Miriam Pollard; Holly Bridge The superior colliculus and amygdala support evaluation of face trait in blindsight Journal Article In: Frontiers in Neurology, vol. 11, pp. 769, 2020. @article{Ajina2020, Humans can respond rapidly to viewed expressions of fear, even in the absence of conscious awareness. This is demonstrated using visual masking paradigms in healthy individuals and in patients with cortical blindness due to damage to the primary visual cortex (V1) - so called affective blindsight. Humans have also been shown to implicitly process facial expressions representing important social dimensions. Two major axes, dominance and trustworthiness, are proposed to characterize the social dimensions of face evaluation. The processing of both types of implicit stimuli is believed to occur via similar subcortical pathways involving the amygdala. However, we do not know whether unconscious processing of more subtle expressions of facial traits can occur in blindsight, and if so, how. To test this, we studied 13 patients with unilateral V1 damage and visual field loss. We assessed their ability to detect and discriminate faces that had been manipulated along two orthogonal axes of trustworthiness and dominance to generate five trait levels inside the blind visual field: dominant, submissive, trustworthy, untrustworthy, and neutral. We compared neural activity and functional connectivity in patients classified as blindsight positive or negative for these stimuli. We found that dominant faces were most likely to be detected above chance, with individuals demonstrating unique interactions between performance and face trait. Only patients with blindsight (n = 8) showed significant preference in the superior colliculus and amygdala for face traits in the blind visual field, and a critical functional connection between the amygdala and superior colliculus in the damaged hemisphere. We also found a significant correlation between behavioral performance and fMRI activity in the amygdala and lateral geniculate nucleus across all participants. Our findings confirm that affective blindsight involving the superior colliculus and amygdala extends to the processing of socially salient but emotionally neutral facial expressions when V1 is damaged. This pathway is distinct from that which supports motion blindsight, as both types of blindsight can exist in the absence of the other with corresponding patterns of residual connectivity. |
Noor Z. Al Dahhan; John R. Kirby; Ying Chen; Donald C. Brien; Douglas P. Munoz Examining the neural and cognitive processes that underlie reading through naming speed tasks Journal Article In: European Journal of Neuroscience, vol. 51, no. 11, pp. 2277–2298, 2020. @article{AlDahhan2020, We combined fMRI with eye tracking and speech recording to examine the neural and cognitive mechanisms that underlie reading. To simplify the study of the complex processes involved during reading, we used naming speed (NS) tasks (also known as rapid automatized naming or RAN) as a focus for this study, in which average reading right-handed adults named sets of stimuli (letters or objects) as quickly and accurately as possible. Due to the possibility of spoken output during fMRI studies creating motion artifacts, we employed both an overt session and a covert session. When comparing the two sessions, there were no significant differences in behavioral performance, sensorimotor activation (except for regions involved in the motor aspects of speech production) or activation in regions within the left-hemisphere-dominant neural reading network. This established that differences found between the tasks within the reading network were not attributed to speech production motion artifacts or sensorimotor processes. Both behavioral and neuroimaging measures showed that letter naming was a more automatic and efficient task than object naming. Furthermore, specific manipulations to the NS tasks to make the stimuli more visually and/or phonologically similar differentially activated the reading network in the left hemisphere associated with phonological, orthographic and orthographic-to-phonological processing, but not articulatory/motor processing related to speech production. These findings further our understanding of the underlying neural processes that support reading by examining how activation within the reading network differs with both task performance and task characteristics. |
Mareike Bacha-Trams; Elisa Ryyppö; Enrico Glerean; Mikko Sams; Iiro P. Jääskeläinen Social perspective-taking shapes brain hemodynamic activity and eye movements during movie viewing Journal Article In: Social Cognitive and Affective Neuroscience, vol. 15, no. 2, pp. 175–191, 2020. @article{BachaTrams2020, Putting oneself into the shoes of others is an important aspect of social cognition.We measured brain hemodynamic activity and eye-gaze patterns while participants were viewing a shortened version of the movie 'My Sister's Keeper' from two perspectives: That of a potential organ donor, who violates moral norms by refusing to donate her kidney, and that of a potential organ recipient, who suffers in pain. Inter-subject correlation (ISC) of brain activity was significantly higher during the potential organ donor's perspective in dorsolateral and inferior prefrontal, lateral and inferior occipital, and inferior-anterior temporal areas. In the reverse contrast, stronger ISC was observed in superior temporal, posterior frontal and anterior parietal areas. Eye-gaze analysis showed higher proportion of fixations on the potential organ recipient during both perspectives. Taken together, these results suggest that during social perspective-taking different brain areas can be flexibly recruited depending on the nature of the perspective that is taken. |
Valerie M. Beck; Timothy J. Vickery Oculomotor capture reveals trial-by-trial neural correlates of attentional guidance by contents of visual working memory Journal Article In: Cortex, vol. 122, pp. 159–169, 2020. @article{Beck2020, Evidence from attentional and oculomotor capture, contingent capture, and other paradigms suggests that mechanisms supporting human visual working memory (VWM) and visual attention are intertwined. Features held in VWM bias guidance toward matching items even when those features are task irrelevant. However, the neural basis of this interaction is underspecified. Prior examinations using fMRI have primarily relied on coarse comparisons across experimental conditions that produce varying amounts of capture. To examine the neural dynamics of attentional capture on a trial-by-trial basis, we applied an oculomotor paradigm that produced discrete measures of capture. On each trial, subjects were shown a memory item, followed by a blank retention interval, then a saccade target that appeared to the left or right. On some trials, an irrelevant distractor appeared above or below fixation. Once the saccade target was fixated, subjects completed a forced-choice memory test. Critically, either the target or distractor could match the feature held in VWM. Although task irrelevant, this manipulation produced differences in behavior: participants were more likely to saccade first to an irrelevant VWM-matching distractor compared with a non-matching distractor – providing a discrete measure of capture. We replicated this finding while recording eye movements and scanning participants' brains using fMRI. To examine the neural basis of oculomotor capture, we separately modeled the retention interval for capture and non-capture trials within the distractor-match condition. We found that frontal activity, including anterior cingulate cortex and superior frontal gyrus regions, differentially predicted subsequent oculomotor capture by a memory-matching distractor. Other regions previously implicated as involved in attentional capture by VWM-matching items showed no differential activity across capture and non-capture trials, even at a liberal threshold. Our findings demonstrate the power of trial-by-trial analyses of oculomotor capture as a means to examine the underlying relationship between VWM and attentional guidance systems. |
Richard F. Betzel; Lisa Byrge; Farnaz Zamani Esfahlani; Daniel P. Kennedy Temporal fluctuations in the brain's modular architecture during movie-watching Journal Article In: NeuroImage, vol. 213, pp. 116687, 2020. @article{Betzel2020, Brain networks are flexible and reconfigure over time to support ongoing cognitive processes. However, tracking statistically meaningful reconfigurations across time has proven difficult. This has to do largely with issues related to sampling variability, making instantaneous estimation of network organization difficult, along with increased reliance on task-free (cognitively unconstrained) experimental paradigms, limiting the ability to interpret the origin of changes in network structure over time. Here, we address these challenges using time-varying network analysis in conjunction with a naturalistic viewing paradigm. Specifically, we developed a measure of inter-subject network similarity and used this measure as a coincidence filter to identify synchronous fluctuations in network organization across individuals. Applied to movie-watching data, we found that periods of high inter-subject similarity coincided with reductions in network modularity and increased connectivity between cognitive systems. In contrast, low inter-subject similarity was associated with increased system segregation and more rest-like architectures. We then used a data-driven approach to uncover clusters of functional connections that follow similar trajectories over time and are more strongly correlated during movie-watching than at rest. Finally, we show that synchronous fluctuations in network architecture over time can be linked to a subset of features in the movie. Our findings link dynamic fluctuations in network integration and segregation to patterns of inter-subject similarity, and suggest that moment-to-moment fluctuations in functional connectivity reflect shared cognitive processing across individuals. |
Rodrigo M. Braga; Lauren M. DiNicola; Hannah C. Becker; Randy L. Buckner Situating the left-lateralized language network in the broader organization of multiple specialized large-scale distributed networks Journal Article In: Journal of neurophysiology, vol. 124, no. 5, pp. 1415–1448, 2020. @article{Braga2020, Using procedures optimized to explore network organization within the individual, the topography of a candidate language network was characterized and situated within the broader context of adjacent networks. The candidate network was first identified using functional connectivity and replicated across individuals, acquisition tasks, and analytical methods. In addition to classical language regions near the perisylvian cortex and temporal pole, regions were also observed in dorsal posterior cingulate, midcingulate, and anterior superior frontal and inferior temporal cortex. The candidate network was selectively activated when processing meaningful (as contrasted with nonword) sentences, whereas spatially adjacent networks showed minimal or even decreased activity. Results were replicated and triplicated across two prospectively acquired cohorts. Examined in relation to adjacent networks, the topography of the language network was found to parallel the motif of other association networks, including the transmodal association networks linked to theory of mind and episodic remembering (often collectively called the default network). The several networks contained juxtaposed regions in multiple association zones. Outside of these juxtaposed higher-order networks, we further noted a distinct frontotemporal network situated between language regions and a frontal orofacial motor region and a temporal auditory region. A possibility is that these functionally related sensorimotor regions might anchor specialization of neighboring association regions that develop into a language network. What is most striking is that the canonical language network appears to be just one of multiple similarly organized, differentially specialized distributed networks that populate the evolutionarily expanded zones of human association cortex. |
Johannes Brand; Marco Piccirelli; Marie Claude Hepp-Reymond; Kynan Eng; Lars Michels Brain activation during visually guided finger movements Journal Article In: Frontiers in Human Neuroscience, vol. 14, pp. 309, 2020. @article{Brand2020a, Computer interaction via visually guided hand movements often employs either abstract cursor-based feedback or virtual hand (VH) representations of varying degrees of realism. The effect of changing this visual feedback in virtual reality settings is currently unknown. In this study, 19 healthy right-handed adults performed index finger movements (“action”) and observed movements (“observation”) with four different types of visual feedback: a simple circular cursor (CU), a point light (PL) pattern indicating finger joint positions, a shadow cartoon hand (SH) and a realistic VH. Finger movements were recorded using a data glove, and eye-tracking was recorded optically. We measured brain activity using functional magnetic resonance imaging (fMRI). Both action and observation conditions showed stronger fMRI signal responses in the occipitotemporal cortex compared to baseline. The action conditions additionally elicited elevated bilateral activations in motor, somatosensory, parietal, and cerebellar regions. For both conditions, feedback of a hand with a moving finger (SH, VH) led to higher activations than CU or PL feedback, specifically in early visual regions and the occipitotemporal cortex. Our results show the stronger recruitment of a network of cortical regions during visually guided finger movements with human hand feedback when compared to a visually incomplete hand and abstract feedback. This information could have implications for the design of visually guided tasks involving human body parts in both research and application or training-related paradigms. |
Batel Buaron; Daniel Reznik; Roee Gilron; Roy Mukamel Voluntary actions modulate perception and neural representation of action-consequences in a hand-dependent manner Journal Article In: Cerebral Cortex, vol. 30, no. 12, pp. 6097–6107, 2020. @article{Buaron2020, Evoked neural activity in sensory regions and perception of sensory stimuli are modulated when the stimuli are the consequence of voluntary movement, as opposed to an external source. It has been suggested that such modulations are due to motor commands that are sent to relevant sensory regions during voluntary movement. However, given the anatomical-functional laterality bias of the motor system, it is plausible that the pattern of such behavioral and neural modulations will also exhibit a similar bias, depending on the effector triggering the stimulus (e.g., right/left hand). Here, we examined this issue in the visual domain using behavioral and neural measures (fMRI). Healthy participants judged the relative brightness of identical visual stimuli that were either self-triggered (using right/left hand button presses), or triggered by the computer. Stimuli were presented either in the right or left visual field. Despite identical physical properties of the visual consequences, we found stronger perceptual modulations when the triggering hand was ipsi- (rather than contra-) lateral to the stimulated visual field. Additionally, fMRI responses in visual cortices differentiated between stimuli triggered by right/left hand. Our findings support a model in which voluntary actions induce sensory modulations that follow the anatomical-functional bias of the motor system. |
Nicoletta Cera; João Castelhano; Cátia Oliveira; Joana Carvalho; Ana Luísa Quinta Gomes; Maria Manuela Peixoto; Raquel Pereira; Erick Janssen; Miguel Castelo-Branco; Pedro Nobre The role of anterior and posterior insula in male genital response and in visual attention: An exploratory multimodal fMRI study Journal Article In: Scientific Reports, vol. 10, pp. 18463, 2020. @article{Cera2020, Several studies highlighted the role of insula on several functions and in sexual behavior. This exploratory study examines the relationships among genital responses, brain responses, and eye movements, to disentangle the role played by the anterior and posterior insula during different stages of male sexual response and during visual attention to sexual stimuli. In 19 healthy men, fMRI, eye movement, and penile tumescence data were collected during a visual sexual stimulation task. After a whole-brain analysis comparing neutral and sexual clips and confirming a role for the bilateral insulae, we selected two bilateral seed regions in anterior and posterior insula for functional connectivity analysis. Single-ROI-GLMs were run for the FC target regions. Single-ROI-GLMs were performed based on areas to which participants fixate: “Faces”, “Genitals,” and “Background” with the contrast “Genitals > Faces”. Single-ROI-GLMs with baseline, onset, and sustained PT response for the sexual clips were performed. We found stronger effects for the posterior than the anterior insula. In the target regions of the posterior insula, we found three different pathways: the first involved in visual attention, onset of erection, and sustained erection; the second involved only in the onset of erection, and the third limited to sustained erection. |
Rutvik H. Desai; Wonil Choi; John M. Henderson Word frequency effects in naturalistic reading Journal Article In: Language, Cognition and Neuroscience, vol. 35, no. 5, pp. 1–12, 2020. @article{Desai2020, Word frequency is a central psycholinguistic variable that accounts for substantial variance in language processing. A number of neuroimaging studies have examined frequency at a single word level, typically demonstrating a strong negative, and sometimes positive correlation between frequency and hemodynamic response. Here, 40 subjects read passages of text in an MRI scanner while their eye movements were recorded. We used fixation-related analysis to identify neural activity tied to the frequency of each fixated word. We found that negative correlations with frequency were reduced, while strong positive correlations were found in the temporal and parietal areas associated with semantics. We propose that the processing cost of low frequency words is reduced due to contextual cues. Meanings of high frequency words are more readily accessed and integrated with context resulting in enhanced processing in the semantic system. The results demonstrate similarities and differences between single word and naturalistic text processing. |
Tianlu Wang; Ronald Peeters; Dante Mantini; Céline R. Gillebert In: NeuroImage: Clinical, vol. 28, pp. 102513, 2020. @article{Wang2020g, The intraparietal sulcus (IPS) plays a key role in the distribution of attention across the visual field. In stroke patients, an imbalance between left and right IPS activity has been related to a spatial bias in visual attention characteristic of hemispatial neglect. In this study, we describe the development and implementation of a real-time functional magnetic resonance imaging neurofeedback protocol to noninvasively and volitionally control the interhemispheric IPS activity balance in neurologically healthy participants. Six participants performed three neurofeedback training sessions across three weeks. Half of them trained to voluntarily increase brain activity in left relative to right IPS, while the other half trained to regulate the IPS activity balance in the opposite direction. Before and after the training, we estimated the distribution of attention across the visual field using a whole and partial report task. Over the course of the training, two of the three participants in the left-IPS group increased the activity in the left relative to the right IPS, while the participants in the right-IPS group were not able to regulate the interhemispheric IPS activity balance. We found no evidence for a decrease in resting-state functional connectivity between left and right IPS, and the spatial distribution of attention did not change over the course of the experiment. This study indicates the possibility to voluntarily modulate the interhemispheric IPS activity balance. Further research is warranted to examine the effectiveness of this technique in the rehabilitation of post-stroke hemispatial neglect. |
Raphael Vallat; Alain Nicolas; Perrine Ruby Brain functional connectivity upon awakening from sleep predicts interindividual differences in dream recall frequency Journal Article In: Sleep, vol. 43, no. 2, pp. 1–11, 2020. @article{Vallat2020, Why do some individuals recall dreams every day while others hardly ever recall one? We hypothesized that sleep inertia—the transient period following awakening associated with brain and cognitive alterations—could be a key mechanism to explain interindividual differences in dream recall at awakening. To test this hypothesis, we measured the brain functional connectivity (combined electroencephalography–functional magnetic resonance imaging) and cognition (memory and mental calculation) of high dream recallers (HR |
