Non-Human and Primate Eye-Tracking Publications

All EyeLink non-human primate research publications are listed below in alphabetical order based on the first author. You can search the publications using key words such as Temporal Cortex, Macaque, Antisaccade, etc. You can also search for individual author names. If we missed any EyeLink non-human primate article, please email us!

428 entries « ‹ 1 of 5 › »

Leah Acker; Erica N Pino; Edward S Boyden; Robert Desimone

FEF inactivation with improved optogenetic methods Journal Article

Proceedings of the National Academy of Sciences, 113 (46), pp. E7297–E7306, 2016.

Abstract | Links | BibTeX

Hamed Zivari Adab; Ivo D Popivanov; Wim Vanduffel; Rufin Vogels

Perceptual learning of simple stimuli modifies stimulus representations in posterior inferior temporal cortex Journal Article

Journal of Cognitive Neuroscience, 26 (10), pp. 2187–2200, 2014.

Abstract | Links | BibTeX

@article{Adab2014,
title = {Perceptual learning of simple stimuli modifies stimulus representations in posterior inferior temporal cortex},
author = {Hamed Zivari Adab and Ivo D Popivanov and Wim Vanduffel and Rufin Vogels},
doi = {10.1162/jocn},
year = {2014},
date = {2014-01-01},
journal = {Journal of Cognitive Neuroscience},
volume = {26},
number = {10},
pages = {2187--2200},
abstract = {Practicing simple visual detection and discrimination tasks improves performance, a signature of adult brain plasticity. The neural mechanisms that underlie these changes in performance are still unclear. Previously, we reported that practice in discriminating the orientation of noisy gratings (coarse orientation discrimination) increased the ability of single neurons in the early visual area V4 to discriminate the trained stimuli. Here, we ask whether practice in this task also changes the stimulus tuning properties of later visual cortical areas, despite the use of simple grating stimuli. To identify candidate areas, we used fMRI to map activations to noisy gratings in trained rhesus monkeys, revealing a region in the posterior inferior temporal (PIT) cortex. Subsequent single unit record- ings in PIT showed that the degree of orientation selectivity was similar to that of area V4 and that the PIT neurons discriminated the trained orientations better than the untrained orientations. Unlike in previous single unit studies of perceptual learning in early visual cortex, more PIT neurons preferred trained compared with untrained orientations. The effects of training on the responses to the grating stimuli were also present when the animals were performing a difficult orthogo- nal task in which the grating stimuli were task-irrelevant, suggesting that the training effect does not need attention to be expressed. The PIT neurons could support orientation discrimination at low signal-to-noise levels. These findings suggest that extensive practice in discriminating simple grating stimuli not only affects early visual cortex but also changes the stimulus tuning of a late visual cortical area.},
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Hamed Zivari Adab; Rufin Vogels

Perturbation of posterior inferior temporal cortical activity impairs coarse orientation discrimination Journal Article

Cerebral Cortex, 26 (9), pp. 3814–3827, 2016.

Abstract | Links | BibTeX

Jordi Aguila; Javier Cudeiro; Casto Rivadulla

Effects of static magnetic fields on the visual cortex: Reversible visual deficits and reduction of neuronal activity Journal Article

Cerebral Cortex, 26 , pp. 628–638, 2016.

Abstract | Links | BibTeX

Jordi Aguila; Javier F Cudeiro; Casto Rivadulla

Suppression of V1 feedback produces a shift in the topographic representation of receptive fields of LGN cells by unmasking latent retinal drives Journal Article

Cerebral Cortex, 27 (6), pp. 3331–3345, 2017.

Abstract | Links | BibTeX

Amir Mohammad Alizadeh; Ilse Van Dromme; Bram Ernst Verhoef; Peter Janssen

Caudal Intraparietal Sulcus and three-dimensional vision: A combined functional magnetic resonance imaging and single-cell study Journal Article

NeuroImage, 166 , pp. 46–59, 2018.

Abstract | Links | BibTeX

Amir-Mohammad Alizadeh; Ilse C Van Dromme; Peter Janssen

Single-cell responses to three-dimensional structure in a functionally defined patch in macaque area TEO Journal Article

Journal of Neurophysiology, 120 (6), pp. 2806–2818, 2018.

Abstract | Links | BibTeX

Ken Ichi Amemori; Ann M Graybiel

Localized microstimulation of primate pregenual cingulate cortex induces negative decision-making Journal Article

Nature Neuroscience, 15 (5), pp. 776–785, 2012.

Abstract | Links | BibTeX

Ken Ichi Amemori; Satoko Amemori; A M Graybiel

Motivation and affective judgments differentially recruit neurons in the primate dorsolateral prefrontal and anterior cingulate cortex Journal Article

Journal of Neuroscience, 35 (5), pp. 1939–1953, 2015.

Abstract | Links | BibTeX

@article{Amemori2015a,
title = {Motivation and affective judgments differentially recruit neurons in the primate dorsolateral prefrontal and anterior cingulate cortex},
author = {Ken Ichi Amemori and Satoko Amemori and A M Graybiel},
doi = {10.1523/JNEUROSCI.1731-14.2015},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neuroscience},
volume = {35},
number = {5},
pages = {1939--1953},
abstract = {The judgment of whether to accept or to reject an offer is determined by positive and negative affect related to the offer, but affect also induces motivational responses. Rewarding and aversive cues influence the firing rates of many neurons in primate prefrontal and cingulate neocortical regions, but it still is unclear whether neurons in these regions are related to affective judgment or to motivation.To address this issue, we recorded simultaneously the neuronal spike activities of single units in the dorsolateral prefrontal cortex (dlPFC) and the anterior cingulate cortex (ACC) of macaque monkeys as they performed approach–avoidance (Ap–Av) and approach–approach (Ap–Ap) decision-making tasks that can behaviorally dissociate affective judgment and motivation. Notably, neurons having activity correlated with motivational condition could be distinguished from neurons having activity related to affective judgment, especially in the Ap–Av task. Although many neurons in both regions exhibited similar, selective patterns of task-related activity, we found a larger proportion of neurons activated in low motivational conditions in the dlPFC than in the ACC, and the onset of this activity was signifi- cantly earlier in the dlPFC than in the ACC. Furthermore, the temporal onsets of affective judgment represented by neuronal activities were significantly slower in the low motivational conditions than in the other conditions. These findings suggest that motivation and affective judgment both recruit dlPFC and ACC neurons but with differential degrees of involvement and timing.},
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Satoko Amemori; Ken ichi Amemori; Margaret L Cantor; Ann M Graybiel

A non-invasive head-holding device for chronic neural recordings in awake behaving monkeys Journal Article

Journal of Neuroscience Methods, 240 , pp. 154–160, 2015.

Abstract | Links | BibTeX

@article{Amemori2015b,
title = {A non-invasive head-holding device for chronic neural recordings in awake behaving monkeys},
author = {Satoko Amemori and Ken ichi Amemori and Margaret L Cantor and Ann M Graybiel},
doi = {10.1016/j.jneumeth.2014.11.006},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neuroscience Methods},
volume = {240},
pages = {154--160},
publisher = {Elsevier B.V.},
abstract = {Background: We have developed a novel head-holding device for behaving non-human primates that affords stability suitable for reliable chronic electrophysiological recording experiments. The device is completely non-invasive, and thus avoids the risk of infection and other complications that can occur with the use of conventional, surgically implanted head-fixation devices. New method: The device consists of a novel non-invasive head mold and bar clamp holder, and is customized to the shape of each monkey's head. The head-holding device that we introduce, combined with our recording system and reflection-based eye-tracking system, allows for chronic behavioral experiments and single-electrode or multi-electrode recording, as well as manipulation of brain activity. Results and comparison with existing methods: With electrodes implanted chronically in multiple brain regions, we could record neural activity from cortical and subcortical structures with stability equal to that recorded with conventional head-post fixation. Consistent with the non-invasive nature of the device, we could record neural signals for more than two years with a single implant. Importantly, the monkeys were able to hold stable eye fixation positions while held by this device, demonstrating the possibility of analyzing eye movement data with only the gentle restraint imposed by the non-invasive head-holding device. Conclusions: We show that the head-holding device introduced here can be extended to the head holding of smaller animals, and note that it could readily be adapted for magnetic resonance brain imaging over extended periods of time.},
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Ken ichi Amemori; Satoko Amemori; Daniel J Gibson; Ann M Graybiel

Striatal microstimulation induces persistent and repetitive negative decision-making predicted by striatal beta-band oscillation Journal Article

Neuron, 99 (4), pp. 829–841, 2018.

Abstract | Links | BibTeX

Britt Anderson; Ryan E B Mruczek; Keisuke Kawasaki; David Sheinberg

Effects of familiarity on neural activity in monkey inferior temporal lobe Journal Article

Cerebral Cortex, 18 (11), pp. 2540–2552, 2008.

Abstract | Links | BibTeX

Britt Anderson; David L Sheinberg

Effects of temporal context and temporal expectancy on neural activity in inferior temporal cortex Journal Article

Neuropsychologia, 46 (4), pp. 947–957, 2008.

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Evan G Antzoulatos; Earl K Miller

Synchronous beta rhythms of frontoparietal networks support only behaviorally relevant representations Journal Article

eLife, 5 (NOVEMBER2016), pp. 1–22, 2016.

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Mari Anzai; Soich Nagao

Motor learning in common marmosets: Vestibulo-ocular reflex adaptation and its sensitivity to inhibitors of Purkinje cell long-term depression Journal Article

Neuroscience Research, 83 , pp. 33–42, 2014.

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Paul L Aparicio; Elias B Issa; James J DiCarlo

Neurophysiological organization of the middle face patch in macaque inferior temporal cortex Journal Article

Journal of Neuroscience, 36 (50), pp. 12729–12745, 2016.

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Iñigo Arandia-Romero; Seiji Tanabe; Jan Drugowitsch; Adam Kohn; Rubén Moreno-Bote

Multiplicative and additive modulation of neuronal tuning with population activity affects encoded information Journal Article

Neuron, 89 (6), pp. 1305–1316, 2016.

