All EyeLink Publications
All 10,000+ peer-reviewed EyeLink research publications up until 2021 (with some early 2022s) are listed below by year. You can search the publications library using keywords such as Visual Search, Smooth Pursuit, Parkinson’s, etc. You can also search for individual author names. Eye-tracking studies grouped by research area can be found on the solutions pages. If we missed any EyeLink eye-tracking papers, please email us!
2021 |
David Torrents-Rodas; Stephan Koenig; Metin Uengoer; Harald Lachnit Evidence for two attentional mechanisms during learning Journal Article In: Quarterly Journal of Experimental Psychology, vol. 74, no. 12, pp. 2112–2123, 2021. @article{TorrentsRodas2021,We sought to provide evidence for a combined effect of two attentional mechanisms during associative learning. Participants' eye movements were recorded as they predicted the outcomes following different pairs of cues. Across the trials of an initial stage, a relevant cue in each pair was consistently followed by one of two outcomes, while an irrelevant cue was equally followed by either of them. Thus, the relevant cue should have been associated with small relative prediction errors, compared to the irrelevant cue. In a later stage, each pair came to be followed by one outcome on a random half of the trials and by the other outcome on the remaining half, and thus there should have been a rise in the overall prediction error. Consistent with an attentional mechanism based on relative prediction error, an attentional advantage for the relevant cue was evident in the first stage. However, in accordance with a mechanism linked to overall prediction error, the attention paid to both types of cues increased at the beginning of the second stage. These results showed up in both dwell times and within-trial patterns of fixations, and they were predicted by a hybrid model of attention. |
Blaine Tomkins In: Laterality, vol. 26, no. 5, pp. 539–563, 2021. @article{Tomkins2021,Previous research suggests that the right visual field advantage on the lexical decision task occurs independent of the visual quality of stimuli [Chiarello, C., Senehi, J., & Soulier, M. (1986). Viewing conditions and hemisphere asymmetry for the lexical decision. Neuropsychologia, 24(4), 521–529]. However, previous studies examining these effects have had methodological limitations that were addressed and controlled for in the present study. Participants performed a divided visual field, lexical decision task for words that varied in size (Experiment 1) and visibility (Experiment 2). Results showed a quality by visual field interaction effect. In both experiments, response times were faster for targets presented to the right visual field in the high quality (i.e., large font, high visibility) conditions; however, visual quality resulted in no differences for targets presented to the left visual field. Furthermore, this quality by visual field interaction effect was only observed when the target was a word. These results suggest that the left hemisphere advantage for lexical decision depends on the perceptual quality of targets, consistent with an early stage of processing account of hemispheric asymmetry during lexical decision. Findings are discussed within the context of word recognition and decision-based models. |
Aleksandra Tomić; Jorge R. Valdés Kroff Expecting the unexpected: Code-switching as a facilitatory cue in online sentence processing Journal Article In: Bilingualism: Language and Cognition, pp. 1–12, 2021. @article{Tomic2021,Despite its prominent use among bilinguals, psycholinguistic studies reported code-switch processing costs (e.g., Meuter & Allport, 1999). This paradox may partly be due to the focus on the code-switch itself instead of its potential subsequent benefits. Motivated by corpus studies on CS patterns and sociopragmatic functions of CS, we asked whether bilinguals use code-switches as a cue to the lexical characteristics of upcoming speech. We report a visual world study testing whether code-switching facilitates the anticipation of lower-frequency words. Results confirm that US Spanish-English bilinguals (n = 30) use minority (Spanish) to majority (English) language code-switches in real-time language processing as a cue that a less frequent word would ensue, as indexed by increased looks at images representing lower- vs. higher-frequency words in the code-switched condition, prior to the target word onset. These results highlight the need to further integrate sociolinguistic and corpus observations into the experimental study of code-switching. |
Shin Tokushige; Shunichi Matsuda; Satomi Inomata-Terada; Masashi Hamada; Yoshikazu Ugawa; Shoji Tsuji; Yasuo Terao Premature saccades: A detailed physiological analysis Journal Article In: Clinical Neurophysiology, vol. 132, no. 1, pp. 63–76, 2021. @article{Tokushige2021,Objective: Premature saccades (PSs) are those made with latencies too short for the direction and amplitude to be specifically programmed. We sought to determine the minimum latency needed to establish accurate direction and amplitude, and observed what occurs when saccades are launched before this minimum latency. Methods: In Experiment 1, 249 normal subjects performed the gap saccade task with horizontal targets. In Experiment 2, 28 normal subjects performed the gap saccade task with the targets placed in eight directions. In Experiment 3, 38 normal subjects, 49 patients with Parkinson's disease (PD), and 10 patients with spinocerebellar degeneration (SCD) performed the gap saccade task with horizontal targets. Results: In Experiment 1, it took 100 ms to accurately establish saccade amplitudes and directions. In Experiment 2, however, the latencies needed for accurate amplitude and direction establishment were both approximately 150 ms. In Experiment 3, the frequencies of PSs in patients with PD and SCD were lower than those of normal subjects. Conclusions: The saccade amplitudes and directions are determined simultaneously, 100–150 ms after target presentation. PSs may result from prediction of the oncoming target direction or latent saccade activities in the superior colliculus. Significance: Saccade direction and amplitude are determined simultaneously. |
Greta Krasimirova Todorova; Frank Earl Pollick; Lars Muckli Special treatment of prediction errors in autism spectrum disorder Journal Article In: Neuropsychologia, vol. 163, pp. 108070, 2021. @article{Todorova2021,For autistic individuals, sensory stimulation can be experienced as overwhelming. Models of predictive coding postulate that cortical mechanisms disamplify predictable information and amplify prediction errors that surpass a defined precision level. In autism, the neuronal processing is putting an inflexibly high precision on prediction errors according to the HIPPEA theory (High, Inflexible Precision of Prediction Errors in Autism). We used an apparent motion paradigm to test this prediction. In apparent motion paradigms, the illusory motion of an object creates a prediction about where and when an internally generated token would be moving along the apparent motion trace. This illusion facilitates the perception of a flashing stimulus (target) appearing in-time with the apparent motion token and is perceived as a predictable event (predictable target). In contrast, a flashing stimulus appearing out-of-time with the apparent motion illusion is an unpredictable target that is less often detected even though it produces a prediction error signal. If a prediction error does not surpass a given precision threshold the stimulation event is discounted and therefore less often detected than predictable tokens. In autism, the precision threshold is lower and the same prediction errors (unpredictable target) triggers a detection similar to that of a predictable flash stimulus. To test this hypothesis, we recruited 11 autistic males and 9 neurotypical matched controls. The participants were tasked to detect flashing stimuli placed on an apparent motion trace either in-time or out-of-time with the apparent motion illusion. Descriptively, 66% (6/9) of neurotypical and 64% (7/11) of autistic participants were better at detecting predictable targets. The prediction established by illusory motion appears to assist autistic and neurotypical individuals equally in the detection of predictable over unpredictable targets. Importantly, 55% (6/11) of autistic participants had faster responses for unpredictable targets, whereas only 22% (2/9) of neurotypicals had faster responses to unpredictable compared to predictable targets. Hence, these tentative results suggest that for autistic participants, unpredictable targets produce an above threshold prediction error, which leads to faster response. This difference in unpredictable target detection can be encapsulated under the HIPPEA theory, suggesting that precision setting could be aberrant in autistic individuals with respect to prediction errors. These tentative results should be considered in light of the small sample. For this reason, we provide the full set of materials necessary to replicate and extend the results. |
Shira Tkacz-Domb; Yaffa Yeshurun Temporal crowding is a unique phenomenon reflecting impaired target encoding over large temporal intervals Journal Article In: Psychonomic Bulletin & Review, vol. 28, no. 6, pp. 1885–1893, 2021. @article{TkaczDomb2021,Crowding refers to impaired object identification when presented with other objects, and it is well established that spatial crowding—crowding from adjacent objects—affects many aspects of visual perception and cognition. A similar interference also occurs across time—the identification of a target object is impaired when distracting objects precede and succeed it. When such interference is observed with relatively long interitem intervals it is termed temporal crowding. Thus far, little was known about temporal crowding and its underlying processes. Particularly it was unknown which aspects of visual processing are impaired by temporal crowding, and the answer to this question bears critical theoretical implications. To reveal the nature of this impairment we used a continuous-report task and a mixture-model analysis. In three experiments, observers viewed sequences of three oriented items separated by relatively long intervals (170–475ms). The target was the second item in the sequence, and the task was to reproduce its orientation. The findings suggest that temporal crowding impairs target encoding and increases substitution errors, but there was no evidence of a reduced signal-to-noise ratio. This pattern of results was similar regardless of stimuli duration and target–distractor similarity. However, it differed considerably from the pattern found for ordinary masking and spatial crowding, indicating that temporal crowding is a unique phenomenon. Moreover, the finding that temporal crowding affected the precision of target encoding even when the items were separated by almost half a second suggests that visual processing requires a surprisingly long time to complete. |
Debra Titone; Julie Mercier; Aruna Sudarshan; Irina Pivneva; Jason Gullifer; Shari Baum Spoken word processing in bilingual older adults Journal Article In: Linguistic Approaches to Bilingualism, vol. 11, no. 4, pp. 578–610, 2021. @article{Titone2021,We investigated whether bilingual older adults experience within- and cross-language competition during spoken word recognition similarly to younger adults matched on age of second language (L2) acquisition, objective and subjective L2 proficiency, and current L2 exposure. In a visual world eye-tracking paradigm, older and younger adults, who were French-dominant or English-dominant English-French bilinguals, listened to English words, and looked at pictures including the target (field), a within-language competitor (feet) or cross-language (French) competitor (fille, “girl”), and unrelated filler pictures while their eye movements were monitored. Older adults showed evidence of greater within-language competition as a function of increased target and competitor phonological overlap. There was some evidence of age-related differences in cross-language competition, however, it was quite small overall and varied as a function of target language proficiency. These results suggest that greater within- and possibly cross-language lexical competition during spoken word recognition may underlie some of the communication difficulties encountered by healthy bilingual older adults. |
Lowell W. Thompson; Byounghoon Kim; Zikang Zhu; Bas Rokers; Ari Rosenberg Perspective Cues Make Eye-specific Contributions to 3-D Motion Perception Journal Article In: Journal of Cognitive Neuroscience, vol. 34, no. 1, pp. 192–208, 2021. @article{Thompson2021,Description: The American Psychological Association (APA) developed this guideline to provide recommendations on psychological and pharmacological treatments for posttraumatic stress disorder (PTSD) in adults. Methods: This guideline used methods recommended by the Institute of Medicine report, Clinical Practice Guidelines We Can Trust (IOM, 2011). Those methods are designed to produce guidelines that are based on evidence and patient preferences and are transparent, free of conflict of interest, and worthy of public trust. The guideline used a comprehensive systematic review (Psychological and Pharmacological Treatments for Adults With Post-traumatic Stress Disorder (PTSD)) conducted by the Research Triangle Institute-University of North Carolina Evidence-based Practice Center as its primary evidence base (Jonas, Cusack, Forneris, Wilkins, Sonis, Middleton, et al., 2013). The systematic review was based on English-language studies published between 1980 and 2012; complementary and alternative treatments were not included in the systematic review. An updated search was conducted by APA to identify studies published between 2012 and June 1, 2016, to determine if the recommendations made by the panel based on the systematic review were likely to hold up based on more recent evidence; risk of bias assessment, strength of evidence rating and meta-analyses were not conducted on the studies identified through the updated search. The guideline development panel (GDP) consisted of health professionals from the disciplines of psychology, psychiatry, social work, and family medicine as well as community members, who self-identified as having had PTSD. The GDP made recommendations based on 1) strength of evidence; 2) treatment outcomes and the balance of benefits vs. harms and burdens of interventions; 3) patient values and preferences; and 4) applicability of the evidence to various treatment populations. PTSD symptom reduction and serious harms were selected by the GDP as critical outcomes for making recommendations. Various other outcomes were selected as important, including those related to remission, quality of life, disability, comorbid conditions and adverse events. The target audience for this guideline includes all clinicians as well as researchers, patients and policy makers. Recommendations: The panel strongly recommends the use of the following psychotherapies/interventions (all interventions that follow listed in alphabetical order) for adult patients with PTSD: cognitive behavioral therapy (CBT), cognitive processing therapy (CPT), cognitive therapy (CT), and prolonged exposure therapy (PE). The panel suggests the use of brief eclectic psychotherapy (BEP), eye movement desensitization and reprocessing (EMDR), and narrative exposure therapy (NET). There is insufficient evidence to recommend for or against offering Seeking Safety (SS) or relaxation (RLX). For medications, the panel suggests offering the following (in alphabetical order): fluoxetine, paroxetine, sertraline, and venlafaxine. There is insufficient evidence to recommend for or against offering risperidone and topiramate. Based on the updated search, the panel concluded that all of its treatment recommendations, except those for EMDR and NET, were unlikely to change. The panel also concluded that, based on studies published between 2012 and June 2016, the recommendations for EMDR and NET may change from conditional (“the panel suggests”) to strong (“the panel recommends”). (Note: This abstract was prepared following approval of the guideline document as APA policy by the APA Council of Representatives at its February 2017 meeting.) |
Elizabeth H. X. Thomas; Maria Steffens; Christopher Harms; Susan L. Rossell; Caroline Gurvich; Ulrich Ettinger Schizotypy, neuroticism, and saccadic eye movements: New data and meta-analysis Journal Article In: Psychophysiology, vol. 58, no. 1, pp. e13706, 2021. @article{Thomas2021a,Deficits on saccade tasks, particularly antisaccade performance, have been reliably reported in schizophrenia. However, less evidence is available on saccade performance in relation to schizotypy, a personality constellation harboring risk for schizophrenia. Here, we report a large empirical study of the associations of schizotypy and neuroticism with antisaccade and prosaccade performance (Study I). Additionally, we carried out meta-analyses of the association between schizotypy and antisaccade error rate (Study II). In Study I |
Armin W. Thomas; Felix Molter; Ian Krajbich Uncovering the computational mechanisms underlying many-alternative choice Journal Article In: eLife, vol. 10, pp. 1–27, 2021. @article{Thomas2021,How do we choose when confronted with many alternatives? There is surprisingly little decision modelling work with large choice sets, despite their prevalence in everyday life. Even further, there is an apparent disconnect between research in small choice sets, supporting a process of gaze-driven evidence accumulation, and research in larger choice sets, arguing for models of optimal choice, satisficing, and hybrids of the two. Here, we bridge this divide by developing and comparing different versions of these models in a many-alternative value-based choice experiment with 9, 16, 25, or 36 alternatives. We find that human choices are best explained by models incorporating an active effect of gaze on subjective value. A gaze-driven, probabilistic version of satisficing generally provides slightly better fits to choices and response times, while the gaze-driven evidence accumulation and comparison model provides the best overall account of the data when also considering the empirical relation between gaze allocation and choice. |
Maria Theobald; Garvin Brod Tackling Scientific Misconceptions: The Element of Surprise Journal Article In: Child Development, vol. 92, no. 5, pp. 2128–2141, 2021. @article{Theobald2021,Misconceptions about scientific concepts often prevail even if learners are confronted with conflicting evidence. This study tested the facilitative role of surprise in children's revision of misconceptions regarding water displacement in a sample of German children (N = 94, aged 6–9 years, 46% female). Surprise was measured via the pupil dilation response. It was induced by letting children generate predictions before presenting them with outcomes that conflicted with their misconception. Compared to a control condition, generating predictions boosted children's surprise and led to a greater revision of misconceptions (d = 0.56). Surprise further predicted successful belief revision during the learning phase. These results suggest that surprise increases the salience of a cognitive conflict, thereby facilitating the revision of misconceptions. |
Chaitanya Thammineni; Hemanth Manjunatha; Ehsan T. Esfahani Selective eye-gaze augmentation to enhance imitation learning in Atari games Journal Article In: Neural Computing and Applications, 2021. @article{Thammineni2021,This paper presents the selective use of eye-gaze information in learning human actions in Atari games. Extensive evidence suggests that our eye movements convey a wealth of information about the direction of our attention and mental states and encode the information necessary to complete a task. Based on this evidence, we hypothesize that selective use of eye-gaze, as a clue for attention direction, will enhance the learning from demonstration. For this purpose, we propose a selective eye-gaze augmentation (SEA) network that learns when to use the eye-gaze information. The proposed network architecture consists of three sub-networks: gaze prediction, gating, and action prediction network. Using the prior 4 game frames, a gaze map is predicted by the gaze prediction network, which is used for augmenting the input frame. The gating network will determine whether the predicted gaze map should be used in learning and is fed to the final network to predict the action at the current frame. To validate this approach, we use publicly available Atari Human Eye-Tracking And Demonstration (Atari-HEAD) dataset consists of 20 Atari games with 28 million human demonstrations and 328 million eye-gazes (over game frames) collected from four subjects. We demonstrate the efficacy of selective eye-gaze augmentation compared to the state-of-the-art Attention Guided Imitation Learning (AGIL) and Behavior Cloning (BC). The results indicate that the selective augmentation approach (the SEA network) performs significantly better than the AGIL and BC. Moreover, to demonstrate the significance of selective use of gaze through the gating network, we compare our approach with the random selection of the gaze. Even in this case, the SEA network performs significantly better, validating the advantage of selectively using the gaze in demonstration learning. |