Clifford I. Workman; Keith J. Yoder; Jean Decety The dark side of morality–neural mechanisms underpinning moral convictions and support for violence Journal Article In: AJOB Neuroscience, vol. 11, no. 4, pp. 269–284, 2020. @article{Workman2020, People are motivated by shared social values that, when held with moral conviction, can serve as compelling mandates capable of facilitating support for ideological violence. The current study examined this dark side of morality by identifying specific cognitive and neural mechanisms associated with beliefs about the appropriateness of sociopolitical violence, and determining the extent to which the engagement of these mechanisms was predicted by moral convictions. Participants reported their moral convictions about a variety of sociopolitical issues prior to undergoing functional MRI scanning. During scanning, they were asked to evaluate the appropriateness of violent protests that were ostensibly congruent or incongruent with their views about sociopolitical issues. Complementary univariate and multivariate analytical strategies comparing neural responses to congruent and incongruent violence identified neural mechanisms implicated in processing salience and in the encoding of subjective value. As predicted, neuro-hemodynamic response was modulated parametrically by individuals' beliefs about the appropriateness of congruent relative to incongruent sociopolitical violence in ventromedial prefrontal cortex, and by moral conviction in ventral striatum. Overall moral conviction was predicted by neural response to congruent relative to incongruent violence in amygdala. Together, these findings indicate that moral conviction about sociopolitical issues serves to increase their subjective value, overriding natural aversion to interpersonal harm. |
Clément Tarrano; Nicolas Wattiez; Cécile Delorme; Eavan M. McGovern; Vanessa Brochard; Stéphane Thobois; Christine Tranchant; David Grabli; Bertrand Degos; Jean Christophe Corvol; Jean Michel Pedespan; Pierre Krystkoviak; Jean Luc Houeto; Adrian Degardin; Luc Defebvre; Romain Valabrègue; Marie Vidailhet; Pierre Pouget; Emmanuel Roze; Yulia Worbe Visual sensory processing is altered in myoclonus dystonia Journal Article In: Movement Disorders, vol. 35, no. 1, pp. 151–160, 2020. @article{Tarrano2020, Background: Abnormal sensory processing, including temporal discrimination threshold, has been described in various dystonic syndromes. Objective: To investigate visual sensory processing in DYT-SGCE and identify its structural correlates. Methods: DYT-SGCE patients without DBS (DYT-SGCE-non-DBS) and with DBS (DYT-SGCE-DBS) were compared to healthy volunteers in three tasks: a temporal discrimination threshold, a movement orientation discrimination, and movement speed discrimination. Response times attributed to accumulation of sensory visual information were computationally modelized, with μ parameter indicating sensory mean growth rate. We also identified the structural correlates of behavioral performance for temporal discrimination threshold. Results: Twenty-four DYT-SGCE-non-DBS, 13 DYT-SGCE-DBS, and 25 healthy volunteers were included in the study. In DYT-SGCE-DBS, the discrimination threshold was higher in the temporal discrimination threshold (P = 0.024), with no difference among the groups in other tasks. The sensory mean growth rate (μ) was lower in DYT-SGCE in all three tasks (P < 0.01), reflecting a slower rate of sensory accumulation for the visual information in these patients independent of DBS. Structural imaging analysis showed a thicker left primary visual cortex (P = 0.001) in DYT-SGCE-non-DBS compared to healthy volunteers, which also correlated with lower μ in temporal discrimination threshold (P = 0.029). In DYT-SGCE-non-DBS, myoclonus severity also correlated with a lower μ in the temporal discrimination threshold task (P = 0.048) and with thicker V1 on the left (P = 0.022). Conclusion: In DYT-SGCE, we showed an alteration of the visual sensory processing in the temporal discrimination threshold that correlated with myoclonus severity and structural changes in the primary visual cortex. |
Johan N. Meer; Michael Breakspear; Luke J. Chang; Saurabh Sonkusare; Luca Cocchi Movie viewing elicits rich and reliable brain state dynamics Journal Article In: Nature Communications, vol. 11, pp. 5004, 2020. @article{Meer2020, Adaptive brain function requires that sensory impressions of the social and natural milieu are dynamically incorporated into intrinsic brain activity. While dynamic switches between brain states have been well characterised in resting state acquisitions, the remodelling of these state transitions by engagement in naturalistic stimuli remains poorly understood. Here, we show that the temporal dynamics of brain states, as measured in fMRI, are reshaped from predominantly bistable transitions between two relatively indistinct states at rest, toward a sequence of well-defined functional states during movie viewing whose transitions are temporally aligned to specific features of the movie. The expression of these brain states covaries with different physiological states and reflects subjectively rated engagement in the movie. In sum, a data-driven decoding of brain states reveals the distinct reshaping of functional network expression and reliable state transitions that accompany the switch from resting state to perceptual immersion in an ecologically valid sensory experience. |
Tobias Talanow; Anna-Maria Kasparbauer; Julia V. Lippold; Bernd Weber; Ulrich Ettinger Neural correlates of proactive and reactive inhibition of saccadic eye movements Journal Article In: Brain Imaging and Behavior, vol. 14, no. 1, pp. 72–88, 2020. @article{Talanow2020, Although research on goal-directed, proactive inhibitory control (IC) and stimulus-driven, reactive IC is growing, no previous study has compared proactive IC in conditions of uncertainty with regard to upcoming inhibition to conditions of certain upcoming IC. Therefore, we investigated effects of certainty and uncertainty on behavior and blood oxygen level dependent (BOLD) signal in proactive and reactive IC. In two studies, healthy adults performed saccadic go/no-go and prosaccade/antisaccade tasks. The certainty manipulation had a highly significant behavioral effect in both studies, with inhibitory control being more successful under certain than uncertain conditions on both tasks (p ≤ 0.001). Saccadic go responses were significantly less efficient under conditions of uncertainty than certain responding (p < 0.001). Event-related functional magnetic resonance imaging (fMRI) (one study) revealed a dissociation of certainty- and uncertainty-related proactive inhibitory neural correlates in the go/no-go task, with lateral and medial prefrontal and occipital cortex showing stronger deactivations during uncertainty than during certain upcoming inhibition, and lateral parietal cortex being activated more strongly during certain upcoming inhibition than uncertainty or certain upcoming responding. In the antisaccade task, proactive BOLD effects arose due to stronger deactivations in uncertain response conditions of both tasks and before certain prosaccades than antisaccades. Reactive inhibition-related BOLD increases occurred in inferior parietal cortex and supramarginal gyrus (SMG) in the go/no-go task only. Proactive IC may imply focusing attention on the external environment for encoding salient or alerting events as well as inhibitory mechanisms that reduce potentially distracting neural processes. SMG and inferior parietal cortex may play an important role in both proactive and reactive IC of saccades. |
Tamar Kolodny; Michael Paul Schallmo; Jennifer Gerdts; Raphael A. Bernier; Scott O. Murray Response dissociation in hierarchical cortical circuits: A unique feature of autism spectrum disorder Journal Article In: Journal of Neuroscience, vol. 40, no. 10, pp. 2269–2281, 2020. @article{Kolodny2020, A prominent hypothesis regarding the pathophysiology of autism is that an increase in the balance between neural excitation and inhibition results in an increase in neural responses. However, previous reports of population-level response magnitude in individuals with autism have been inconsistent. Critically, network interactions have not been considered in previous neuroimaging studies of excitation and inhibition imbalance in autism. In particular, a defining characteristic of cortical organization is its hierarchical and interactive structure; sensory and cognitive systems are comprised of networks where later stages inherit and build upon the processing of earlier input stages, and also influence and shape earlier stages by top-down modulation. Here we used the well established connections of the human visual system to examine response magnitudes in a higher-order motion processing region [middle temporal area (MT+)] and its primary input region (V1). Simple visual stimuli were presented to adult individuals with autism spectrum disorders (ASD; n = 24, mean age 23 years, 8 females) and neurotypical controls (n = 24, mean age 22, 8 females) during fMRI scanning. We discovered a strong dissociation of fMRI response magnitude between region MT+ and V1 in individuals with ASD: individuals with high MT+ responses had attenuated V1 responses. The magnitude of MT+ amplification and of V1 attenuation was associated with autism severity, appeared to result from amplified suppressive feedback from MT+ to V1, and was not present in neurotypical controls. Our results reveal the potential role of altered hierarchical network interactions in the pathophysiology of ASD. |
Elizabeth S. Lorenc; Annelinde R. E. Vandenbroucke; Derek E. Nee; Floris P. Lange; Mark D'Esposito Dissociable neural mechanisms underlie currently-relevant, future-relevant, and discarded working memory representations Journal Article In: Scientific Reports, vol. 10, pp. 11195, 2020. @article{Lorenc2020, In daily life, we use visual working memory (WM) to guide our actions. While attending to currently-relevant information, we must simultaneously maintain future-relevant information, and discard information that is no longer relevant. However, the neural mechanisms by which unattended, but future-relevant, information is maintained in working memory, and future-irrelevant information is discarded, are not well understood. Here, we investigated representations of these different information types, using functional magnetic resonance imaging in combination with multivoxel pattern analysis and computational modeling based on inverted encoding model simulations. We found that currently-relevant WM information in the focus of attention was maintained through representations in visual, parietal and posterior frontal brain regions,whereas deliberate forgetting led to suppression of the discarded representations in early visual cortex. In contrast, future-relevant information was neither inhibited nor actively maintained in these areas. These findings suggest that different neural mechanisms underlie the WM representation of currently- and future-relevant information, as compared to information that is discarded from WM. |
Masih Rahmati; Kevin DeSimone; Clayton E. Curtis; Kartik K. Sreenivasan Spatially-specific working memory activity in the human superior colliculus Journal Article In: Journal of Neuroscience, vol. 40, no. 49, pp. 9487–9495, 2020. @article{Rahmati2020, Theoretically, working memory (WM) representations are encoded by population activity of neurons with distributed tuning across the stored feature. Here, we leverage computational neuroimaging approaches to map the topographic organization of human superior colliculus (SC) and model how population activity in SC encodes WM representations. We first modeled receptive field properties of voxels in SC, deriving a detailed topographic organization resembling that of the primate SC. Neural activity within human (5 male and 1 female) SC persisted throughout a retention interval of several types of modified memory-guided saccade tasks. Assuming an underlying neural architecture of the SC based on its retinotopic organization, we used an encoding model to show that the pattern of activity in human SC represents locations stored in WM. Our tasks and models allowed us to dissociate the locations of visual targets and the motor metrics of memory-guided saccades from the spatial locations stored in WM, thus confirming that human SC represents true WM information. These data have several important implications. They add the SC to a growing number of cortical and subcortical brain areas that form distributed networks supporting WM functions. Moreover, they specify a clear neural mechanism by which topographically organized SC encodes WM representations. |
Zvi N. Roth; Minyoung Ryoo; Elisha P. Merriam Task-related activity in human visual cortex Journal Article In: PLoS Biology, vol. 18, no. 11, pp. 1–28, 2020. @article{Roth2020, The brain exhibits widespread endogenous responses in the absence of visual stimuli, even at the earliest stages of visual cortical processing. Such responses have been studied in monkeys using optical imaging with a limited field of view over visual cortex. Here, we used functional MRI (fMRI) in human participants to study the link between arousal and endogenous responses in visual cortex. The response that we observed was tightly entrained to task timing, was spatially extensive, and was independent of visual stimulation. We found that this response follows dynamics similar to that of pupil size and heart rate, suggesting that task-related activity is related to arousal. Finally, we found that higher reward increased response amplitude while decreasing its trial-To-Trial variability (i.e., the noise). Computational simulations suggest that increased temporal precision underlies both of these observations. Our findings are consistent with optical imaging studies in monkeys and support the notion that arousal increases precision of neural activity. |
Tom Salomon; Rotem Botvinik-Nezer; Shiran Oren; Tom Schonberg Enhanced striatal and prefrontal activity is associated with individual differences in nonreinforced preference change for faces Journal Article In: Human Brain Mapping, vol. 41, no. 4, pp. 1043–1060, 2020. @article{Salomon2020, Developing effective preference modification paradigms is crucial to improve the quality of life in a wide range of behaviors. The cue-approach training (CAT) paradigm has been introduced as an effective tool to modify preferences lasting months, without external reinforcements, using the mere association of images with a cue and a speeded button response. In the current work for the first time, we used fMRI with faces as stimuli in the CAT paradigm, focusing on face-selective brain regions. We found a behavioral change effect of CAT with faces immediately and 1-month after training, however face-selective regions were not indicative of behavioral change and thus preference change is less likely to rely on face processing brain regions. Nevertheless, we found that during training, fMRI activations in the ventral striatum were correlated with individual preference change. We also found a correlation between preference change and activations in the ventromedial prefrontal cortex during the binary choice phase. Functional connectivity among striatum, prefrontal regions, and high-level visual regions was also related to individual preference change. Our work sheds new light on the involvement of neural mechanisms in the process of valuation. This could lead to development of novel real-world interventions. |
Alexandre Sayal; Teresa Sousa; João V. Duarte; Gabriel N. Costa; Ricardo Martins; Miguel Castelo-Branco Identification of competing neural mechanisms underlying positive and negative perceptual hysteresis in the human visual system Journal Article In: NeuroImage, vol. 221, pp. 117153, 2020. @article{Sayal2020, Hysteresis is a well-known phenomenon in physics that relates changes in a system with its prior history. It is also part of human visual experience (perceptual hysteresis), and two different neural mechanisms might explain it: persistence (a cause of positive hysteresis), which forces to keep a current percept for longer, and adaptation (a cause of negative hysteresis), which in turn favors the switch to a competing percept early on. In this study, we explore the neural correlates underlying these mechanisms and the hypothesis of their competitive balance, by combining behavioral assessment with fMRI. We used machine learning on the behavioral data to distinguish between positive and negative hysteresis, and discovered a neural correlate of persistence at a core region of the ventral attention network, the anterior insula. Our results add to the understanding of perceptual multistability and reveal a possible mechanistic explanation for the regulation of different forms of perceptual hysteresis. |
Daniel J. Schad; Michael A. Rapp; Maria Garbusow; Stephan Nebe; Miriam Sebold; Elisabeth Obst; Christian Sommer; Lorenz Deserno; Milena Rabovsky; Eva Friedel; Nina Romanczuk-Seiferth; Hans Ulrich Wittchen; Ulrich S. Zimmermann; Henrik Walter; Philipp Sterzer; Michael N. Smolka; Florian Schlagenhauf; Andreas Heinz; Peter Dayan; Quentin J. M. M. Huys Dissociating neural learning signals in human sign- and goal-trackers Journal Article In: Nature Human Behaviour, vol. 4, no. 2, pp. 201–214, 2020. @article{Schad2020, Individuals differ in how they learn from experience. In Pavlovian conditioning models, where cues predict reinforcer delivery at a different goal location, some animals—called sign-trackers—come to approach the cue, whereas others, called goal-trackers, approach the goal. In sign-trackers, model-free phasic dopaminergic reward-prediction errors underlie learning, which renders stimuli ‘wanted'. Goal-trackers do not rely on dopamine for learning and are thought to use model-based learning. We demonstrate this double dissociation in 129 male humans using eye-tracking, pupillometry and functional magnetic resonance imaging informed by computational models of sign- and goal-tracking. We show that sign-trackers exhibit a neural reward prediction error signal that is not detectable in goal-trackers. Model-free value only guides gaze and pupil dilation in sign-trackers. Goal-trackers instead exhibit a stronger model-based neural state prediction error signal. This model-based construct determines gaze and pupil dilation more in goal-trackers. |
Constanze Schmitt; Bianca R. Baltaretu; J. Douglas Crawford; Frank Bremmer A causal role of area hMST for self-motion perception in humans Journal Article In: Cerebral Cortex Communications, pp. 1–14, 2020. @article{Schmitt2020, Previous studies in the macaque monkey have provided clear causal evidence for an involvement of the medial-superior-temporal area (MST) in the perception of self-motion. These studies also revealed an overrepresentation of contraversive heading. Human imaging studies have identified a functional equivalent (hMST) of macaque area MST. Yet, causal evidence of hMST in heading perception is lacking. We employed neuronavigated transcranial magnetic stimulation (TMS) to test for such a causal relationship. We expected TMS over hMST to induce increased perceptual variance (i.e., impaired precision), while leaving mean heading perception (accuracy) unaffected. We presented 8 human participants with an optic flow stimulus simulating forward self-motion across a ground plane in one of 3 directions. Participants indicated perceived heading. In 57% of the trials, TMS pulses were applied, temporally centered on self-motion onset. TMS stimulation site was either right-hemisphere hMST, identified by a functional magnetic resonance imaging (fMRI) localizer, or a control-area, just outside the fMRI localizer activation. As predicted, TMS over area hMST, but not over the control-area, increased response variance of perceived heading as compared with noTMS stimulation trials. As hypothesized, this effect was strongest for contraversive self-motion. These data provide a first causal evidence for a critical role of hMST in visually guided navigation. |