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Fabrice Arcizet; Richard J Krauzlis

Covert spatial selection in primate basal ganglia Journal Article

PLoS Biology, 16 (10), pp. 1–28, 2018.

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Wael F Asaad; Navaneethan Santhanam; Steven McClellan; David J Freedman

High-performance execution of psychophysical tasks with complex visual stimuli in MATLAB Journal Article

Journal of Neurophysiology, 109 (1), pp. 249–260, 2013.

Abstract | Links | BibTeX

Habiba Azab; Benjamin Y Hayden

Correlates of decisional dynamics in the dorsal anterior cingulate cortex Journal Article

PLoS Biology, 15 (11), pp. 1–25, 2017.

Abstract | Links | BibTeX

Habiba Azab; Benjamin Y Hayden

Correlates of economic decisions in the dorsal and subgenual anterior cingulate cortices Journal Article

European Journal of Neuroscience, 47 (8), pp. 979–993, 2018.

Abstract | Links | BibTeX

Sahand Babapoor-Farrokhran; Martin Vinck; Thilo Womelsdorf; Stefan Everling

Theta and beta synchrony coordinate frontal eye fields and anterior cingulate cortex during sensorimotor mapping Journal Article

Nature Communications, 8 , pp. 1–14, 2017.

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Theda Backen; Stefan Treue; Julio C Martinez-Trujillo

Encoding of spatial attention by primate prefrontal cortex neuronal ensembles Journal Article

Eneuro, 5 (1), pp. 1–19, 2018.

Abstract | Links | BibTeX

@article{Backen2018,
title = {Encoding of spatial attention by primate prefrontal cortex neuronal ensembles},
author = {Theda Backen and Stefan Treue and Julio C Martinez-Trujillo},
doi = {10.1523/eneuro.0372-16.2017},
year = {2018},
date = {2018-01-01},
journal = {Eneuro},
volume = {5},
number = {1},
pages = {1--19},
abstract = {Single neurons in the primate lateral prefrontal cortex (LPFC) encode information about the allocation of visual attention and the features of visual stimuli. However, how this compares to the performance of neuronal ensembles at encoding the same information is poorly understood. Here, we recorded the responses of neuronal ensembles in the LPFC of two macaque monkeys while they performed a task that required attending to one of two moving random dot patterns positioned in different hemifields and ignoring the other pattern. We found single units selective for the location of the attended stimulus as well as for its motion direction. To determine the coding of both variables in the population of recorded units, we used a linear classifier and progressively built neuronal ensembles by iteratively adding units according to their individual performance (best single units), or by iteratively adding units based on their contribution to the ensemble performance (best ensemble). For both methods, ensembles of relatively small sizes (n textless 60) yielded substantially higher decoding performance relative to individual single units. However, the decoder reached similar performance using fewer neurons with the best ensemble building method compared to the best single units method. Our results indicate that neuronal ensembles within the LPFC encode more information about the attended spatial and non-spatial features of visual stimuli than individual neurons. They further suggest that efficient coding of attention can be achieved by relatively small neuronal ensembles characterized by a certain relationship between signal and noise correlation structures. Significance Statement Single neurons in the primate lateral prefrontal cortex (LPFC) are known to encode the spatial location of attended stimuli as well as other visual features. Here, we investigate how these single neuron coding properties translate into how ensembles of neurons encode information. Our results show that LPFC neuronal ensembles encode both the allocation of attention and the direction of motion of moving stimuli with higher efficiency than single units. Furthermore, relatively small ensembles reach the same decoding accuracy as the full ensembles. Our findings indicate that information coding by neuronal ensembles within the LPFC depends on complex network properties that cannot be solely estimated from coding properties of individual neurons.},
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Single neurons in the primate lateral prefrontal cortex (LPFC) encode information about the allocation of visual attention and the features of visual stimuli. However, how this compares to the performance of neuronal ensembles at encoding the same information is poorly understood. Here, we recorded the responses of neuronal ensembles in the LPFC of two macaque monkeys while they performed a task that required attending to one of two moving random dot patterns positioned in different hemifields and ignoring the other pattern. We found single units selective for the location of the attended stimulus as well as for its motion direction. To determine the coding of both variables in the population of recorded units, we used a linear classifier and progressively built neuronal ensembles by iteratively adding units according to their individual performance (best single units), or by iteratively adding units based on their contribution to the ensemble performance (best ensemble). For both methods, ensembles of relatively small sizes (n textless 60) yielded substantially higher decoding performance relative to individual single units. However, the decoder reached similar performance using fewer neurons with the best ensemble building method compared to the best single units method. Our results indicate that neuronal ensembles within the LPFC encode more information about the attended spatial and non-spatial features of visual stimuli than individual neurons. They further suggest that efficient coding of attention can be achieved by relatively small neuronal ensembles characterized by a certain relationship between signal and noise correlation structures. Significance Statement Single neurons in the primate lateral prefrontal cortex (LPFC) are known to encode the spatial location of attended stimuli as well as other visual features. Here, we investigate how these single neuron coding properties translate into how ensembles of neurons encode information. Our results show that LPFC neuronal ensembles encode both the allocation of attention and the direction of motion of moving stimuli with higher efficiency than single units. Furthermore, relatively small ensembles reach the same decoding accuracy as the full ensembles. Our findings indicate that information coding by neuronal ensembles within the LPFC depends on complex network properties that cannot be solely estimated from coding properties of individual neurons.

Dong Hyun Baek; Jeyeon Lee; Hang Jin Byeon; Hoseok Choi; In Young Kim; Kyoung-Min Lee; James Jungho Pak; Dong Pyo Jang; Sang Hoon Lee

A thin film polyimide mesh microelectrode for chronic epidural electrocorticography recording with enhanced contactability Journal Article

Journal of Neural Engineering, 11 (4), pp. 1–10, 2014.

Abstract | Links | BibTeX

Zahra Bahmani; Mohammad Reza Daliri; Yaser Merrikhi; Kelsey Clark; Behrad Noudoost

Working memory enhances cortical representations via spatially specific coordination of spike times Journal Article

Neuron, 97 (4), pp. 967–979, 2018.

Abstract | Links | BibTeX

David L Barack; Steve W C Chang; Michael L Platt

Posterior cingulate neurons dynamically signal decisions to disengage during foraging Journal Article

Neuron, 96 (2), pp. 339–347, 2017.

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Jalal K Baruni; Brian Lau; Daniel C Salzman

Reward expectation differentially modulates attentional behavior and activity in visual area V4 Journal Article

Nature Neuroscience, 18 (11), pp. 1656–1663, 2015.

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Charles B Beaman; Sarah L Eagleman; Valentin Dragoi

Sensory coding accuracy and perceptual performance are improved during the desynchronized cortical state Journal Article

Nature Communications, 8 (1), pp. 1–14, 2017.

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Joachim Bellet; Chih-Yang Chen; Ziad M Hafed

Sequential hemifield gating of alpha and beta behavioral performance oscillations after microsaccades Journal Article

Journal of Neurophysiology, 118 , pp. 2789–2805, 2017.

Abstract | Links | BibTeX

Giacomo Benvenuti; Yuzhi Chen; Charu Ramakrishnan; Karl Deisseroth; Wilson S Geisler; Eyal Seidemann

Scale-invariant visual capabilities explained by topographic representations of luminance and texture in primate V1 Journal Article

Neuron, 100 (6), pp. 1504–1512., 2018.

Abstract | Links | BibTeX

Narcisse P Bichot; Matthew T Heard; Robert Desimone

Stimulation of the nucleus accumbens as behavioral reward in awake behaving monkeys Journal Article

Journal of Neuroscience Methods, 199 (2), pp. 265–272, 2011.

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Narcisse P Bichot; Matthew T Heard; Ellen M DeGennaro; Robert Desimone

A source for feature-based attention in the prefrontal cortex Journal Article

Neuron, 88 (4), pp. 832–844, 2015.

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T C Blanchard; J M Pearson; B Y Hayden

Postreward delays and systematic biases in measures of animal temporal discounting Journal Article

Proceedings of the National Academy of Sciences, 110 (38), pp. 15491–15496, 2013.

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T C Blanchard; B Y Hayden

Neurons in dorsal anterior cingulate cortex signal postdecisional variables in a foraging task Journal Article

Journal of Neuroscience, 34 (2), pp. 646–655, 2014.

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Tommy C Blanchard; Andreas Wilke; Benjamin Y Hayden

Hot-hand bias in rhesus monkeys Journal Article

Journal of Experimental Psychology: Animal Behavior Processes, 40 (3), pp. 280–286, 2014.

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Tommy C Blanchard; Lauren S Wolfe; Ivo Vlaev; Joel S Winston; Benjamin Y Hayden

Biases in preferences for sequences of outcomes in monkeys Journal Article

Cognition, 130 (3), pp. 289–299, 2014.

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Tommy C Blanchard; Benjamin Y Hayden

Monkeys are more patient in a foraging task than in a standard intertemporal choice task Journal Article

PLoS ONE, 10 (2), pp. 1–11, 2015.

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Tommy C Blanchard; Caleb E Strait; Benjamin Y Hayden

Ramping ensemble activity in dorsal anterior cingulate neurons during persistent commitment to a decision Journal Article

Journal of Neurophysiology, 114 (4), pp. 2439–2449, 2015.

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Anil Bollimunta; Amarender R Bogadhi; Richard J Krauzlis

Comparing frontal eye field and superior colliculus contributions to covert spatial attention Journal Article

Nature Communications, 9 , pp. 1–11, 2018.

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Yehudit Botschko; Merav Yarkoni; Mati Joshua

Smooth pursuit eye movement of monkeys naive to laboratory setups with pictures and artificial stimuli Journal Article

Frontiers in Systems Neuroscience, 12 , pp. 1–11, 2018.