Katharine N. Thakkar; Livon Ghermezi; Steven M. Silverstein; Rachael Slate; Beier Yao; Eric D. Achtyes; Jan W. Brascamp Stronger tilt aftereffects in persons with schizophrenia Journal Article In: Journal of abnormal psychology, vol. 130, no. 2, pp. 186–197, 2021. @article{Thakkar2021,Individuals with schizophrenia may fail to appropriately use temporal context and apply past environmental regularities to the interpretation of incoming sensory information. Here we use the visual system as a test bed for investigating how prior experience shapes perception in individuals with schizophrenia. Specifically, we use visual aftereffects, illusory percepts resulting from prior exposure to visual input, to measure the influence of prior events on current processing. At a neural level, visual aftereffects arise due to attenuation in the responses of neurons that code the features of the prior stimulus (neuronal adaptation) and subsequent disinhibition of neurons signaling activity at the opposite end of the feature dimension. In the current study, we measured tilt aftereffects and negative afterimages, 2 types of aftereffects that reflect, respectively, adaptation of cortical orientation-coding neurons and adaptation of subcortical and retinal luminance-coding cells in persons with schizophrenia (PSZ; n = 36) and demographically matched healthy controls (HC; n = 22). We observed stronger tilt aftereffects in PSZ compared to HC, but no difference in negative afterimages. Stronger tilt aftereffects were related to more severe negative symptoms. These data suggest oversensitivity to recent regularities, in the form of stronger visual adaptation, at cortical, but not subcortical, levels in schizophrenia. (PsycInfo Database Record (c) 2021 APA, all rights reserved). |
Benjamin Tari; Luc Tremblay; Matthew Heath Visually guided saccades and acoustic distractors: No evidence for the remote distractor effect or global effect Journal Article In: Experimental Brain Research, vol. 239, no. 1, pp. 1–8, 2021. @article{Tari2021b,A remote visual distractor increases saccade reaction time (RT) to a visual target and may reflect the time required to resolve conflict between target- and distractor-related information within a common retinotopic representation in the superior colliculus (SC) (i.e., the remote distractor effect: RDE). Notably, because the SC serves as a sensorimotor interface it is possible that the RDE may be associated with the pairing of an acoustic distractor with a visual target; that is, the conflict related to saccade generation signals may be sensory-independent. To address that issue, we employed a traditional RDE experiment involving a visual target and visual proximal and remote distractors (Experiment 1) and an experiment wherein a visual target was presented with acoustic proximal and remote distractors (Experiment 2). As well, Experiments 1 and 2 employed no-distractor trials. Experiment 1 RTs elicited a reliable RDE, whereas Experiment 2 RTs for proximal and remote distractors were shorter than their no distractor counterparts. Accordingly, findings demonstrate that the RDE is sensory specific and arises from conflicting visual signals within a common retinotopic map. As well, Experiment 2 findings indicate that an acoustic distractor supports an intersensory facilitation that optimizes oculomotor planning. |
Benjamin Tari; Mustafa Shirzad; Nikan Behboodpour; Glen R. Belfry; Matthew Heath Exercise intensity-specific changes to cerebral blood velocity do not modulate a postexercise executive function benefit Journal Article In: Neuropsychologia, vol. 161, pp. 108018, 2021. @article{Tari2021a,Executive function is transiently improved (i.e., <60-min) following a single bout of aerobic exercise. A candidate mechanism for this improvement is an exercise-mediated increase in cerebral blood flow (CBF). Further, it has been proposed that an increase in CBF across the continuum of increasing exercise intensities improves the magnitude of a postexercise executive function benefit (i.e., drive theory); however, this proposal has not been empirically tested. Here, participants completed four experimental sessions: a V̇O2peak test to determine cardiorespiratory fitness and estimated lactate threshold (LT), followed by separate 10-min sessions of light- (i.e., 25 W), moderate- (i.e., 80% estimated LT), and heavy-intensity (i.e., 15% of the difference between LT and V̇O2peak) aerobic exercise. An estimate of CBF during exercise was achieved via transcranial Doppler ultrasound and near-infrared spectroscopy to quantify blood velocity (BV) through the middle cerebral artery and deoxygenated hemoglobin (HHb), respectively. Executive function was assessed before and after each session via the executive-mediated antisaccade task (i.e., saccade mirror-symmetrical to a target). Results demonstrated that BV increased in relation to increasing exercise intensity, whereas HHb decreased by a comparable magnitude independent of intensity. In terms of executive function, null hypothesis and equivalence tests indicated a comparable magnitude postexercise reduction in antisaccade reaction time across exercise intensities. Accordingly, the magnitude of CBF change during exercise does not impact the magnitude of a postexercise executive function benefit. |
Benjamin Tari; Mustafa Shirzad; Nicholas A. Badcock; Glen R. Belfry; Matthew Heath ‘Delaying' a saccade: Preparatory phase cortical hemodynamics evince the neural cost of response inhibition Journal Article In: Brain and Cognition, vol. 154, pp. 1–7, 2021. @article{Tari2021,Minimally delayed (MD) saccades require inhibition of a prepotent response until a target is extinguished, and unlike the more extensively studied antisaccade task, do not require the additional cognitive component of vector inversion (i.e., 180° target spatial transposition). Here, participants completed separate blocks of MD and prepotent stimulus-driven saccades (i.e., respond at target onset) while cortical hemodynamics were measured via functional transcranial Doppler ultrasound. MD saccades produced longer and more variable reaction times (RT). In turn, MD and stimulus-driven saccade preparatory phase cortical hemodynamics increased and decreased, respectively, relative to baseline and the two conditions differed from one another throughout the preparatory phase. The longer RTs and increased cortical hemodynamics of MD saccades is taken to evince response complexity and the increased neural activity to accommodate response inhibition. To our knowledge, such findings provide the first work to examine the neural foundations of MD saccades. |
Nathan Tardiff; John D. Medaglia; Danielle S. Bassett; Sharon L. Thompson-Schill The modulation of brain network integration and arousal during exploration Journal Article In: NeuroImage, vol. 240, pp. 118369, 2021. @article{Tardiff2021,There is growing interest in how neuromodulators shape brain networks. Recent neuroimaging studies provide evidence that brainstem arousal systems, such as the locus coeruleus-norepinephrine system (LC-NE), influence functional connectivity and brain network topology, suggesting they have a role in flexibly reconfiguring brain networks in order to adapt behavior and cognition to environmental demands. To date, however, the relationship between brainstem arousal systems and functional connectivity has not been assessed within the context of a task with an established relationship between arousal and behavior, with most prior studies relying on incidental variations in arousal or pharmacological manipulation and static brain networks constructed over long periods of time. These factors have likely contributed to a heterogeneity of effects across studies. To address these issues, we took advantage of the association between LC-NE-linked arousal and exploration to probe the relationships between exploratory choice, arousal—as measured indirectly via pupil diameter—and brain network dynamics. Exploration in a bandit task was associated with a shift toward fewer, more weakly connected modules that were more segregated in terms of connectivity and topology but more integrated with respect to the diversity of cognitive systems represented in each module. Functional connectivity strength decreased, and changes in connectivity were correlated with changes in pupil diameter, in line with the hypothesis that brainstem arousal systems influence the dynamic reorganization of brain networks. More broadly, we argue that carefully aligning dynamic network analyses with task designs can increase the temporal resolution at which behaviorally- and cognitively-relevant modulations can be identified, and offer these results as a proof of concept of this approach. |
Anthony Tapper; David Gonzalez; Mina Nouredanesh; Ewa Niechwiej-Szwedo In: Vision Research, vol. 184, pp. 43–51, 2021. @article{Tapper2021,Research shows that concussions cause long-term deficits in executive functions when tested using challenging tasks with high cognitive load. The neurophysiological mechanism(s) associated with executive dysfunction are not well understood. Pupillometry provides a non-invasive index of arousal and cognitive load; therefore, the current study investigated whether pupillometry could help explain the persistent deficits in dual-task performance in individuals with a history of concussion (n = 14) compared to controls (n = 13). Participants were tested using a computerized Corsi block task which increased in difficulty as a function of set size (i.e., number of blocks to be remembered) and task condition (i.e., performed alone and concurrently with an auditory task). Pupil size was measured during the initial fixation prior to the Corsi task to assess arousal level, and during the encoding phase to assess task evoked pupil response. Results showed that: 1) in contrast to the control group, pupil size was not modulated by task condition in the concussed group indicating that arousal level was similar in the single and dual task; 2) task evoked pupil dilation increased as a function of set size in the single task in both groups, 3) in contrast to the control group, those with a history of concussion had similar pupil size during the single and dual task conditions. One interpretation of these results is that individuals with a history of concussion exert greater effort when performing relatively easier tasks, and they reach capacity limits when the cognitive load is lower in comparison to non-concussed individuals. In conclusion, pupillometry may provide insight into persisting deficits in executive functions following concussion(s). |
Ken W. S. Tan; Chris Scholes; Neil W. Roach; Elizabeth M. Haris; Paul V. McGraw Impact of microsaccades on visual shape processing Journal Article In: Journal of neurophysiology, vol. 125, no. 2, pp. 609–619, 2021. @article{Tan2021,Sensitivity to subtle changes in the shape of visual objects has been attributed to the existence of global pooling mechanisms that integrate local form information across space. Although global pooling is typically demonstrated under steady fixation, other work suggests prolonged fixation can lead to a collapse of global structure. Here, we ask whether small ballistic eye movements that naturally occur during periods of fixation affect the global processing of radial frequency (RF) patterns-closed contours created by sinusoidally modulating the radius of a circle. Observers were asked to discriminate the shapes of circular patterns and RF-modulated patterns while fixational eye movements were recorded binocularly at 500 Hz. Microsaccades were detected using a velocity-based algorithm, allowing trials to be sorted according to the relative timing of stimulus and microsaccade onset. Results revealed clear perisaccadic changes in shape discrimination thresholds. Performance was impaired when microsaccades occurred close to stimulus onset, but facilitated when they occurred shortly afterward. In contrast, global integration of shape was unaffected by the timing of microsaccades. These findings suggest that microsaccades alter the discrimination sensitivity to briefly presented shapes but do not disrupt the spatial pooling of local form signals.NEW & NOTEWORTHY Microsaccades cause rapid displacement of visual images during fixation and dramatically alter the perception of basic image features. However, their effect on more complex aspects of visual processing is not well understood. Here, we demonstrate a dissociation in the impact of microsaccades on shape perception. Although overall shape discrimination performance is modulated around the time of microsaccades, the pooling efficiency of global mechanisms that combine local form information across space remains unaffected. |
Noam Tal-Perry; Shlomit Yuval-Greenberg Prestimulus inhibition of eye movements reflects temporal expectation rather than time estimation Journal Article In: Attention, Perception, and Psychophysics, vol. 83, no. 6, pp. 2473–2485, 2021. @article{TalPerry2021,Eye movements are inhibited prior to the occurrence of temporally predictable events. This ‘oculomotor inhibition effect' has been demonstrated with various tasks and modalities. Specifically, it was shown that when intervals between cue and target are fixed, saccade rate prior to the target is lower than when they are varied. However, it is still an open question whether this effect is linked to temporal expectation to the predictable target, or to the duration estimation of the interval preceding it. Here, we examined this question in 20 participants while they performed an implicit temporal expectation and an explicit time estimation task. In each trial, following cue onset, two consecutive grating patches were presented, each preceded by an interval. Temporal expectation was manipulated by setting the first interval duration to be either fixed or varied within each block. Participants were requested to compare either the durations of the two intervals (time estimation), or the tilts of the two grating patches (temporal expectation). Saccade rate, measured prior to the first grating, was lower in the fixed relative to the varied condition of both tasks. This suggests that the inhibition effect is elicited by target predictability and indicates that it is linked to temporal expectation, rather than to time estimation processes. Additionally, this finding suggests that the oculomotor inhibition is independent of motor readiness, as it was elicited even when no response was required. We conclude that the prestimulus oculomotor inhibition effect can be used as a marker of temporal expectation, and discuss its potential underlying mechanisms. |
Bharath Chandra Talluri; Anne E. Urai; Zohar Z. Bronfman; Noam Brezis; Konstantinos Tsetsos; Marius Usher; Tobias H. Donner Choices change the temporal weighting of decision evidence Journal Article In: Journal of Neurophysiology, vol. 125, no. 4, pp. 1468–1481, 2021. @article{Talluri2021,Many decisions result from the accumulation of decision-relevant information (evidence) over time. Even when maximizing decision accuracy requires weighting all the evidence equally, decision-makers often give stronger weight to evidence occurring early or late in the evidence stream. Here, we show changes in such temporal biases within participants as a function of intermittent judgments about parts of the evidence stream. Human participants performed a decision task that required a continuous estimation of the mean evidence at the end of the stream. The evidence was either perceptual (noisy random dot motion) or symbolic (variable sequences of numbers). Participants also reported a categorical judgment of the preceding evidence half-way through the stream in one condition or executed an evidence-independent motor response in another condition. The relative impact of early versus late evidence on the final estimation flipped between these two conditions. In particular, participants' sensitivity to late evidence after the intermittent judgment, but not the simple motor response, was decreased. Both the intermittent response as well as the final estimation reports were accompanied by nonluminance-mediated increases of pupil diameter. These pupil dilations were bigger during intermittent judgments than simple motor responses and bigger during estimation when the late evidence was consistent than inconsistent with the initial judgment. In sum, decisions activate pupil-linked arousal systems and alter the temporal weighting of decision evidence. Our results are consistent with the idea that categorical choices in the face of uncertainty induce a change in the state of the neural circuits underlying decision-making. NEW & NOTEWORTHY The psychology and neuroscience of decision-making have extensively studied the accumulation of decision-relevant information toward a categorical choice. Much fewer studies have assessed the impact of a choice on the processing of subsequent information. Here, we show that intermittent choices during a protracted stream of input reduce the sensitivity to subsequent decision information and transiently boost arousal. Choices might trigger a state change in the neural machinery for decision-making. |
Louisa A. Talipski; Stephanie C. Goodhew; Mark Edwards No effect of spatial attention on the processing of a motion ensemble: Evidence from Posner cueing Journal Article In: Attention, Perception, and Psychophysics, pp. 1–13, 2021. @article{Talipski2021,The formation of ensemble codes is an efficient means through which the visual system represents vast arrays of information. This has led to the claim that ensemble representations are formed with minimal reliance on attentional resources. However, evidence is mixed regarding the effects of attention on ensemble processing, and researchers do not always make it clear how attention is being manipulated by their paradigm of choice. In this study, we examined the effects of Posner cueing – a well-established method of manipulating spatial attention – on the processing of a global motion stimulus, a naturalistic ensemble that requires the pooling of local motion signals. In Experiment 1, using a centrally presented, predictive attentional cue, we found no effect of spatial attention on global motion performance: Accuracy in invalid trials, where attention was misdirected by the cue, did not differ from accuracy in valid trials, where attention was directed to the location of the motion stimulus. In Experiment 2, we maximized the potential for our paradigm to reveal any attentional effects on global motion processing by using a threshold-based measure of performance; however, despite this change, there was again no evidence of an attentional effect on performance. Together, our results show that the processing of a global motion stimulus is unaffected when spatial attention is misdirected, and speak to the efficiency with which such ensemble stimuli are processed. |
Travis N. Talcott; Nicholas Gaspelin Eye movements are not mandatorily preceded by the N2pc component Journal Article In: Psychophysiology, vol. 58, no. 6, pp. e13821, 2021. @article{Talcott2021,Researchers typically distinguish between two mechanisms of attentional selection in vision: overt and covert attention. A commonplace assumption is that overt eye movements are automatically preceded by shifts of covert attention during visual search. Although the N2pc component is a putative index of covert attentional orienting, little is currently known about its relationship with overt eye movements. This is because most previous studies of the N2pc component prohibit overt eye movements. The current study assessed this relationship by concurrently measuring covert attention (via the N2pc) and overt eye movements (via eye tracking). Participants searched displays for a lateralized target stimulus and were allowed to generate overt eye movements during the search. We then assessed whether overt eye movements were preceded by the N2pc component. The results indicated that saccades were preceded by an N2pc component, but only when participants were required to carefully inspect the target stimulus before initiating the eye movement. When participants were allowed to make naturalistic eye movements in service of visual search, there was no evidence of an N2pc component before eye movements. These findings suggest that the N2pc component does not always precede overt eye movements during visual search. Implications for understanding the relationship between covert and overt attention are discussed. |