Rebekka Schröder; Anna-Maria Kasparbauer; Inga Meyhöfer; Maria Steffens; Peter Trautner; Ulrich Ettinger Functional connectivity during smooth pursuit eye movements Journal Article In: Journal of Neurophysiology, vol. 124, pp. 1839–1856, 2020. @article{Schroeder2020, Smooth pursuit eye movements (SPEM) hold the image of a slowly moving stimulus on the fovea. The neural system underlying SPEM primarily includes visual, parietal and frontal areas. In the present study, we investigated how these areas are functionally coupled and how these couplings are influenced by target motion frequency. To this end, healthy participants (N=57) were instructed to follow a sinusoidal target stimulus moving horizontally at two different frequencies (0.2 Hz, 0.4 Hz). Eye movements and BOLD activity were recorded simultaneously. Functional connectivity of the key areas of the SPEM network was investigated using a Psychophysiological Interaction (PPI) approach. It was analyzed how activity in five eye movement related seed regions (lateral geniculate nucleus, V1, V5, posterior parietal cortex, frontal eye fields) relates to activity in other parts of the brain during SPEM. The behavioral results showed clear deterioration of SPEM performance at higher target frequency. BOLD activity during SPEM vs. fixation occurred in a geniculo-occipito-parieto-frontal network, replicating previous findings. PPI analysis yielded wide-spread, partially overlapping networks. Especially frontal eye fields and posterior parietal cortex showed task-dependent connectivity to large parts of the entire cortex, while other seed regions demonstrated more regionally focused connectivity. Higher target frequency was associated with stronger activations in visual areas but had no effect on functional connectivity. In summary, the results confirm and extend previous knowledge regarding the neural mechanisms underlying SPEM and provide a valuable basis for further investigations such as in patients with SPEM impairments and known alterations in brain connectivity. |
Sarah Schuster; Stefan Hawelka; Nicole Alexandra Himmelstoss; Fabio Richlan; Florian Hutzler The neural correlates of word position and lexical predictability during sentence reading: Evidence from fixation-related fMRI Journal Article In: Language, Cognition and Neuroscience, vol. 35, no. 5, pp. 613–624, 2020. @article{Schuster2020, By means of combining eye-tracking and fMRI, the present study aimed to investigate aspects of higher linguistic processing during natural reading which were formerly hard to assess with traditional paradigms. Specifically, we investigated the haemodynamic effects of incremental sentence comprehension–as operationalised by word position–and its relation to context-based word-level effects of lexical predictability. We observed that an increasing amount of words being processed was associated with an increase in activation in the left posterior middle temporal and angular gyri. At the same time, left occipito-temporal regions showed a decrease in activation with increasing word position. Region of interest (ROI) analyses revealed differential effects of word position and predictability within dissociable parts of the semantic network–showing that it is expedient to consider these effects conjointly. |
Simon R. Steinkamp; Simone Vossel; Gereon R. Fink; Ralph Weidner Attentional reorientation along the meridians of the visual field: Are there different neural mechanisms at play? Journal Article In: Human Brain Mapping, vol. 41, no. 13, pp. 3765–3780, 2020. @article{Steinkamp2020, Hemispatial neglect, after unilateral lesions to parietal brain areas, is characterized by an inability to respond to unexpected stimuli in contralesional space. As the visual field's horizontal meridian is most severely affected, the brain networks controlling visuospatial processes might be tuned explicitly to this axis. We investigated such a potential directional tuning in the dorsal and ventral frontoparietal attention networks, with a particular focus on attentional reorientation. We used an orientation-discrimination task where a spatial precue indicated the target position with 80% validity. Healthy participants (n = 29) performed this task in two runs and were required to (re-)orient attention either only along the horizontal or the vertical meridian, while fMRI and behavioral measures were recorded. By using a general linear model for behavioral and fMRI data, dynamic causal modeling for effective connectivity, and other predictive approaches, we found strong statistical evidence for a reorientation effect for horizontal and vertical runs. However, neither neural nor behavioral measures differed between vertical and horizontal reorienting. Moreover, models from one run successfully predicted the cueing condition in the respective other run. Our results suggest that activations in the dorsal and ventral attention networks represent higher-order cognitive processes related to spatial attentional (re-)orientating that are independent of directional tuning and that unilateral attention deficits after brain damage are based on disrupted interactions between higher-level attention networks and sensory areas. |
Emily R. Stern; Carina Brown; Molly Ludlow; Rebbia Shahab; Katherine Collins; Alexis Lieval; Russell H. Tobe; Dan V. Iosifescu; Katherine E. Burdick; Lazar Fleysher The buildup of an urge in obsessive–compulsive disorder: Behavioral and neuroimaging correlates Journal Article In: Human Brain Mapping, vol. 41, no. 6, pp. 1611–1625, 2020. @article{Stern2020, Obsessive–compulsive disorder (OCD) is highly heterogeneous. While obsessions often involve fear of harm, many patients report uncomfortable sensations and/or urges that drive repetitive behaviors in the absence of a specific fear. Prior work suggests that urges in OCD may be similar to everyday “urges-for-action” (UFA) such as the urge to blink, swallow, or scratch, but very little work has investigated the pathophysiology underlying urges in OCD. In the current study, we used an urge-to-blink approach to model sensory-based urges that could be experimentally elicited and compared across patients and controls using the same task stimuli. OCD patients and controls suppressed eye blinking over a period of 60 s, alternating with free blinking blocks, while brain activity was measured using functional magnetic resonance imaging. OCD patients showed significantly increased activation in several regions during the early phase of eyeblink suppression (first 30 s), including mid-cingulate, insula, striatum, parietal cortex, and occipital cortex, with lingering group differences in parietal and occipital regions during late eyeblink suppression (last 30 s). There were no differences in brain activation during free blinking blocks, and no conditions where OCD patients showed reduced activation compared to controls. In an exploratory analysis of blink counts performed in a subset of subjects, OCD patients were less successful than controls in suppressing blinks. These data indicate that OCD patients exhibit altered brain function and behavior when experiencing and suppressing the urge to blink, raising the possibility that the disorder is associated with a general abnormality in the UFA system that could ultimately be targeted by future treatments. |
Susanne Stoll; Nonie J. Finlayson; D. Samuel Schwarzkopf Topographic signatures of global object perception in human visual cortex Journal Article In: NeuroImage, vol. 220, pp. 116926, 2020. @article{Stoll2020, Our visual system readily groups dynamic fragmented input into global objects. How the brain represents global object perception remains however unclear. To address this question, we recorded brain responses using functional magnetic resonance imaging whilst observers viewed a dynamic bistable stimulus that could either be perceived globally (i.e., as a grouped and coherently moving shape) or locally (i.e., as ungrouped and incoherently moving elements). We further estimated population receptive fields and used these to back-project the brain activity measured during stimulus perception into visual space via a searchlight procedure. Global perception resulted in universal suppression of responses in lower visual cortex accompanied by wide-spread enhancement in higher object-sensitive cortex. However, follow-up experiments indicated that higher object-sensitive cortex is suppressed if global perception lacks shape grouping, and that grouping-related suppression can be diffusely confined to stimulated sites and accompanied by background enhancement once stimulus size is reduced. These results speak to a non-generic involvement of higher object-sensitive cortex in perceptual grouping and point to an enhancement-suppression mechanism mediating the perception of figure and ground. |
2019 |
Rotem Botvinik-Nezer; Roni Iwanir; Felix Holzmeister; Jürgen Huber; Magnus Johannesson; Michael Kirchler; Anna Dreber; Colin F. Camerer; Russell A. Poldrack; Tom Schonberg fMRI data of mixed gambles from the Neuroimaging Analysis Replication and Prediction Study Journal Article In: Scientific Data, vol. 6, pp. 106, 2019. @article{BotvinikNezer2019, There is an ongoing debate about the replicability of neuroimaging research. It was suggested that one of the main reasons for the high rate of false positive results is the many degrees of freedom researchers have during data analysis. In the Neuroimaging Analysis Replication and Prediction Study (NARPS), we aim to provide the first scientific evidence on the variability of results across analysis teams in neuroscience. We collected fMRI data from 108 participants during two versions of the mixed gambles task, which is often used to study decision-making under risk. For each participant, the dataset includes an anatomical (T1 weighted) scan and fMRI as well as behavioral data from four runs of the task. The dataset is shared through OpenNeuro and is formatted according to the Brain Imaging Data Structure (BIDS) standard. Data pre-processed with fMRIprep and quality control reports are also publicly shared. This dataset can be used to study decision-making under risk and to test replicability and interpretability of previous results in the field. |
Chun-Ting Hsu; Roy Clariana; Benjamin Schloss; Ping Li Neurocognitive signatures of naturalistic reading of scientific texts: A fixation-related fMRI study Journal Article In: Scientific Reports, vol. 9, pp. 10678, 2019. @article{Hsu2019, How do students gain scientific knowledge while reading expository text? This study examines the underlying neurocognitive basis of textual knowledge structure and individual readers' cognitive differences and reading habits, including the influence of text and reader characteristics, on outcomes of scientific text comprehension. By combining fixation-related fMRI and multiband data acquisition, the study is among the first to consider self-paced naturalistic reading inside the MRI scanner. Our results revealed the underlying neurocognitive patterns associated with information integration of different time scales during text reading, and significant individual differences due to the interaction between text characteristics (e.g., optimality of the textual knowledge structure) and reader characteristics (e.g., electronic device use habits). Individual differences impacted the amount of neural resources deployed for multitasking and information integration for constructing the underlying scientific mental models based on the text being read. Our findings have significant implications for understanding science reading in a population that is increasingly dependent on electronic devices. |
Jessica E. Goold; Wonil Choi; John M. Henderson Cortical control of eye movements in natural reading: Evidence from MVPA Journal Article In: Experimental Brain Research, vol. 237, no. 12, pp. 3099–3107, 2019. @article{Goold2019, Language comprehension during reading requires fine-grained management of saccadic eye movements. A critical question, therefore, is how the brain controls eye movements in reading. Neural correlates of simple eye movements have been found in multiple cortical regions, but little is known about how this network operates in reading. To investigate this question in the present study, participants were presented with normal text, pseudo-word text, and consonant string text in a magnetic resonance imaging (MRI) scanner with eyetracking. Participants read naturally in the normal text condition and moved their eyes “as if they were reading” in the other conditions. Multi-voxel pattern analysis was used to analyze the fMRI signal in the oculomotor network. We found that activation patterns in a subset of network regions differentiated between stimulus types. These results suggest that the oculomotor network reflects more than simple saccade generation and are consistent with the hypothesis that specific network areas interface with cognitive systems. |
Kristin Koller; Christopher M. Hatton; Robert D. Rogers; Robert D. Rafal Stria terminalis microstructure in humans predicts variability in orienting towards threat Journal Article In: European Journal of Neuroscience, vol. 50, no. 11, pp. 3804–3813, 2019. @article{Koller2019, Current concepts of the extended amygdala posit that basolateral to central amygdala projections mediate fear-conditioned autonomic alerting, whereas projections to the bed nucleus of the stria terminalis mediate sustained anxiety. Using diffusion tensor imaging tractography in humans, we show that microstructure of the stria terminalis correlates with an orienting bias towards threat in a saccade decision task, providing the first evidence that this circuit supports decisions guiding evaluation of threatening stimuli. |
Benjamin T. Carter; Steven G. Luke In: Data in Brief, vol. 25, pp. 1–21, 2019. @article{Carter2019a, The data presented in this document was created to explore the effect of including or excluding word length, word frequency, the lexical predictability of function words and first pass reading time (or the duration of the first fixation on a word) as either baseline regressors or duration modulators on the final analysis for a fixation-related fMRI investigation of linguistic processing. The effect of these regressors was a central question raised during the review of Linguistic networks associated with lexical, semantic and syntactic predictability in reading: A fixation-related fMRI study [1]. Three datasets were created and compared to the original dataset to determine their effect. The first examines the effect of adding word length and word frequency as baseline regressors. The second examines the effect of removing first pass reading time as a duration modulator. The third examines the inclusion of function word predictability into the baseline hemodynamic response function. Statistical maps were created for each dataset and compared to the primary dataset (published in [1]) across the linguistic conditions of the initial dataset (lexical predictability, semantic predictability or syntax predictability). |
Justin Riddle; Kai Hwang; Dillan Cellier; Sofia Dhanani; Mark D'esposito Causal evidence for the role of neuronal oscillations in top–down and bottom–up attention Journal Article In: Journal of Cognitive Neuroscience, vol. 31, no. 5, pp. 768–779, 2019. @article{Riddle2019, Beta and gamma frequency neuronal oscillations have been implicated in top–down and bottom–up attention. In this study, we used rhythmic TMS to modulate ongoing beta and gamma frequency neuronal oscillations in frontal and parietal cortex while human participants performed a visual search task that manipulates bottom–up and top–down attention (single feature and conjunction search). Both task conditions will engage bottom–up attention processes, although the conjunction search condition will require more top–down attention. Gamma frequency TMS to superior precentral sulcus (sPCS) slowed saccadic RTs during both task conditions and induced a response bias to the contralateral visual field. In contrary, beta frequency TMS to sPCS and intraparietal sulcus decreased search accuracy only during the conjunction search condition that engaged more top–down attention. Furthermore, beta frequency TMS increased trial errors specifically when the target was in the ipsilateral visual field for the conjunction search condition. These results indicate that beta frequency TMS to sPCS and intraparietal sulcus disrupted top–down attention, whereas gamma frequency TMS to sPCS disrupted bottom–up, stimulus-driven attention processes. These findings provide causal evidence suggesting that beta and gamma oscillations have distinct functional roles for cognition. |
Philip A. Kragel; Marianne C. Reddan; Kevin S. LaBar; Tor D. Wager Emotion schemas are embedded in the human visual system Journal Article In: Science Advances, vol. 5, no. 7, pp. eaaw4358, 2019. @article{Kragel2019, Theorists have suggested that emotions are canonical responses to situations ancestrally linked to survival. If so, then emotions may be afforded by features of the sensory environment. However, few computational models describe how combinations of stimulus features evoke different emotions. Here, we develop a convolutional neural network that accurately decodes images into 11 distinct emotion categories. We validate the model using more than 25,000 images and movies and show that image content is sufficient to predict the category and valence of human emotion ratings. In two functional magnetic resonance imaging studies, we demonstrate that patterns of human visual cortex activity encode emotion category–related model output and can decode multiple categories of emotional experience. These results suggest that rich, category-specific visual features can be reliably mapped to distinct emotions, and they are coded in distributed representations within the human visual system. |
Milosz Krala; Bianca Kemenade; Benjamin Straube; Tilo Kircher; Frank Bremmer Predictive coding in a multisensory path integration task: An fMRI study Journal Article In: Journal of vision, vol. 19, no. 11, pp. 1–15, 2019. @article{Krala2019, During self-motion through an environment, our sensory systems are confronted with a constant flow of information from different modalities. To successfully navigate, self-induced sensory signals have to be dissociated from externally induced sensory signals. Previous studies have suggested that the processing of self-induced sensory information is modulated by means of predictive coding mechanisms. However, the neural correlates of processing self-induced sensory information from different modalities during self-motion are largely unknown. Here, we asked if and how the processing of visually simulated self-motion and/or associated auditory stimuli is modulated by self-controlled action. Participants were asked to actively reproduce a previously observed simulated self-displacement (path integration). Blood oxygen level-dependent (BOLD) activation during this path integration was compared with BOLD activation during a condition in which we passively replayed the exact sensory stimulus that had been produced by the participants in previous trials. We found supramodal BOLD suppression in parietal and frontal regions. Remarkably, BOLD contrast in sensory areas was enhanced in a modality-specific manner. We conclude that the effect of action on sensory processing is strictly dependent on the respective behavioral task and its relevance. |
Satwant Kumar; Ivo D. Popivanov; Rufin Vogels Transformation of visual representations across ventral stream body-selective patches Journal Article In: Cerebral Cortex, vol. 29, no. 1, pp. 215–229, 2019. @article{Kumar2019a, Although the neural processing of visual images of bodies is critical for survival, it is much less well understood than face processing. Functional imaging studies demonstrated body selective regions in primate inferior temporal cortex. To advance our understanding of how the visual brain represents bodies, we compared the representation of animate and inanimate objects in two such body patches with fMRI-guided single unit recordings in rhesus monkeys. We found that the middle Superior Temporal Sulcus body patch (MSB) distinguishes to a greater extent bodies from non-bodies than the anterior Superior Temporal Sulcus body patch (ASB). Importantly, ASB carried more viewpoint-tolerant information about body posture and body identity than MSB, while MSB showed greater orientation selectivity. Combined with previous work on faces, this suggests that an increase in view-tolerant representations, coupled with a refined individuation, along the visual hierarchy is a general property of information processing within the inferior temporal cortex. |
Hai Lin; Wei-ping Li; Synnöve Carlson A privileged working memory state and potential top-down modulation for faces, not scenes Journal Article In: Frontiers in Human Neuroscience, vol. 13, pp. 2, 2019. @article{Lin2019a, Top-down modulation is engaged during multiple stages of working memory (WM), including expectation, encoding, and maintenance. During WM maintenance period, an “incidental cue” can bring one of the two items into a privileged state and make the privileged item be recalled with higher precision, despite being irrelevant to which one to be probed as the target. With regard to the different representational states of WM, it's unclear whether there is top-down modulation on earth sensory cortical areas. Here, We used this behavioral paradigm of “incidental cue” and event-related fMRI to investigate whether there were a privileged WM state and top-down modulation for complex stimuli including faces and natural scenes. We found that faces, not scenes, could enter into the privileged state with improved accuracy and response time of WM task. Meanwhile, cue-driven baseline activity shifts in fusiform face area (FFA) were identified by univariate analysis in the recognition of privileged faces, compared to that of non-privileged ones. In addition, the functional connectivity between FFA and right inferior frontal junction (IFJ), middle frontal gyrus (MFG), inferior frontal gyrus, right intraparietal sulcus (IPS), right precuneus and supplementary motor area was significantly enhanced, corresponding to the improved WM performance. Moreover, FFA connectivity with IFJ and IPS could predict WM improvements. These findings indicated that privileged WM state and potential top-down modulation existed for faces, but not scenes, during WM maintenance period. |