Abstract | Links | BibTeX

@article{Botschko2018,
title = {Smooth pursuit eye movement of monkeys naive to laboratory setups with pictures and artificial stimuli},
author = {Yehudit Botschko and Merav Yarkoni and Mati Joshua},
doi = {10.3389/fnsys.2018.00015},
year = {2018},
date = {2018-01-01},
journal = {Frontiers in Systems Neuroscience},
volume = {12},
pages = {1--11},
abstract = {When animal behavior is studied in a laboratory environment, the animals are often extensively trained to shape their behavior. A crucial question is whether the behavior observed after training is part of the natural repertoire of the animal or represents an outlier in the animal's natural capabilities. This can be investigated by assessing the extent to which the target behavior is manifested during the initial stages of training and the time course of learning. We explored this issue by examining smooth pursuit eye movements in monkeys naïve to smooth pursuit tasks. We recorded the eye movements of monkeys from the first days of training on a step-ramp paradigm. We used bright spots, monkey pictures and scrambled versions of the pictures as moving targets. We found that during the initial stages of training, the pursuit initiation was largest for the monkey pictures and in some direction conditions close to target velocity. When the pursuit initiation was large, the monkeys mostly continued to track the target with smooth pursuit movements while correcting for displacement errors with small saccades. Two weeks of training increased the pursuit eye velocity in all stimulus conditions, whereas further extensive training enhanced pursuit slightly more. The training decreased the coefficient of variation of the eye velocity. Anisotropies that grade pursuit across directions were observed from the first day of training and mostly persisted across training. Thus, smooth pursuit in the step-ramp paradigm appears to be part of the natural repertoire of monkeys' behavior and training adjusts monkeys' natural predisposed behavior.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Chadwick B Boulay; Florian Pieper; Matthew Leavitt; Julio Martinez-Trujillo; Adam J Sachs

Single-trial decoding of intended eye movement goals from lateral prefrontal cortex neural ensembles Journal Article

Journal of Neurophysiology, 115 (1), pp. 486–499, 2016.

Abstract | Links | BibTeX

@article{Boulay2016,
title = {Single-trial decoding of intended eye movement goals from lateral prefrontal cortex neural ensembles},
author = {Chadwick B Boulay and Florian Pieper and Matthew Leavitt and Julio Martinez-Trujillo and Adam J Sachs},
doi = {10.1152/jn.00788.2015},
year = {2016},
date = {2016-01-01},
journal = {Journal of Neurophysiology},
volume = {115},
number = {1},
pages = {486--499},
abstract = {Neurons in the lateral prefrontal cortex (LPFC) encode sensory and cognitive signals, as well as commands for goal-directed actions. Therefore, the LPFC might be a good signal source for a goal-selection brain-computer interface (BCI) that decodes the intended goal of a motor action previous to its execution. As a first step in the development of a goal-selection BCI, we set out to determine if we could decode simple behavioral intentions to direct gaze to eight different locations in space from single-trial LPFC neural activity. We recorded neuronal spiking activity from microelectrode arrays implanted in area 8A of the LPFC of two adult macaques while they made visually guided saccades to one of eight targets in a center-out task. Neuronal activity encoded target location immediately after target presentation, during a delay epoch, during the execution of the saccade, and every combination thereof. Many (40%) of the neurons that encoded target location during multiple epochs preferred different locations during different epochs. Despite heterogeneous and dynamic responses, the neuronal feature set that best predicted target location was the averaged firing rates from the entire trial and it was best classified using linear discriminant analysis (63.6$backslash$textendash96.9% in 12 sessions, mean 80.3%; information transfer rate: 21$backslash$textendash59, mean 32.8 bits/min). Our results demonstrate that it is possible to decode intended saccade target location from single-trial LPFC activity and suggest that the LPFC is a suitable signal source for a goal-selection cognitive BCI.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Scott L Brincat; Earl K Miller

Frequency-specific hippocampal-prefrontal interactions during associative learning Journal Article

Nature Neuroscience, 18 (4), pp. 576–581, 2015.

Abstract | Links | BibTeX

Scott L Brincat; Earl K Miller

Prefrontal cortex networks shift from external to internal modes during learning Journal Article

Journal of Neuroscience, 36 (37), pp. 9739–9754, 2016.

Abstract | Links | BibTeX

Kelly R Bullock; Florian Pieper; Adam J Sachs; Julio C Martinez-Trujillo

Visual and presaccadic activity in area 8Ar of the macaque monkey lateral prefrontal cortex Journal Article

Journal of Neurophysiology, 118 (1), pp. 15–28, 2017.

Abstract | Links | BibTeX

@article{Bullock2017,
title = {Visual and presaccadic activity in area 8Ar of the macaque monkey lateral prefrontal cortex},
author = {Kelly R Bullock and Florian Pieper and Adam J Sachs and Julio C Martinez-Trujillo},
doi = {10.1152/jn.00278.2016},
year = {2017},
date = {2017-01-01},
journal = {Journal of Neurophysiology},
volume = {118},
number = {1},
pages = {15--28},
abstract = {Common trends observed in many visual and oculomotor-related cortical areas include retinotopically organized receptive and movement fields exhibiting a Gaussian shape and increasing size with eccentricity. These trends are demonstrated in the frontal eye fields (FEF), many visual areas, and the superior colliculus (SC), but have not been thoroughly characterized in prearcuate area 8Ar of the prefrontal cortex. This is important since area 8Ar, located anterior to the FEF, is more cytoarchitectonically similar to prefrontal areas than premotor areas. Here we recorded the responses of 166 neurons in area 8Ar of two male macaques while the animals made visually guided saccades to a peripheral sine-wave grating stimulus positioned at one of 40 possible locations (8 angles along 5 eccentricities). To characterize the neurons' receptive and movement fields, we fit a bivariate Gaussian model to the baseline-subtracted average firing rate during stimulus presentation (early and late visual epoch) and prior to saccade onset (presaccadic epoch). 121/166 neurons showed spatially selective visual and presaccadic responses. Of the visually selective neurons, 76% preferred the contralateral visual hemifield, whereas 24% preferred the ipsilateral hemifield. The angular width of visual and movement-related fields scaled positively with increasing eccentricity. Moreover, responses of neurons with visual receptive fields were modulated by target contrast exhibiting sigmoid tuning curves that resemble those of visual neurons in upstream areas such as MT and V4. Finally, we found that neurons with receptive fields at similar spatial locations were clustered within the area; however, this organization did not appear retinotopic.},
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pubstate = {published},
tppubtype = {article}
}

Timothy J Buschman; Eric L Denovellis; Cinira Diogo; Daniel Bullock; Earl K Miller

Synchronous oscillatory neural ensembles for rules in the prefrontal cortex Journal Article

Neuron, 76 (4), pp. 838–846, 2012.

Abstract | Links | BibTeX

Brittany N Bushnell; Philip J Harding; Yoshito Kosai; Wyeth Bair; Anitha Pasupathy

Equiluminance cells in visual cortical area V4 Journal Article

Journal of Neuroscience, 31 (35), pp. 12398–12412, 2011.

Abstract | Links | BibTeX

Brittany N Bushnell; Philip J Harding; Yoshito Kosai; Anitha Pasupathy

Partial occlusion modulates contour-based shape encoding in primate area V4 Journal Article

Journal of Neuroscience, 31 (11), pp. 4012–4024, 2011.

Abstract | Links | BibTeX

@article{Bushnell2011a,
title = {Partial occlusion modulates contour-based shape encoding in primate area V4},
author = {Brittany N Bushnell and Philip J Harding and Yoshito Kosai and Anitha Pasupathy},
doi = {10.1523/JNEUROSCI.4766-10.2011},
year = {2011},
date = {2011-01-01},
journal = {Journal of Neuroscience},
volume = {31},
number = {11},
pages = {4012--4024},
abstract = {Past studies of shape coding in visual cortical area V4 have demonstrated that neurons can accurately represent isolated shapes in terms of their component contour features. However, rich natural scenes contain many partially occluded objects, which have "accidental" contours at the junction between the occluded and occluding objects. These contours do not represent the true shape of the occluded object and are known to be perceptually discounted. To discover whether V4 neurons differentially encode accidental contours, we studied the responses of single neurons in fixating monkeys to complex shapes and contextual stimuli presented either in isolation or adjoining each other to provide a percept of partial occlusion. Responses to preferred contours were suppressed when the adjoining context rendered those contours accidental. The observed suppression was reversed when the partial occlusion percept was compromised by introducing a small gap between the component stimuli. Control experiments demonstrated that these results likely depend on contour geometry at T-junctions and cannot be attributed to mechanisms based solely on local color/luminance contrast, spatial proximity of stimuli, or the spatial frequency content of images. Our findings provide novel insights into how occluded objects, which are fundamental to complex visual scenes, are encoded in area V4. They also raise the possibility that the weakened encoding of accidental contours at the junction between objects could mark the first step of image segmentation along the ventral visual pathway.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Brittany N Bushnell; Anitha Pasupathy

Shape encoding consistency across colors in primate V4 Journal Article

Journal of Neurophysiology, 108 (5), pp. 1299–1308, 2012.

Abstract | Links | BibTeX

Charles F Cadieu; Ha Hong; Daniel L K Yamins; Nicolas Pinto; Diego Ardila; Ethan A Solomon; Najib J Majaj; James J DiCarlo

Deep neural networks rival the representation of primate IT cortex for core visual object recognition Journal Article

PLoS Computational Biology, 10 (12), pp. 1–18, 2014.