Ryuji Takeya; Shuntaro Nakamura; Masaki Tanaka Spontaneous grouping of saccade timing in the presence of task-irrelevant objects Journal Article In: PLoS ONE, vol. 16, no. 3, pp. e0248530, 2021. @article{Takeya2021,Sequential movements are often grouped into several chunks, as evidenced by the modulation of the timing of each elemental movement. Even during synchronized tapping with a metronome, we sometimes feel subjective accent for every few taps. To examine whether motor segmentation emerges during synchronized movements, we trained monkeys to generate a series of predictive saccades synchronized with visual stimuli which sequentially appeared for a fixed interval (400 or 600 ms) at six circularly arranged landmark locations. We found two types of motor segmentations that featured periodic modulation of saccade timing. First, the intersaccadic interval (ISI) depended on the target location and saccade direction, indicating that particular combinations of saccades were integrated into motor chunks. Second, when a task-irrelevant rectangular contour surrounding three landmarks ("inducer") was presented, the ISI significantly modulated depending on the relative target location to the inducer. All patterns of individual differences seen in monkeys were also observed in humans. Importantly, the effects of the inducer greatly decreased or disappeared when the animals were trained to generate only reactive saccades (latency >100 ms), indicating that the motor segmentation may depend on the internal rhythms. Thus, our results demonstrate two types of motor segmentation during synchronized movements: one is related to the hierarchical organization of sequential movements and the other is related to the spontaneous grouping of rhythmic events. This experimental paradigm can be used to investigate the underlying neural mechanism of temporal grouping during rhythm production. |
Norihiro Takakuwa; Kaoru Isa; Hirotaka Onoe; Jun Takahashi; Tadashi Isa Contribution of the pulvinar and lateral geniculate nucleus to the control of visually guided saccades in blindsight monkeys Journal Article In: Journal of Neuroscience, vol. 41, no. 8, pp. 1755–1768, 2021. @article{Takakuwa2021,After damage to the primary visual cortex (V1), conscious vision is impaired. However, some patients can respond to visual stimuli presented in their lesion-affected visual field using residual visual pathways bypassing V1. This phenomenon is called “blindsight.” Many studies have tried to identify the brain regions responsible for blindsight, and the pulvinar and/or lateral geniculate nucleus (LGN) are suggested to play key roles as the thalamic relay of visual signals. However, there are critical problems regarding these preceding studies in that subjects with different sized lesions and periods of time after lesioning were investigated; furthermore, the ability of blindsight was assessed with different measures. In this study, we used double dissociation to clarify the roles of the pulvinar and LGN by pharmacological inactivation of each region and investigated the effects in a simple task with visually guided saccades (VGSs) using monkeys with a unilateral V1 lesion, by which nearly all of the contralesional visual field was affected. Inactivating either the ipsilesional pulvinar or LGN impaired VGS toward a visual stimulus in the affected field. In contrast, inactivation of the contralesional pulvinar had no clear effect, but inactivation of the contralesional LGN impaired VGS to the intact visual field. These results suggest that the pulvinar and LGN play key roles in performing the simple VGS task after V1 lesioning, and that the visuomotor functions of blindsight monkeys were supported by plastic changes in the visual pathway involving the pulvinar, which emerged after V1 lesioning. |
Junichi Takahashi; Kenichiro Miura; Kentaro Morita; Michiko Fujimoto; Seiko Miyata; Kosuke Okazaki; Junya Matsumoto; Naomi Hasegawa; Yoji Hirano; Hidenaga Yamamori; Yuka Yasuda; Manabu Makinodan; Kiyoto Kasai; Norio Ozaki; Toshiaki Onitsuka; Ryota Hashimoto Effects of age and sex on eye movement characteristics Journal Article In: Neuropsychopharmacology Reports, vol. 41, no. 2, pp. 152–158, 2021. @article{Takahashi2021a,Abnormal eye movements are often associated with psychiatric disorders. Eye movements are sensorimotor functions of the brain, and aging and sex would affect their characteristics. A precise understanding of normal eye movements is required to distinguish disease-related abnormalities from natural differences associated with aging or sex. To date, there is no multicohort study examining age-related dependency and sex effects of eye movements in healthy, normal individuals using large samples to ensure the robustness and reproducibility of the results. In this study, we aimed to provide findings showing the impact of age and sex on eye movement measures. The present study used eye movement measures of more than seven hundred healthy individuals from three large independent cohorts. We herein evaluated eye movement measures quantified by using a set of standard eye movement tests that have been utilized for the examination of patients with schizophrenia. We assessed the statistical significance of the effects of age and sex and its reproducibility across cohorts. We found that 4-18 out of 35 eye movement measures were significantly correlated with age, depending on the cohort, and that 10 of those, which are related to the fixation and motor control of smooth pursuit and saccades, showed high reproducibility. On the other hand, the effects of sex, if any, were less reproducible. The present results suggest that we should take age into account when we evaluate abnormalities in eye movements. |
Junichi Takahashi; Yoji Hirano; Kenichiro Miura; Kentaro Morita; Michiko Fujimoto; Hidenaga Yamamori; Yuka Yasuda; Noriko Kudo; Emiko Shishido; Kosuke Okazaki; Tomoko Shiino; Tomohiro Nakao; Kiyoto Kasai; Ryota Hashimoto; Toshiaki Onitsuka Eye movement abnormalities in major depressive disorder Journal Article In: Frontiers in Psychiatry, vol. 12, pp. 673443, 2021. @article{Takahashi2021,Background: Despite their high lifetime prevalence, major depressive disorder (MDD) is often difficult to diagnose, and there is a need for useful biomarkers for the diagnosis of MDD. Eye movements are considered a non-invasive potential biomarker for the diagnosis of psychiatric disorders such as schizophrenia. However, eye movement deficits in MDD remain unclear. Thus, we evaluated detailed eye movement measurements to validate its usefulness as a biomarker in MDD. Methods: Eye movements were recorded from 37 patients with MDD and 400 healthy controls (HCs) using the same system at five University hospitals. We administered free-viewing, fixation stability, and smooth pursuit tests, and obtained 35 eye movement measurements. We performed analyses of covariance with group as an independent variable and age as a covariate. In 4 out of 35 measurements with significant group-by-age interactions, we evaluated aging effects. Discriminant analysis and receiver operating characteristic (ROC) analysis were conducted. Results: In the free-viewing test, scanpath length was significantly shorter in MDD (p = 4.2 × 10−3). In the smooth pursuit test, duration of saccades was significantly shorter and peak saccade velocity was significantly lower in MDD (p = 3.7 × 10−3 |
Yu Takagi; Laurence Tudor Hunt; Mark W. Woolrich; Timothy E. J. Behrens; Miriam C. Klein-Flügge Adapting non-invasive human recordings along multiple task-axes shows unfolding of spontaneous and over-trained choice Journal Article In: eLife, vol. 10, pp. 1–27, 2021. @article{Takagi2021,Choices rely on a transformation of sensory inputs into motor responses. Using invasive single neuron recordings, the evolution of a choice process has been tracked by projecting population neural responses into state spaces. Here, we develop an approach that allows us to recover similar trajectories on a millisecond timescale in non-invasive human recordings. We selectively suppress activity related to three task-axes, relevant and irrelevant sensory inputs and response direction, in magnetoencephalography data acquired during context-dependent choices. Recordings from premotor cortex show a progression from processing sensory input to processing the response. In contrast to previous macaque recordings, information related to choice-irrelevant features is represented more weakly than choice-relevant sensory information. To test whether this mechanistic difference between species is caused by extensive over-training common in non-human primate studies, we trained humans on >20,000 trials of the task. Choice-irrelevant features were still weaker than relevant features in premotor cortex after over-training. |
Vijay K Tailor; Tessa M Dekker; John A Greenwood; Maria Theodorou; Annegret H. Dahlmann- Noor; Tessa M Dekker; John A Greenwood Eye movements elevate crowding in idiopathic infantile nystagmus syndrome Journal Article In: Journal of Vision, vol. 21, no. 13, pp. 1–23, 2021. @article{Tailor2021,Idiopathic infantile nystagmus syndrome is a disorder characterised by involuntary eye movements, which leads to decreased acuity and visual function. One such function is visual crowding – a process whereby objects that are easily recognised in isolation become impaired by nearby flankers. Crowding typically occurs in the peripheral visual field, although elevations in foveal vision have been reported in congenital nystagmus, similar to those found with amblyopia. Here, we examine whether elevated foveal crowding with nystagmus is driven by similar mechanisms to those of amblyopia – long-term neural changes associated with a sensory deficit – or by the momentary displacement of the stimulus through nystagmus eye movements. A Landolt-C orientation identification task was used to measure threshold gap sizes with and without either horizontally or vertically placed Landolt-C flankers. We assume that a sensory deficit should give equivalent crowding in these two dimensions, whereas an origin in eye movements should give stronger crowding with horizontal flankers given the predominantly horizontal eye movements of nystagmus. We observe elevations in nystagmic crowding that are above crowding in typical vision but below that of amblyopia. Consistent with an origin in eye movements, elevations were stronger with horizontal than vertical flankers in nystagmus, but not in typical or amblyopic vision. We further demonstrate the same horizontal elongation in typical vision with stimulus movement that simulates nystagmus. Consequently, we propose that the origin of nystagmic crowding lies in the eye movements, either through image smear of the target and flanker elements or through relocation of the stimulus into the peripheral retina. |
Niels A. Taatgen; Marieke K. Vugt; Jeroen Daamen; Ioanna Katidioti; Stefan Huijser; Jelmer P. Borst The resource-availability model of distraction and mind-wandering Journal Article In: Cognitive Systems Research, vol. 68, pp. 84–104, 2021. @article{Taatgen2021,This article presents a cognitive model of distraction and mind-wandering that combines and formalizes several existing theories. It assumes that task-related goals and opportunities for distraction are continuously in competition for mental resources. If the task-related goal does not need a particular resource at a particular moment, the likelihood that it is captured by a distraction is high. We applied this model to explain the results of three distraction experiments that differ from each other in a number of ways. The first experiment is a slow-paced mind-wandering study; the main result is that less mind-wandering occurs if subjects have to maintain an item in working memory. The second experiment is a working memory task in which mind-wandering is triggered by the presence of self-referential words in a secondary task; these words increase mental elaboration and reduce memory performance. The third experiment is a mental arithmetic/ memory/visual attention task, in which subjects became more distracted by a flanking (irrelevant) video as the task increased in complexity: as subjects need more time to think, they leave the visual resource vulnerable to distraction. Although these phenomena have been treated separately in the literature, we show that these phenomena can be explained by a single comprehensive model that is based on the assumption that distractions target unused cognitive resources. |
Georgia F Symons; Meaghan Clough; Steven Mutimer; Brendan P Major; William T O'Brien; Daniel Costello; Stuart J McDonald; Zhibin Chen; Owen White; Richelle Mychasiuk; Meng Law; David K Wright; Terence J O'Brien; Joanne Fielding; Scott C Kolbe; Sandy R Shultz Cognitive ocular motor deficits and white matter damage chronically after sports-related concussion Journal Article In: Brain Communications, vol. 3, no. 3, pp. 1–12, 2021. @article{Symons2021,A history of concussion has been linked to long-term cognitive deficits; however, the neural underpinnings of these abnormalities are poorly understood. This study recruited 26 asymptomatic male Australian footballers with a remote history of concussion (i.e. at least six months since last concussion), and 23 non-collision sport athlete controls with no history of concussion. Participants completed three ocular motor tasks (prosaccade, antisaccade and a cognitively complex switch task) to assess processing speed, inhibitory control and cognitive flexibility, respectively. Diffusion tensor imaging data were acquired using a 3 T MRI scanner, and analysed using tract-based spatial statistics, to investigate white matter abnormalities and how they relate to ocular motor performance. Australian footballers had significantly slower adjusted antisaccade latencies compared to controls (P = 0.035). A significant switch cost (i.e. switch trial error > repeat trial error) was also found on the switch task, with Australian footballers performing increased magnitude of errors on prosaccade switch trials relative to prosaccade repeat trials (P = 0.023). Diffusion tensor imaging analysis found decreased fractional anisotropy, a marker of white matter damage, in major white matter tracts (i.e. corpus callosum, corticospinal tract) in Australian footballers relative to controls. Notably, a larger prosaccade switch cost was significantly related to reduced fractional anisotropy in anterior white matter regions found to connect to the prefrontal cortex (i.e. a key cortical ocular motor centre involved in executive functioning and task switching). Taken together, Australian footballers with a history of concussion have ocular motor deficits indicative of poorer cognitive processing speed and cognitive flexibility, which are related to reduce white matter integrity in regions projecting to important cognitive ocular motor structures. These findings provide novel insights into the neural mechanisms that may underly chronic cognitive impairments in individuals with a history of concussion. |
Benjamin Swets; Susanne Fuchs; Jelena Krivokapić; Caterina Petrone A cross-linguistic study of individual differences in speech planning Journal Article In: Frontiers in Psychology, vol. 12, pp. 655516, 2021. @article{Swets2021,Although previous research has shown that there exist individual and cross-linguistic differences in planning strategies during language production, little is known about how such individual differences might vary depending on which language a speaker is planning. The present series of studies examines individual differences in planning strategies exhibited by speakers of American English, French, and German. Participants were asked to describe images on a computer monitor while their eye movements were monitored. In addition, we measured participants' working memory capacity and speed of processing. The results indicate that in the present study, English and German were planned less incrementally (further in advance) prior to speech onset compared to French, which was planned more incrementally (not as far in advance). Crucially, speed of processing predicted the scope of planning for French speakers, but not for English or German speakers. These results suggest that the different planning strategies that are invoked by syntactic choices available in different languages are associated with the tendency for speakers to rely on different cognitive support systems as they plan sentences. |
David W. Sutterer; Sean M. Polyn; Geoffrey F. Woodman a-Band activity tracks a two-dimensional spotlight of attention during spatial working memory maintenance Journal Article In: Journal of Neurophysiology, vol. 125, no. 3, pp. 957–971, 2021. @article{Sutterer2021a,Covert spatial attention is thought to facilitate the maintenance of locations in working memory, and EEG a-band activity (8–12Hz) is proposed to track the focus of covert attention. Recent work has shown that multivariate patterns of a-band activity track the polar angle of remembered locations relative to fixation. However, a defining feature of covert spatial attention is that it facilitates processing in a specific region of the visual field, and prior work has not determined whether patterns of a-band activity track the two-dimensional (2-D) coordinates of remembered stimuli within a visual hemifield or are instead maximally sensitive to the polar angle of remembered locations around fixation. Here, we used a lateralized spatial estimation task, in which observers remembered the location of one or two target dots presented to one side of fixation, to test this question. By applying a linear discriminant classifier to the topography of a-band activity, we found that we were able to decode the location of remembered stimuli. Critically, model comparison revealed that the pattern of classifier choices observed across remembered positions was best explained by a model assuming that a-band activity tracks the 2-D coordinates of remembered locations rather than a model assuming that a-band activity tracks the polar angle of remembered locations relative to fixation. These results support the hypothesis that this a-band activity is involved in the spotlight of attention, and arises from mid- to lower-level visual areas involved in maintaining spatial locations in working memory. NEW & NOTEWORTHY A substantial body of work has shown that patterns of EEG a-band activity track the angular coordinates of attended and remembered stimuli around fixation, but whether these patterns track the two-dimensional coordinates of stimuli presented within a visual hemifield remains an open question. Here, we demonstrate that a-band activity tracks the two-dimensional coordinates of remembered stimuli within a hemifield, showing that a-band activity reflects a spotlight of attention focused on locations maintained in working memory. |
David W. Sutterer; Andrew J. Coia; Vincent Sun; Steven K. Shevell; Edward Awh Decoding chromaticity and luminance from patterns of EEG activity Journal Article In: Psychophysiology, vol. 58, no. 4, pp. e13779, 2021. @article{Sutterer2021,A long-standing question in the field of vision research is whether scalp-recorded EEG activity contains sufficient information to identify stimulus chromaticity. Recent multivariate work suggests that it is possible to decode which chromaticity an observer is viewing from the multielectrode pattern of EEG activity. There is debate, however, about whether the claimed effects of stimulus chromaticity on visual evoked potentials (VEPs) are instead caused by unequal stimulus luminances, which are achromatic differences. Here, we tested whether stimulus chromaticity could be decoded when potential confounds with luminance were minimized by (1) equating chromatic stimuli in luminance using heterochromatic flicker photometry for each observer and (2) independently varying the chromaticity and luminance of target stimuli, enabling us to test whether the pattern for a given chromaticity generalized across wide variations in luminance. We also tested whether luminance variations can be decoded from the topography of voltage across the scalp. In Experiment 1, we presented two chromaticities (appearing red and green) at three luminance levels during separate trials. In Experiment 2, we presented four chromaticities (appearing red, orange, yellow, and green) at two luminance levels. Using a pattern classifier and the multielectrode pattern of EEG activity, we were able to accurately decode the chromaticity and luminance level of each stimulus. Furthermore, we were able to decode stimulus chromaticity when we trained the classifier on chromaticities presented at one luminance level and tested at a different luminance level. Thus, EEG topography contains robust information regarding stimulus chromaticity, despite large variations in stimulus luminance. |
Emma Sumner; Samuel B. Hutton; Elisabeth L. Hill Subtle oculomotor difficulties and their relation to motor skill in children with autism spectrum disorder Journal Article In: Advances in Neurodevelopmental Disorders, vol. 5, no. 2, pp. 144–155, 2021. @article{Sumner2021,Objectives: Sensorimotor difficulties are often reported in autism spectrum disorders (ASD). Visual and motor skills are linked in that the processing ofvisual information can help in guiding motor movements. The present study investigated oculomotor skill and its relation to general motor skill in ASD by providing a comprehensive assessment of oculomotor control. Methods: Fifty children (25 ASD; 25 typically developing [TD]), aged 7–10 years, completed a motor assessment (comprising fine and gross motor tasks) and oculomotor battery (comprising fixation, smooth pursuit, prosaccade and antisaccade tasks). Results: No group differences were found for antisaccade errors, nor saccade latencies in prosaccade and antisaccade tasks, but increased saccade amplitude variability was observed in children with ASD, suggesting a reduced consistency in saccade accuracy. Children with ASD also demonstrated poorer fixation stability than their peers and spent less time in pursuit of a moving target. Motor skill was not correlated with saccade amplitude variability. However, regression analyses revealed that motor skill (and not diagnosis) accounted for variance in fixation performance and fast smooth pursuit. Conclusions: The findings highlight the importance of considering oculomotor paradigms to inform the functional impact of neuropathologies in ASD and also assessing the presentation of co-occurring difficulties to further our understanding ofASD. Avenues for future research are suggested. |