Sahil Luthra; Sara Guediche; Sheila E. Blumstein; Emily B. Myers Neural substrates of subphonemic variation and lexical competition in spoken word recognition Journal Article In: Language, Cognition and Neuroscience, vol. 34, no. 2, pp. 151–169, 2019. @article{Luthra2019, In spoken word recognition, subphonemic variation influences lexical activation, with sounds near a category boundary increasing phonetic competition as well as lexical competition. The current study investigated the interplay of these factors using a visual world task in which participants were instructed to look at a picture of an auditory target (e.g. peacock). Eyetracking data indicated that participants were slowed when a voiced onset competitor (e.g. beaker) was also displayed, and this effect was amplified when acoustic-phonetic competition was increased. Simultaneously-collected fMRI data showed that several brain regions were sensitive to the presence of the onset competitor, including the supramarginal, middle temporal, and inferior frontal gyri, and functional connectivity analyses revealed that the coordinated activity of left frontal regions depends on both acoustic-phonetic and lexical factors. Taken together, results suggest a role for frontal brain structures in resolving lexical competition, particularly as atypical acoustic-phonetic information maps on to the lexicon. |
Charles R. Marshall; Christopher J. D. Hardy; Lucy L. Russell; Rebecca L. Bond; Harri Sivasathiaseelan; Caroline Greaves; Katrina M. Moore; Jennifer L. Agustus; Janneke E. P. Leeuwen; Stephen J. Wastling; Jonathan D. Rohrer; James M. Kilner; Jason D. Warren The functional neuroanatomy of emotion processing in frontotemporal dementias Journal Article In: Brain, vol. 142, no. 9, pp. 2873–2887, 2019. @article{Marshall2019, Impaired processing of emotional signals is a core feature of frontotemporal dementia syndromes, but the underlying neural mechanisms have proved challenging to characterize and measure. Progress in this field may depend on detecting functional changes in the working brain, and disentangling components of emotion processing that include sensory decoding, emotion categorization and emotional contagion. We addressed this using functional MRI of naturalistic, dynamic facial emotion processing with concurrent indices of autonomic arousal, in a cohort of patients representing all major frontotemporal dementia syndromes relative to healthy age-matched individuals. Seventeen patients with behavioural variant frontotemporal dementia [four female; mean (standard deviation) age 64.8 (6.8) years], 12 with semantic variant primary progressive aphasia [four female; 66.9 (7.0) years], nine with non-fluent variant primary progressive aphasia [five female; 67.4 (8.1) years] and 22 healthy controls [12 female; 68.6 (6.8) years] passively viewed videos of universal facial expressions during functional MRI acquisition, with simultaneous heart rate and pupillometric recordings; emotion identification accuracy was assessed in a post-scan behavioural task. Relative to healthy controls, patient groups showed significant impairments (analysis of variance models, all P 5 0.05) of facial emotion identification (all syndromes) and cardiac (all syndromes) and pupillary (non-fluent variant only) reactivity. Group-level functional neuroanatomical changes were assessed using statistical parametric mapping, thresholded at P 5 0.05 after correction for multiple comparisons over the whole brain or within pre-specified regions of interest. In response to viewing facial expressions, all participant groups showed comparable activation of primary visual cortex while patient groups showed differential hypo-activation of fusiform and posterior temporo-occipital junctional cortices. Bi-hemispheric, syndrome-specific activations predicting facial emotion identification performance were identified (behavioural variant, anterior insula and caudate; semantic variant, anterior temporal cortex; non-fluent variant, frontal operculum). The semantic and non-fluent variant groups additionally showed complex profiles of central parasympathetic and sympathetic autonomic involvement that overlapped signatures of emotional visual and categorization processing and extended (in the non-fluent group) to brainstem effector pathways. These findings open a window on the functional cerebral mechanisms underpinning complex socio-emotional phenotypes of frontotemporal dementia, with implications for novel physiological biomarker development. |
Abhijit Rajan; Sreenivasan Meyyappan; Harrison Walker; Immanuel Babu; Henry Samuel; Zhenhong Hu; Mingzhou Ding Neural mechanisms of internal distraction suppression in visual attention Journal Article In: Cortex, vol. 117, pp. 77–88, 2019. @article{Rajan2019, When performing a demanding cognitive task, internal distraction in the form of task-irrelevant thoughts and mind wandering can shift our attention away from the task, negatively affecting task performance. Behaviorally, individuals with higher executive function indexed by higher working memory capacity (WMC) exhibit less mind wandering during cognitive tasks, but the underlying neural mechanisms are unknown. To address this problem, we recorded functional magnetic resonance imaging (fMRI) data from subjects performing a cued visual attention task, and assessed their WMC in a separate experiment. Applying machine learning and time-series analysis techniques, we showed that (1) higher WMC individuals experienced lower internal distraction through stronger suppression of posterior cingulate cortex (PCC) activity, (2) higher WMC individuals had better neural representations of attended information as evidenced by higher multivoxel decoding accuracy of cue-related activities in the dorsal attention network (DAN), (3) the positive relationship between WMC and DAN decoding accuracy was mediated by suppression of PCC activity, (4) the dorsal anterior cingulate (dACC) was a source of top-down signals that regulate PCC activity as evidenced by the negative association between Granger-causal influence dACC/PCC and PCC activity levels, and (5) higher WMC individuals exhibiting stronger dACC/PCC Granger-causal influence. These results shed light on the neural mechanisms underlying the executive suppression of internal distraction in tasks requiring externally oriented attention and provide an explanation of the individual differences in such suppression. |
Birgit Rauchbauer; Bruno Nazarian; Morgane Bourhis; Magalie Ochs; Laurent Prévot; Thierry Chaminade Brain activity during reciprocal social interaction investigated using conversational robots as control condition Journal Article In: Philosophical Transactions of the Royal Society B: Biological Sciences, vol. 374, pp. 1–8, 2019. @article{Rauchbauer2019, We present a novel functional magnetic resonance imaging paradigm for second-person neuroscience. The paradigm compares a human social interaction (human-human interaction, HHI) to an interaction with a conversational robot (human-robot interaction, HRI). The social interaction consists of 1 min blocks of live bidirectional discussion between the scanned participant and the human or robot agent. A final sample of 21 participants is included in the corpus comprising physiological (blood oxygen level-dependent, respiration and peripheral blood flow) and behavioural (recorded speech from all interlocutors, eye tracking from the scanned participant, face recording of the human and robot agents) data. Here, we present the first analysis of this corpus, contrasting neural activity between HHI and HRI. We hypothesized that independently of differences in behaviour between interactions with the human and robot agent, neural markers of mentalizing (temporoparietal junction (TPJ) and medial prefrontal cortex) and social motivation (hypothalamus and amygdala) would only be active in HHI. Results confirmed significantly increased response associated with HHI in the TPJ, hypothalamus and amygdala, but not in the medial prefrontal cortex. Future analysis of this corpus will include fine-grained characterization of verbal and non-verbal behaviours recorded during the interaction to investigate their neural correlates. |
Ryan V. Raut; Anish Mitra; Abraham Z. Snyder; Marcus E. Raichle On time delay estimation and sampling error in resting-state fMRI Journal Article In: NeuroImage, vol. 194, pp. 211–227, 2019. @article{Raut2019, Accumulating evidence indicates that resting-state functional magnetic resonance imaging (rsfMRI) signals correspond to propagating electrophysiological infra-slow activity (<0.1 Hz). Thus, pairwise correlations (zero-lag functional connectivity (FC)) and temporal delays among regional rsfMRI signals provide useful, complementary descriptions of spatiotemporal structure in infra-slow activity. However, the slow nature of fMRI signals implies that practical scan durations cannot provide sufficient independent temporal samples to stabilize either of these measures. Here, we examine factors affecting sampling variability in both time delay estimation (TDE) and FC. Although both TDE and FC accuracy are highly sensitive to data quantity, we use surrogate fMRI time series to study how the former is additionally related to the magnitude of a given pairwise correlation and, to a lesser extent, the temporal sampling rate. These contingencies are further explored in real data comprising 30-min rsfMRI scans, where sampling error (i.e., limited accuracy owing to insufficient data quantity) emerges as a significant but underappreciated challenge to FC and, even more so, to TDE. Exclusion of high-motion epochs exacerbates sampling error; thus, both sides of the bias-variance (or data quality-quantity) tradeoff associated with data exclusion should be considered when analyzing rsfMRI data. Finally, we present strategies for TDE in motion-corrupted data, for characterizing sampling error in TDE and FC, and for mitigating the influence of sampling error on lag-based analyses. |
Christiane S. Rohr; Dennis Dimond; Manuela Schuetze; Ivy Y. K. Cho; Limor Lichtenstein-Vidne; Hadas Okon-Singer; Deborah Dewey; Signe Bray Girls' attentive traits associate with cerebellar to dorsal attention and default mode network connectivity Journal Article In: Neuropsychologia, vol. 127, pp. 84–92, 2019. @article{Rohr2019, Attention traits are a cornerstone to the healthy development of children's performance in the classroom, their interactions with peers, and in predicting future success and problems. The cerebellum is increasingly appreciated as a region involved in complex cognition and behavior, and moreover makes important connections to key brain networks known to support attention: the dorsal attention and default mode networks (DAN; DMN). The cerebellum has also been implicated in childhood disorders affecting attention, namely autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD), suggesting that attention networks extending to the cerebellum may be important to consider in relation to attentive traits. Yet, direct investigations into the association between cerebellar FC and attentive traits are lacking. Therefore, in this study we examined attentive traits, assessed using parent reports of ADHD and ASD symptoms, in a community sample of 52 girls aged 4–7 years, i.e. around the time of school entry, and their association with cerebellar connections with the DAN and DMN. We found that cortico-cerebellar functional connectivity (FC) jointly and differentially correlated with attentive traits, through a combination of weaker and stronger FC across anterior and posterior DAN and DMN nodes. These findings suggest that cortico-cerebellar integration may play an important role in the manifestation of attentive traits. |
Pia Schröder; Timo Torsten Schmidt; Felix Blankenburg Neural basis of somatosensory target detection independent of uncertainty, relevance, and reports Journal Article In: eLife, vol. 8, pp. 1–19, 2019. @article{Schroeder2019, Research on somatosensory awareness has yielded highly diverse findings with putative neural correlates ranging from activity within somatosensory cortex to activation of widely distributed frontoparietal networks. Divergent results from previous studies may reside in cognitive processes that often coincide with stimulus awareness in experimental settings. To scrutinise the specific relevance of regions implied in the target detection network, we used functional magnetic resonance imaging (n = 27) on a novel somatosensory detection task that explicitly controls for stimulus uncertainty, behavioural relevance, overt reports, and motor responses. Using Bayesian Model Selection, we show that responses reflecting target detection are restricted to secondary somatosensory cortex, whereas activity in insular, cingulate, and motor regions is best explained in terms of stimulus uncertainty and overt reports. Our results emphasise the role of sensory-specific cortex for the emergence of perceptual awareness and dissect the contribution of the frontoparietal network to classical detection tasks. |
Sarah E. Schwettmann; Joshua B. Tenenbaum; Nancy Kanwisher Invariant representations of mass in the human brain Journal Article In: eLife, vol. 8, pp. 1–26, 2019. @article{Schwettmann2019, An intuitive understanding of physical objects and events is critical for successfully interacting with the world. Does the brain achieve this understanding by running simulations in a mental physics engine, which represents variables such as force and mass, or by analyzing patterns of motion without encoding underlying physical quantities? To investigate, we scanned participants with fMRI while they viewed videos of objects interacting in scenarios indicating their mass. Decoding analyses in brain regions previously implicated in intuitive physical inference revealed mass representations that generalized across variations in scenario, material, friction, and motion energy. These invariant representations were found during tasks without action planning, and tasks focusing on an orthogonal dimension (object color). Our results support an account of physical reasoning where abstract physical variables serve as inputs to a forward model of dynamics, akin to a physics engine, in parietal and frontal cortex. |
Michael J. Spilka; Daniel J. Pittman; Signe L. Bray; Vina M. Goghari Manipulating visual scanpaths during facial emotion perception modulates functional brain activation in schizophrenia patients and controls Journal Article In: Journal of Abnormal Psychology, vol. 128, no. 8, pp. 855–866, 2019. @article{Spilka2019, Individuals with schizophrenia exhibit deficits in facial emotion processing, which have been associated with abnormalities in visual gaze behavior and functional brain activation. However, the relationship between gaze behavior and brain activation in schizophrenia remains unexamined. Studies in healthy individuals and other clinical samples indicate a relationship between gaze behavior and functional activation in brain regions implicated in facial emotion processing deficits in schizophrenia (e.g., fusiform gyrus), prompting the question of whether a similar relationship exists in schizophrenia. This study examined whether manipulating visual scanpaths during facial emotion perception would modulate functional brain activation in a sample of 23 schizophrenia patients and 26 community controls. Participants underwent functional magnetic resonance imaging (MRI) while viewing pictures of emotional faces. During the typical viewing condition, a fixation cue directed participants' gaze primarily to the eyes and mouth, whereas during the atypical viewing condition gaze was directed to peripheral features. Both viewing conditions elicited a robust response throughout face-processing regions. Typical viewing led to greater activation in visual association cortex including the right inferior occipital gyrus/occipital face area, whereas atypical viewing elicited greater activation in primary visual cortex and regions involved in attentional control. There were no between-groups activation differences in response to faces or interaction between group and gaze manipulation. The results indicate that gaze behavior modulates functional activation in early face-processing regions in individuals with and without schizophrenia, suggesting that abnormal gaze behavior in schizophrenia may contribute to activation abnormalities during facial emotion perception. |
Gabor Stefanics; Klaas Enno Stephan; Jakob Heinzle Feature-specific prediction errors for visual mismatch Journal Article In: NeuroImage, vol. 196, pp. 142–151, 2019. @article{Stefanics2019, Predictive coding (PC) theory posits that our brain employs a predictive model of the environment to infer the causes of its sensory inputs. A fundamental but untested prediction of this theory is that the same stimulus should elicit distinct precision weighted prediction errors (pwPEs) when different (feature-specific) predictions are violated, even in the absence of attention. Here, we tested this hypothesis using functional magnetic resonance imaging (fMRI) and a multi-feature roving visual mismatch paradigm where rare changes in either color (red, green), or emotional expression (happy, fearful) of faces elicited pwPE responses in human participants. Using a computational model of learning and inference, we simulated pwPE and prediction trajectories of a Bayes-optimal observer and used these to analyze changes in blood oxygen level dependent (BOLD) responses to changes in color and emotional expression of faces while participants engaged in a distractor task. Controlling for visual attention by eye-tracking, we found pwPE responses to unexpected color changes in the fusiform gyrus. Conversely, unexpected changes of facial emotions elicited pwPE responses in cortico-thalamo-cerebellar structures associated with emotion and theory of mind processing. Predictions pertaining to emotions activated fusiform, occipital and temporal areas. Our results are consistent with a general role of PC across perception, from low-level to complex and socially relevant object features, and suggest that monitoring of the social environment occurs continuously and automatically, even in the absence of attention. |
Timothy H. Muller; Rogier B. Mars; Timothy E. Behrens; Jill X. O'Reilly Control of entropy in neural models of environmental state Journal Article In: eLife, vol. 8, pp. 1–30, 2019. @article{Muller2019a, Humans and animals construct internal models of their environment in order to select appropriate courses of action. The representation of uncertainty about the current state of the environment is a key feature of these models that controls the rate of learning as well as directly affecting choice behaviour. To maintain flexibility, given that uncertainty naturally decreases over time, most theoretical inference models include a dedicated mechanism to drive up model uncertainty. Here we probe the long-standing hypothesis that noradrenaline is involved in determining the uncertainty, or entropy, and thus flexibility, of neural models. Pupil diameter, which indexes neuromodulatory state including noradrenaline release, predicted increases (but not decreases) in entropy in a neural state model encoded in human medial orbitofrontal cortex, as measured using multivariate functional MRI. Activity in anterior cingulate cortex predicted pupil diameter. These results provide evidence for top-down, neuromodulatory control of entropy in neural state models. |
Jonathan F. O'rawe; Anna S. Huang; Daniel N. Klein; Hoi-Chung Leung In: Neuropsychologia, vol. 127, pp. 158–170, 2019. @article{Orawe2019, Visual processing in the primate brain is highly organized along the ventral visual pathway, although it is still unclear how categorical selectivity emerges in this system. While many theories have attempted to explain the pattern of visual specialization within the ventral occipital and temporal areas, the biased connectivity hypothesis provides a framework which postulates extrinsic connectivity as a potential mechanism in shaping the development of category selectivity. As the posterior parietal cortex plays a central role in visual attention, we examined whether the pattern of parietal connectivity with the face and scene processing regions is closely linked with the functional properties of these two visually selective networks in a cohort of 60 children ages 9 to 12. Functionally localized face and scene selective regions were used in deriving each visual network's resting-state functional connectivity. The children's face and scene processing networks appeared to show a weak network segregation during resting state, which was confirmed when compared to that of a group of gender and handedness matched adults. Parietal regions of these children showed differential connectivity with the face and scene networks, and the extent of this differential parietal-visual connectivity predicted individual differences in the degree of segregation between the two visual networks, which in turn predicted individual differences in visual perception performance. Finally, the pattern of parietal connectivity with the face processing network also predicted the foci of face-related activation in the right fusiform gyrus across children. These findings provide evidence that extrinsic connectivity with regions such as the posterior parietal cortex may have important implications in the development of specialized visual processing networks. |