Abstract | Links | BibTeX

@article{Cadieu2014,
title = {Deep neural networks rival the representation of primate IT cortex for core visual object recognition},
author = {Charles F Cadieu and Ha Hong and Daniel L K Yamins and Nicolas Pinto and Diego Ardila and Ethan A Solomon and Najib J Majaj and James J DiCarlo},
doi = {10.1016/j.apergo.2010.02.001},
year = {2014},
date = {2014-01-01},
journal = {PLoS Computational Biology},
volume = {10},
number = {12},
pages = {1--18},
abstract = {The primate visual system achieves remarkable visual object recognition performance even in brief presentations, and under changes to object exemplar, geometric transformations, and background variation (a.k.a. core visual object recognition). This remarkable performance is mediated by the representation formed in inferior temporal (IT) cortex. In parallel, recent advances in machine learning have led to ever higher performing models of object recognition using artificial deep neural networks (DNNs). It remains unclear, however, whether the representational performance of DNNs rivals that of the brain. To accurately produce such a comparison, a major difficulty has been a unifying metric that accounts for experimental limitations, such as the amount of noise, the number of neural recording sites, and the number of trials, and computational limitations, such as the complexity of the decoding classifier and the number of classifier training examples. In this work, we perform a direct comparison that corrects for these experimental limitations and computational considerations. As part of our methodology, we propose an extension of ‘‘kernel analysis'' that measures the generalization accuracy as a function of representational complexity. Our evaluations show that, unlike previous bio-inspired models, the latest DNNs rival the representational performance of IT cortex on this visual object recognition task. Furthermore, we show that models that perform well on measures of representational performance also perform well on measures of representational similarity to IT, and on measures of predicting individual IT multi-unit responses. Whether these DNNs rely on computational mechanisms similar to the primate visual system is yet to be determined, but, unlike all previous bio- inspired models, that possibility cannot be ruled out merely on representational performance grounds.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

X Cai; Camillo Padoa-Schioppa

Neuronal encoding of subjective value in dorsal and ventral anterior cingulate cortex Journal Article

Journal of Neuroscience, 32 (11), pp. 3791–3808, 2012.

Abstract | Links | BibTeX

@article{Cai2012,
title = {Neuronal encoding of subjective value in dorsal and ventral anterior cingulate cortex},
author = {X Cai and Camillo Padoa-Schioppa},
doi = {10.1523/JNEUROSCI.3864-11.2012},
year = {2012},
date = {2012-01-01},
journal = {Journal of Neuroscience},
volume = {32},
number = {11},
pages = {3791--3808},
abstract = {We examined the activity of individual cells in the primate anterior cingulate cortex during an economic choice task. In the experiments, monkeys chose between different juices offered in variables amounts and subjective values were inferred from the animals' choices. We analyzed neuronal firing rates in relation to a large number of behaviorally relevant variables. We report three main results. First, there were robust differences between the dorsal bank (ACCd) and the ventral bank (ACCv) of the cingulate sulcus. Specifically, neurons in ACCd but not in ACCv were modulated by the movement direction. Furthermore, neurons in ACCd were most active before movement initiation, whereas neurons in ACCv were most active after juice delivery. Second, neurons in both areas encoded the identity and the subjective value of the juice chosen by the animal. In contrast, neither region encoded the value of individual offers. Third, the population of value-encoding neurons in both ACCd and ACCv underwent range adaptation. With respect to economic choice, it is interesting to compare these areas with the orbitofrontal cortex (OFC), previously examined. While neurons in OFC encoded both pre-decision and post-decision variables, neurons in ACCd and ACCv only encoded post-decision variables. Moreover, the encoding of the choice outcome (chosen value and chosen juice) in ACCd and ACCv trailed that found in OFC. These observations indicate that economic decisions (i.e., value comparisons) take place upstream of ACCd and ACCv. The coexistence of choice outcome and movement signals in ACCd suggests that this area constitutes a gateway through which the choice system informs motor systems.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Xinying Cai; Camillo Padoa-Schioppa

Contributions of orbitofrontal and lateral prefrontal cortices to economic choice and the good-to-action transformation Journal Article

Neuron, 81 (5), pp. 1140–1151, 2014.

Abstract | Links | BibTeX

Irene Caprara; Elsie Premereur; Maria C Romero; Pedro Faria; Peter Janssen

Shape responses in a macaque frontal area connected to posterior parietal cortex Journal Article

NeuroImage, 179 , pp. 298–312, 2018.

Abstract | Links | BibTeX

Valeria C Caruso; Daniel S Pages; Marc A Sommer; Jennifer M Groh

Journal of Neurophysiology, 115 (6), pp. 3162–3173, 2016.

Abstract | Links | BibTeX

Aaron L Cecala; Ivan Smalianchuk; Sanjeev B Khanna; Matthew A Smith; Neeraj J Gandhi

Context cue-dependent saccadic adaptation in rhesus macaques cannot be elicited using color Journal Article

Journal of Neurophysiology, 114 (1), pp. 570–584, 2015.

Abstract | Links | BibTeX

@article{Cecala2015,
title = {Context cue-dependent saccadic adaptation in rhesus macaques cannot be elicited using color},
author = {Aaron L Cecala and Ivan Smalianchuk and Sanjeev B Khanna and Matthew A Smith and Neeraj J Gandhi},
doi = {10.1152/jn.00666.2014},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurophysiology},
volume = {114},
number = {1},
pages = {570--584},
abstract = {When the head does not move, rapid movements of the eyes called saccades are used to redirect the line of sight. Saccades are defined by a series of metrical and kinematic (evolution of a movement as a function of time) relationships. For example, the amplitude of a saccade made from one visual target to another is roughly 90% of the distance between the initial fixation point (T0) and the peripheral target (T1). However, this stereotypical relationship between saccade amplitude and initial retinal error (T1-T0) may be altered, either increased or decreased, by surreptitiously displacing a visual target during an ongoing saccade. This form of motor learning (called saccadic adaptation) has been described in both humans and monkeys. Recent experiments in humans and monkeys have suggested that internal (proprioceptive) and external (target shape, color, and/or motion) cues may be used to produce context-dependent adaptation. We tested the hypothesis that an external contextual cue (target color) could be used to evoke differential gain (actual saccade/initial retinal error) states in rhesus monkeys. We did not observe differential gain states correlated with target color regardless of whether targets were displaced along the same vector as the primary saccade or perpendicular to it. Furthermore, this observation held true regardless of whether adaptation trials using various colors and intrasaccade target displacements were randomly intermixed or presented in short or long blocks of trials. These results are consistent with hypotheses that state that color cannot be used as a contextual cue and are interpreted in light of previous studies of saccadic adaptation in both humans and monkeys.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Jason L Chan; Michael J Koval; Thilo Womelsdorf; Stephen G Lomber; Stefan Everling

Dorsolateral prefrontal cortex deactivation in monkeys reduces preparatory beta and gamma power in the superior colliculus Journal Article

Cerebral Cortex, 25 (12), pp. 4704–4714, 2015.

Abstract | Links | BibTeX

Jason Lloyd Chan; Michael J Koval; Kevin Johnston; Stefan Everling

Neural correlates for task switching in the macaque superior colliculus Journal Article

Journal of Neurophysiology, 118 , pp. 2156–2170, 2017.

Abstract | Links | BibTeX

Steve W C Chang; Amy A Winecoff; Michael L Platt

Vicarious reinforcement in rhesus macaques (Macaca mulatta) Journal Article

Frontiers in Neuroscience, 5 , pp. 1–10, 2011.

Abstract | Links | BibTeX

@article{Chang2011,
title = {Vicarious reinforcement in rhesus macaques (Macaca mulatta)},
author = {Steve W C Chang and Amy A Winecoff and Michael L Platt},
doi = {10.3389/fnins.2011.00027},
year = {2011},
date = {2011-01-01},
journal = {Frontiers in Neuroscience},
volume = {5},
pages = {1--10},
publisher = {10},
address = {doi},
abstract = {What happens to others profoundly influences our own behavior. Such other-regarding outcomes can drive observational learning, as well as motivate cooperation, charity, empathy, and even spite. Vicarious reinforcement may serve as one of the critical mechanisms mediating the influence of other-regarding outcomes on behavior and decision-making in groups. Here we show that rhesus macaques spontaneously derive vicarious reinforcement from observing rewards given to another monkey, and that this reinforcement can motivate them to subsequently deliver or withhold rewards from the other animal. We exploited Pavlovian and instrumental conditioning to associate rewards to self (M1) and/or rewards to another monkey (M2) with visual cues. M1s made more errors in the instrumental trials when cues predicted reward to M2 compared to when cues predicted reward to M1, but made even more errors when cues predicted reward to no one. In subsequent preference tests between pairs of conditioned cues, M1s preferred cues paired with reward to M2 over cues paired with reward to no one. By contrast, M1s preferred cues paired with reward to self over cues paired with reward to both monkeys simultaneously. Rates of attention to M2 strongly predicted the strength and valence of vicarious reinforcement. These patterns of behavior, which were absent in non-social control trials, are consistent with vicarious reinforcement based upon sensitivity to observed, or counterfactual, outcomes with respect to another individual. Vicarious reward may play a critical role in shaping cooperation and competition, as well as motivating observational learning and group coordination in rhesus macaques, much as it does in humans. We propose that vicarious reinforcement signals mediate these behaviors via homologous neural circuits involved in reinforcement learning and decision-making.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Steve W C Chang; Joseph W Barter; Becket R Ebitz; Karli K Watson; Michael L Platt

Inhaled oxytocin amplifies both vicarious reinforcement and self reinforcement in rhesus macaques (Macaca mulatta) Journal Article

Proceedings of the National Academy of Sciences, 109 (3), pp. 959–964, 2012.

Abstract | Links | BibTeX

Steve W C Chang; Jean François Gariépy; Michael L Platt

Neuronal reference frames for social decisions in primate frontal cortex Journal Article

Nature Neuroscience, 16 (2), pp. 243–250, 2013.

Abstract | Links | BibTeX

Steve W C Chang; Nicholas A Fagan; Koji Toda; Amanda V Utevsky; John M Pearson; Michael L Platt

Neural mechanisms of social decision-making in the primate amygdala Journal Article

Proceedings of the National Academy of Sciences, 112 (52), pp. 16012–16017, 2015.