Margot D. Sullivan; Ringo Huang; Joseph Rovetti; Erika P. Sparrow; Julia Spaniol Associations between phasic arousal and decisions under risk in younger and older adults Journal Article In: Neurobiology of Aging, vol. 105, pp. 262–271, 2021. @article{Sullivan2021,Higher arousal is linked to simple decision strategies and an increased preference for immediate rewards in younger adults, but little is known about the influence of arousal on decision making in older adults. In light of age-related locus coeruleus-norepinephrine system declines, we predicted a reduced association between arousal and decision behavior in older adults. Younger and older participants made a series of choices between smaller, higher-probability and larger, lower-probability financial gains. Each choice was preceded by the presentation of a high-arousal or low-arousal sound. Pupil dilation was continuously recorded as an index of task-evoked arousal. Both age groups showed significant modulation of pupil dilation as a function of arousal condition. Higher-arousal sounds were associated with shorter response times, particularly in younger adults. Furthermore, higher-arousal sounds were associated with greater risk aversion in younger adults and greater risk seeking in older adults, in line with an arousal-related amplification of baseline preferences in both age groups. Jointly, these findings help inform current theories of the effects of arousal on information processing in younger and older adults. |
Jennifer Sudkamp; Mateusz Bocian; David Souto The role of eye movements in perceiving vehicle speed and time-to-arrival at the roadside Journal Article In: Scientific Reports, vol. 11, pp. 23312, 2021. @article{Sudkamp2021,To avoid collisions, pedestrians depend on their ability to perceive and interpret the visual motion of other road users. Eye movements influence motion perception, yet pedestrians' gaze behavior has been little investigated. In the present study, we ask whether observers sample visual information differently when making two types of judgements based on the same virtual road-crossing scenario and to which extent spontaneous gaze behavior affects those judgements. Participants performed in succession a speed and a time-to-arrival two-interval discrimination task on the same simple traffic scenario—a car approaching at a constant speed (varying from 10 to 90 km/h) on a single-lane road. On average, observers were able to discriminate vehicle speeds of around 18 km/h and times-to-arrival of 0.7 s. In both tasks, observers placed their gaze closely towards the center of the vehicle's front plane while pursuing the vehicle. Other areas of the visual scene were sampled infrequently. No differences were found in the average gaze behavior between the two tasks and a pattern classifier (Support Vector Machine), trained on trial-level gaze patterns, failed to reliably classify the task from the spontaneous eye movements it elicited. Saccadic gaze behavior could predict time-to-arrival discrimination performance, demonstrating the relevance of gaze behavior for perceptual sensitivity in road-crossing. |
Rhonda J. N. Stopyn; Thomas Hadjistavropoulos; Jeff Loucks An eye tracking investigation of pain decoding based on older and younger adults' facial expressions Journal Article In: Journal of Nonverbal Behavior, vol. 45, pp. 31–52, 2021. @article{Stopyn2021,Nonverbal pain cues such as facial expressions, are useful in the systematic assessment of pain in people with dementia who have severe limitations in their ability to communicate. Nonetheless, the extent to which observers rely on specific pain-related facial responses (e.g., eye movements, frowning) when judging pain remains unclear. Observers viewed three types of videos of patients expressing pain (younger patients, older patients without dementia, older patients with dementia) while wearing an eye tracker device that recorded their viewing behaviors. They provided pain ratings for each patient in the videos. These observers assigned higher pain ratings to older adults compared to younger adults and the highest pain ratings to patients with dementia. Pain ratings assigned to younger adults showed greater correspondence to objectively coded facial reactions compared to older adults. The correspondence of observer ratings was not affected by the cognitive status of target patients as there were no differences between the ratings assigned to older adults with and without dementia. Observers' percentage of total dwell time (amount of time that an observer glances or fixates within a defined visual area of interest) across specific facial areas did not predict the correspondence of observers' pain ratings to objective coding of facial responses. Our results demonstrate that patient characteristics such as age and cognitive status impact the pain decoding process by observers when viewing facial expressions of pain in others. |
Kate Stone; João Veríssimo; Daniel J. Schad; Elise Oltrogge; Shravan Vasishth; Sol Lago The interaction of grammatically distinct agreement dependencies in predictive processing Journal Article In: Language, Cognition and Neuroscience, vol. 36, no. 9, pp. 1159–1179, 2021. @article{Stone2021,Previous research has found that comprehenders sometimes predict information that is grammatically unlicensed by sentence constraints. An open question is why such grammatically unlicensed predictions occur. We examined the possibility that unlicensed predictions arise in situations of information conflict, for instance when comprehenders try to predict upcoming words while simultaneously building dependencies with previously encountered elements in memory. German possessive pronouns are a good testing ground for this hypothesis because they encode two grammatically distinct agreement dependencies: a retrospective one between the possessive and its previously mentioned referent, and a prospective one between the possessive and its following nominal head. In two visual world eye-tracking experiments, we estimated the onset of predictive effects in participants' fixations. The results showed that the retrospective dependency affected resolution of the prospective dependency by shifting the onset of predictive effects. We attribute this effect to an interaction between predictive and memory retrieval processes. |
Andrew J. Stewart; Henrik Singmann; Matthew Haigh; Jeffrey S. Wood; Igor Douven Tracking the eye of the beholder: Is explanation subjective? Journal Article In: Journal of Cognitive Psychology, vol. 33, no. 2, pp. 199–206, 2021. @article{Stewart2021,There is much recent evidence showing that explanation is central to various cognitive processes. On the other hand, philosophers have argued that the notions of explanation and explanation quality are too subjective for explanation to play any role in science: what may be an adequate explanation for one person may fail to be so for another. We compare the results of a study tasking participants with rating explanation quality with those of an eye-tracking study, finding that ratings of explanation quality from participants in the former study were strongly predictive of the ease with which participants in the latter study processed text fragments presenting the same explanations that were used in the rating study. This finding undermines the thought that explanation is only in the eye of the beholder. |
Chloé Stengel; Marine Vernet; Julià L. Amengual; Antoni Valero-Cabré In: Scientific Reports, vol. 11, pp. 3807, 2021. @article{Stengel2021,Correlational evidence in non-human primates has reported increases of fronto-parietal high-beta (22–30 Hz) synchrony during the top-down allocation of visuo-spatial attention. But may inter-regional synchronization at this specific frequency band provide a causal mechanism by which top-down attentional processes facilitate conscious visual perception? To address this question, we analyzed electroencephalographic (EEG) signals from a group of healthy participants who performed a conscious visual detection task while we delivered brief (4 pulses) rhythmic (30 Hz) or random bursts of Transcranial Magnetic Stimulation (TMS) to the right Frontal Eye Field (FEF) prior to the onset of a lateralized target. We report increases of inter-regional synchronization in the high-beta band (25–35 Hz) between the electrode closest to the stimulated region (the right FEF) and right parietal EEG leads, and increases of local inter-trial coherence within the same frequency band over bilateral parietal EEG contacts, both driven by rhythmic but not random TMS patterns. Such increases were accompained by improvements of conscious visual sensitivity for left visual targets in the rhythmic but not the random TMS condition. These outcomes suggest that high-beta inter-regional synchrony can be modulated non-invasively and that high-beta oscillatory activity across the right dorsal fronto-parietal network may contribute to the facilitation of conscious visual perception. Our work supports future applications of non-invasive brain stimulation to restore impaired visually-guided behaviors by operating on top-down attentional modulatory mechanisms. |
Marianna Stella; Paul E. Engelhardt Comprehension and eye movements in the processing of subject-and object-relative clauses: Evidence from dyslexia and individual differences Journal Article In: Brain Sciences, vol. 11, pp. 915, 2021. @article{Stella2021,In this study, we examined eye movements and comprehension in sentences containing a relative clause. To date, few studies have focused on syntactic processing in dyslexia and so one goal of the study is to contribute to this gap in the experimental literature. A second goal is to contribute to theoretical psycholinguistic debate concerning the cause and the location of the processing difficulty associated with object-relative clauses. We compared dyslexic readers (n = 50) to a group of non-dyslexic controls (n = 50). We also assessed two key individual differences variables (working memory and verbal intelligence), which have been theorised to impact reading times and comprehension of subject-and object-relative clauses. The results showed that dyslexics and controls had similar comprehension accuracy. However, reading times showed participants with dyslexia spent significantly longer reading the sentences compared to controls (i.e., a main effect of dyslexia). In general, sentence type did not interact with dyslexia status. With respect to individual differences and the theoretical debate, we found that processing difficulty between the subject and object relatives was no longer significant when individual differences in working memory were controlled. Thus, our findings support theories, which assume that working memory demands are responsible for the processing difficulty incurred by (1) individuals with dyslexia and (2) object-relative clauses as compared to subject relative clauses. |
Niklas Stein; Diederick C. Niehorster; Tamara Watson; Frank Steinicke; Katharina Rifai; Siegfried Wahl; Markus Lappe A comparison of eye tracking latencies among several commercial head-mounted displays Journal Article In: i-Perception, vol. 12, no. 1, pp. 1–16, 2021. @article{Stein2021,A number of virtual reality head-mounted displays (HMDs) with integrated eye trackers have recently become commercially available. If their eye tracking latency is low and reliable enough for gaze-contingent rendering, this may open up many interesting opportunities for researchers. We measured eye tracking latencies for the Fove-0, the Varjo VR-1, and the High Tech Computer Corporation (HTC) Vive Pro Eye using simultaneous electrooculography measurements. We determined the time from the occurrence of an eye position change to its availability as a data sample from the eye tracker (delay) and the time from an eye position change to the earliest possible change of the display content (latency). For each test and each device, participants performed 60 saccades between two targets 20° of visual angle apart. The targets were continuously visible in the HMD, and the saccades were instructed by an auditory cue. Data collection and eye tracking calibration were done using the recommended scripts for each device in Unity3D. The Vive Pro Eye was recorded twice, once using the SteamVR SDK and once using the Tobii XR SDK. Our results show clear differences between the HMDs. Delays ranged from 15 ms to 52 ms, and the latencies ranged from 45 ms to 81 ms. The Fove-0 appears to be the fastest device and best suited for gaze-contingent rendering. |
Jeremy Steffman Prosodic prominence effects in the processing of spectral cues Journal Article In: Language, Cognition and Neuroscience, vol. 36, no. 5, pp. 586–611, 2021. @article{Steffman2021,Two experiments test how phrasal prominence influences listeners' perception of vowel contrasts and how prominence information and vowel formant cues are integrated in processing. Experiment 1 finds that listeners incorporate phrasal prominence in their perception of vowels, in line with how spectral structure is modulated by prominence in speech. Experiment 2 explores how prominence information is integrated with formant cues in a visual world eyetracking task. Prominence shows an overall later influence in processing in line with current models of prosodic and segmental integration. However, listeners' perception of formants was also impacted more subtly by prominence immediately in processing such that prominence information directly shapes how formant cues are perceived. Results are discussed in terms of their implications for models of prosodic effects in segmental perception and possible differences between prosodic prominence and prosodic boundaries in this regard. |
Benjamin J Stauch; Alina Peter; Heike Schuler; Pascal Fries Stimulus-specific plasticity in human visual gamma-band activity and functional connectivity Journal Article In: eLife, vol. 10, pp. e68240, 2021. @article{Stauch2021,Under natural conditions, the visual system often sees a given input repeatedly. This provides an opportunity to optimize processing of the repeated stimuli. Stimulus repetition has been shown to strongly modulate neuronal-gamma band synchronization, yet crucial questions remained open. Here we used magnetoencephalography in 30 human subjects and find that gamma decreases across ≈10 repetitions and then increases across further repetitions, revealing plastic changes of the activated neuronal circuits. Crucially, increases induced by one stimulus did not affect responses to other stimuli, demonstrating stimulus specificity. Changes partially persisted when the inducing stimulus was repeated after 25 minutes of intervening stimuli. They were strongest in early visual cortex and increased interareal feedforward influences. Our results suggest that early visual cortex gamma synchronization enables adaptive neuronal processing of recurring stimuli. These and previously reported changes might be due to an interaction of oscillatory dynamics with established synaptic plasticity mechanisms. |
Jemaine E. Stacey; Mark Crook-Rumsey; Alexander Sumich; Christina J. Howard; Trevor Crawford; Kinneret Livne; Sabrina Lenzoni; Stephen Badham Age differences in resting state EEG and their relation to eye movements and cognitive performance Journal Article In: Neuropsychologia, vol. 157, pp. 107887, 2021. @article{Stacey2021,Prior research has focused on EEG differences across age or EEG differences across cognitive tasks/eye tracking. There are few studies linking age differences in EEG to age differences in behavioural performance which is necessary to establish how neuroactivity corresponds to successful and impaired ageing. Eighty-six healthy participants completed a battery of cognitive tests and eye-tracking measures. Resting state EEG (n = 75, 31 young, 44 older adults) was measured for delta, theta, alpha and beta power as well as for alpha peak frequency. Age deficits in cognition were aligned with the literature, showing working memory and inhibitory deficits along with an older adult advantage in vocabulary. Older adults showed poorer eye movement accuracy and response times, but we did not replicate literature showing a greater age deficit for antisaccades than for prosaccades. We replicated EEG literature showing lower alpha peak frequency in older adults but not literature showing lower alpha power. Older adults also showed higher beta power and less parietal alpha power asymmetry than young adults. Interaction effects showed that better prosaccade performance was related to lower beta power in young adults but not in older adults. Performance at the trail making test part B (measuring task switching and inhibition) was improved for older adults with higher resting state delta power but did not depend on delta power for young adults. It is argued that individuals with higher slow-wave resting EEG may be more resilient to age deficits in tasks that utilise cross-cortical processing. |
Thomas St. Pierre; Elizabeth K. Johnson Looking for wugs in all the right places: Children's use of prepositions in word learning Journal Article In: Cognitive Science, vol. 45, no. 8, pp. e13028, 2021. @article{St.Pierre2021,To help infer the meanings of novel words, children frequently capitalize on their current linguistic knowledge to constrain the hypothesis space. Children's syntactic knowledge of function words has been shown to be especially useful in helping to infer the meanings of novel words, with most previous research focusing on how children use preceding determiners and pronouns/auxiliary to infer whether a novel word refers to an entity or an action, respectively. In the current visual world experiment, we examined whether 28- to 32-month-olds could exploit their lexical semantic knowledge of an additional class of function words—prepositions—to learn novel nouns. During the experiment, children were tested on their ability to use the prepositions in, on, under, and next to to identify novel creatures displayed on a screen (e.g., The wug is on the table), as well as their ability to later identify the creature without accompanying prepositions (e.g., Look at the wug). Children overall demonstrated understanding of all the prepositions but next to and were able to use their knowledge of prepositions to learn the associations between novel words and their intended referents, as shown by greater-than chance looks to the target referent when no prepositional phrase was provided. |
David Souto; Olivia Marsh; Claire Hutchinson; Simon Judge; Kevin B. Paterson Cognitive plasticity induced by gaze-control technology: Gaze-typing improves performance in the antisaccade task Journal Article In: Computers in Human Behavior, vol. 122, pp. 106831, 2021. @article{Souto2021,The last twenty years have seen the development of gaze-controlled computer interfaces for augmentative communication and other assistive technology applications. In many applications, the user needs to look at symbols on a virtual on-screen keyboard and maintain gaze to make a selection. Executive control is essential to learning to use gaze-control, affecting the uptake of the technology. Specifically, the user of a gaze-controlled interface must suppress looking for its own sake, the so-called “Midas touch” problem. In a pre-registered study (https://osf.io/2mak4), we tested whether gaze-typing performance depends on executive control and whether learning-dependent plasticity leads to improved executive control as measured using the antisaccade task. Forty-two university students were recruited as participants. After five 30-min training sessions, we found shorter antisaccade latencies in a gaze-control compared to a mouse-control group, and similar error-rates. Subjective workload ratings were also similar across groups, indicating the task in both groups was matched for difficulty. These findings suggest that executive control contributes to gaze-typing performance and leads to learning-induced plasticity. |
Ziming Song; Xiaowei Liang; Yongsheng Wang; Guoli Yan Effect of alternating-color words on oral reading in grades 2–5 Chinese children: Evidence from eye movements Journal Article In: Reading and Writing, vol. 34, no. 10, pp. 2627–2643, 2021. @article{Song2021b,There is no obvious boundary information in Chinese reading. It has been shown that the introduction of word boundary information presented with alternating colors without changing the text distribution could significantly improve the reading speed of Chinese children in grade 2 (Perea and Wang in Mem Cognit 45(7):1160−1170, 2017. https://doi.org/10.3758/s13421-017-0717-0). However, few studies have examined how the effect of word boundary information on children's oral reading develops and changes as children's grade increases. The present study asked Chinese children in grades 2–5 to read alternating-color and mono-color text orally and used eye-tracking technology to explore the developmental trajectory of the influence of word boundary information on oral reading. The results indicated that children in grade 2 and grade 3 showed faster reading speeds in the alternating-color condition than in the mono-color condition. In contrast, there was no difference between the two conditions in children in grade 4 and grade 5. We discuss the mechanisms of the findings and the implications for education. |