Eduard Ort; Johannes J. Fahrenfort; Reshanne Reeder; Stefan Pollmann; Christian N. L. Olivers Frontal cortex differentiates between free and imposed target selection in multiple-target search Journal Article In: NeuroImage, vol. 202, pp. 116133, 2019. @article{Ort2019, Cognitive control can involve proactive (preparatory) and reactive (corrective) mechanisms. Using a gaze-contingent eye tracking paradigm combined with fMRI, we investigated the involvement of these different modes of control and their underlying neural networks, when switching between different targets in multiple-target search. Participants simultaneously searched for two possible targets presented among distractors, and selected one of them. In one condition, only one of the targets was available in each display, so that the choice was imposed, and reactive control would be required. In the other condition, both targets were present, giving observers free choice over target selection, and allowing for proactive control. Switch costs emerged only when targets were imposed and not when target selection was free. We found differential levels of activity in the frontoparietal control network depending on whether target switches were free or imposed. Furthermore, we observed core regions of the default mode network to be active during target repetitions, indicating reduced control on these trials. Free and imposed switches jointly activated parietal and posterior frontal cortices, while free switches additionally activated anterior frontal cortices. These findings highlight unique contributions of proactive and reactive control during visual search. |
Rasmus M. Birn; Alexander K. Converse; Abigail Z. Rajala; Andrew L. Alexander; Walter F. Block; Alan B. McMillan; Bradley T. Christian; Caitlynn N. Filla; Dhanabalan Murali; Samuel A. Hurley; Rick L. Jenison; Luis C. Populin Changes in endogenous dopamine induced by methylphenidate predict functional connectivity in nonhuman primates Journal Article In: Journal of Neuroscience, vol. 39, no. 8, pp. 1436–1444, 2019. @article{Birn2019, Dopamine (DA) levels in the striatum are increased by many therapeutic drugs, such as methylphenidate (MPH), which also alters behavioral and cognitive functions thought to be controlled by the PFC dose-dependently. We linked DA changes and functional connectivity (FC) using simultaneous [18F]fallypride PET and resting-state fMRI in awake male rhesus monkeys after oral administration of various doses of MPH. We found a negative correlation between [18F]fallypride nondisplaceable binding potential (BPND) and MPH dose in the head of the caudate (hCd), demonstrating increased extracellular DA resulting from MPH administration. The decreased BPND was negatively correlated with FC between the hCd and the PFC. Subsequent voxelwise analyses revealed negative correlations with FC between the hCd and the dorsolateral PFC, hippocampus, and precuneus. These results, showing that MPH-induced changes in DA levels in the hCd predict resting-state FC, shed light on a mechanism by which changes in striatal DA could influence function in the PFC. |
Ilona M. Bloem; Sam Ling Normalization governs attentional modulation within human visual cortex Journal Article In: Nature Communications, vol. 10, pp. 5660, 2019. @article{Bloem2019, Although attention is known to increase the gain of visuocortical responses, its underlying neural computations remain unclear. Here, we use fMRI to test the hypothesis that a neural population's ability to be modulated by attention is dependent on divisive normalization. To do so, we leverage the feature-tuned properties of normalization and find that visuocortical responses to stimuli sharing features normalize each other more strongly. Comparing these normalization measures to measures of attentional modulation, we demonstrate that subpopulations which exhibit stronger normalization also exhibit larger attentional benefits. In a converging experiment, we reveal that attentional benefits are greatest when a subpopulation is forced into a state of stronger normalization. Taken together, these results suggest that the degree to which a subpopulation exhibits normalization plays a role in dictating its potential for attentional benefits. |
Rodrigo M. Braga; Koene R. A. Van Dijk; Jonathan R. Polimeni; Mark C. Eldaief; Randy L. Buckner Parallel distributed networks resolved at high resolution reveal close juxtaposition of distinct regions Journal Article In: Journal of Neurophysiology, vol. 121, no. 4, pp. 1513–1534, 2019. @article{Braga2019, Examination of large-scale distributed networks within the individual reveals details of cortical network organization that are absent in group-averaged studies. One recent discovery is that a distributed transmodal network, often referred to as the “default network,” comprises two closely interdigitated networks, only one of which is coupled to posterior parahippocampal cortex. Not all studies of individuals have identified the same networks, and questions remain about the degree to which the two networks are separate, particularly within regions hypothesized to be interconnected hubs. In this study we replicate the observation of network separation across analytical (seed-based connectivity and parcellation) and data projection (volume and surface) methods in two individuals each scanned 31 times. Additionally, three individuals were examined with highresolution (7T; 1.35 mm) functional magnetic resonance imaging to gain further insight into the anatomical details. The two networks were identified with separate regions localized to adjacent portions of the cortical ribbon, sometimes inside the same sulcus. Midline regions previously implicated as hubs revealed near complete spatial separation of the two networks, displaying a complex spatial topography in the posterior cingulate and precuneus. The network coupled to parahippocampal cortex also revealed a separate region directly within the hippocampus, at or near the subiculum. These collective results support that the default network is composed of at least two spatially juxtaposed networks. Fine spatial details and juxtapositions of the two networks can be identified within individuals at high resolution, providing insight into the network organization of association cortex and placing further constraints on interpretation of group-averaged neuroimaging data. |
Benjamin T. Carter; Brent Foster; Nathan M. Muncy; Steven G. Luke Linguistic networks associated with lexical, semantic and syntactic predictability in reading: A fixation-related fMRI study Journal Article In: NeuroImage, vol. 189, pp. 224–240, 2019. @article{Carter2019, The ability to make predictions is thought to facilitate language processing. During language comprehension such predictions appear to occur at multiple levels of linguistic representations (i.e. semantic, syntactic and lexical). The neural mechanisms that define the network sensitive to linguistic predictability have yet to be adequately defined. The purpose of the present study was to explore the neural network underlying predictability during the normal reading of connected text. Predictability values for different linguistic information were obtained from a pre-existing text corpus. Forty-one subjects underwent simultaneous eye-tracking and fMRI scans while reading these select paragraphs. Lexical, semantic, and syntactic predictability measures were then correlated with functional activation associated with fixation onset on the individual words. Activation patterns showed both positive and negative correlations to lexical, semantic, and syntactic predictabilities. Conjunction analysis revealed regions specific to or shared between each type of predictability. The regions associated with the different predictability measures were largely separate. Results suggest that most linguistic predictions are graded in nature, activating components of the existing language system. A number of regions were also found to be uniquely associated with full lexical predictability, most notably the anterior temporal lobe and the inferior posterior temporal cortex. |
Joao Castelhano; Isabel C. Duarte; Carlos Ferreira; Joao Duraes; Henrique Madeira; Miguel Castelo-Branco The role of the insula in intuitive expert bug detection in computer code: an fMRI study Journal Article In: Brain Imaging and Behavior, vol. 13, no. 3, pp. 623–637, 2019. @article{Castelhano2019, Software programming is a complex and relatively recent human activity, involving the integration of mathematical, recursive thinking and language processing. The neural correlates of this recent human activity are still poorly understood. Error monitoring during this type of task, requiring the integration of language, logical symbol manipulation and other mathematical skills, is particularly challenging. We therefore aimed to investigate the neural correlates of decision-making during source code understanding and mental manipulation in professional participants with high expertise. The present fMRI study directly addressed error monitoring during source code comprehension, expert bug detection and decision-making. We used C code, which triggers the same sort of processing irrespective of the native language of the programmer. We discovered a distinct role for the insula in bug monitoring and detection and a novel connectivity pattern that goes beyond the expected activation pattern evoked by source code understanding in semantic language and mathematical processing regions. Importantly, insula activity levels were critically related to the quality of error detection, involving intuition, as signalled by reported initial bug suspicion, prior to final decision and bug detection. Activity in this salience network (SN) region evoked by bug suspicion was predictive of bug detection precision, suggesting that it encodes the quality of the behavioral evidence. Connectivity analysis provided evidence for top-down circuit “reutilization” stemming from anterior cingulate cortex (BA32), a core region in the SN that evolved for complex error monitoring such as required for this type of recent human activity. Cingulate (BA32) and anterolateral (BA10) frontal regions causally modulated decision processes in the insula, which in turn was related to activity of math processing regions in early parietal cortex. In other words, earlier brain regions used during evolution for other functions seem to be reutilized in a top-down manner for a new complex function, in an analogous manner as described for other cultural creations such as reading and literacy. |
Alexandra E. D'Agostino; David Kattan; Turhan Canli An fMRI study of loneliness in younger and older adults Journal Article In: Social Neuroscience, vol. 14, no. 2, pp. 136–148, 2019. @article{DAgostino2019, Loneliness, the subjective experience of social isolation, may reflect, in part, underlying neural processing of social signals. Aging may exacerbate loneliness due to decreased social networks and increased social isolation, or it may reduce loneliness due to preferential attentional processing of positive information and increased interactions with emotionally close partners. Here, we conducted a functional magnetic resonance imaging (fMRI) study of loneliness in younger (N = 50, 26 female, M age = 20.4) and older (N = 49, 30 female, M age = 62.9) adults. Compared to younger adults, older adults were less lonely and dwelled longer on faces, regardless of valence. Previous studies in younger adults found that loneliness was negatively correlated with ventral striatal (VS) activation to pleasant social pictures of strangers yet positively correlated with VS activation to faces of close others. In the present study, we observed no association between loneliness and VS activation to social pictures of strangers in either age group. Further, unlike previous studies, we observed no association between social network size and amygdala activation to social stimuli. Additional research is needed to examine the effect of loneliness and social network size on neural processing of different dimensions of social stimuli. |
Abdurahman S. Elkhetali; Leland L. Fleming; Ryan J. Vaden; Rodolphe Nenert; Jane E. Mendle; Kristina M. Visscher Background connectivity between frontal and sensory cortex depends on task state, independent of stimulus modality Journal Article In: NeuroImage, vol. 184, pp. 790–800, 2019. @article{Elkhetali2019, The human brain has the ability to process identical information differently depending on the task. In order to perform a given task, the brain must select and react to the appropriate stimuli while ignoring other irrelevant stimuli. The dynamic nature of environmental stimuli and behavioral intentions requires an equally dynamic set of responses within the brain. Collectively, these responses act to set up and maintain states needed to perform a given task. However, the mechanisms that allow for setting up and maintaining a task state are not fully understood. Prior evidence suggests that one possible mechanism for maintaining a task state may be through altering 'background connectivity,' connectivity that exists independently of the trials of a task. Although previous studies have suggested that background connectivity contributes to a task state, these studies have typically not controlled for stimulus characteristics, or have focused primarily on relationships among areas involved with visual sensory processing. In the present study we examined background connectivity during tasks involving both visual and auditory stimuli. We examined the connectivity profiles of both visual and auditory sensory cortex that allow for selection of task-relevant stimuli, demonstrating the existence of a potentially universal pattern of background connectivity underlying attention to a stimulus. Participants were presented with simultaneous auditory and visual stimuli and were instructed to respond to only one, while ignoring the other. Using functional MRI, we observed task-based modulation of the background connectivity profile for both the auditory and visual cortex to certain brain regions. There was an increase in background connectivity between the task-relevant sensory cortex and control areas in the frontal cortex. This increase in synchrony when receiving the task-relevant stimulus as compared to the task irrelevant stimulus may be maintaining paths for passing information within the cortex. These task-based modulations of connectivity occur independently of stimuli and could be one way the brain sets up and maintains a task state. |
Magdalena Fafrowicz; Bartosz Bohaterewicz; Anna Ceglarek; Monika Cichocka; Koryna Lewandowska; Barbara Sikora-Wachowicz; Halszka Oginska; Anna Beres; Justyna Olszewska; Tadeusz Marek Beyond the low frequency fluctuations: Morning and evening differences in human brain Journal Article In: Frontiers in Human Neuroscience, vol. 13, pp. 288, 2019. @article{Fafrowicz2019, Human performance, alertness, and most biological functions express rhythmic fluctuations across a 24-h-period. This phenomenon is believed to originate from differences in both circadian and homeostatic sleep-wake regulatory processes. Interactions between these processes result in time-of-day modulations of behavioral performance as well as brain activity patterns. Although the basic mechanism of the 24-h clock is conserved across evolution, there are interindividual differences in the timing of sleep-wake cycles, subjective alertness and functioning throughout the day. The study of circadian typology differences has increased during the last few years, especially research on extreme chronotypes, which provide a unique way to investigate the effects of sleep-wake regulation on cerebral mechanisms. Using functional magnetic resonance imaging (fMRI), we assessed the influence of chronotype and time-of-day on resting-state functional connectivity. Twenty-nine extreme morning- and 34 evening-type participants underwent two fMRI sessions: about 1 h after wake-up time (morning) and about 10 h after wake-up time (evening), scheduled according to their declared habitual sleep-wake pattern on a regular working day. Analysis of obtained neuroimaging data disclosed only an effect of time of day on resting-state functional connectivity; there were different patterns of functional connectivity between morning (MS) and evening (ES) sessions. The results of our study showed no differences between extreme morning-type and evening-type individuals. We demonstrate that circadian and homeostatic influences on the resting-state functional connectivity have a universal character, unaffected by circadian typology. |
Jesse Gomez; Alexis Drain; Brianna Jeska; Vaidehi S. Natu; Michael Barnett; Kalanit Grill-Spector Development of population receptive fields in the lateral visual stream improves spatial coding amid stable structural-functional coupling Journal Article In: NeuroImage, vol. 188, pp. 59–69, 2019. @article{Gomez2019, Human visual cortex encompasses more than a dozen visual field maps across three major processing streams. One of these streams is the lateral visual stream, which extends from V1 to lateral-occipital (LO) and temporal-occipital (TO) visual field maps and plays a prominent role in shape as well as motion perception. However, it is unknown if and how population receptive fields (pRFs) in the lateral visual stream develop from childhood to adulthood, and what impact this development may have on spatial coding. Here, we used functional magnetic resonance imaging and pRF modeling in school-age children and adults to investigate the development of the lateral visual stream. Our data reveal four main findings: 1) The topographic organization of eccentricity and polar angle maps of the lateral stream is stable after age five. 2) In both age groups there is a reliable relationship between eccentricity map transitions and cortical folding: the middle occipital gyrus predicts the transition between the peripheral representation of LO and TO maps. 3) pRFs in LO and TO maps undergo differential development from childhood to adulthood, resulting in increasing coverage of the central visual field in LO and of the peripheral visual field in TO. 4) Model-based decoding shows that the consequence of pRF and visual field coverage development is improved spatial decoding from LO and TO distributed responses in adults vs. children. Together, these results explicate both the development and topography of the lateral visual stream. Our data show that the general structural-functional organization is laid out early in development, but fine-scale properties, such as pRF distribution across the visual field and consequently, spatial precision, become fine-tuned across childhood development. These findings advance understanding of the development of the human visual system from childhood to adulthood and provide an essential foundation for understanding developmental deficits. |
Joseph C. Griffis; Nicholas V. Metcalf; Maurizio Corbetta; Gordon L. Shulman Structural disconnections explain brain network dysfunction after stroke Journal Article In: Cell Reports, vol. 28, no. 10, pp. 2527–2540, 2019. @article{Griffis2019, Stroke causes focal brain lesions that disrupt functional connectivity (FC), a measure of activity synchronization, throughout distributed brain networks. It is often assumed that FC disruptions reflect damage to specific cortical regions. However, an alternative explanation is that they reflect the structural disconnection (SDC) of white matter pathways. Here, we compare these explanations using data from 114 stroke patients. Across multiple analyses, we find that SDC measures outperform focal damage measures, including damage to putative critical cortical regions, for explaining FC disruptions associated with stroke. We also identify a core mode of structure-function covariation that links the severity of interhemispheric SDCs to widespread FC disruptions across patients and that correlates with deficits in multiple behavioral domains. We conclude that a lesion's impact on the structural connectome is what determines its impact on FC and that interhemispheric SDCs may play a particularly important role in mediating FC disruptions after stroke. |