Abstract | Links | BibTeX

@article{Chang2015,
title = {Neural mechanisms of social decision-making in the primate amygdala},
author = {Steve W C Chang and Nicholas A Fagan and Koji Toda and Amanda V Utevsky and John M Pearson and Michael L Platt},
doi = {10.1073/pnas.1514761112},
year = {2015},
date = {2015-01-01},
journal = {Proceedings of the National Academy of Sciences},
volume = {112},
number = {52},
pages = {16012--16017},
abstract = {SignificanceMaking social decisions requires evaluation of benefits and costs to self and others. Long associated with emotion and vigilance, neurons in primate amygdala also signal reward and punishment as well as information about the faces and eyes of others. Here we show that neurons in the basolateral amygdala signal the value of rewards for self and others when monkeys make social decisions. These value-mirroring neurons reflected monkeys tendency to make prosocial decisions on a momentary as well as long-term basis. We also found that delivering the social peptide oxytocin into basolateral amygdala enhances both prosocial tendencies and attention to the recipients of prosocial decisions. Our findings endorse the amygdala as a critical neural nexus regulating social decisions. Social decisions require evaluation of costs and benefits to oneself and others. Long associated with emotion and vigilance, the amygdala has recently been implicated in both decision-making and social behavior. The amygdala signals reward and punishment, as well as facial expressions and the gaze of others. Amygdala damage impairs social interactions, and the social neuropeptide oxytocin (OT) influences human social decisions, in part, by altering amygdala function. Here we show in monkeys playing a modified dictator game, in which one individual can donate or withhold rewards from another, that basolateral amygdala (BLA) neurons signaled social preferences both across trials and across days. BLA neurons mirrored the value of rewards delivered to self and others when monkeys were free to choose but not when the computer made choices for them. We also found that focal infusion of OT unilaterally into BLA weakly but significantly increased both the frequency of prosocial decisions and attention to recipients for context-specific prosocial decisions, endorsing the hypothesis that OT regulates social behavior, in part, via amygdala neuromodulation. Our findings demonstrate both neurophysiological and neuroendocrinological connections between primate amygdala and social decisions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

SignificanceMaking social decisions requires evaluation of benefits and costs to self and others. Long associated with emotion and vigilance, neurons in primate amygdala also signal reward and punishment as well as information about the faces and eyes of others. Here we show that neurons in the basolateral amygdala signal the value of rewards for self and others when monkeys make social decisions. These value-mirroring neurons reflected monkeys tendency to make prosocial decisions on a momentary as well as long-term basis. We also found that delivering the social peptide oxytocin into basolateral amygdala enhances both prosocial tendencies and attention to the recipients of prosocial decisions. Our findings endorse the amygdala as a critical neural nexus regulating social decisions. Social decisions require evaluation of costs and benefits to oneself and others. Long associated with emotion and vigilance, the amygdala has recently been implicated in both decision-making and social behavior. The amygdala signals reward and punishment, as well as facial expressions and the gaze of others. Amygdala damage impairs social interactions, and the social neuropeptide oxytocin (OT) influences human social decisions, in part, by altering amygdala function. Here we show in monkeys playing a modified dictator game, in which one individual can donate or withhold rewards from another, that basolateral amygdala (BLA) neurons signaled social preferences both across trials and across days. BLA neurons mirrored the value of rewards delivered to self and others when monkeys were free to choose but not when the computer made choices for them. We also found that focal infusion of OT unilaterally into BLA weakly but significantly increased both the frequency of prosocial decisions and attention to recipients for context-specific prosocial decisions, endorsing the hypothesis that OT regulates social behavior, in part, via amygdala neuromodulation. Our findings demonstrate both neurophysiological and neuroendocrinological connections between primate amygdala and social decisions.

Mircea I Chelaru; Valentin Dragoi

Negative correlations in visual cortical networks Journal Article

Cerebral Cortex, 26 (1), pp. 246–256, 2016.

Abstract | Links | BibTeX

@article{Chelaru2016,
title = {Negative correlations in visual cortical networks},
author = {Mircea I Chelaru and Valentin Dragoi},
doi = {10.1093/cercor/bhu207},
year = {2016},
date = {2016-01-01},
journal = {Cerebral Cortex},
volume = {26},
number = {1},
pages = {246--256},
abstract = {The amount of information encoded by cortical circuits depends critically on the capacity of nearby neurons to exhibit trial-to-trial (noise) correlations in their responses. Depending on their sign and relationship to signal correlations, noise correlations can either increase or decrease the population code accuracy relative to uncorrelated neuronal firing. Whereas positive noise correlations have been extensively studied using experimental and theoretical tools, the functional role of negative correlations in cortical circuits has remained elusive. We addressed this issue by performing multiple-electrode recording in the superficial layers of the primary visual cortex (V1) of alert monkey. Despite the fact that positive noise correlations decayed exponentially with the difference in the orientation preference between cells, negative correlations were uniformly distributed across the population. Using a statistical model for Fisher Information estimation, we found that a mild increase in negative correlations causes a sharp increase in network accuracy even when mean correlations were held constant. To examine the variables controlling the strength of negative correlations, we implemented a recurrent spiking network model of V1. We found that increasing local inhibition and reducing excitation causes a decrease in the firing rates of neurons while increasing the negative noise correlations, which in turn increase the population signal-to-noise ratio and network accuracy. Altogether, these results contribute to our understanding of the neuronal mechanism involved in the generation of negative correlations and their beneficial impact on cortical circuit function.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Xiaodong Chen; Feng Han; Mu-ming Poo; Yang Dan

Excitatory and suppressive receptive field subunits in awake monkey primary visual cortex (V1) Journal Article

Proceedings of the National Academy of Sciences, 104 (48), pp. 19120–19125, 2007.

Abstract | Links | BibTeX

Xiaomo Chen; Katherine Wilson Scangos; Veit Stuphorn

Supplementary motor area exerts proactive and reactive control of arm movements Journal Article

Journal of Neuroscience, 30 (44), pp. 14657–14675, 2010.

Abstract | Links | BibTeX

@article{Chen2010,
title = {Supplementary motor area exerts proactive and reactive control of arm movements},
author = {Xiaomo Chen and Katherine Wilson Scangos and Veit Stuphorn},
doi = {10.1523/JNEUROSCI.2669-10.2010},
year = {2010},
date = {2010-01-01},
journal = {Journal of Neuroscience},
volume = {30},
number = {44},
pages = {14657--14675},
abstract = {Adaptive behavior requires the ability to flexibly control actions. This can occur either proactively to anticipate task requirements, or reactively in response to sudden changes. Here we report neuronal activity in the supplementary motor area (SMA) that is correlated with both forms of behavioral control. Single-unit and multiunit activity and intracranial local field potentials (LFPs) were recorded in macaque monkeys during a stop-signal task, which elicits both proactive and reactive behavioral control. The LFP power in high- (60-150 Hz) and low- (25-40 Hz) frequency bands was significantly correlated with arm movement reaction time, starting before target onset. Multiunit and single-unit activity also showed a significant regression with reaction time. In addition, LFPs and multiunit and single-unit activity changed their activity level depending on the trial history, mirroring adjustments on the behavioral level. Together, these findings indicate that neuronal activity in the SMA exerts proactive control of arm movements by adjusting the level of motor readiness. On trials when the monkeys successfully canceled arm movements in response to an unforeseen stop signal, the LFP power, particularly in a low (10-50 Hz) frequency range, increased early enough to be causally related to the inhibition of the arm movement on those trials. This indicated that neuronal activity in the SMA is also involved in response inhibition in reaction to sudden task changes. Our findings indicate, therefore, that SMA plays a role in the proactive control of motor readiness and the reactive inhibition of unwanted movements.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Chih Yang Chen; Ziad M Hafed

Postmicrosaccadic enhancement of slow eye movements Journal Article

Journal of Neuroscience, 33 (12), pp. 5375–5386, 2013.

Abstract | Links | BibTeX

@article{Chen2013,
title = {Postmicrosaccadic enhancement of slow eye movements},
author = {Chih Yang Chen and Ziad M Hafed},
doi = {10.1523/JNEUROSCI.3703-12.2013},
year = {2013},
date = {2013-01-01},
journal = {Journal of Neuroscience},
volume = {33},
number = {12},
pages = {5375--5386},
abstract = {Active sensation poses unique challenges to sensory systems because moving the sensor necessarily alters the input sensory stream. Sensory input quality is additionally compromised if the sensor moves rapidly, as during rapid eye movements, making the period immediately after the movement critical for recovering reliable sensation. Here, we studied this immediate postmovement interval for the case of microsaccades during fixation, which rapidly jitter the "sensor" exactly when it is being voluntarily stabilized to maintain clear vision. We characterized retinal-image slip in monkeys immediately after microsaccades by analyzing postmovement ocular drifts. We observed enhanced ocular drifts by up to ~28% relative to premicrosaccade levels, and for up to ~50 ms after movement end. Moreover, we used a technique to trigger full-field image motion contingent on real-time microsaccade detection, and we used the initial ocular following response to this motion as a proxy for changes in early visual motion processing caused by microsaccades. When the full-field image motion started during microsaccades, ocular following was strongly suppressed, consistent with detrimental retinal effects of the movements. However, when the motion started after microsaccades, there was up to ~73% increase in ocular following speed, suggesting an enhanced motion sensitivity. These results suggest that the interface between even the smallest possible saccades and "fixation" includes a period of faster than usual image slip, as well as an enhanced responsiveness to image motion, and that both of these phenomena need to be considered when interpreting the pervasive neural and perceptual modulations frequently observed around the time of microsaccades.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Ming Chen; Peichao Li; Shude Zhu; Chao Han; Haoran Xu; Yang Fang; Jiaming Hu; Anna W Roe; Lu HD; Haidong D Lu

An orientation map for motion boundaries in macaque V2 Journal Article

Cerebral Cortex, 26 (1), pp. 279–287, 2016.

Abstract | Links | BibTeX

Chih Yang Chen; Lukas Sonnenberg; Simone Weller; Thede Witschel; Ziad M Hafed

Spatial frequency sensitivity in macaque midbrain Journal Article

Nature Communications, 9 (1), pp. 1–13, 2018.

Abstract | Links | BibTeX

Hoseok Choi; Seho Lee; Jeyeon Lee; Kyeongran Min; Seokbeen Lim; Jinsick Park; Kyoung ha Ahn; In Young Kim; Kyoung-Min Lee; Dong Pyo Jang

Long-term evaluation and feasibility study of the insulated screw electrode for ECoG recording Journal Article

Journal of Neuroscience Methods, 308 , pp. 261–268, 2018.