Youngmin Song; Lydia Ouchene; Aarlenne Zein Khan Saccadic adaptation in the presence of artificial central scotomas Journal Article In: Journal of Vision, vol. 21, no. 1, pp. 1–15, 2021. @article{Song2021a,Saccadic adaptation can occur over a short period of time through a constant adjustment of the saccade target during the saccade, resulting in saccadic re-referencing, which directs the saccade to a location different from the target that elicited the saccade. Saccade re-referencing could be used to help patients with age-related macular degeneration to optimally use their residual visual function. However, it remains unknown whether saccade adaptation can take place in the presence of central scotomas (i.e., without central vision).We tested participants in two experiments in a conventional double-step paradigm with a central gaze-contingent artificial scotoma. Experiment 1 (N = 12) comprised a backward adaptation paradigm with no scotoma control, visible, and invisible 3 diameter scotoma conditions. Experiment 2 (N = 13) comprised a forward adaptation paradigm with no scotoma control, invisible 2 , and 4 diameter scotoma conditions. In Experiment 1, we observed significant adaptation in both the visible and invisible scotoma conditions comparable to the control condition with no scotoma. This was the case even when the saccade landed such that the target was occluded by the scotoma.We observed that adaptation occurred based on peripheral viewing of the stepped target during the deceleration period. In Experiment 2, we found that both scotoma conditions showed adaptation again comparable to the control condition with no scotoma. We conclude that saccadic adaptation can occur with central scotomas, showing that it does not require central vision and can be driven primarily by peripheral retinal error. |
Jiwon Song; Yuna Kwak; Chai Youn Kim Familiarity and novelty in aesthetic preference: The effects of the properties of the artwork and the beholder Journal Article In: Frontiers in Psychology, vol. 12, pp. 694927, 2021. @article{Song2021,Familiarity and novelty are fundamental yet competing factors influencing aesthetic preference. However, whether people prefer familiar paintings or novel paintings has not been clear. Using both behavioral and eye-tracking measures, the present study aimed to investigate whether the effect of familiarity-novelty on aesthetic preference is independent or dependent on artwork properties (painting content, visual complexity) and viewer characteristics (experience in art). Participants were presented with two images of paintings, one of which was repeatedly presented but was always paired with a new painting in a randomized lateral arrangement. They were asked to indicate which of the two images they preferred with the degree of their preference. Behavioral results demonstrated an interactive influence of painting content and complexity on familiarity-novelty preference, especially alongside the distinction between representational and abstract paintings. Also, the familiarity-novelty preference was modulated by the degree of art experience, for abstract paintings in particular. Gaze results showed the differential effects of painting content, complexity, and art experience echoing the behavioral results. Taken together, the convergent results derived from behavioral and eye-tracking measures imply that novelty is an important feature of aesthetic appreciation, but its influence is modulated by properties of both the artwork and the beholder. |
Myeongeun Son; Jongbong Lee; Aline Godfroid Attention to form and meaning revisited Journal Article In: Studies in Second Language Acquisition, pp. 1–30, 2021. @article{Son2021,Motivated by a series of interconnected studies on simultaneous attention to form and meaning, we revisit L2 learners' real-time processing of text by using eye-tracking as an unobtrusive method to provide concurrent data on attention allocation. Seventy-five L2 Spanish learners were instructed to attend to an assigned form in a reading passage and to press a button when they noticed it. After reading the passage, the learners answered 10 multiple-choice comprehension questions. The participants' responses to the comprehension questions and their reading behaviors reflected in eye-movement data suggest that attention to grammatical form may hinder L2 learners' simultaneous attention to form and meaning. However, individual differences in global text processing contributed to the differences in the participants' text-comprehension scores over and above the task instruction to attend to form: Slower L2 readers who read the passage more carefully showed better text comprehension. |
Emma J. Solly; Meaghan Clough; Allison M. McKendrick; Paige Foletta; Owen B. White; Joanne Fielding Eye movement characteristics provide an objective measure of visual processing changes in patients with visual snow syndrome Journal Article In: Scientific Reports, vol. 11, pp. 9607, 2021. @article{Solly2021,Visual snow syndrome (VSS) is a poorly understood neurological disorder that features a range of disabling sensory changes. Visual processing changes revealed previously in VSS appear consistent with poor attentional control, specifically, with difficulty controlling environmentally driven shifts of attention. This study sought to confirm this proposal by determining whether these changes were similarly evident where attention is internally driven. Sixty seven VSS patients and 37 controls completed two saccade tasks: the endogenously cued saccade task and saccadic Simon task. The endogenously cued saccade task correctly (valid trial) or incorrectly (invalid trial) pre-cues a target location using a centrally presented arrow. VSS patients generated significantly shorter saccade latencies for valid trials (p = 0.03), resulting in a greater magnitude cue effect (p = 0.02), i.e. the difference in latency between valid and invalid trials. The saccadic Simon task presents a peripheral cue which may be spatially congruent or incongruent with the subsequent target location. Latencies on this task were comparable for VSS patients and controls, with a normal Simon effect, i.e. shorter latencies for saccades to targets spatially congruent with the preceding cue. On both tasks, VSS patients generated more erroneous saccades than controls towards non-target locations (Endogenously cued saccade task: p = 0.02, saccadic Simon task: p = 0.04). These results demonstrate that cued shifts of attention differentially affect saccade generation in VSS patients. We propose that these changes are not due to impairment of frontally-mediated inhibitory control, but to heightened saccade-related activity in visual regions. These results contribute to a VSS ocular motor signature that may provide clinical utility as well as an objective measure of dysfunction to facilitate future research. |
Rodolfo Solís-Vivanco; Ole Jensen; Mathilde Bonnefond New insights on the ventral attention network: Active suppression and involuntary recruitment during a bimodal task Journal Article In: Human Brain Mapping, vol. 42, no. 6, pp. 1699–1713, 2021. @article{SolisVivanco2021,Detection of unexpected, yet relevant events is essential in daily life. fMRI studies have revealed the involvement of the ventral attention network (VAN), including the temporo-parietal junction (TPJ), in such process. In this MEG study with 34 participants (17 women), we used a bimodal (visual/auditory) attention task to determine the neuronal dynamics associated with suppression of the activity of the VAN during top-down attention and its recruitment when information from the unattended sensory modality is involuntarily integrated. We observed an anticipatory power increase of alpha/beta oscillations (12–20 Hz, previously associated with functional inhibition) in the VAN following a cue indicating the modality to attend. Stronger VAN power increases were associated with better task performance, suggesting that the VAN suppression prevents shifting attention to distractors. Moreover, the TPJ was synchronized with the frontal eye field in that frequency band, indicating that the dorsal attention network (DAN) might participate in such suppression. Furthermore, we found a 12–20 Hz power decrease and enhanced synchronization, in both the VAN and DAN, when information between sensory modalities was congruent, suggesting an involvement of these networks when attention is involuntarily enhanced due to multisensory integration. Our results show that effective multimodal attentional allocation includes the modulation of the VAN and DAN through upper-alpha/beta oscillations. Altogether these results indicate that the suppressing role of alpha/beta oscillations might operate beyond sensory regions. |
Maria Solé Puig; August Romeo; Hans Supèr Vergence eye movements during figure-ground perception Journal Article In: Consciousness and Cognition, vol. 92, pp. 103138, 2021. @article{SolePuig2021,Figure-ground, that is the segmentation of visual information into objects and their surrounding backgrounds, provides structure for visual attention. Recent evidence shows a novel role of vergence eye movements in visual attention. In the present work, vergence responses during figure-ground segregation tasks are psychophysically investigated. We show that during a figure-ground detection task, subjects convergence their eyes. Vergence eye movements are larger in figure trials than in ground trials. In detected figures trials, vergence are stronger than in trials where the figure went unnoticed. Moreover in figure trials, vergence responses are stronger to low-contrast figures than to high-contrast figures. We argue that these discriminative vergence responses have a role in figure-ground. |
Adam C. Snyder; Byron M. Yu; Matthew A. Smith A stable population code for attention in prefrontal cortex leads a dynamic attention code in visual cortex Journal Article In: Journal of Neuroscience, vol. 41, no. 44, pp. 9163–9176, 2021. @article{Snyder2021,Attention often requires maintaining a stable mental state over time while simultaneously improving perceptual sensitivity. These requirements place conflicting demands on neural populations, as sensitivity implies a robust response to perturbation by incoming stimuli, which is antithetical to stability. Functional specialization of cortical areas provides one potential mechanism to resolve this conflict. We reasoned that attention signals in executive control areas might be highly stable over time, reflecting maintenance of the cognitive state, thereby freeing up sensory areas to be more sensitive to sensory input (i.e., unstable), which would be reflected by more dynamic attention signals in those areas. To test these predictions, we simultaneously recorded neural populations in prefrontal cortex (PFC) and visual cortical area V4 in rhesus macaque monkeys performing an endogenous spatial selective attention task. Using a decoding approach, we found that the neural code for attention states in PFC was substantially more stable over time compared with the attention code in V4 on a moment-bymoment basis, in line with our guiding thesis. Moreover, attention signals in PFC predicted the future attention state of V4 better than vice versa, consistent with a top-down role for PFC in attention. These results suggest a functional specialization of attention mechanisms across cortical areas with a division of labor. PFC signals the cognitive state and maintains this state stably over time, whereas V4 responds to sensory input in a manner dynamically modulated by that cognitive state. |
Stephanie M. Smith; Ian Krajbich Mental representations distinguish value-based decisions from perceptual decisions Journal Article In: Psychonomic Bulletin & Review, vol. 28, no. 4, pp. 1413–1422, 2021. @article{Smith2021a,In our daily lives, we make a wide variety of decisions. One major distinction that has been made is between perceptual decisions and value-based (economic) decisions. We argue that this distinction is ill-defined, because these decisions vary on multiple dimensions. We present an alternative way to categorize decisions, based on two dimensions: subjective versus objective criteria, and evaluation of a stimulus versus a representation. We experimentally study the decision-making process (with eye-tracking) in each of the four resulting categories, using the same stimulus set of food images. Using a combination of individual-level and group-level modeling, we find surprisingly consistent patterns of behavior across the categories. However, we find stronger similarities between the subjective and objective categories, and stronger differences between the stimulus and representation categories. |
Maverick E. Smith; Lester C. Loschky; Heather R. Bailey Knowledge guides attention to goal-relevant information in older adults Journal Article In: Cognitive Research: Principles and Implications, vol. 6, no. 1, pp. 56, 2021. @article{Smith2021,How does viewers' knowledge guide their attention while they watch everyday events, how does it affect their memory, and does it change with age? Older adults have diminished episodic memory for everyday events, but intact semantic knowledge. Indeed, research suggests that older adults may rely on their semantic memory to offset impairments in episodic memory, and when relevant knowledge is lacking, older adults' memory can suffer. Yet, the mechanism by which prior knowledge guides attentional selection when watching dynamic activity is unclear. To address this, we studied the influence of knowledge on attention and memory for everyday events in young and older adults by tracking their eyes while they watched videos. The videos depicted activities that older adults perform more frequently than young adults (balancing a checkbook, planting flowers) or activities that young adults perform more frequently than older adults (installing a printer, setting up a video game). Participants completed free recall, recognition, and order memory tests after each video. We found age-related memory deficits when older adults had little knowledge of the activities, but memory did not differ between age groups when older adults had relevant knowledge and experience with the activities. Critically, results showed that knowledge influenced where viewers fixated when watching the videos. Older adults fixated less goal-relevant information compared to young adults when watching young adult activities, but they fixated goal-relevant information similarly to young adults, when watching more older adult activities. Finally, results showed that fixating goal-relevant information predicted free recall of the everyday activities for both age groups. Thus, older adults may use relevant knowledge to more effectively infer the goals of actors, which guides their attention to goal-relevant actions, thus improving their episodic memory for everyday activities. |
Ian Skinner; Markus Hübscher; Hopin Lee; Adrian C. Traeger; G. Lorimer Moseley; Benedict M. Wand; Sylvia M. Gustin; James H. McAuley Do people with acute low back pain have an attentional bias to threat-related words? Journal Article In: Scandinavian Journal of Pain, vol. 21, no. 3, pp. 485–494, 2021. @article{Skinner2021,It has been hypothesised that attentional bias to environmental threats can contribute to persistent pain. It is unclear whether people with acute low back pain (LBP) have an attentional bias to environmental threats. We investigated if attentional bias of threat related words is different in people with acute LBP and pain-free controls. People with acute LBP and pain-free people completed a free viewing eye tracking task. Participants were simultaneously presented with two words, a threat related word and a neutral control word. Threat related words were general threat, affective pain and sensory pain. We conducted linear mixed models to detect differences between acute LBP and pain-free participants on five eye tracking outcome measures (dwell time, first fixation, latency to first fixation, first run dwell time and number of fixations). We calculated absolute reliability, (standard error of measure), and relative reliability (intraclass correlation coefficients [ICC 2,1]) for each eye tracking outcome measures. We recruited 65 people with acute LBP and 65 pain-free controls. Participants with acute LBP had a higher proportion of fixations towards the affective pain words (M=0.5009, 95% CI=0.4941, 0.5076) than the pain-free controls had (M=0.4908, 95% CI=0.4836, 0.4979), mean between group difference = -0.0101, 95% CI [-0.0198, -0.0004] |
Alyssa H Sinclair; Grace M Manalili; Iva K Brunec; R. Alison Adcock; Morgan D Barense Prediction errors disrupt hippocampal representations and update episodic memories Journal Article In: Proceedings of the National Academy of Sciences, vol. 118, no. 51, pp. e2117625118, 2021. @article{Sinclair2021,The brain supports adaptive behavior by generating predictions, learning from errors, and updating memories to incorporate new information. Prediction error, or surprise, triggers learning when reality contradicts expectations. Prior studies have shown that the hippocampus signals prediction errors, but the hypothesized link to memory updating has not been demonstrated. In a human functional MRI study, we elicited mnemonic prediction errors by interrupting familiar narrative videos immediately before the expected endings. We found that prediction errors reversed the relationship between univariate hippocampal activation and memory: greater hippocampal activation predicted memory preservation after expected endings, but memory updating after surprising endings. In contrast to previous studies, we show that univariate activation was insufficient for understanding hippocampal prediction error signals. We explain this surprising finding by tracking both the evolution of hippocampal activation patterns and the connectivity between the hippocampus and neuromodulatory regions. We found that hippocampal activation patterns stabilized as each narrative episode unfolded, suggesting sustained episodic representations. Prediction errors disrupted these sustained representations and the degree of disruption predicted memory updating. The relationship between hippocampal activation and subsequent memory depended on concurrent basal forebrain activation, supporting the idea that cholinergic modulation regulates attention and memory. We conclude that prediction errors create conditions that favor memory updating, prompting the hippocampus to abandon ongoing predictions and make memories malleable. |
Yeonju Sin; HeeYoung Seon; Yun Kyoung Shin; Oh-Sang Kwon; Dongil Chung Subjective optimality in finite sequential decision-making Journal Article In: PLoS Computational Biology, vol. 17, no. 12, pp. e1009633, 2021. @article{Sin2021,Many decisions in life are sequential and constrained by a time window. Although mathematically derived optimal solutions exist, it has been reported that humans often deviate from making optimal choices. Here, we used a secretary problem, a classic example of finite sequential decision-making, and investigated the mechanisms underlying individuals' suboptimal choices. Across three independent experiments, we found that a dynamic programming model comprising subjective value function explains individuals' deviations from optimality and predicts the choice behaviors under fewer and more opportunities. We further identified that pupil dilation reflected the levels of decision difficulty and subsequent choices to accept or reject the stimulus at each opportunity. The value sensitivity, a model-based estimate that characterizes each individual's subjective valuation, correlated with the extent to which individuals' physiological responses tracked stimuli information. Our results provide model-based and physiological evidence for subjective valuation in finite sequential decision-making, rediscovering human suboptimality in subjectively optimal decision-making processes. |
María Silva-Gago; Flora Ioannidou; Annapaola Fedato; Timothy Hodgson; Emiliano Bruner Visual attention and cognitive archaeology: An eye-tracking study of palaeolithic stone tools Journal Article In: Perception, pp. 1–22, 2021. @article{SilvaGago2021,The study of lithic technology can provide information on human cultural evolution. This article aims to analyse visual behaviour associated with the exploration of ancient stone artefacts and how this relates to perceptual mechanisms in humans. In Experiment 1, we used eye tracking to record patterns of eye fixations while participants viewed images of stone tools, including examples of worked pebbles and handaxes. The results showed that the focus of gaze was directed more towards the upper regions of worked pebbles and on the basal areas for handaxes. Knapped surfaces also attracted more fixation than natural cortex for both tool types. Fixation distribution was different to that predicted by models that calculate visual salience. Experiment 2 was an online study using a mouse-click attention tracking technique and included images of unworked pebbles and ‘mixed' images combining the handaxe's outline with the pebble's unworked texture. The pattern of clicks corresponded to that revealed using eye tracking and there were differences between tools and other images. Overall, the findings suggest that visual exploration is directed towards functional aspects of tools. Studies of visual attention and exploration can supply useful information to inform understanding of human cognitive evolution and tool use. |