Christoph Helmchen; Matthias Rother; Andreas Sprenger Increased brain responsivity to galvanic vestibular stimulation in bilateral vestibular failure Journal Article In: NeuroImage: Clinical, vol. 24, pp. 101942, 2019. @article{Helmchen2019, In this event-related functional magnetic resonance imaging (fMRI) study we investigated how the brain of patients with bilateral vestibular failure (BVF) responds to vestibular stimuli. We used imperceptible noisy galvanic vestibular stimulation (GVS) and perceptible bi-mastoidal GVS intensities and related the corresponding brain activity to the evoked motion perception. In contrast to caloric irrigation, GVS stimulates the vestibular organ at its potentially intact afferent nerve site. Motion perception thresholds and cortical responses were compared between 26 BVF patients to 27 age-matched healthy control participants. To identify the specificity of vestibular cortical responses we used a parametric design with different stimulus intensities (noisy imperceptible, low perceptible, high perceptible) allowing region-specific stimulus response functions. In a 2 × 3 flexible factorial design all GVS-related brain activities were contrasted with a sham condition that did not evoke perceived motion. Patients had a higher motion perception threshold and rated the vestibular stimuli higher than the healthy participants. There was a stimulus intensity related and region-specific increase of activity with steep stimulus response functions in parietal operculum (e.g. OP2), insula, superior temporal gyrus, early visual cortices (V3) and cerebellum while activity in the hippocampus and intraparietal sulcus did not correlate with vestibular stimulus intensity. Using whole brain analysis, group comparisons revealed increased brain activity in early visual cortices (V3) and superior temporal gyrus of patients but there was no significant interaction, i.e. stimulus response function in these regions were still similar in both groups. Brain activity in these regions during (high)GVS increased with higher dizziness-related handicap scores but was not related to the degree of vestibular impairment or disease duration. nGVS did not evoke cortical responses in any group. Our data indicate that perceptible GVS-related cortical responsivity is not diminished but increased in mul-tisensory (visual-vestibular) cortical regions despite bilateral failure of the peripheral vestibular organ. The increased activity in early visual cortices (V3) and superior temporal gyrus of BVF patients has several potential implications: (i) their cortical reciprocal inhibitory visuo-vestibular interaction is dysfunctional, (ii) it may contribute to the visual dependency of BVF patients, and (iii) it needs to be considered when BVF patients receive peripheral vestibular stimulation devices, e.g. vestibular implants or portable GVS devices. Imperceptible nGVS did not elicit cortical brain responses making it unlikely that the reported balance improvement of BVF by nGVS is mediated by cortical mechanisms. |
Linda Henriksson; Marieke Mur; Nikolaus Kriegeskorte Rapid invariant encoding of scene layout in human OPA Journal Article In: Neuron, vol. 103, no. 1, pp. 161–171.e3, 2019. @article{Henriksson2019, Successful visual navigation requires a sense of the geometry of the local environment. How do our brains extract this information from retinal images? Here we visually presented scenes with all possible combinations of five scene-bounding elements (left, right, and back walls; ceiling; floor) to human subjects during functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG). The fMRI response patterns in the scene-responsive occipital place area (OPA) reflected scene layout with invariance to changes in surface texture. This result contrasted sharply with the primary visual cortex (V1), which reflected low-level image features of the stimuli, and the parahippocampal place area (PPA), which showed better texture than layout decoding. MEG indicated that the texture-invariant scene layout representation is computed from visual input within ∼100 ms, suggesting a rapid computational mechanism. Taken together, these results suggest that the cortical representation underlying our instant sense of the environmental geometry is located in the OPA. |
Anna E. Hughes; John A. Greenwood; Nonie J. Finlayson; D. Samuel Schwarzkopf Population receptive field estimates for motion-defined stimuli Journal Article In: NeuroImage, vol. 199, pp. 245–260, 2019. @article{Hughes2019, The processing of motion changes throughout the visual hierarchy, from spatially restricted ‘local motion' in early visual cortex to more complex large-field ‘global motion' at later stages. Here we used functional magnetic resonance imaging (fMRI) to examine spatially selective responses in these areas related to the processing of random-dot stimuli defined by differences in motion. We used population receptive field (pRF) analyses to map retinotopic cortex using bar stimuli comprising coherently moving dots. In the first experiment, we used three separate background conditions: no background dots (dot-defined bar-only), dots moving coherently in the opposite direction to the bar (kinetic boundary) and dots moving incoherently in random directions (global motion). Clear retinotopic maps were obtained for the bar-only and kinetic-boundary conditions across visual areas V1–V3 and in higher dorsal areas. For the global-motion condition, retinotopic maps were much weaker in early areas and became clear only in higher areas, consistent with the emergence of global-motion processing throughout the visual hierarchy. However, in a second experiment we demonstrate that this pattern is not specific to motion-defined stimuli, with very similar results for a transparent-motion stimulus and a bar defined by a static low-level property (dot size) that should have driven responses particularly in V1. We further exclude explanations based on stimulus visibility by demonstrating that the observed differences in pRF properties do not follow the ability of observers to localise or attend to these bar elements. Rather, our findings indicate that dorsal extrastriate retinotopic maps may primarily be determined by the visibility of the neural responses to the bar relative to the background response (i.e. neural signal-to-noise ratios) and suggests that claims about stimulus selectivity from pRF experiments must be interpreted with caution. |
Andreas Jarvstad; Iain D. Gilchrist Cognitive control of saccadic selection and inhibition from within the core cortical saccadic network Journal Article In: Journal of Neuroscience, vol. 39, no. 13, pp. 2497–2508, 2019. @article{Jarvstad2019, The ability to select the task-relevant stimulus for a saccadic eye movement, while inhibiting saccades to task-irrelevant stimuli, is crucial for active vision. Here, we present a novel saccade-contingent behavioral paradigm and investigate the neural basis of the central cognitive functions underpinning such behavior, saccade selection, saccade inhibition, and saccadic choice, in female and male human participants. The paradigm allows for exceptionally well-matched contrasts, with task demands formalized with stochastic accumulation-to-threshold models. Using fMRI, we replicated the core cortical eye-movement network for saccade generation (frontal eye fields, posterior parietal cortex, and higher-level visual areas). However, in contrast to previously published tasks, saccadic selection and inhibition recruited only this core network. Brain-behavior analyses further showed that inhibition efficiency may be underpinned by white-matter integrity of tracts between key saccade-generating regions, and that inhibition efficiency is associated with right inferior frontal gyrus engagement, potentially implementing general-purpose inhibition. The core network, however, was insufficient for saccadic choice, which recruited anterior regions commonly attributed to saccadic action selection, including dorsolateral prefrontal cortex and anterior cingulate cortex. Jointly, the results indicate that extra-saccadic activity observed for free choice, and in previously published tasks probing saccadic control, is likely due to increased load on higher-level cognitive processes, and not saccadic selection per se, which is achieved within the canonical cortical eye movement network. |
Yaoda Xu; Maryam Vaziri-Pashkam Task modulation of the 2-pathway characterization of occipitotemporal and posterior parietal visual object representations Journal Article In: Neuropsychologia, vol. 132, pp. 107140, 2019. @article{Xu2019, Recent studies have reported the existence of rich non-spatial visual object representations in both human and monkey posterior parietal cortex (PPC), similar to those found in occipito-temporal cortex (OTC). Despite this similarity, we recently showed that visual object representation still differ between OTC and PPC in two aspects. In one study, by manipulating whether object shape or color was task relevant, we showed that visual object representations were under greater top-down attention and task control in PPC than in OTC (Vaziri-Pashkam & Xu, 2017, J Neurosci). In another study, using a bottom-up data driven approach, we showed that there exists a large separation between PPC and OTC regions in the representational space, with OTC regions lining up hierarchically along an OTC pathway and PPC regions lining up hierarchically along an orthogonal PPC pathway (Vaziri-Pashkam & Xu, 2019, Cereb Cortex). To understand the interaction of goal-driven visual processing and the two-pathway structure in the representational space, here we performed a set of new analyses of the data from the three experiments of Vaziri-Pashkam and Xu (2017) and directly compared the two-pathway separation of OTC and PPC regions when object shapes were attended and task relevant and when they were not. We found that in all three experiments the correlation of visual object representational structure between superior IPS (a key PPC visual region) and lateral and ventral occipito-temporal regions (higher OTC visual regions) became greater when object shapes were attended than when they were not. This modified the two-pathway structure, with PPC regions moving closer to higher OTC regions and a compression of the PPC pathway towards the OTC pathway in the representational space when shapes were attended. Consistent with this observation, the correlation between neural and behavioral measures of visual representational structure was also higher in superior IPS when shapes were attended than when they were not. By comparing representational structures across experiments and tasks, we further showed that attention to object shape resulted in the formation of more similar object representations in superior IPS across experiments than between the two tasks within the same experiment despite noise and stimulus differences across the experiments. Overall, these results demonstrated that, despite the separation of the OTC and PPC pathways in the representational space, the visual representational structure of PPC is flexible and can be modulated by the task demand. This reaffirms the adaptive nature of visual processing in PPC and further distinguishes it from the more invariant nature of visual processing in OTC. |
Noriya Watanabe; Jamil P. Bhanji; Hideki Ohira; Mauricio R. Delgado Reward-driven arousal impacts preparation to perform a task via amygdala-caudate mechanisms Journal Article In: Cerebral Cortex, vol. 29, no. 7, pp. 3010–3022, 2019. @article{Watanabe2019a, Preparing for a challenging task can increase physiological arousal, in particular when potential incentives are large (e.g., a solo musical performance in front of an audience). Here, we examine how potential reward and its influence on arousal, measured by pupil dynamics, are represented in the brain while preparing for a challenging task. We further ask how neural representations during preparation relate to actual performance. Trials resulting in performance failure were characterized by increased pupil dilation as a function of increasing reward magnitude during preparation. Such failure trials were also associated with activation of the right amygdala representing pupil dilation, and the left caudate representing reward magnitude. Notably, increases in functional connectivity between amygdala and caudate preceded performance failure. These findings highlight increased connectivity between neural regions representing reward and arousal in circumstances where reward-driven arousal impairs performance. |
Noriya Watanabe; Jamil P. Bhanji; Hiroki C. Tanabe; Mauricio R. Delgado Ventromedial prefrontal cortex contributes to performance success by controlling reward-driven arousal representation in amygdala Journal Article In: NeuroImage, vol. 202, pp. 116136, 2019. @article{Watanabe2019, When preparing for a challenging task, potential rewards can cause physiological arousal that may impair performance. In this case, it is important to control reward-driven arousal while preparing for task execution. We recently examined neural representations of physiological arousal and potential reward magnitude during preparation, and found that performance failure was explained by relatively increased reward representation in the left caudate nucleus and arousal representation in the right amygdala (Watanabe, et al., 2019). Here we examine how prefrontal cortex influences the amygdala and caudate to control reward-driven arousal. Ventromedial prefrontal cortex (VMPFC) exhibited activity that was negatively correlated with trial-wise physiological arousal change, which identified this region as a potential modulator of amygdala and caudate. Next we tested the VMPFC - amygdala - caudate effective network using dynamic causal modeling (Friston et al., 2003). Post-hoc Bayesian model selection (Friston and Penny, 2011) identified a model that best fit data, in which amygdala activation was suppressively controlled by the VMPFC only in success trials. Furthermore, fixed connectivity strength from VMPFC to amygdala explained individual task performance. These findings highlight the role of effective connectivity from VMPFC to amygdala in order to control arousal during preparation for successful performance. |
Yuan-hao Wu; Lisa A. Velenosi; Pia Schröder; Simon Ludwig; Felix Blankenburg Decoding vibrotactile choice independent of stimulus order and saccade selection during sequential comparisons Journal Article In: Human Brain Mapping, vol. 40, no. 6, pp. 1898–1907, 2019. @article{Wu2019, Decision-making in the somatosensory domain has been intensively studied using vibrotactile frequency discrimination tasks. Results from human and monkey electrophysiological studies from this line of research suggest that perceptual choices are encoded within a sensorimotor network. These findings, however, rely on experimental settings in which perceptual choices are inextricably linked to sensory and motor components of the task. Here, we devised a novel version of the vibrotactile frequency discrimination task with saccade responses which has the crucial advantage of decoupling perceptual choices from sensory and motor processes. We recorded human fMRI data from 32 participants while they performed the task. Using a whole-brain searchlight multivariate classification technique, we identify the left lateral prefrontal cortex and the oculomotor system, including the bilateral frontal eye fields (FEF) and intraparietal sulci, as representing vibrotactile choices. Moreover, we show that the decoding accuracy of choice information in the right FEF correlates with behavioral performance. Not only are these findings in remarkable agreement with previous work, they also provide novel fMRI evidence for choice coding in human oculomotor regions, which is not limited to saccadic decisions, but pertains to contexts where choices are made in a more abstract form. |
Liping Wang; Marie Amalric; Wen Fang; Xinjian Jiang; Christophe Pallier; Santiago Figueira; Mariano Sigman; Stanislas Dehaene Representation of spatial sequences using nested rules in human prefrontal cortex Journal Article In: NeuroImage, vol. 186, pp. 245–255, 2019. @article{Wang2019f, Memory for spatial sequences does not depend solely on the number of locations to be stored, but also on the presence of spatial regularities. Here, we show that the human brain quickly stores spatial sequences by detecting geometrical regularities at multiple time scales and encoding them in a format akin to a programming language. We measured gaze-anticipation behavior while spatial sequences of variable regularity were repeated. Participants' behavior suggested that they quickly discovered the most compact description of each sequence in a language comprising nested rules, and used these rules to compress the sequence in memory and predict the next items. Activity in dorsal inferior prefrontal cortex correlated with the amount of compression, while right dorsolateral prefrontal cortex encoded the presence of embedded structures. Sequence learning was accompanied by a progressive differentiation of multi-voxel activity patterns in these regions. We propose that humans are endowed with a simple “language of geometry” which recruits a dorsal prefrontal circuit for geometrical rules, distinct from but close to areas involved in natural language processing. |
Katharina Voigt; Carsten Murawski; Sebastian Speer; Stefan Bode Hard decisions shape the neural coding of preferences Journal Article In: Journal of Neuroscience, vol. 39, no. 4, pp. 718–726, 2019. @article{Voigt2019, Hard decisions between equally valued alternatives can result in preference changes, meaning that subsequent valuations for chosen items increaseanddecrease for rejected items. Previous research suggests that thisphenomenon is aconsequenceofcognitive dissonance reduction after the decision, induced by the mismatch between initial preferences and decision outcomes. In contrast, this functional magnetic resonance imaging and eye-tracking study with male and female human participants found that preferences are already updated online during the process of decision-making. Preference changes were predicted from activity in left dorsolateral prefrontal cortexandprecuneus whilemakinghard decisions. Fixation durations during this phase predicted both choice outcomesandsubsequent preference changes. These preference adjustments became behaviorally relevant only for choices that were rememberedand were in turn associated with hippocampus activity. Our results suggest that preferences evolve dynamically as decisions arise, potentially as a mechanism to prevent stalemate situations in underdetermined decision scenarios. |
Lorenzo Vignali; Stefan Hawelka; Florian Hutzler; Fabio Richlan Processing of parafoveally presented words. An fMRI study Journal Article In: NeuroImage, vol. 184, pp. 1–9, 2019. @article{Vignali2019, The present fMRI study investigated neural correlates of parafoveal preprocessing during reading and the type of information that is accessible from the upcoming - not yet fixated - word. Participants performed a lexical decision flanker task while the constraints imposed by the first three letters (the initial trigram) of parafoveally presented words were controlled. Behavioral results evidenced that the amount of information extracted from parafoveal stimuli, was affected by the difficulty of the foveal stimulus. Easy to process foveal stimuli (i.e., high frequency nouns) allowed parafoveal information to be extracted up to the lexical level. Conversely, when foveal stimuli were difficult to process (orthographically legal nonwords) only constraining trigrams modulated the task performance. Neuroimaging findings showed no effects of lexicality (i.e., difference between words and pseudowords) in the parafovea independently from the difficulty of the foveal stimulus. The constraints imposed by the initial trigrams, however, modulated the hemodynamic response in the left supramarginal gyrus. We interpreted the supramarginal activation as reflecting sublexical (phonological) processes. The missing parafoveal lexicality effect was discussed in relation to findings of experiments which observed effects of parafoveal semantic congruency on electrophysiological correlates. |