Abstract | Links | BibTeX

@article{Choi2018,
title = {Long-term evaluation and feasibility study of the insulated screw electrode for ECoG recording},
author = {Hoseok Choi and Seho Lee and Jeyeon Lee and Kyeongran Min and Seokbeen Lim and Jinsick Park and Kyoung ha Ahn and In Young Kim and Kyoung-Min Lee and Dong Pyo Jang},
doi = {10.1016/j.jneumeth.2018.06.027},
year = {2018},
date = {2018-01-01},
journal = {Journal of Neuroscience Methods},
volume = {308},
pages = {261--268},
publisher = {Elsevier},
abstract = {Background: A screw-shaped electrode can offer a compromise between signal quality and invasiveness. However, the standard screw electrode can be vulnerable to electrical noise while directly contact with the skull or skin, and the feasibility and stability for chronic implantation in primate have not been fully evaluated. New Method: We designed a novel screw electrocorticogram (ECoG) electrode composed of three parts: recording electrode, insulator, and nut. The recording electrode was made of titanium with high biocompatibility and high electrical conductivity. Zirconia is used for insulator and nut to prevent electrical noise. Result: In computer simulations, the screw ECoG with insulator showed a significantly higher performance in signal acquisition compared to the condition without insulator. In a non-human primate, using screw ECoG, clear visual-evoked potential (VEP) waveforms were obtained, VEP components were reliably maintained, and the electrode's impedance was stable during the whole evaluation period. Moreover, it showed higher SNR and wider frequency band compared to the electroencephalogram (EEG). We also observed the screw ECoG has a higher sensitivity that captures different responses on various stimuli than the EEG. Comparison: The screw ECoG showed reliable electrical characteristic and biocompatibility for three months, that shows great promise for chronic implants. These results contrasted with previous reports that general screw electrode was only applicable for acute applications. Conclusion: The suggested electrode can offer whole-brain monitoring with high signal quality and minimal invasiveness. The screw ECoG can be used to provide more in-depth understanding, not only relationship between functional networks and cognitive behavior, but also pathomechanisms in brain diseases.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Jan Churan; Farhan A Khawaja; James M G Tsui; Christopher C Pack

Brief motion stimuli preferentially activate surround-suppressed neurons in macaque visual area MT Journal Article

Current Biology, 18 (22), pp. 1–6, 2008.

Abstract | Links | BibTeX

@article{Churan2008,
title = {Brief motion stimuli preferentially activate surround-suppressed neurons in macaque visual area MT},
author = {Jan Churan and Farhan A Khawaja and James M G Tsui and Christopher C Pack},
doi = {10.1016/j.cub.2008.10.003},
year = {2008},
date = {2008-01-01},
journal = {Current Biology},
volume = {18},
number = {22},
pages = {1--6},
abstract = {Intuitively one might think that larger objects should be easier to see, and indeed performance on visual tasks generally improves with increasing stimulus size [1,2]. Recently, a remarkable exception to this rule was reported [3]: when a high-contrast, moving stimulus is presented very briefly, motion perception deteriorates as stimulus size increases. This psychophysical surround suppression has been interpreted as a correlate of the neuronal surround suppression that is commonly found in the visual cortex [3-5]. However, many visual cortical neurons lack surround suppression, and so one might expect that the brain would simply use their outputs to discriminate the motion of large stimuli. Indeed previous work has generally found that observers rely on whichever neurons are most informative about the stimulus to perform similar psychophysical tasks [6]. Here we show that the responses of neurons in the middle temporal (MT) area of macaque monkeys provide a simple resolution to this paradox. We find that surround-suppressed MT neurons integrate motion signals relatively quickly, so that by comparison non-suppressed neurons respond poorly to brief stimuli. Thus, psychophysical surround suppression for brief stimuli can be viewed as a consequence of a strategy that weights neuronal responses according to how informative they are about a given stimulus. If this interpretation is correct, then it follows that any psychophysical experiment that uses brief motion stimuli will effectively probe the responses of MT neurons that have strong surround suppression.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Jan Churan; Daniel Guitton; Christopher C Pack

Context dependence of receptive field remapping in superior colliculus Journal Article

Journal of Neurophysiology, 106 (4), pp. 1862–1874, 2011.

Abstract | Links | BibTeX

@article{Churan2011,
title = {Context dependence of receptive field remapping in superior colliculus},
author = {Jan Churan and Daniel Guitton and Christopher C Pack},
doi = {10.1152/jn.00288.2011},
year = {2011},
date = {2011-01-01},
journal = {Journal of Neurophysiology},
volume = {106},
number = {4},
pages = {1862--1874},
abstract = {Our perception of the positions of objects in our surroundings is surprisingly unaffected by movements of the eyes, head, and body. This suggests that the brain has a mechanism for maintaining perceptual stability, based either on the spatial relationships among visible objects or internal copies of its own motor commands. Strong evidence for the latter mechanism comes from the remapping of visual receptive fields that occurs around the time of a saccade. Remapping occurs when a single neuron responds to visual stimuli placed presaccadically in the spatial location that will be occupied by its receptive field after the completion of a saccade. Although evidence for remapping has been found in many brain areas, relatively little is known about how it interacts with sensory context. This interaction is important for understanding perceptual stability more generally, as the brain may rely on extraretinal signals or visual signals to different degrees in different contexts. Here, we have studied the interaction between visual stimulation and remapping by recording from single neurons in the superior colliculus of the macaque monkey, using several different visual stimulus conditions. We find that remapping responses are highly sensitive to low-level visual signals, with the overall luminance of the visual background exerting a particularly powerful influence. Specifically, although remapping was fairly common in complete darkness, such responses were usually decreased or abolished in the presence of modest background illumination. Thus the brain might make use of a strategy that emphasizes visual landmarks over extraretinal signals whenever the former are available.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Jan Churan; Daniel Guitton; Christopher C Pack

Perisaccadic remapping and rescaling of visual responses in macaque superior colliculus Journal Article

PLoS ONE, 7 (12), pp. 1–10, 2012.

Abstract | Links | BibTeX

@article{Churan2012,
title = {Perisaccadic remapping and rescaling of visual responses in macaque superior colliculus},
author = {Jan Churan and Daniel Guitton and Christopher C Pack},
doi = {10.1371/journal.pone.0052195},
year = {2012},
date = {2012-01-01},
journal = {PLoS ONE},
volume = {7},
number = {12},
pages = {1--10},
publisher = {10. 1371/journal.pone.0052195},
address = {e52195. doi},
abstract = {Visual neurons have spatial receptive fields that encode the positions of objects relative to the fovea. Because foveate animals execute frequent saccadic eye movements, this position information is constantly changing, even though the visual world is generally stationary. Interestingly, visual receptive fields in many brain regions have been found to exhibit changes in strength, size, or position around the time of each saccade, and these changes have often been suggested to be involved in the maintenance of perceptual stability. Crucial to the circuitry underlying perisaccadic changes in visual receptive fields is the superior colliculus (SC), a brainstem structure responsible for integrating visual and oculomotor signals. In this work we have studied the time-course of receptive field changes in the SC. We find that the distribution of the latencies of SC responses to stimuli placed outside the fixation receptive field is bimodal: The first mode is comprised of early responses that are temporally locked to the onset of the visual probe stimulus and stronger for probes placed closer to the classical receptive field. We suggest that such responses are therefore consistent with a perisaccadic rescaling, or enhancement, of weak visual responses within a fixed spatial receptive field. The second mode is more similar to the remapping that has been reported in the cortex, as responses are time-locked to saccade onset and stronger for stimuli placed in the postsaccadic receptive field location. We suggest that these two temporal phases of spatial updating may represent different sources of input to the SC.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Jan Churan; Doris I Braun; Karl R Gegenfurtner; Frank Bremmer

Comparison of the precision of smooth pursuit in humans and head unrestrained monkeys Journal Article

Journal of Eye Movement Research, 11 (4), pp. 1–15, 2018.

Abstract | Links | BibTeX

Evy Cleeren; Cindy Casteels; Karolien Goffin; Peter Janssen; Wim Van Paesschen

Ictal perfusion changes associated with seizure progression in the amygdala kindling model in the rhesus monkey Journal Article

Epilepsia, 56 (9), pp. 1366–1375, 2015.

Abstract | Links | BibTeX

Michael Colombo; James S Magnuson

Eye movements reveal planning in humans: A comparison with Scarf and Colombo's (2009) monkeys Journal Article

Journal of Experimental Psychology: Animal Learning and Cognition, 40 (2), pp. 178–184, 2014.

Abstract | Links | BibTeX

Benjamin W Corrigan; Roberto A Gulli; Guillaume Doucet; Julio C Martinez-Trujillo

Characterizing eye movement behaviors and kinematics of non-human primates during virtual navigation tasks Journal Article

Journal of Vision, 17 (12), pp. 1–22, 2017.

Abstract | Links | BibTeX

@article{Corrigan2017,
title = {Characterizing eye movement behaviors and kinematics of non-human primates during virtual navigation tasks},
author = {Benjamin W Corrigan and Roberto A Gulli and Guillaume Doucet and Julio C Martinez-Trujillo},
doi = {10.1167/17.12.15},
year = {2017},
date = {2017-01-01},
journal = {Journal of Vision},
volume = {17},
number = {12},
pages = {1--22},
abstract = {Virtual environments (VE) allow testing complex behaviors in naturalistic settings by combining highly controlled visual stimuli with spatial navigation and other cognitive tasks. They also allow for the recording of eye movements using high-precision eye tracking techniques, which is important in electrophysiological studies examining the response properties of neurons in visual areas of nonhuman primates. However, during virtual navigation, the pattern of retinal stimulation can be highly dynamic which may influence eye movements. Here we examine whether and how eye movement patterns change as a function of dynamic visual stimulation during virtual navigation tasks, relative to standard oculomotor tasks. We trained two rhesus macaques to use a joystick to navigate in a VE to complete two tasks. To contrast VE behavior with classic measurements, the monkeys also performed a simple Cued Saccade task. We used a robust algorithm for rapid classification of saccades, fixations, and smooth pursuits. We then analyzed the kinematics of saccades during all tasks, and specifically during different phases of the VE tasks. We found that fixation to smooth pursuit ratios were smaller in VE tasks (4:5) compared to the Cued Saccade task (7:1), reflecting a more intensive use of smooth pursuit to foveate targets in VE than in a standard visually guided saccade task or during spontaneous fixations. Saccades made to rewarded targets (exploitation) tended to have increased peak velocities compared to saccades made to unrewarded objects (exploration). VE exploitation saccades were 6% slower than saccades to discrete targets in the Cued Saccade task. Virtual environments represent a technological advance in experimental design for nonhuman primates. Here we provide a framework to study the ways that eye movements change between and within static and dynamic displays.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Joshua D Cosman; Kaleb A Lowe; Wolf Zinke; Geoffrey F Woodman; Jeffrey D Schall

Prefrontal control of visual distraction Journal Article

Current Biology, 28 (3), pp. 414–420, 2018.