Carlos Sillero-Rejon; Ute Leonards; Marcus R. Munafò; Craig Hedge; Janet Hoek; Benjamin Toll; Harry Gove; Isabel Willis; Rose Barry; Abi Robinson; Olivia M. Maynard Avoidance of tobacco health warnings? An eye-tracking approach Journal Article In: Addiction, vol. 116, no. 1, pp. 126–138, 2021. @article{SilleroRejon2021,Aims: Among three eye-tracking studies, we examined how cigarette pack features affected visual attention and self-reported avoidance of and reactance to warnings. Design: Study 1: smoking status × warning immediacy (short-term versus long-term health consequences) × warning location (top versus bottom of pack). Study 2: smoking status × warning framing (gain-framed versus loss-framed) × warning format (text-only versus pictorial). Study 3: smoking status × warning severity (highly severe versus moderately severe consequences of smoking). Setting: University of Bristol, UK, eye-tracking laboratory. Participants: Study 1: non-smokers (n = 25), weekly smokers (n = 25) and daily smokers (n = 25). Study 2: non-smokers (n = 37), smokers contemplating quitting (n = 37) and smokers not contemplating quitting (n = 43). Study 3: non-smokers (n = 27), weekly smokers (n = 26) and daily smokers (n = 26). Measurements: For all studies: visual attention, measured as the ratio of the number of fixations to the warning versus the branding, self-reported predicted avoidance of and reactance to warnings and for study 3, effect of warning on quitting motivation. Findings: Study 1: greater self-reported avoidance [mean difference (MD) = 1.14; 95% confidence interval (CI) = 0.94, 1.35, P < 0.001, $eta$p2 = 0.64] and visual attention (MD = 0.89, 95% CI = 0.09, 1.68 |
Jack W. Silcox; Brennan R. Payne The costs (and benefits) of effortful listening on context processing: A simultaneous electrophysiology, pupillometry, and behavioral study Journal Article In: Cortex, vol. 142, pp. 296–316, 2021. @article{Silcox2021,There is an apparent disparity between the fields of cognitive audiology and cognitive electrophysiology as to how linguistic context is used when listening to perceptually challenging speech. To gain a clearer picture of how listening effort impacts context use, we conducted a pre-registered study to simultaneously examine electrophysiological, pupillometric, and behavioral responses when listening to sentences varying in contextual constraint and acoustic challenge in the same sample. Participants (N = 44) listened to sentences that were highly constraining and completed with expected or unexpected sentence-final words (“The prisoners were planning their escape/party”) or were low-constraint sentences with unexpected sentence-final words (“All day she thought about the party”). Sentences were presented either in quiet or with +3 dB SNR background noise. Pupillometry and EEG were simultaneously recorded and subsequent sentence recognition and word recall were measured. While the N400 expectancy effect was diminished by noise, suggesting impaired real-time context use, we simultaneously observed a beneficial effect of constraint on subsequent recognition memory for degraded speech. Importantly, analyses of trial-to-trial coupling between pupil dilation and N400 amplitude showed that when participants' showed increased listening effort (i.e., greater pupil dilation), there was a subsequent recovery of the N400 effect, but at the same time, higher effort was related to poorer subsequent sentence recognition and word recall. Collectively, these findings suggest divergent effects of acoustic challenge and listening effort on context use: while noise impairs the rapid use of context to facilitate lexical semantic processing in general, this negative effect is attenuated when listeners show increased effort in response to noise. However, this effort-induced reliance on context for online word processing comes at the cost of poorer subsequent memory. |
Les Sikos; Katharina Stein; Maria Staudte A rose by any other verb: The effect of expectations and word category on processing effort in situated sentence comprehension Journal Article In: Frontiers in Psychology, vol. 12, pp. 661898, 2021. @article{Sikos2021,Recent work has shown that linguistic and visual contexts jointly modulate linguistic expectancy and, thus, the processing effort for a (more or less) expected critical word. According to these findings, uncertainty about the upcoming referent in a visually-situated sentence can be reduced by exploiting the selectional restrictions of a preceding word (e.g., a verb or an adjective), which then reduces processing effort on the critical word (e.g., a referential noun). Interestingly, however, no such modulation was observed in these studies on the expectation-generating word itself. The goal of the current study is to investigate whether the reduction of uncertainty (i.e., the generation of expectations) simply does not modulate processing effort-or whether the particular subject-verb-object (SVO) sentence structure used in these studies (which emphasizes the referential nature of the noun as direct pointer to visually co-present objects) accounts for the observed pattern. To test these questions, the current design reverses the functional roles of nouns and verbs by using sentence constructions in which the noun reduces uncertainty about upcoming verbs, and the verb provides the disambiguating and reference-resolving piece of information. Experiment 1 (a Visual World Paradigm study) and Experiment 2 (a Grammaticality Maze study) both replicate the effect found in previous work (i.e., the effect of visually-situated context on the word which uniquely identifies the referent), albeit on the verb in the current study. Results on the noun, where uncertainty is reduced and expectations are generated in the current design, were mixed and were most likely influenced by design decisions specific to each experiment. These results show that processing of the reference-resolving word—whether it be a noun or a verb—reliably benefits from the prior linguistic and visual information that lead to the generation of concrete expectations. |
Olga Shurygina; Arezoo Pooresmaeili; Martin Rolfs Pre-saccadic attention spreads to stimuli forming a perceptual group with the saccade target Journal Article In: Cortex, vol. 140, pp. 179–198, 2021. @article{Shurygina2021,The pre-saccadic attention shift—a rapid increase in visual sensitivity at the target—is an inevitable precursor of saccadic eye movements. Saccade targets are often parts of the objects that are of interest to the active observer. Although the link between saccades and covert attention shifts is well established, it remains unclear if pre-saccadic attention selects the location of the eye movement target or rather the entire object that occupies this location. Indeed, several neurophysiological studies suggest that attentional modulations of neural activity in visual cortex spreads across parts of objects (e.g., elements grouped by Gestalt principles) that contain the target location of a saccade. To understand the nature of pre-saccadic attentional selection, we examined how visual sensitivity, measured in a challenging orientation discrimination task, changes during saccade preparation at locations that are perceptually grouped with the saccade target. In Experiment 1, using grouping by color in a delayed-saccade task, we found no consistent spread of attention to locations that formed a perceptual group with the saccade target. However, performance depended on the side of the stimulus arrangement relative to the saccade target location, an effect we discuss with respect to attentional momentum. In Experiment 2, employing stronger perceptual grouping cues (color and motion) and an immediate-saccade task, we obtained a reliable grouping effect: Attention spread to locations that were perceptually grouped with the saccade target while saccade preparation was underway. We also replicated the side effect observed in Experiment 1. These results provide evidence that the pre-saccadic attention spreads beyond the target location along the saccade direction, and selects scene elements that—based on Gestalt criteria—are likely to belong to the same object as the saccade target. |
Diksha Shukla; Matthew Heath A single bout of exercise provides a persistent benefit to cognitive flexibility Journal Article In: Research Quarterly for Exercise and Sport, pp. 1–12, 2021. @article{Shukla2021,Purpose: A single bout of exercise enhances activity within the cortical networks that support executive function. It is, however, unclear whether exercise improves each core component of executive function and for how long a putative benefit might persist. Method: In Experiment 1, participants completed 20-min of aerobic exercise (via cycle ergometer) and cognitive flexibility—a core component of executive function—was examined pre-exercise, and at immediate, 30- and 60-min post-exercise assessments. Experiment 2 entailed a non-exercise control (i.e., participants sat on the ergometer without exercising) involving the same timeline of cognitive flexibility assessment. Cognitive flexibility was measured via stimulus-driven (SD) and minimally delayed (MD) saccades arranged in an AABB paradigm. SD and MD saccades require a response at target onset and after target offset, respectively, with the latter requiring executive control. Work has shown that reaction times for a SD saccade preceded by a MD saccade are longer than when a SD saccade is preceded by its same task-type, whereas the converse switch does not influence performance (i.e., the unidirectional switch-cost). Results: Experiment 1 showed a unidirectional switch-cost at each assessment; however, the switch-cost magnitude was decreased at immediate and 30-min assessments compared to the pre- and 60-min assessments. In contrast, Experiment 2 did not elicit a change in switch-cost magnitude across the different assessments. Discussion/Conclusion: Thus, a single-bout of exercise benefitted the cognitive flexibility component of executive function in the immediate and 30-min post-exercise assessments. |
Ran Shi; Gongyang Li; Weijie Wei; Xiaofei Zhou; Zhi Liu Personalized image observation behavior learning in fixation based personalized salient object segmentation Journal Article In: Neurocomputing, vol. 445, pp. 255–266, 2021. @article{Shi2021,Fixation as representation of one viewer's attention are very intuitive to reflect the viewer's observation procedure. The viewer's observation behavior can be further revealed by analyzing fixations features. In this paper, we propose a fixation based personalized salient object segmentation method involving personal observation behavior learning. Concretely, we design three neural networks and deploy a meta-learning method. The first network is a base segmentation network that can be converted into a meta-segmentation network by meta-learning. The meta- segmentation network can learn one viewer's observation behavior from only one sample and then generates the viewer's segmentation network to segment the other samples. Moreover, a fusion network plays an important role in alleviating an unsuitable transmission problem and generating a final segmentation result. The experimental results demonstrate the reasonability of our observation behavior learning and the effectiveness of the three proposed neural networks. |
Heather Sheridan; Abigail L. Kleinsmith Music reading expertise affects visual change detection: Evidence from a music-related flicker paradigm Journal Article In: Quarterly Journal of Experimental Psychology, pp. 1–10, 2021. @article{Sheridan2021,To study the mechanisms and boundary conditions of expertise effects on change detection, we introduced a novel music-related variant of the flicker paradigm. Specifically, we monitored the eye movements of expert musicians (with 10 years of music experience) and non-musicians (who could not read music) while they located changes across two rapidly alternating versions of a music score, with a blank screen presented between each screen change. Relative to the non-musicians, experts were faster at change detection, with shorter fixations and larger saccade amplitudes. Expertise effects on accuracy and saccade amplitude were magnified for visually complex relative to simple music scores. Consistent with the assumptions of chunking and template theories of expertise, our results suggest that expert musicians can use chunking (i.e., perceptual grouping) mechanisms to facilitate perceptual encoding during change detection. |
Timothy G. Shepard; Zhong Lin Lu; Deyue Yu Test-retest reliability of the qReading method in normally sighted young adults Journal Article In: Optometry and Vision Science, vol. 98, no. 8, pp. 936–946, 2021. @article{Shepard2021,SIGNIFICANCE We recently developed a novel Bayesian adaptive method, qReading, to measure reading function. The qReading method has both the efficiency and excellent test-retest reliability in normally sighted young adults to make it an excellent candidate for future studies of its value in diagnosis and longitudinal evaluation of treatment and/or rehabilitation outcomes. PURPOSE A novel Bayesian adaptive method, qReading, was recently developed to measure reading function. Here we performed a systematic assessment of the test-retest reliability of the qReading method. METHODS The variability of five repeated measurements of the reading curve was examined in two settings: within session and between sessions. For the within-session design, we considered two subpopulations: naive observers and experienced observers. All observers were normally sighted young adults. For each set of data, in addition to examining the intrinsic precision of the qReading method (the half width of the credible interval of the posterior distribution of the estimated performance), we computed four metrics to assess repeatability: standard deviation, Bland-Altman coefficient of repeatability, correlation coefficient, and Fractional Rank Precision. RESULTS Extrinsic factors such as observer, time interval between repeated measures, and observer experience all contribute to the variation across measurements. Nevertheless, the four metrics consistently show that the variability across five repeated measurements is small for each set of data. This is true even without taking learning effects into account (standard deviations, ≤0.092 log10 units; Bland-Altman coefficient of repeatability, ≤0.15 (log10)2 units; correlation coefficient, ≥0.91; and Fractional Rank Precision, ≥0.81). CONCLUSIONS The qReading method has excellent test-retest reliability in normally sighted young adults. |
Zhuowen Shen; Yun Ding; Jason Satel; Zhiguo Wang A concurrent working memory load does not necessarily impair spatial attention: Evidence from inhibition of return Journal Article In: Visual Cognition, vol. 29, pp. 38–50, 2021. @article{Shen2021b,Inhibition of return (IOR), an inhibitory aftereffect of attentional orienting, usually reveals itself in slower responses to targets appearing at previously attended locations in spatial cueing tasks. Many of the neural substrates underlying visual working memory are also closely linked to attention. The present study examined whether the contents held in working memory interfere with IOR by requiring participants to keep a set of spatial locations in working memory while they performed a spatial cueing task. Results revealed that the presence of a concurrent working memory load modulated IOR when the cueing task involved saccadic responses (Experiment 4), but not when more resource-demanding responses were required in the cueing task (Experiments 1–3). The present study also revealed that working memory load had little effect on the time course of IOR. We suggest that the attentional control setting (ACS) selected to accommodate the cognitive tasks at hand determines whether working memory will interfere with IOR and spatial attention in general. |
Wei Shen; Jukka Hyönä; Youxi Wang; Meiling Hou; Jing Zhao The role of tonal information during spoken-word recognition in Chinese: Evidence from a printed-word eye-tracking study Journal Article In: Memory and Cognition, vol. 49, no. 1, pp. 181–192, 2021. @article{Shen2021a,Two experiments were conducted to investigate the extent to which the lexical tone can affect spoken-word recognition in Chinese using a printed-word paradigm. Participants were presented with a visual display of four words—namely, a target word (e.g., 象限, xiang4xian4, “quadrant”), a tone-consistent phonological competitor (e.g., 相册, xiang4ce4, “photo album”), or a tone-inconsistent phonological competitor (e.g., 香菜, xiang1cai4, “coriander”), and two unrelated distractors. Simultaneously, they were asked to listen to a spoken target word presented in isolation (Experiment 1) or embedded in neutral/predictive sentence contexts (Experiment 2), and then click on the target word on the screen. Results showed significant phonological competitor effects (i.e., the fixation proportion on the phonological competitor was higher than that on the distractors) under both tone conditions. Specifically, a larger phonological competitor effect was observed in the tone-consistent condition than in the tone-inconsistent condition when the spoken word was presented in isolation and the neutral sentence contexts. This finding suggests a partial role of lexical tone in constraining spoken-word recognition. However, when embedded in a predictive sentence context, the phonological competitor effect was only observed in the tone-consistent condition and absent in the tone-inconsistent condition. This result indicates that the predictive sentence context can strengthen the role of lexical tone. |
Jing Shen Pupillary response to dynamic pitch alteration during speech perception in noise Journal Article In: JASA Express Letters, vol. 1, no. 11, pp. 115202, 2021. @article{Shen2021,Dynamic pitch, also known as intonation, conveys both semantic and pragmatic meaning in speech communica- tion. While alteration of this cue is detrimental to speech intelligibility in noise, the mechanism involved is poorly understood. Using the psychophysiological measure of task-evoked pupillary response, this study examined the perceptual effect of altered dynamic pitch cues on speech perception in noise. The data showed that pupil dilation increased with dynamic pitch strength in a sentence recognition in noise task. Taken together with recognition accuracy data, the results suggest the involvement of perceptual arousal in speech perception with dynamic pitch alteration |
Adi Shechter; Amit Yashar Mixture model investigation of the inner–outer asymmetry in visual crowding reveals a heavier weight towards the visual periphery Journal Article In: Scientific Reports, vol. 11, pp. 2116, 2021. @article{Shechter2021,Crowding, the failure to identify a peripheral item in clutter, is an essential bottleneck in visual information processing. A hallmark characteristic of crowding is the inner–outer asymmetry in which the outer flanker (more eccentric) produces stronger interference than the inner one (closer to the fovea). We tested the contribution of the inner-outer asymmetry to the pattern of crowding errors in a typical radial crowding display in which both flankers are presented simultaneously on the horizontal meridian. In two experiments, observers were asked to estimate the orientation of a Gabor target. Instead of the target, observers reported the outer flanker much more frequently than the inner one. When the target was the outer Gabor, crowding was reduced. Furthermore, when there were four flankers, two on each side of the target, observers misreported the outer flanker adjacent to the target, not the outermost flanker. Model comparisons suggested that orientation crowding reflects sampling over a weighted sum of the represented features, in which the outer flanker is more heavily weighted compared to the inner one. Our findings reveal a counterintuitive phenomenon: in a radial arrangement of orientation crowding, within a region of selection, the outer item dominates appearance more than the inner one. |
Adi Shechter; David L. Share Keeping an eye on effort: A pupillometric investigation of effort and effortlessness in visual word recognition Journal Article In: Psychological Science, vol. 32, no. 1, pp. 80–95, 2021. @article{Shechter2021a,Rapid and seemingly effortless word recognition is a virtually unquestioned characteristic of skilled reading, yet the definition and operationalization of the concept of cognitive effort have proven elusive. We investigated the cognitive effort involved in oral and silent word reading using pupillometry among adults (Experiment 1 |