Maryam Vaziri-Pashkam; Yaoda Xu An Information-Driven 2-Pathway Characterization of Occipitotemporal and Posterior Parietal Visual Object Representations Journal Article In: Cerebral Cortex, vol. 29, no. 5, pp. 2034–2050, 2019. @article{VaziriPashkam2019, Recent studies have demonstrated the existence of rich visual representations in both occipitotemporal cortex (OTC) and posterior parietal cortex (PPC). Using fMRI decoding and a bottom-up data-driven approach, we showed that although robust object category representations exist in both OTC and PPC, there is an information-driven 2-pathway separation among these regions in the representational space, with occipitotemporal regions arranging hierarchically along 1 pathway and posterior parietal regions along another pathway. We obtained 10 independent replications of this 2-pathway distinction, accounting for 58-81% of the total variance of the region-wise differences in visual representation. The separation of the PPC regions from higher occipitotemporal regions was not driven by a difference in tolerance to changes in low-level visual features, did not rely on the presence of special object categories, and was present whether or not object category was task relevant. Our information-driven 2-pathway structure differs from the well-known ventral-what and dorsal-where/how characterization of posterior brain regions. Here both pathways contain rich nonspatial visual representations. The separation we see likely reflects a difference in neural coding scheme used by PPC to represent visual information compared with that of OTC. |
Raphael Vallat; David Meunier; Alain Nicolas; Perrine Ruby Hard to wake up? The cerebral correlates of sleep inertia assessed using combined behavioral, EEG and fMRI measures Journal Article In: NeuroImage, vol. 184, pp. 266–278, 2019. @article{Vallat2019, The first minutes following awakening from sleep are typically marked by reduced vigilance, increased sleepiness and impaired performance, a state referred to as sleep inertia. Although the behavioral aspects of sleep inertia are well documented, its cerebral correlates remain poorly understood. The present study aimed at filling this gap by measuring in 34 participants the changes in behavioral performance (descending subtraction task, DST), EEG spectral power, and resting-state fMRI functional connectivity across three time points: before an early-afternoon 45-min nap, 5 min after awakening from the nap and 25 min after awakening. Our results showed impaired performance at the DST at awakening and an intrusion of sleep-specific features (spectral power and functional connectivity) into wakefulness brain activity, the intensity of which was dependent on the prior sleep duration and depth for the functional connectivity (14 participants awakened from N2 sleep, 20 from N3 sleep). Awakening in N3 (deep) sleep induced the most robust changes and was characterized by a global loss of brain functional segregation between task-positive (dorsal attention, salience, sensorimotor) and task-negative (default mode) networks. Significant correlations were observed notably between the EEG delta power and the functional connectivity between the default and dorsal attention networks, as well as between the percentage of mistake at the DST and the default network functional connectivity. These results highlight (1) significant correlations between EEG and fMRI functional connectivity measures, (2) significant correlations between the behavioral aspect of sleep inertia and measures of the cerebral functioning at awakening (both EEG and fMRI), and (3) the important difference in the cerebral underpinnings of sleep inertia at awakening from N2 and N3 sleep. |
Imme C. Zillekens; Marie Luise Brandi; Juha M. Lahnakoski; Atesh Koul; Valeria Manera; Cristina Becchio; Leonhard Schilbach Increased functional coupling of the left amygdala and medial prefrontal cortex during the perception of communicative point-light stimuli Journal Article In: Social Cognitive and Affective Neuroscience, vol. 14, no. 1, pp. 97–107, 2019. @article{Zillekens2019, Interpersonal predictive coding (IPPC) describes the behavioral phenomenon whereby seeing a communicative rather than an individual action helps to discern a masked second agent. As little is known, yet, about the neural correlates of IPPC, we conducted a functional magnetic resonance imaging study in a group of 27 healthy participants using point-light displays of moving agents embedded in distractors. We discovered that seeing communicative compared to individual actions was associated with higher activation of right superior frontal gyrus, whereas the reversed contrast elicited increased neural activation in an action observation network that was activated during all trials. Our findings, therefore, potentially indicate the formation of action predictions and a reduced demand for executive control in response to communicative actions. Further, in a regression analysis, we revealed that increased perceptual sensitivity was associated with a deactivation of the left amygdala during the perceptual task. A consecutive psychophysiological interaction analysis showed increased connectivity of the amygdala with medial prefrontal cortex in the context of communicative compared to individual actions. Thus, whereas increased amygdala signaling might interfere with task-relevant processes, increased co-activation of the amygdala and the medial prefrontal cortex in a communicative context might represent the integration of mentalizing computations. |
Sonja Well; John P. O'Doherty; Frans Winden Relief from incidental fear evokes exuberant risk taking Journal Article In: PLoS ONE, vol. 14, no. 1, pp. e0211018, 2019. @article{Well2019, Incidental emotions are defined as feelings that are unrelated to a decision task at hand and thereby not normatively relevant for making choices. The precise influence and formal theoretical implications of incidental emotions regarding financial risk taking are still largely unclear. An effect of incidental emotion on decision-making would challenge the main extant formal theoretical economic models because such models do not allow for an effect of incidental emotions. As financial risk taking is pervasive in modern economies, the role of incidental emotions is an important issue. The goal of this experimental study is threefold. First, we examine the impact of incidental fear on the choice between a sure and a risky monetary option. A well-validated method of fear induction, using electric shocks, is employed for that purpose. Based on emotion studies we hypothesize less risk taking under fear and more risk taking when relieved of fear. Our second goal is to investigate the relative performance of the main existing formal theoretical economic models (based on Expected Utility Theory, Prospect Theory, or the Mean-Variance model) in explaining the behavioral data. We also investigate how these models can be adjusted to accommodate any observed influence of incidental emotion. For that reason, we first theoretically model the potential pathways of incidental fear (and the relief thereof) via the valuation of the choice option rewards or risk-assessment. We then estimate the relevant parameters allowing for both additive as well as interactive effects. Our third and final goal is to explore the neural basis of any observed influence of incidental emotions on decision-making by means of a model-based fMRI analysis, using the findings of existing neuroeconomic studies as the basis for our hypotheses. Our results indicate that the relief of fear can give a substantial boost to financial risk taking (suggestive of exuberance). This impact is best captured by Prospect Theory if we allow for an increase in participants' valuation of option outcomes when relieved of fear. Moreover, this impact is manifested at the neural level by the activity of the ventromedial prefrontal cortex (vmPFC), a brain area widely regarded as being central for valuation. |
Chayenne Van Meel; Annelies Baeck; Céline R. Gillebert; Johan Wagemans; Hans P. Op de Beeck The representation of symmetry in multi-voxel response patterns and functional connectivity throughout the ventral visual stream Journal Article In: NeuroImage, vol. 191, pp. 216–224, 2019. @article{VanMeel2019, Several computational models explain how symmetry might be detected and represented in the human brain. However, while there is an abundance of psychophysical studies on symmetry detection and several neural studies showing where and when symmetry is detected in the brain, important questions remain about how this detection happens and how symmetric patterns are represented. We studied the representation of (vertical) symmetry in regions of the ventral visual stream, using multi-voxel pattern analyses (MVPA) and functional connectivity analyses. Our results suggest that neural representations gradually change throughout the ventral visual stream, from very similar part-based representations for symmetrical and asymmetrical stimuli in V1 and V2, over increasingly different representations for symmetrical and asymmetrical stimuli which are nevertheless still part-based in both V3 and V4, to a more holistic representation for symmetrical compared to asymmetrical stimuli in high-level LOC. This change in representations is accompanied by increased communication between left and right retinotopic areas, evidenced by higher interhemispheric functional connectivity during symmetry perception in areas V2 and V4. |
Eelke Vries; Daniel Baldauf In: Journal of Cognitive Neuroscience, vol. 31, no. 10, pp. 1573–1588, 2019. @article{Vries2019, We recorded magnetoencephalography using a neural entrainment paradigm with compound face stimuli that allowed for entraining the processing of various parts of a face (eyes, mouth) as well as changes in facial identity. Our magnetic response image-guided magnetoencephalography analyses revealed that different subnodes of the human face processing network were entrained differentially according to their functional specialization. Whereas the occipital face area was most responsive to the rate at which face parts (e.g., the mouth) changed, and face patches in the STS were mostly entrained by rhythmic changes in the eye region, the fusiform face area was the only subregion that was strongly entrained by the rhythmic changes in facial identity. Furthermore, top–down attention to the mouth, eyes, or identity of the face selectively modulated the neural processing in the respective area (i.e., occipital face area, STS, or fusiform face area), resembling behavioral cue validity effects observed in the participants' RT and detection rate data. Our results show the attentional weighting of the visual processing of different aspects and dimensions of a single face object, at various stages of the involved visual processing hierarchy. |
Rozemarijn S. Kleef; Claudi L. H. Bockting; Evelien Valen; André Aleman; Jan Bernard C. Marsman; Marie José Tol In: BMC Psychiatry, vol. 19, pp. 1–11, 2019. @article{Kleef2019, Background: Major Depressive Disorder (MDD) is a psychiatric disorder with a highly recurrent character, making prevention of relapse an important clinical goal. Preventive Cognitive Therapy (PCT) has been proven effective in preventing relapse, though not for every patient. A better understanding of relapse vulnerability and working mechanisms of preventive treatment may inform effective personalized intervention strategies. Neurocognitive models of MDD suggest that abnormalities in prefrontal control over limbic emotion-processing areas during emotional processing and regulation are important in understanding relapse vulnerability. Whether changes in these neurocognitive abnormalities are induced by PCT and thus play an important role in mediating the risk for recurrent depression, is currently unclear. In the Neurocognitive Working Mechanisms of the Prevention of Relapse In Depression (NEWPRIDE) study, we aim to 1) study neurocognitive factors underpinning the vulnerability for relapse, 2) understand the neurocognitive working mechanisms of PCT, 3) predict longitudinal treatment effects based on pre-treatment neurocognitive characteristics, and 4) validate the pupil dilation response as a marker for prefrontal activity, reflecting emotion regulation capacity and therapy success. Methods: In this randomized controlled trial, 75 remitted recurrent MDD (rrMDD) patients will be included. Detailed clinical and cognitive measurements, fMRI scanning and pupillometry will be performed at baseline and three-month follow-up. In the interval, 50 rrMDD patients will be randomized to eight sessions of PCT and 25 rrMDD patients to a waiting list. At baseline, 25 healthy control participants will be additionally included to objectify cross-sectional residual neurocognitive abnormalities in rrMDD. After 18 months, clinical assessments of relapse status are performed to investigate which therapy induced changes predict relapse in the 50 patients allocated to PCT. Discussion: The present trial is the first to study the neurocognitive vulnerability factors underlying relapse and mediating relapse prevention, their value for predicting PCT success and whether pupil dilation acts as a valuable marker in this regard. Ultimately, a deeper understanding of relapse prevention could contribute to the development of better targeted preventive interventions. Trial registration: Trial registration: Netherlands Trial Register, August 18, 2015, trial number NL5219. |
2018 |
Koen Lith; Dick Johan Veltman; Moran Daniel Cohn; Louise Else Pape; Marieke Eleonora Akker-Nijdam; Amanda Wilhelmina Geertruida Loon; Pierre Bet; Guido Alexander Wingen; Wim Brink; Theo Doreleijers; Arne Popma Effects of methylphenidate during fear learning in antisocial adolescents: A randomized controlled fMRI trial Journal Article In: Journal of the American Academy of Child and Adolescent Psychiatry, vol. 57, no. 12, pp. 934–943, 2018. @article{Lith2018, Objective: Although the neural underpinnings of antisocial behavior have been studied extensively, research on pharmacologic interventions targeting specific neural mechanisms remains sparse. Hypoactivity of the amygdala and ventromedial prefrontal cortex (vmPFC) has been reported in antisocial adolescents, which could account for deficits in fear learning (amygdala) and impairments in decision making (vmPFC), respectively. Limited clinical research suggests positive effects of methylphenidate, a dopamine agonist, on antisocial behavior in adolescents. Dopamine is a key neurotransmitter involved in amygdala and vmPFC functioning. The objective of this study was to investigate whether methylphenidate targets dysfunctions in these brain areas in adolescents with antisocial behavior. Method: A group of 42 clinical referred male adolescents (14–17 years old) with a disruptive behavior disorder performed a fear learning/reversal paradigm in a randomized double-blinded placebo-controlled pharmacologic functional magnetic resonance imaging study. Participants with disruptive behavior disorder were randomized to receive a single dose of methylphenidate 0.3 to 0.4 mg/kg (n = 22) or placebo (n = 20) and were compared with 21 matched healthy controls not receiving medication. Results: In a region-of-interest analysis of functional magnetic resonance imaging data during fear learning, the placebo group showed hyporeactivity of the amygdala compared with healthy controls, whereas amygdala reactivity was normalized in the methylphenidate group. There were no group differences in vmPFC reactivity during fear reversal learning. Whole-brain analyses showed no group differences. Conclusion: These findings suggest that methylphenidate is a promising pharmacologic intervention for youth antisocial behavior that could restore amygdala functioning. |
Regine Zopf; Marina Butko; Alexandra Woolgar; Mark A. Williams; Anina N. Rich Representing the location of manipulable objects in shape-selective occipitotemporal cortex: Beyond retinotopic reference frames? Journal Article In: Cortex, vol. 106, pp. 132–150, 2018. @article{Zopf2018, When interacting with objects, we have to represent their location relative to our bodies. To facilitate bodily reactions, location may be encoded in the brain not just with respect to the retina (retinotopic reference frame), but also in relation to the head, trunk or arm (collectively spatiotopic reference frames). While spatiotopic reference frames for location encoding can be found in brain areas for action planning, such as parietal areas, there is debate about the existence of spatiotopic reference frames in higher-level occipitotemporal visual areas. In an extensive multi-voxel pattern analysis (MVPA) fMRI study using faces, headless bodies and scenes stimuli, Golomb and Kanwisher (2012) did not find evidence for spatiotopic reference frames in shape-selective occipitotemporal cortex. This finding is important for theories of how stimulus location is encoded in the brain. It is possible, however, that their failure to find spatiotopic reference frames is related to their stimuli: we typically do not manipulate faces, headless bodies or scenes. It is plausible that we only represent body-centred location when viewing objects that are typically manipulated. Here, we tested for object location encoding in shape-selective occipitotemporal cortex using manipulable object stimuli (balls and cups) in a MVPA fMRI study. We employed Bayesian analyses to determine sample size and evaluate the sensitivity of our data to test the hypothesis that location can be encoded in a spatiotopic reference frame in shape-selective occipitotemporal cortex over the null hypothesis of no spatiotopic location encoding. We found strong evidence for retinotopic location encoding consistent with previous findings that retinotopic reference frames are common neural representations of object location. In contrast, when testing for spatiotopic encoding, we found evidence that object location information for small manipulable objects is not decodable in relation to the body in shape-selective occipitotemporal cortex. Post-hoc exploratory analyses suggested that spatiotopic aspects might modulate retinotopic location encoding. |
Daniel Marten Es; Jan Theeuwes; Tomas Knapen Spatial sampling in human visual cortex is modulated by both spatial and feature-based attention Journal Article In: eLife, vol. 7, pp. 1–28, 2018. @article{Es2018, Spatial attention changes the sampling of visual space. Behavioral studies suggest that feature-based attention modulates this resampling to optimize the attended feature's sampling. We investigate this hypothesis by estimating spatial sampling in visual cortex while independently varying both feature-based and spatial attention. Our results show that spatial and feature-based attention interacted: resampling of visual space depended on both the attended location and feature (color vs. temporal frequency). This interaction occurred similarly throughout visual cortex, regardless of an area's overall feature preference. However, the interaction did depend on spatial sampling properties of voxels that prefer the attended feature. These findings are parsimoniously explained by variations in the precision of an attentional gain field. Our results demonstrate that the deployment of spatial attention is tailored to the spatial sampling properties of units that are sensitive to the attended feature. |
Anouk Mariette Loon; Katya Olmos-Solis; Johannes J. Fahrenfort; Christian N. L. Olivers Current and future goals are represented in opposite patterns in object-selective cortex Journal Article In: eLife, vol. 7, pp. 1–25, 2018. @article{Loon2018, Adaptive behavior requires the separation of current from future goals in working memory. We used fMRI of object-selective cortex to determine the representational (dis)similarities of memory representations serving current and prospective perceptual tasks. Participants remembered an object drawn from three possible categories as the target for one of two consecutive visual search tasks. A cue indicated whether the target object should be looked for first (currently relevant), second (prospectively relevant), or if it could be forgotten (irrelevant). Prior to the first search, representations of current, prospective and irrelevant objects were similar, with strongest decoding for current representations compared to prospective (Experiment 1) and irrelevant (Experiment 2). Remarkably, during the first search, prospective representations could also be decoded, but revealed anti-correlated voxel patterns compared to currently relevant representations of the same category. We propose that the brain separates current from prospective memories within the same neuronal ensembles through opposite representational patterns. |
Maryam Vaziri-Pashkam; JohnMark Taylor; Yaoda Xu Spatial frequency tolerant visual object representations in the human ventral and dorsal visual processing pathways Journal Article In: Journal of Cognitive Neuroscience, vol. 31, no. 1, pp. 49–63, 2018. @article{VaziriPashkam2018, Primate ventral and dorsal visual pathways both contain visual object representations. Dorsal regions receive more input from magnocellular system while ventral regions receive inputs from both magnocellular and parvocellular systems. Due to potential differences in the spatial sensitivites of man- ocellular and parvocellular systems, object representations in ventral and dorsal regions may differ in how they represent visual input from different spatial scales. To test this prediction, we asked observers to view blocks of images from six object catego- ries, shown in full spectrum, high spatial frequency (SF), or low SF. We found robust object category decoding in all SF conditions as well as SF decoding in nearly all the early visual, ventral, and dorsal regions examined. Cross-SF decoding further revealed that object category representations in all regions exhibited sub- stantial tolerance across the SF components. No difference between ventral and dorsal regions was found in their preference for the different SF components. Further comparisons revealed that, whereas differences in the SF component separated object category representations in early visual areas, such a separation was much smaller in downstream ventral and dorsal regions. In those regions, variations among the object categories played a more significant role in shaping the visual representational structures. Our findings show that ventral and dorsal regions are sim- ilar in how they represent visual input from different spatial scales and argue against a dissociation of these regions based on differential sensitivity to different SFs. |