Abstract | Links | BibTeX

@article{Cosman2018,
title = {Prefrontal control of visual distraction},
author = {Joshua D Cosman and Kaleb A Lowe and Wolf Zinke and Geoffrey F Woodman and Jeffrey D Schall},
doi = {10.1016/j.cub.2017.12.023},
year = {2018},
date = {2018-02-01},
journal = {Current Biology},
volume = {28},
number = {3},
pages = {414--420},
abstract = {Avoiding distraction by conspicuous but irrelevant stimuli is critical to accomplishing daily tasks. Regions of prefrontal cortex control attention by enhancing the representation of task-relevant information in sensory cortex, which can be measured in modulation of both single neurons and event-related electrical potentials (ERPs) on the cranial surface [1, 2]. When irrelevant information is particularly conspicuous, it can distract attention and interfere with the selection of behaviorally relevant information. Such distraction can be minimized via top-down control [3–5], but the cognitive and neural mechanisms giving rise to this control over distraction remain uncertain and debated [6–9]. Bridging neurophysiology to electrophysiology, we simultaneously recorded neurons in prefrontal cortex and ERPs over extrastriate visual cortex to track the processing of salient distractors during a visual search task. Critically, when the salient distractor was successfully ignored, but not otherwise, we observed robust suppression of salient distractor representations. Like target selection, the distractor suppression was observed in prefrontal cortex before it appeared over extrastriate cortical areas. Furthermore, all prefrontal neurons that showed suppression of the task-irrelevant distractor also contributed to selecting the target. This suggests a common prefrontal mechanism is responsible for both selecting task-relevant and suppressing task-irrelevant information in sensory cortex. Taken together, our results resolve a long-standing debate over the mechanisms that prevent distraction, and provide the first evidence directly linking suppressed neural firing in prefrontal cortex with surface ERP measures of distractor suppression.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Gabriela M Costello; Dantong Zhu; Emilio Salinas; Terrence R Stanford

Perceptual modulation of motor-but not visual-responses in the frontal eye field during an urgent-decision task Journal Article

Journal of Neuroscience, 33 (41), pp. 16394–16408, 2013.

Abstract | Links | BibTeX

@article{Costello2013,
title = {Perceptual modulation of motor-but not visual-responses in the frontal eye field during an urgent-decision task},
author = {Gabriela M Costello and Dantong Zhu and Emilio Salinas and Terrence R Stanford},
doi = {10.1523/JNEUROSCI.1899-13.2013},
year = {2013},
date = {2013-01-01},
journal = {Journal of Neuroscience},
volume = {33},
number = {41},
pages = {16394--16408},
abstract = {Neuronal activity in the frontal eye field (FEF) ranges from purely motor (related to saccade production) to purely visual (related to stimulus presence). According to numerous studies, visual responses correlate strongly with early perceptual analysis of the visual scene, including the deployment of spatial attention, whereas motor responses do not. Thus, functionally, the consensus is that visually responsive FEF neurons select a target among visible objects, whereas motor-related neurons plan specific eye movements based on such earlier target selection. However, these conclusions are based on behavioral tasks that themselves promote a serial arrangement of perceptual analysis followed by motor planning. So, is the presumed functional hierarchy in FEF an intrinsic property of its circuitry or does it reflect just one possible mode of operation? We investigate this in monkeys performing a rapid-choice task in which, crucially, motor planning always starts ahead of task-critical perceptual analysis, and the two relevant spatial locations are equally informative and equally likely to be target or distracter. We find that the choice is instantiated in FEF as a competition between oculomotor plans, in agreement with model predictions. Notably, although perception strongly influences the motor neurons, it has little if any measurable impact on the visual cells; more generally, the more dominant the visual response, the weaker the perceptual modulation. The results indicate that, contrary to expectations, during rapid saccadic choices perceptual information may directly modulate ongoing saccadic plans, and this process is not contingent on prior selection of the saccadic goal by visually driven FEF responses.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Gabriela M Costello; Dantong Zhu; Paul J May; Emilio Salinas; Terrence R Stanford

Task dependence of decision- and choice-related activity in monkey oculomotor thalamus Journal Article

Journal of Neurophysiology, 115 (1), pp. 581–601, 2016.

Abstract | Links | BibTeX

@article{Costello2016,
title = {Task dependence of decision- and choice-related activity in monkey oculomotor thalamus},
author = {Gabriela M Costello and Dantong Zhu and Paul J May and Emilio Salinas and Terrence R Stanford},
doi = {10.1152/jn.00592.2015},
year = {2016},
date = {2016-01-01},
journal = {Journal of Neurophysiology},
volume = {115},
number = {1},
pages = {581--601},
abstract = {Oculomotor signals circulate within putative recurrent feedback loops that include the frontal eye field (FEF) and the oculomotor thalamus (OcTh). To examine how OcTh contributes to visuomotor control, and perceptually informed saccadic choices in particular, neural correlates of perceptual judgment and motor selection in OcTh were evaluated and compared with those previously reported for FEF in the same subjects. Monkeys performed three tasks: a choice task in which perceptual decisions are urgent, a choice task in which identical decisions are made without time pressure, and a single-target, delayed saccade task. The OcTh yielded far fewer task-responsive neurons than the FEF, but across responsive pools, similar neuron types were found, ranging from purely visual to purely saccade related. Across such types, the impact of the perceptual information relevant to saccadic choices was qualitatively the same in FEF and OcTh. However, distinct from that in FEF, activity in OcTh was strongly task dependent, typically being most vigorous in the urgent task, less so in the easier choice task, and least in the single-target task. This was true for responsive and nonresponsive cells alike. Neurons with exclusively motor-related activity showed strong task dependence, fired less, and differed most patently from their FEF counterparts, whereas those that combined visual and motor activity fired most similarly to their FEF counterparts. The results suggest that OcTh activity is more distantly related to saccade production per se, because its degree of commitment to a motor choice varies markedly as a function of ongoing cognitive or behavioral demands.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

David D Cox; Alexander M Papanastassiou; Daniel Oreper; Benjamin B Andken; James J DiCarlo

High-resolution three-dimensional microelectrode brain mapping using stereo microfocal x-ray imaging Journal Article

Journal of Neurophysiology, 100 (5), pp. 2966–2976, 2008.

Abstract | Links | BibTeX

Michele A Cox; Michael C Schmid; Andrew J Peters; Richard C Saunders; David A Leopold; Alexander Maier

Receptive field focus of visual area V4 neurons determines responses to illusory surfaces Journal Article

Proceedings of the National Academy of Sciences, 110 (42), pp. 17095–17100, 2013.

Abstract | Links | BibTeX

Michele A Cox; Kacie Dougherty; Geoffrey K Adams; Eric A Reavis; Jacob A Westerberg; Brandon S Moore; David A Leopold; Alexander Maier

Spiking suppression precedes cued attentional enhancement of neural responses in primary visual Cortex Journal Article

Cerebral Cortex, 29 (1), pp. 77–90, 2017.

Abstract | Links | BibTeX

Yuwei Cui; Liu D Liu; Farhan A Khawaja; Christopher C Pack; Daniel A Butts

Diverse suppressive Iinfluences in area MT and selectivity to complex motion features Journal Article

Journal of Neuroscience, 33 (42), pp. 16715–16728, 2013.

Abstract | Links | BibTeX

@article{Cui2013cb,
title = {Diverse suppressive Iinfluences in area MT and selectivity to complex motion features},
author = {Yuwei Cui and Liu D Liu and Farhan A Khawaja and Christopher C Pack and Daniel A Butts},
doi = {10.1523/JNEUROSCI.0203-13.2013},
year = {2013},
date = {2013-01-01},
journal = {Journal of Neuroscience},
volume = {33},
number = {42},
pages = {16715--16728},
abstract = {Neuronal selectivity results from both excitatory and suppressive inputs to a given neuron. Suppressive influences can often significantly modulate neuronal responses and impart novel selectivity in the context of behaviorally relevant stimuli. In this work, we use a naturalistic optic flow stimulus to explore the responses of neurons in the middle temporal area (MT) of the alert macaque monkey; these responses are interpreted using a hierarchical model that incorporates relevant nonlinear properties of upstream processing in the primary visual cortex (V1). In this stimulus context, MT neuron responses can be predicted from distinct excitatory and suppressive components. Excitation is spatially localized and matches the measured preferred direction of each neuron. Suppression is typically composed of two distinct components: (1) a directionally untuned component, which appears to play the role of surround suppression and normalization; and (2) a direction-selective component, with comparable tuning width as excitation and a distinct spatial footprint that is usually partially overlapping with excitation. The direction preference of this direction-tuned suppression varies widely across MT neurons: approximately one-third have overlapping suppression in the opposite direction as excitation, and many other neurons have suppression with similar direction preferences to excitation. There is also a population of MT neurons with orthogonally oriented suppression. We demonstrate that direction-selective suppression can impart selectivity of MT neurons to more complex velocity fields and that it can be used for improved estimation of the three-dimensional velocity of moving objects. Thus, considering MT neurons in a complex stimulus context reveals a diverse set of computations likely relevant for visual processing in natural visual contexts.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Yuwei Cui; Liu D Liu; James M McFarland; Christopher C Pack; Daniel A Butts

Inferring cortical variability from local field potentials Journal Article

Journal of Neuroscience, 36 (14), pp. 4121–4135, 2016.