Omer Sharon; Firas Fahoum; Yuval Nir Transcutaneous vagus nerve stimulation in humans induces pupil dilation and attenuates alpha oscillations Journal Article In: Journal of Neuroscience, vol. 41, no. 2, pp. 320–330, 2021. @article{Sharon2021,Vagus nerve stimulation (VNS) is widely used to treat drug-resistant epilepsy and depression. While the precise mechanisms mediating its long-term therapeutic effects are not fully resolved, they likely involve locus coeruleus (LC) stimulation via the nucleus of the solitary tract, which receives afferent vagal inputs. In rats, VNS elevates LC firing and forebrain noradrenaline levels, whereas LC lesions suppress VNS therapeutic efficacy. Noninvasive transcutaneous VNS (tVNS) uses electrical stimulation that targets the auricular branch of the vagus nerve at the cymba conchae of the ear. However, the extent to which tVNS mimics VNS remains unclear. Here, we investigated the short-term effects of tVNS in healthy human male volunteers (n = 24), using high-density EEG and pupillometry during visual fixation at rest. We compared short (3.4 s) trials of tVNS to sham electrical stimulation at the earlobe (far from the vagus nerve branch) to control for somatosensory stimulation. Although tVNS and sham stimulation did not differ in subjective intensity ratings, tVNS led to robust pupil dilation (peaking 4-5 s after trial onset) that was significantly higher than following sham stimulation. We further quantified, using parallel factor analysis, how tVNS modulates idle occipital alpha (8-13Hz) activity identified in each participant. We found greater attenuation of alpha oscillations by tVNS than by sham stimulation. This demonstrates that tVNS reliably induces pupillary and EEG markers of arousal beyond the effects of somatosensory stimulation, thus supporting the hypothesis that tVNS elevates noradrenaline and other arousal-promoting neuromodulatory signaling, and mimics invasive VNS. |
Anca Sfärlea; Linda Lukas; Gerd Schulte-Körne; Belinda Platt In: Journal of Eating Disorders, vol. 9, no. 1, pp. 139, 2021. @article{Sfaerlea2021a,Background: Anorexia nervosa (AN) is characterized by dysfunctional cognitions including cognitive biases at various levels of information processing. However, less is known about the specificity of these biases, i.e., if they occur for eating-disorder-related information alone or also for non-eating-disorder-related emotional information in AN patients (content-specificity) and if they are unique to individuals with AN or are also shown by individuals with other mental disorders (disorder-specificity). Methods: The present study systematically assesses cognitive biases in 12–18-year-old female adolescents with AN on three levels of information processing (attention, interpretation, and memory) and with regard to two types of information content (eating-disorder-related, i.e., stimuli related to body weight and shape, and non-eating-disorder-related). To address not only content- but also disorder-specificity, adolescents with AN will be compared not only to a healthy control group but also to a clinical control group (adolescents with major depression or particular anxiety disorders). Cognitive biases are assessed within a single experimental paradigm based on the Scrambled Sentences Task. During the task eye movements are recorded in order to assess attention biases while interpretation biases are derived from the behavioural outcome. An incidental free recall test afterwards assesses memory biases. We expect adolescents with AN to show more pronounced negative cognitive biases on all three levels of information processing and for both types of content compared to healthy adolescents. In addition, we expect the specificity of biases to translate into differential results for the two types of content: AN patients are expected to show stronger biases for disorder-related stimuli but similar or less pronounced biases for non-disorder-related stimuli compared to the clinical control group. Discussion: This is the first study to comprehensively assess cognitive biases in adolescents with AN. It will have essential implications not only for cognitive-behavioural models of AN but also for subsequent studies aiming to modify cognitive biases in this population, thereby addressing important maintaining factors already at an early stage of the disorder. |
A. Sfärlea; K. Takano; C. Buhl; J. Loechner; E. Greimel; E. Salemink; G. Schulte-Körne; B. Platt In: Research on Child and Adolescent Psychopathology, vol. 49, no. 10, pp. 1345–1358, 2021. @article{Sfaerlea2021,Contemporary cognitive models of depression propose that cognitive biases for negative information at the level of attention (attention biases; AB) and interpretation (interpretation biases; IB) increase depression risk by promoting maladaptive emotion regulation (ER). So far, empirical support testing interactions between these variables is restricted to non-clinical and clinical adult samples. The aim of the current study was to extend these findings to a sample of children and adolescents. This cross-sectional study included 109 children aged 9–14 years who completed behavioural measures of AB (passive-viewing task) and IB (scrambled sentences task) as well as self-report measures of ER and depressive symptoms. In order to maximize the variance in these outcomes we included participants with a clinical diagnosis of depression as well as non-depressed youth with an elevated familial risk of depression and non-depressed youth with a low familial risk of depression. Path model analysis indicated that all variables (AB, IB, adaptive and maladaptive ER) had a direct effect on depressive symptoms. IB and AB also had significant indirect effects on depressive symptoms via maladaptive and adaptive ER. These findings provide initial support for the role of ER as a mediator between cognitive biases and depressive symptoms and provide the foundations for future experimental and longitudinal studies. In contrast to studies in adult samples, both adaptive as well as maladaptive ER mediated the effect of cognitive biases on depressive symptoms. This suggests potentially developmental differences in the role of ER across the lifespan. |
Janahan Selvanayagam; Kevin D. Johnston; Raymond K. Wong; David Schaeffer; Stefan Everling Ketamine disrupts gaze patterns during face viewing in the common marmoset Journal Article In: Journal of Neurophysiology, vol. 126, no. 1, pp. 330–339, 2021. @article{Selvanayagam2021,Faces are stimuli of critical importance for primates. The common marmoset (Callithrix jacchus) is a promising model for investigations of face processing, as this species possesses oculomotor and face-processing networks resembling those of macaques and humans. Face processing is often disrupted in neuropsychiatric conditions such as schizophrenia (SZ), and thus, it is important to recapitulate underlying circuitry dysfunction preclinically. The N-methyl-D-aspartate (NMDA) noncompetitive antagonist ketamine has been used extensively to model the cognitive symptoms of SZ. Here, we investigated the effects of a subanesthetic dose of ketamine on oculomotor behavior in marmosets during face viewing. Four marmosets received systemic ketamine or saline injections while viewing phase-scrambled or intact videos of conspecifics' faces. To evaluate effects of ketamine on scan paths during face viewing, we identified regions of interest in each face video and classified locations of saccade onsets and landing positions within these areas. A preference for the snout over eye regions was observed following ketamine administration. In addition, regions in which saccades landed could be significantly predicted by saccade onset region in the saline but not the ketamine condition. Effects on saccade control were limited to an increase in saccade peak velocity in all conditions and a reduction in saccade amplitudes during viewing of scrambled videos. Thus, ketamine induced a significant disruption of scan paths during viewing of conspecific faces but limited effects on saccade motor control. These findings support the use of ketamine in marmosets for investigating changes in neural circuits underlying social cognition in neuropsychiatric disorders. NEW & NOTEWORTHY Face processing, an important social cognitive ability, is impaired in neuropsychiatric conditions such as schizophrenia. The highly social common marmoset model presents an opportunity to investigate these impairments. We administered subanesthetic doses of ketamine to marmosets to model the cognitive symptoms of schizophrenia. We observed a disruption of scan paths during viewing of conspecifics' faces. These findings support the use of ketamine in marmosets as a model for investigating social cognition in neuropsychiatric disorders. |
Elena Selezneva; Michael Brosch; Sanchit Rathi; T. Vighneshvel; Nicole Wetzel Comparison of pupil dilation responses to unexpected sounds in monkeys and humans Journal Article In: Frontiers in Psychology, vol. 12, pp. 754604, 2021. @article{Selezneva2021,Pupil dilation in response to unexpected stimuli has been well documented in human as well as in non-human primates; however, this phenomenon has not been systematically compared between the species. This analogy is also crucial for the role of non-human primates as an animal model to investigate neural mechanisms underlying the processing of unexpected stimuli and their evoked pupil dilation response. To assess this qualitatively, we used an auditory oddball paradigm in which we presented subjects a sequence of the same sounds followed by occasional deviants while we measured their evoked pupil dilation response (PDR). We used deviants (a frequency deviant, a pink noise burst, a monkey vocalization and a whistle sound) which differed in the spectral composition and in their ability to induce arousal from the standard. Most deviants elicited a significant pupil dilation in both species with decreased peak latency and increased peak amplitude in monkeys compared to humans. A temporal Principal Component Analysis (PCA) revealed two components underlying the PDRs in both species. The early component is likely associated to the parasympathetic nervous system and the late component to the sympathetic nervous system, respectively. Taken together, the present study demonstrates a qualitative similarity between PDRs to unexpected auditory stimuli in macaque and human subjects suggesting that macaques can be a suitable model for investigating the neuronal bases of pupil dilation. However, the quantitative differences in PDRs between species need to be investigated in further comparative studies. |
Vladislava Segen; Marios N. Avraamides; Timothy J. Slattery; Jan M. Wiener Age-related changes in visual encoding strategy preferences during a spatial memory task Journal Article In: Psychological Research, pp. 1–17, 2021. @article{Segen2021,Ageing is associated with declines in spatial memory, however, the source of these deficits remains unclear. Here we used eye-tracking to investigate age-related differences in spatial encoding strategies and the cognitive processes underlying the age-related deficits in spatial memory tasks. To do so we asked young and older participants to encode the locations of objects in a virtual room shown as a picture on a computer screen. The availability and utility of room-based landmarks were manipulated by removing landmarks, presenting identical landmarks rendering them uninformative, or by presenting unique landmarks that could be used to encode object locations. In the test phase, participants viewed a second picture of the same room taken from the same (0°) or a different perspective (30°) and judged whether the objects occupied the same or different locations in the room. We found that the introduction of a perspective shift and swapping of objects between encoding and testing impaired performance in both age groups. Furthermore, our results revealed that although older adults performed the task as well as younger participants, they relied on different visual encoding strategies to solve the task. Specifically, gaze analysis revealed that older adults showed a greater preference towards a more categorical encoding strategy in which they formed relationships between objects and landmarks. |
Vladislava Segen; Marios N. Avraamides; Timothy J. Slattery; Jan M. Wiener Age-related differences in visual encoding and response strategies contribute to spatial memory deficits Journal Article In: Memory and Cognition, vol. 49, no. 2, pp. 249–264, 2021. @article{Segen2021a,Successful navigation requires memorising and recognising the locations of objects across different perspectives. Although these abilities rely on hippocampal functioning, which is susceptible to degeneration in older adults, little is known about the effects of ageing on encoding and response strategies that are used to recognise spatial configurations. To investigate this, we asked young and older participants to encode the locations of objects in a virtual room shown as a picture on a computer screen. Participants were then shown a second picture of the same room taken from the same (0°) or a different perspective (45° or 135°) and had to judge whether the objects occupied the same or different locations. Overall, older adults had greater difficulty with the task than younger adults although the introduction of a perspective shift between encoding and testing impaired performance in both age groups. Diffusion modelling revealed that older adults adopted a more conservative response strategy, while the analysis of gaze patterns showed an age-related shift in visual-encoding strategies with older adults attending to more information when memorising the positions of objects in space. Overall, results suggest that ageing is associated with declines in spatial processing abilities, with older individuals shifting towards a more conservative decision style and relying more on encoding target object positions using room-based cues compared to younger adults, who focus more on encoding the spatial relationships among object clusters. |
Shira C. Segal; Alexandra R. Marquis; Margaret C. Moulson Are our samples representative? Understanding whether temperament influences infant dropout rates at 3 and 7 months Journal Article In: Infant Behavior and Development, vol. 65, pp. 101630, 2021. @article{Segal2021,In this study, we examined whether infant temperament predicted study dropout at 3.5 and 7 months and whether dropout was stable across time. Dropout was measured across four experimental tasks (free-play, ERP, still-face, and eye tracking). Temperament was not related to dropout at either timepoint. Dropout was not stable across time, nor was it stable across tasks. These findings suggest that individual differences in temperament are not systematically related to study completion across experimental tasks with varied requirements. These findings additionally suggest that dropout is not consistent across tasks, which may support the utility of multi-study data collection methods. |
Ehsan Sedaghat-Nejad; Reza Shadmehr The cost of correcting for error during sensorimotor adaptation Journal Article In: Proceedings of the National Academy of Sciences, vol. 118, no. 40, pp. e2101717118, 2021. @article{SedaghatNejad2021,Learning from error is often a slow process. In machine learning, the learning rate depends on a loss function that specifies a cost for error. Here, we hypothesized that during motor learning, error carries an implicit cost for the brain because the act of correcting for error consumes time and energy. Thus, if this implicit cost could be increased, it may robustly alter how the brain learns from error. To vary the implicit cost of error, we designed a task that combined saccade adaptation with motion discrimination: movement errors resulted in corrective saccades, but those corrections took time away from acquiring information in the discrimination task. We then modulated error cost using coherence of the discrimination task and found that when error cost was large, pupil diameter increased and the brain learned more from error. However, when error cost was small, the pupil constricted and the brain learned less from the same error. Thus, during sensorimotor adaptation, the act of correcting for error carries an implicit cost for the brain. Modulating this cost affects how much the brain learns from error. |
Ana I. Schwartz; Karla S. Tarin The impact of a discourse context on bilingual cross-language lexical activation Journal Article In: Bilingualism: Language and Cognition, vol. 24, no. 5, pp. 879–890, 2021. @article{Schwartz2021,Four hypotheses regarding the impact of discourse context on cross-language lexical activation were tested. Highly-proficient, Spanish-English bilinguals read all-English paragraphs containing non-identical and identical cognates or noncognate controls while their eye-movements were tracked. There were four paragraph conditions based on a full crossing of semantic bias from the topic sentence and sentence containing the critical word. In analyses in which cognate status was treated categorically there was an interaction between global bias and cognates status such that the observed inhibitory effects of cognate status were attenuated in global-neutral contexts. Follow-up analyses on the non-identical cognates in which orthographic overlap was treated continuously revealed a U-shaped function between orthographic overlap and processing time, which was more pronounced in global-neutral contexts. The overall pattern of findings is consistent with a combined operation of resonant-based and feature-restriction mechanisms of context effects. |
Sarah Schuster; Nicole Alexandra; Florian Hutzler; Fabio Richlan; Martin Kronbichler; Stefan Hawelka Cloze enough? Hemodynamic effects of predictive processing during natural reading Journal Article In: NeuroImage, vol. 228, pp. 117687, 2021. @article{Schuster2021,Evidence accrues that readers form multiple hypotheses about upcoming words. The present study investigated the hemodynamic effects of predictive processing during natural reading by means of combining fMRI and eye movement recordings. In particular, we investigated the neural and behavioral correlates of precision-weighted prediction errors, which are thought to be indicative of subsequent belief updating. Participants silently read sentences in which we manipulated the cloze probability and the semantic congruency of the final word that served as an index for precision and prediction error respectively. With respect to the neural correlates, our findings indicate an enhanced activation within the left inferior frontal and middle temporal gyrus suggesting an effect of precision on prediction update in higher (lexico-)semantic levels. Despite being evident at the neural level, we did not observe any evidence that this mechanism resulted in disproportionate reading times on participants' eye movements. The results speak against discrete predictions, but favor the notion that multiple words are activated in parallel during reading. 1. |
Rebekka Schröder; Martin Reuter; Kaja Faßbender; Thomas Plieger; Jessie Poulsen; Simon S. Y. Lui; Raymond C. K. Chan; Ulrich Ettinger The role of the SLC6A3 3' UTR VNTR in nicotine effects on cognitive, affective, and motor function Journal Article In: Psychopharmacology, pp. 1–19, 2021. @article{Schroeder2021a,Rationale: Nicotine has been widely studied for its pro-dopaminergic effects. However, at the behavioural level, past investigations have yielded heterogeneous results concerning effects on cognitive, affective, and motor outcomes, possibly linked to individual differences at the level of genetics. A candidate polymorphism is the 40-base-pair variable number of tandem repeats polymorphism (rs28363170) in the SLC6A3 gene coding for the dopamine transporter (DAT). The polymorphism has been associated with striatal DAT availability (9R-carriers > 10R-homozygotes), and 9R-carriers have been shown to react more strongly to dopamine agonistic pharmacological challenges than 10R-homozygotes. Objectives: In this preregistered study, we hypothesized that 9R-carriers would be more responsive to nicotine due to genotype-related differences in DAT availability and resulting dopamine activity. Methods: N=194 non-smokers were grouped according to their genotype (9R-carriers, 10R-homozygotes) and received either 2-mg nicotine or placebo gum in a between-subject design. Spontaneous blink rate (SBR) was obtained as an indirect measure of striatal dopamine activity and smooth pursuit, stop signal, simple choice and affective processing tasks were carried out in randomized order. Results: Reaction times were decreased under nicotine compared to placebo in the simple choice and stop signal tasks, but nicotine and genotype had no effects on any of the other task outcomes. Conditional process analyses testing the mediating effect of SBR on performance and how this is affected by genotype yielded no significant results. Conclusions: Overall, we could not confirm our main hypothesis. Individual differences in nicotine response could not be explained by rs28363170 genotype. |