Rachel Millin; Tamar Kolodny; Anastasia V. Flevaris; Alexander M. Kale; Michael Paul Schallmo; Jennifer Gerdts; Raphael A. Bernier; Scott Murray Reduced auditory cortical adaptation in autism spectrum disorder Journal Article In: eLife, vol. 7, pp. 1–15, 2018. @article{Millin2018, <p>Adaptation is a fundamental property of cortical neurons and has been suggested to be altered in individuals with autism spectrum disorder (ASD). We used fMRI to measure adaptation induced by repeated audio-visual stimulation in early sensory cortical areas in individuals with ASD and neurotypical (NT) controls. The initial transient responses were equivalent between groups in both visual and auditory cortices and when stimulation occurred with fixed-interval and randomized-interval timing. However, in auditory but not visual cortex, the post-transient sustained response was greater in individuals with ASD than NT controls in the fixed-interval timing condition, reflecting reduced adaptation. Further, individual differences in the sustained response in auditory cortex correlated with ASD symptom severity. These findings are consistent with hypotheses that ASD is associated with increased neural responsiveness but that responsiveness differences only manifest after repeated stimulation, are specific to the temporal pattern of stimulation, and are confined to specific cortical regions.</p> |
Olga Mishulina; Olga Skripko; Anastasia Korosteleva Some features of eye movements during reading and retelling the text by people with stuttering Journal Article In: Procedia Computer Science, vol. 123, pp. 328–333, 2018. @article{Mishulina2018, The connection between cognitive processes and the movement of the human eye during the reading and retelling the text is investigated. A series of experiments were performed, in which people with normal speech, people with stuttering and in the treatment stage of stuttering took part. The results of the experiment were fixed by the eye tracker and the functional magnetic resonance tomograph. The statistical processing of the tracking data was performed, which discovered stable differences of fixation duration in groups of participants when performing test tasks. |
Christoph Naegeli; Thomas Zeffiro; Marco Piccirelli; Assia Jaillard; Anina Weilenmann; Katayun Hassanpour; Matthis Schick; Michael Rufer; Scott P. Orr; Christoph Mueller-Pfeiffer Locus coeruleus activity mediates hyperresponsiveness in posttraumatic stress disorder Journal Article In: Biological Psychiatry, vol. 83, no. 3, pp. 254–262, 2018. @article{Naegeli2018, Background: Patients with posttraumatic stress disorder (PTSD) are hyperresponsive to unexpected or potentially threatening environmental stimuli. Research in lower animals and humans suggests that sensitization of the locus coeruleus–norepinephrine system may underlie behavioral and autonomic hyperresponsiveness in PTSD. However, direct evidence linking locus coeruleus system hyperactivity to PTSD hyperresponsiveness is sparse. Methods: Psychophysiological recording and functional magnetic resonance imaging were used during passive listening to brief, 95-dB sound pressure level, white noise bursts presented intermittently to determine whether behavioral and autonomic hyperresponsiveness to sudden sounds in PTSD is associated with locus coeruleus hyperresponsiveness. Results: Participants with PTSD (n = 28) showed more eye-blink reflexes and larger heart rate, skin conductance, and pupil area responses to loud sounds (multivariate p =.007) compared with trauma-exposed participants without PTSD (n = 26). PTSD participants exhibited larger responses in locus coeruleus (t = 2.60, region of interest familywise error corrected), intraparietal sulcus, caudal dorsal premotor cortex, and cerebellar lobule VI (t ≥ 4.18, whole-brain familywise error corrected). Caudal dorsal premotor cortex activity was associated with both psychophysiological response magnitude and levels of exaggerated startle responses in daily life in PTSD participants (t ≥ 4.39, whole-brain familywise error corrected). Conclusions: Behavioral and autonomic hyperresponsiveness in PTSD may arise from a hyperactive alerting/orienting system in which processes related to attention and motor preparation localized to lateral premotor cortex, intraparietal sulcus, and posterior superior cerebellar cortex are modulated by atypically high phasic noradrenergic influences originating in the locus coeruleus. |
Vaidehi S. Natu; Jesse Gomez; Kalanit Grill-Spector; Brianna Jeska; Michael Barnett Development differentially sculpts receptive fields across early and high-level human visual cortex Journal Article In: Nature Communications, vol. 9, pp. 788, 2018. @article{Natu2018, Receptive fields (RFs) processing information in restricted parts of the visual field are a key property of visual system neurons. However, how RFs develop in humans is unknown. Using fMRI and population receptive field (pRF) modeling in children and adults, we determine where and how pRFs develop across the ventral visual stream. Here we report that pRF properties in visual field maps, from the first visual area, V1, through the first ventro-occipital area, VO1, are adult-like by age 5. However, pRF properties in face-selective and character- selective regions develop into adulthood, increasing the foveal coverage bias for faces in the right hemisphere and words in the left hemisphere. Eye-tracking indicates that pRF changes are related to changing fixation patterns on words and faces across development. These findings suggest a link between face and word viewing behavior and the differential development of pRFs across visual cortex, potentially due to competition on foveal coverage. |
Matthias Nau; Tobias Navarro Schröder; Jacob L. S. Bellmund; Christian F. Doeller Hexadirectional coding of visual space in human entorhinal cortex Journal Article In: Nature Neuroscience, vol. 21, no. 2, pp. 188–190, 2018. @article{Nau2018, Entorhinal grid cells map the local environment, but their involvement beyond spatial navigation remains elusive. We examined human functional MRI responses during a highly controlled visual tracking task and show that entorhinal cortex exhibited a sixfold rotationally symmetric signal encoding gaze direction. Our results provide evidence for a grid-like entorhinal code for visual space and suggest a more general role of the entorhinal grid system in coding information along continuous dimensions. |
Claire K. Naughtin; Jason B. Mattingley; Angela D. Bender; Paul E. Dux Decoding early and late cortical contributions to individuation of attended and unattended objects Journal Article In: Cortex, vol. 99, pp. 45–54, 2018. @article{Naughtin2018, To isolate a visual stimulus as a unique object with a specific spatial location and time of occurrence, it is necessary to first register (individuate) the stimulus as a distinct perceptual entity. Recent investigations into the neural substrates of object individuation have suggested it is subserved by a distributed neural network, but previous manipulations of individuation load have introduced extraneous visual confounds, which might have yielded ambiguous findings, particularly in early cortical areas. Furthermore, while it has been assumed that selective attention is required for object individuation, there is no definitive evidence on the brain regions recruited for attended and ignored objects. Here we addressed these issues by combining functional magnetic resonance imaging (fMRI) with a novel object-enumeration paradigm in which to-be-individuated objects were defined by illusory contours, such that the physical elements of the display remained constant across individuation conditions. Multi-voxel pattern analyses revealed that attended objects modulated patterns of activity in early visual cortex, as well as frontal and parietal brain areas, as a function of object-individuation load. These findings suggest that object indi-viduation recruits both early and later cortical areas, consistent with theoretical accounts proposing that this operation acts at the junction of feed-forward and feedback processing stages in visual analysis. We also found dissociations between brain regions involved in individuation of attended and unattended objects, suggesting that voluntary spatial attention influences the brain regions recruited for this process. |
Akitoshi Ogawa; Atsushi Ueshima; Keigo Inukai; Tatsuya Kameda Deciding for others as a neutral party recruits risk-neutral perspective-taking: Model-based behavioral and fMRI experiments Journal Article In: Scientific Reports, vol. 8, pp. 12857, 2018. @article{Ogawa2018, Risky decision making for others is ubiquitous in our societies. Whereas financial decision making for oneself induces strong concern about the worst outcome (maximin concern) as well as the expected value, behavioral and neural characteristics of decision making for others are less well understood. We conducted behavioral and functional magnetic resonance imaging (fMRI) experiments to examine the neurocognitive underpinnings of risky decisions for an anonymous other, using decisions for self as a benchmark. We show that, although the maximin concern affected both types of decisions equally strongly, decision making for others recruited a more risk-neutral computational mechanism than decision making for self. Specifically, participants exhibited more balanced information search when choosing a risky option for others. Activity of right temporoparietal junction (rTPJ, associated with cognitive perspective taking) was parametrically modulated by options' expected values in decisions for others, and by the minimum amounts in decisions for self. Furthermore, individual differences in self-reported empathic concern modified these attentional and neural processes. Overall, these results indicate that the typical maximin concern is attenuated in a risk-neutral direction in decisions for others as compared to self. We conjecture that, given others' diverse preferences, deciding as a neutral party may cognitively recruit such risk-neutrality. |
Tanya Orlov; Ehud Zohary Object representations in human visual cortex formed through temporal integration of dynamic partial shape views Journal Article In: Journal of Neuroscience, vol. 38, no. 3, pp. 659–678, 2018. @article{Orlov2018, We typically recognize visual objects, by utilizing the spatial layout of their parts, simultaneously present on the retina. Thus, shape extraction is based on integration of the relevant retinal information over space. The lateral occipital complex (LOC) can faithfully represent shape in such conditions. However, sometimes, integration over time is required to determine object shape. To study shape extraction through temporal integration of successive partial-shape views, we presented human participants (both men and women) with artificial shapes that moved behind a narrow vertical or horizontal slit. Only a tiny fraction of the shape was visible at any instant, at the sameretinal location. Yet, observers perceived a coherent whole shape instead of a jumbled pattern.Using fMRI and multivoxel-pattern analysis we searched for brain regions that encode temporally-integrated shape identity. We further required that the representation of shape should be invariant to changes in the slit-orientation. We show that slit-invariant shape information is most accurate in LOC. Importantly, the slit-invariant shape representations matched the conventional whole-shape representations assessed during full-image runs. Moreover, when the same slit-dependent shape-slivers were shuffled, thereby preventing their spatiotemporal integration, slit-invariant shape information was dramatically reduced. The slit-invariant representation of the various shapes also mirrored the structure of shape perceptual space, as assessed by perceptual similarity-judgment tests. Thus, LOC is likely to mediate temporal integration of slit-dependent shape-views, generating a slit-invariant whole-shape percept. These findings provide strong evidence for a global encoding of shape in LOC, regardless of integration processes required to generate the shape percept. |
E. A. Allen; E. Damaraju; T. Eichele; L. Wu; V. D. Calhoun EEG signatures of dynamic functional network connectivity states Journal Article In: Brain Topography, vol. 31, no. 1, pp. 101–116, 2018. @article{Allen2018, The human brain operates by dynamically mod- ulating different neural populations to enable goal directed behavior. The synchrony or lack thereof between different brain regions is thought to correspond to observed functional connectivity dynamics in resting state brain imaging data. In a large sample of healthy human adult subjects and utilizing a sliding windowed correlation method on functional imaging data, earlier we demonstrated the presence of seven distinct functional connectivity states/patterns between different brain networks that reliably occur across time and subjects. Whether these connectivity states correspond to meaningful electrophysiological signatures was not clear. In this study, using a dataset with concurrent EEG and resting state functional imaging data acquired during eyes open and eyes closed states, we demonstrate the replicability of previous findings in an independent sample, and identify EEG spectral signatures associated with these functional network connectivity changes. Eyes open and eyes closed conditions show common and different connectivity patterns that are associated with distinct EEG spectral signatures. Certain connectivity states are more prevalent in the eyes open case and some occur only in eyes closed state. Both conditions exhibit a state of increased thalamo-cortical anticorrelation associated with reduced EEG spec- tral alpha power and increased delta and theta power possi- bly reflecting drowsiness. This state occurs more frequently in the eyes closed state. In summary, we find a link between dynamic connectivity in fMRI data and concurrently collected EEG data, including a large effect of vigilance on functional connectivity. As demonstrated with EEG and fMRI, the stationarity of connectivity cannot be assumed, even for relatively short periods. |
Noah C. Benson; Keith W. Jamison; Michael J. Arcaro; An T. Vu; Matthew F. Glasser; Timothy S. Coalson; David C. Van Essen; Essa Yacoub; Kamil Ugurbil; Jonathan Winawer; Kendrick N. Kay The Human Connectome Project 7 Tesla retinotopy dataset: Description and population receptive field analysis Journal Article In: Journal of Vision, vol. 18, no. 13, pp. 1–22, 2018. @article{Benson2018, About a quarter of human cerebral cortex is dedicated mainly to visual processing. The large-scale spatial organization of visual cortex can be measured with functional magnetic resonance imaging (fMRI) while subjects view spatially modulated visual stimuli, also known as ‘‘retinotopic mapping.'' One of the datasets collected by the Human Connectome Project involved ultra high-field (7 Tesla) fMRI retinotopic mapping in 181 healthy young adults (1.6-mm resolution), yielding the largest freely available collection of retinotopy data. Here, we describe the experimental paradigm and the results of model-based analysis of the fMRI data. These results provide estimates of population receptive field position and size. Our analyses include both results from individual subjects as well as results obtained by averaging fMRI time series across subjects at each cortical and subcortical location and then fitting models. Both the group-average and individual-subject results reveal robust signals across much of the brain, including occipital, temporal, parietal, and frontal cortex as well as subcortical areas. The group-average results agree well with previously published parcellations of visual areas. In addition, split-half analyses show strong within-subject reliability, further demonstrating the high quality of the data. We make publicly available the analysis results for individual subjects and the group avera ge, as well as associated stimuli and analysis code. These resources provide an opportunity for studying fine-scale individual variability in cortical and subcortical organization and the properties of high-resolution fMRI. In addition, they provide a set of observations that can be compared with other Human Connectome Project measures acquired in these same participants. |
Daniel K. Bjornn; Bonnie Brinton Anderson; Anthony Vance; Jeffrey L. Jenkins; C. Brock Kirwan Tuning out security warnings: A longitudinal examination of habituation through fMRI, eye tracking, and field experiments Journal Article In: MIS Quarterly, vol. 42, no. 2, pp. 355–380, 2018. @article{Bjornn2018, Research in the fields of information systems and human-computer interaction has shown that habituation— decreased response to repeated stimulation—is a serious threat to the effectiveness of security warnings. Although habituation is a neurobiological phenomenon that develops over time, past studies have only examined this problem cross-sectionally. Further, past studies have not examined how habituation influences actual security warning adherence in the field. For these reasons, the full extent of the problem of habituation is unknown. We address these gaps by conducting two complementary longitudinal experiments. First, we performed an experiment collecting fMRI and eye-tracking data simultaneously to directly measure habituation to security warnings as it develops in the brain over a five-day workweek. Our results show not only a general decline of participants' attention to warnings over time but also that attention recovers at least partially between workdays without exposure to the warnings. Further, we found that updating the appearance of a warning— that is, a polymorphic design—substantially reduced habituation of attention. Second, we performed a three-week field experiment in which users were naturally exposed to privacy permis-sion warnings as they installed apps on their mobile devices. Consistent with our fMRI results, users' warning adherence substantially decreased over the three weeks. However, for users who received polymorphic permis-sion warnings, adherence dropped at a substantially lower rate and remained high after three weeks, compared to users who received standard warnings. Together, these findings provide the most complete view yet of the problem of habituation to security warnings and demonstrate that polymorphic warnings can substantially improve adherence. |
Johannes Bloechle; Stefan Huber; Elise Klein; Julia Bahnmueller; Korbinian Moeller; Johannes Rennig Neuro-cognitive mechanisms of global Gestalt perception in visual quantification Journal Article In: NeuroImage, vol. 181, pp. 359–369, 2018. @article{Bloechle2018, Recent neuroimaging studies identified posterior regions in the temporal and parietal lobes as neuro-functional correlates of subitizing and global Gestalt perception. Beyond notable overlap on a neuronal level both mechanisms are remarkably similar on a behavioral level representing both a specific form of visual top-down processing where single elements are integrated into a superordinate entity. In the present study, we investigated whether subitizing draws on principles of global Gestalt perception enabling rapid top-down processes of visual quantification. We designed two functional neuroimaging experiments: a task identifying voxels responding to global Gestalt stimuli in posterior temporo-parietal brain regions and a visual quantification task on dot patterns with magnitudes within and outside the subitizing range. We hypothesized that voxels activated in global Gestalt perception should respond stronger to dot patterns within than those outside the subitizing range. The results confirmed this prediction for left-hemispheric posterior temporo-parietal brain areas. Additionally, we trained a classifier with response patterns from global Gestalt perception to predict neural responses of visual quantification. With this approach we were able to classify from TPJ Gestalt ROIs of both hemispheres whether a trial requiring subitizing was processed. The present study demonstrates that mechanisms of subitizing seem to build on processes of high-level visual perception. |