Rebekka Schröder; Philine Margarete Baumert; Ulrich Ettinger Replicability and reliability of the background and target velocity effects in smooth pursuit eye movements Journal Article In: Acta psychologica, vol. 219, pp. 103364, 2021. @article{Schroeder2021,When we follow a slowly moving target with our eyes, we perform smooth pursuit eye movements (SPEM). Previous investigations point to significantly and robustly reduced SPEM performance in the presence of a stationary background and at higher compared to lower target velocities. However, the reliability of these background and target velocity effects has not yet been investigated systematically. To address this issue, 45 healthy participants (17 m, 28 f) took part in two experimental sessions 7 days apart. In each session, participants were instructed to follow a horizontal SPEM target moving sinusoidally between ±7.89° at three different target velocities, corresponding to frequencies of 0.2, 0.4 and 0.6 Hz. Each target velocity was presented once with and once without a stationary background, resulting in six blocks. The blocks were presented twice per session in order to additionally explore potential task length effects. To assess SPEM performance, velocity gain was calculated as the ratio of eye to target velocity. In line with previous research, detrimental background and target velocity effects were replicated robustly in both sessions with large effect sizes. Good to excellent test-retest reliabilities were obtained at higher target velocities and in the presence of a stationary background, whereas lower reliabilities occurred with slower targets and in the absence of background stimuli. Target velocity and background effects resulted in largely good to excellent reliabilities. These findings not only replicated robust experimental effects of background and target velocity at group level, but also revealed that these effects can be translated into reliable individual difference measures. |
Jörg Schorer; Nico Heibült; Stuart G. Wilson; Florian Loffing Sleep facilitates anticipation training of a handball goalkeeping task in novices Journal Article In: Psychology of Sport and Exercise, vol. 53, pp. 101841, 2021. @article{Schorer2021,Sleep facilitates perceptual, cognitive and motor learning; however, the role of sleep for perceptual learning in sports is yet unclear. Here, we tested the impact of sleep on novices' visual anticipation training using a handball goalkeeping task. To this end, 30 novices were divided randomly in two groups and asked to predict the directional outcome of handball penalties presented as videos. One group did the pre-test and a single session of training in the morning, post-test in the evening on the same day, and the retention test in the next morning again. Conversely, the second group started and finished in the evening. Analyses of prediction accuracy revealed that the group starting in the evening improved largest between pre- and post-test (sleep in-between), while the greatest improvement for the group starting in the morning was found between post- and retention-test (sleep in-between). Overall, our results provide first insight into the potential relevance of sleep for effective anticipation training in sports. |
Chris Scholes; Paul V. McGraw; Neil W. Roach Learning to silence saccadic suppression Journal Article In: Proceedings of the National Academy of Sciences, vol. 118, no. 6, pp. e2012937118, 2021. @article{Scholes2021,Perceptual stability is facilitated by a decrease in visual sensitivity during rapid eye movements, called saccadic suppression. While a large body of evidence demonstrates that saccadic programming is plastic, little is known about whether the perceptual consequences of saccades can be modified. Here, we demonstrate that saccadic suppression is attenuated during learning on a standard visual detection-in-noise task, to the point that it is effectively silenced. Across a period of 7 days, 44 participants were trained to detect brief, low-contrast stimuli embedded within dynamic noise, while eye position was tracked. Although instructed to fixate, participants regularly made small fixational saccades. Data were accumulated over a large number of trials, allowing us to assess changes in performance as a function of the temporal proximity of stimuli and saccades. This analysis revealed that improvements in sensitivity over the training period were accompanied by a systematic change in the impact of saccades on performance-robust saccadic suppression on day 1 declined gradually over subsequent days until its magnitude became indistinguishable from zero. This silencing of suppression was not explained by learning-related changes in saccade characteristics and generalized to an untrained retinal location and stimulus orientation. Suppression was restored when learned stimulus timing was perturbed, consistent with the operation of a mechanism that temporarily reduces or eliminates saccadic suppression, but only when it is behaviorally advantageous to do so. Our results indicate that learning can circumvent saccadic suppression to improve performance, without compromising its functional benefits in other viewing contexts. |
Sebastian Schneegans; William J. Harrison; Paul M. Bays Location-independent feature binding in visual working memory for sequentially presented objects Journal Article In: Attention, Perception, and Psychophysics, vol. 83, no. 6, pp. 2377–2393, 2021. @article{Schneegans2021,Spatial location is believed to have a privileged role in binding features held in visual working memory. Supporting this view, Pertzov and Husain (Attention, Perception, & Psychophysics, 76(7), 1914–1924, 2014) reported that recall of bindings between visual features was selectively impaired when items were presented sequentially at the same location compared to sequentially at different locations. We replicated their experiment, but additionally tested whether the observed impairment could be explained by perceptual interference during encoding. Participants viewed four oriented bars in highly discriminable colors presented sequentially either at the same or different locations, and after a brief delay were cued with one color to reproduce the associated orientation. When we used the same timing as the original study, we reproduced its key finding of impaired binding memory in the same-location condition. Critically, however, this effect was significantly modulated by the duration of the inter-stimulus interval, and disappeared if memoranda were presented with longer delays between them. In a second experiment, we tested whether the effect generalized to other visual features, namely reporting of colors cued by stimulus shape. While we found performance deficits in the same-location condition, these did not selectively affect binding memory. We argue that the observed effects are best explained by encoding interference, and that memory for feature binding is not necessarily impaired when memoranda share the same location. |
Ulf H. Schnabel; Tobias Van der Bijl; Pieter R. Roelfsema; Jeannette A. M. Lorteije A direct comparison of spatial attention and stimulus–response compatibility between mice and humans Journal Article In: Journal of Cognitive Neuroscience, vol. 33, no. 5, pp. 771–783, 2021. @article{Schnabel2021,Mice are becoming an increasingly popular model for investigating the neural substrates of visual processing and higher cognitive functions. To validate the translation of mouse visual attention and sensorimotor processing to humans, we compared their performance in the same visual task. Mice and human participants judged the orientation of a grating presented on either the right or left side in the visual field. To induce shifts of spatial attention, we varied the stimulus probability on each side. As expected, human participants showed faster RTs and a higher accuracy for the side with a higher probability, a well-established effect of visual attention. The attentional effect was only present in mice when their response was slow. Although the task demanded a judgment of grating orientation, the accuracy of the mice was strongly affected by whether the side of the stimulus corresponded to the side of the behavioral response. This stimulus–response compatibility (Simon) effect was much weaker in humans and only significant for their fastest responses. Both species exhibited a speed– accuracy trade-off in their responses, because slower responses were more accurate than faster responses. We found that mice typically respond very fast, which contributes to the stronger stimulus–response compatibility and weaker attentional effects, which were only apparent in the trials with slowest responses. Humans responded slower and had stronger attentional effects, combined with a weak influence of stimulus–response compatibility, which was only apparent in trials with fast responses. We conclude that spatial attention and stimulus–response compatibility influence the responses of humans and mice but that strategy differences between species determine the dominance of these effects. |
Lea-Maria Schmitt; Julia Erb; Sarah Tune; Anna U. Rysop; Gesa Hartwigsen; Jonas Obleser Predicting speech from a cortical hierarchy of event-based time scales Journal Article In: Science Advances, vol. 7, no. 49, pp. eabi6070, 2021. @article{Schmitt2021a,How do predictions in the brain incorporate the temporal unfolding of context in our natural environment? We here provide evidence for a neural coding scheme that sparsely updates contextual representations at the boundary of events. This yields a hierarchical, multilayered organization of predictive language comprehension. Training artificial neural networks to predict the next word in a story at five stacked time scales and then using model-based functional magnetic resonance imaging, we observe an event-based “surprisal hierarchy” evolving along a temporoparietal pathway. Along this hierarchy, surprisal at any given time scale gated bottom-up and top-down connectivity to neighboring time scales. In contrast, surprisal derived from continuously updated context influenced temporoparietal activity only at short time scales. Representing context in the form of increasingly coarse events constitutes a network architecture for making predictions that is both computationally efficient and contextually diverse. |
Constanze Schmitt; Jakob C. B. Schwenk; Adrian Schütz; Jan Churan; André Kaminiarz; Frank Bremmer Preattentive processing of visually guided self-motion in humans and monkeys Journal Article In: Progress in Neurobiology, vol. 205, pp. 102117, 2021. @article{Schmitt2021,The visually-based control of self-motion is a challenging task, requiring – if needed – immediate adjustments to keep on track. Accordingly, it would appear advantageous if the processing of self-motion direction (heading) was predictive, thereby accelerating the encoding of unexpected changes, and un-impaired by attentional load. We tested this hypothesis by recording EEG in humans and macaque monkeys with similar experimental protocols. Subjects viewed a random dot pattern simulating self-motion across a ground plane in an oddball EEG paradigm. Standard and deviant trials differed only in their simulated heading direction (forward-left vs. forward-right). Event-related potentials (ERPs) were compared in order to test for the occurrence of a visual mismatch negativity (vMMN), a component that reflects preattentive and likely also predictive processing of sensory stimuli. Analysis of the ERPs revealed signatures of a prediction mismatch for deviant stimuli in both humans and monkeys. In humans, a MMN was observed starting 110 ms after self-motion onset. In monkeys, peak response amplitudes following deviant stimuli were enhanced compared to the standard already 100 ms after self-motion onset. We consider our results strong evidence for a preattentive processing of visual self-motion information in humans and monkeys, allowing for ultrafast adjustments of their heading direction. |
Daniel Schmidtke; Julie A. Van Dyke; Victor Kuperman CompLex: an eye-movement database of compound word reading in English Journal Article In: Behavior Research Methods, vol. 53, no. 1, pp. 59–77, 2021. @article{Schmidtke2021a,The CompLex database presents a large-scale collection of eye-movement studies on English compound-word processing. A combined total of 440 participants completed eye-tracking experiments in which they silently read unspaced English compound words (e.g., goalpost) embedded in sentence contexts (e.g., Dylan hit the goalpost when he was aiming for the net.). Three studies were conducted using participants representing the non-college-bound population (300 participants), and four studies included participants recruited from the student population (140 participants). The database comprises trial-level eye-movement data (47,763 trials), participant data (including a measure of reading experience estimated via the Author Recognition Test), and lexical characteristics for the set of 931 English compound words used as critical stimuli in the studies. One contribution of the present paper is a set of regression analyses conducted on the full database and individual experiments. We report that the most reliable and consistent main effects were those elicited by compound word length, left constituent frequency, right constituent frequency, compound frequency and semantic transparency. Separately, we also found that the effect of left frequency and compound word length is weaker among more frequent compounds. Another contribution is a power analysis, in which we determined the sample sizes required to reliably detect effect sizes that are comparable to those observed in our regression models. These sample size estimates serve as a recommendation for researchers wishing to either collect eye-movement data for compound word reading, or use the current database as a resource for the study of English compound word processing. |
Daniel Schmidtke; Anna L. Moro Determinants of word-reading development in English learner university students: A longitudinal eye movement study Journal Article In: Reading Research Quarterly, vol. 56, no. 4, pp. 819–854, 2021. @article{Schmidtke2021,We investigated the word-reading development of adult second-language learners of English. A sample of 70 (Mandarin or Cantonese) Chinese-speaking students enrolled in a university-level English bridging program at a Canadian university silently read passages of text at the beginning and end of the program while their eye movements were recorded. At each timepoint, we also administered a battery of tests that measure key component skills of second-language reading (phonological processing, vocabulary knowledge, and listening comprehension). We found longitudinal changes in lexical processing for long words in early (refixation probability and gaze duration) and late (go-past time and total reading time) eye movement measures, indicating a shift from a sublexical to a holistic word-processing strategy. We found the largest gains in sublexical processing among students with stronger phonological awareness upon entry to the program and students who acquired more vocabulary than their peers during the program. We interpret the results of this study as evidence of a transition from a lexical processing strategy that is heavily reliant on phonological decoding to word-reading behavior that is more actively engaged in higher order cognitive processes, such as meaning integration. This research offers novel insights into predictors of reading skill in postsecondary English-language bridging programs. |
Karly M. Schleicher; Ana I. Schwartz Bilingual discourse comprehension: The role of language overlap in updating the discourse representation Journal Article In: Discourse Processes, pp. 1–25, 2021. @article{Schleicher2021,In the present study we examined whether overlap in language across texts influences the integration of information into a coherent discourse represen- tation for bilingual readers. Across two experiments highly proficient Spanish–English bilinguals read pairs of expository passages describing two fictional science facts while their eye-movements were monitored. One of the facts was revised in the second passage, requiring a discourse updating. The language of the two passages and follow-up questions was fully crossed. Accuracy was lower for questions pertaining to revised facts when the second passage was in the second language (L2). This cost was exacer- bated when the first passage was in the dominant language, suggesting strong interference from the representation of the first passage which impeded updating the discourse model in the L2. This interference was eliminated in Experiment 2 when second passages were written based on a refutation-style text structure. Analyses of reading times on the pseudo- terms before and after the revised fact was stated indicated that the previous version of the fact was reactivated and interfered with processing. This interference was similar regardless of whether passages were written in the same or different languages. |
Sebastian Schindler; Clara Tirloni; Maximilian Bruchmann; Thomas Straube Face and emotional expression processing under continuous perceptual load tasks: An ERP study Journal Article In: Biological Psychology, vol. 161, pp. 108056, 2021. @article{Schindler2021a,High perceptual load is thought to impair already the early stages of visual processing of task-irrelevant visual stimuli. However, recent studies showed no effects of perceptual load on early ERPs in response to task-irrelevant emotional faces. In this preregistered EEG study (N = 40), we investigated the effects of continuous perceptual load on ERPs to fearful and neutral task-irrelevant faces and their phase-scrambled versions. Perceptual load did not modulate face or emotion effects for the P1 or N170. In contrast, larger face-scramble and fearful-neutral differentiation were found during low as compared to high load for the Early Posterior Negativity (EPN). Further, face-independent P1, but face-dependent N170 emotional modulations were observed. Taken together, our findings show that P1 and N170 face and emotional modulations are highly resistant to load manipulations, indicating a high degree of automaticity during this processing stage, whereas the EPN might represent a bottleneck in visual information processing. |
Sebastian Schindler; Niko Busch; Maximilian Bruchmann; Maren Isabel Wolf; Thomas Straube Early ERP functions are indexed by lateralized effects to peripherally presented emotional faces and scrambles Journal Article In: Psychophysiology, vol. 59, no. 2, pp. e13959, 2021. @article{Schindler2021,A large body of research suggests that early event-related potentials (ERPs), such as the P1 and N1, are potentiated by attention and represent stimulus amplification. However, recent accounts suggest that the P1 is associated with inhibiting the irrelevant visual field evidenced by a pronounced ipsilateral P1 during sustained attention to peripherally presented stimuli. The current EEG study further investigated this issue to reveal how lateralized ERP findings are modulated by face and emotional information. Therefore, participants were asked to fixate the center of the screen and pay sustained attention either to the right or left visual field, where angry or neutral faces or their Fourier phase-scrambled versions were presented. We found a bilateral P1 to all stimuli with relatively increased, but delayed, ipsilateral P1 amplitudes to faces but not to scrambles. Explorative independent component analyses dissociated an earlier lateralized larger contralateral P1 from a later bilateral P1. By contrast, the N170 showed a contralateral enhancement to all stimuli, which was most pronounced for neutral faces attended in the left hemifield. Finally, increased contralateral alpha power was found for both attended hemifields but was not significantly related to poststimulus ERPs. These results provide evidence against a general inhibitory role of the P1 but suggest stimulus-specific relative enhancements of the ipsilateral P1 for the irrelevant visual hemifield. The lateralized N170, however, is associated with stimulus amplification as a function of facial features. |
Alexander Schielke; Bart Krekelberg N-methyl D-aspartate receptor hypofunction reduces visual contextual integration Journal Article In: Journal of Vision, vol. 21, no. 6, pp. 1–11, 2021. @article{Schielke2021,Visual cognition is finely tuned to the elements in a scene but also relies on contextual integration to improve visual detection and discrimination. This integration is impaired in patients with schizophrenia. Studying impairments in contextual integration may lead to biomarkers of schizophrenia, tools to monitor disease progression, and, in animal models, insight into the underlying neural deficits. We developed a nonhuman primate model to test the hypothesis that hypofunction of the N-methyl D-aspartate receptor (NMDAR) impairs contextual integration. Two male rhesus macaques (Macaca mulatta)were trained to indicate which of two patterns on the screen had the highest contrast. One of these patterns appeared in isolation, and the other was surrounded by a high-contrast pattern. In humans, this high-contrast context is known to lead to an underestimation of contrast. This so-called Chubb illusion is thought to result from surround suppression, a key contextual integration mechanism. To test the involvement of NMDAR in this process, we compared animals' perceptual bias with and without intramuscular injections of a subanesthetic dose of the NMDAR antagonist ketamine. In the absence of ketamine, the animals reported a Chubb illusion - matching reports in healthy humans. Hence, monkeys - just like humans - perform visual contextual integration. This reaffirms the importance of nonhuman primates to help understand visual cognition. Injection of ketamine significantly reduced the strength of the illusion and thus impaired contextual integration. This supports the hypothesis that NMDAR hypofunction plays a causal role in specific behavioral impairments observed in schizophrenia. |