Abstract | Links | BibTeX

Olga Dal Monte; Matthew Piva; Jason A Morris; Steve W C Chang

Live interaction distinctively shapes social gaze dynamics in rhesus macaques Journal Article

Journal of Neurophysiology, 116 (4), pp. 1626–1643, 2016.

Abstract | Links | BibTeX

Olga Dal Monte; Matthew Piva; Kevin M Anderson; Marios Tringides; Avram J Holmes; Steve W C Chang

Oxytocin under opioid antagonism leads to supralinear enhancement of social attention Journal Article

Proceedings of the National Academy of Sciences, 114 (20), pp. 5247–5252, 2017.

Abstract | Links | BibTeX

Suryadeep Dash; Tyler R Peel; Stephen G Lomber; Brian D Corneil

Frontal eye field inactivation reduces saccade preparation in the superior colliculus but does not alter how preparatory activity relates to saccades of a given latency Journal Article

Eneuro, 5 (2), pp. 1–16, 2018.

Abstract | Links | BibTeX

@article{Dash2018,
title = {Frontal eye field inactivation reduces saccade preparation in the superior colliculus but does not alter how preparatory activity relates to saccades of a given latency},
author = {Suryadeep Dash and Tyler R Peel and Stephen G Lomber and Brian D Corneil},
doi = {10.1523/eneuro.0024-18.2018},
year = {2018},
date = {2018-01-01},
journal = {Eneuro},
volume = {5},
number = {2},
pages = {1--16},
abstract = {A neural correlate for saccadic reaction times (SRTs) in the gap saccade task is the level of low-frequency activity in the intermediate layers of the superior colliculus (iSC) just before visual target onset: greater levels of such preparatory iSC low-frequency activity precede shorter SRTs. The frontal eye fields (FEFs) are one likely source of iSC preparatory activity, since FEF preparatory activity is also inversely related to SRT. To better understand the FEF's role in saccade preparation, and the way in which such preparation relates to SRT, in two male rhesus monkeys, we compared iSC preparatory activity across unilateral reversible cryogenic inactivation of the FEF. FEF inactivation increased contralesional SRTs, and lowered ipsilesional iSC preparatory activity. FEF inactivation also reduced rostral iSC activity during the gap period. Importantly, the distributions of SRTs generated with or without FEF inactivation overlapped, enabling us to conduct a novel population-level analyses examining iSC preparatory activity just before generation of SRT-matched saccades. When matched for SRTs, we observed no change during FEF inactivation in the relationship between iSC preparatory activity and SRT-matched saccades across a range of SRTs, even for the occasional express saccade. Thus, while our results emphasize that the FEF has an overall excitatory influence on preparatory activity in the iSC, the communication between the iSC and downstream oculomotor brainstem is unaltered for SRT-matched saccades.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

S V David; B Y Hayden; J L Gallant

Spectral receptive field properties explain shape selectivity in area V4 Journal Article

Journal of Neurophysiology, 96 (6), pp. 3492–3505, 2006.

Abstract | Links | BibTeX

@article{David2006,
title = {Spectral receptive field properties explain shape selectivity in area V4},
author = {S V David and B Y Hayden and J L Gallant},
doi = {10.1152/jn.00575.2006},
year = {2006},
date = {2006-01-01},
journal = {Journal of Neurophysiology},
volume = {96},
number = {6},
pages = {3492--3505},
abstract = {Neurons in cortical area V4 respond selectively to complex visual patterns such as curved contours and non-Cartesian gratings. Most previous experiments in V4 have measured responses to small, idiosyncratic stimulus sets and no single functional model yet accounts for all of the disparate results. We propose that one model, the spectral receptive field (SRF), can explain many observations of selectivity in V4. The SRF describes tuning in terms of the orientation and spatial frequency spectrum and can, in principle, predict the response to any visual stimulus. We estimated SRFs for neurons in V4 of awake primates by linearized reverse correlation of responses to a large set of natural images. We find that V4 neurons have large orientation and spatial frequency bandwidth and often bimodal orientation tuning. For comparison, we estimated SRFs for neurons in primary visual cortex (V1). Consistent with previous observations, we find that V1 neurons have narrower bandwidth than that of V4. To determine whether estimated SRFs can account for previous observations of selectivity, we used them to predict responses to Cartesian gratings, non-Cartesian gratings, natural images, and curved contours. Based on these predictions, we find that the majority of neurons in V1 are selective for Cartesian gratings, whereas the majority of V4 neurons are selective for non-Cartesian gratings or natural images. The SRF describes visual tuning properties with a second-order nonlinear model. These results support the hypothesis that a second-order model is sufficient to describe the general mechanisms mediating shape selectivity in area V4.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Stephen V David; Benjamin Y Hayden; James A Mazer; Jack L Gallant

Attention to stimulus features shifts spectral tuning of V4 neurons during natural vision Journal Article

Neuron, 59 (3), pp. 509–521, 2008.

Abstract | Links | BibTeX

T S Davis; K Torab; P House; B Greger

A minimally invasive approach to long-term head fixation in behaving nonhuman primates Journal Article

Journal of Neuroscience Methods, 181 (1), pp. 106–110, 2009.

Abstract | Links | BibTeX

T S Davis; R A Parker; P A House; E Bagley; S Wendelken; R A Normann; B Greger

Spatial and temporal characteristics of V1 microstimulation during chronic implantation of a microelectrode array in a behaving macaque Journal Article

Journal of Neural Engineering, 9 (6), pp. 1–12, 2012.

Abstract | Links | BibTeX

@article{Davis2012,
title = {Spatial and temporal characteristics of V1 microstimulation during chronic implantation of a microelectrode array in a behaving macaque},
author = {T S Davis and R A Parker and P A House and E Bagley and S Wendelken and R A Normann and B Greger},
doi = {10.1088/1741-2560/9/6/065003},
year = {2012},
date = {2012-01-01},
journal = {Journal of Neural Engineering},
volume = {9},
number = {6},
pages = {1--12},
abstract = {OBJECTIVE: It has been hypothesized that a vision prosthesis capable of evoking useful visual percepts can be based upon electrically stimulating the primary visual cortex (V1) of a blind human subject via penetrating microelectrode arrays. As a continuation of earlier work, we examined several spatial and temporal characteristics of V1 microstimulation. APPROACH: An array of 100 penetrating microelectrodes was chronically implanted in V1 of a behaving macaque monkey. Microstimulation thresholds were measured using a two-alternative forced choice detection task. Relative locations of electrically-evoked percepts were measured using a memory saccade-to-target task. MAIN RESULTS: The principal finding was that two years after implantation we were able to evoke behavioural responses to electric stimulation across the spatial extent of the array using groups of contiguous electrodes. Consistent responses to stimulation were evoked at an average threshold current per electrode of 204 ± 49 µA (mean ± std) for groups of four electrodes and 91 ± 25 µA for groups of nine electrodes. Saccades to electrically-evoked percepts using groups of nine electrodes showed that the animal could discriminate spatially distinct percepts with groups having an average separation of 1.6 ± 0.3 mm (mean ± std) in cortex and 1.0° ± 0.2° in visual space. Significance. These results demonstrate chronic perceptual functionality and provide evidence for the feasibility of a cortically-based vision prosthesis for the blind using penetrating microelectrodes.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Thomas Deffieux; Youliana Younan; Nicolas Wattiez; Mickael Tanter; Pierre Pouget; Jean François Aubry

Low-intensity focused ultrasound modulates monkey visuomotor behavior Journal Article

Current Biology, 23 , pp. 2430–2433, 2013.

Abstract | Links | BibTeX

Mohammad-Reza A Dehaqani; Abdol-Hossein Vahabie; Mohammadbagher Parsa; Behrad Noudoost; Alireza Soltani

Selective changes in noise correlations contribute to an enhanced representation of saccadic targets in prefrontal neuronal ensembles Journal Article

Cerebral Cortex, 28 (8), pp. 3046–3063, 2018.

Abstract | Links | BibTeX

T M Desrochers; D Z Jin; N D Goodman; A M Graybiel

Optimal habits can develop spontaneously through sensitivity to local cost Journal Article

Proceedings of the National Academy of Sciences, 107 (47), pp. 20512–20517, 2010.

Abstract | Links | BibTeX

@article{Desrochers2010,
title = {Optimal habits can develop spontaneously through sensitivity to local cost},
author = {T M Desrochers and D Z Jin and N D Goodman and A M Graybiel},
doi = {10.1073/pnas.1013470107},
year = {2010},
date = {2010-01-01},
journal = {Proceedings of the National Academy of Sciences},
volume = {107},
number = {47},
pages = {20512--20517},
abstract = {Habits and rituals are expressed universally across animal species. These behaviors are advantageous in allowing sequential behaviors to be performed without cognitive overload, and appear to rely on neural circuits that are relatively benign but vulnerable to takeover by extreme contexts, neuropsychiatric sequelae, and processes leading to addiction. Reinforcement learning (RL) is thought to underlie the formation of optimal habits. However, this theoretic formulation has principally been tested experimentally in simple stimulus-response tasks with relatively few available responses. We asked whether RL could also account for the emergence of habitual action sequences in realistically complex situations in which no repetitive stimulus-response links were present and in which many response options were present. We exposed naïve macaque monkeys to such experimental conditions by introducing a unique free saccade scan task. Despite the highly uncertain conditions and no instruction, the monkeys developed a succession of stereotypical, self-chosen saccade sequence patterns. Remarkably, these continued to morph for months, long after session-averaged reward and cost (eye movement distance) reached asymptote. Prima facie, these continued behavioral changes appeared to challenge RL. However, trial-by-trial analysis showed that pattern changes on adjacent trials were predicted by lowered cost, and RL simulations that reduced the cost reproduced the monkeys' behavior. Ultimately, the patterns settled into stereotypical saccade sequences that minimized the cost of obtaining the reward on average. These findings suggest that brain mechanisms underlying the emergence of habits, and perhaps unwanted repetitive behaviors in clinical disorders, could follow RL algorithms capturing extremely local explore/exploit tradeoffs.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

Nicholas K DeWind; Jiyun Peng; Andrew Luo; Elizabeth M Brannon; Michael L Platt

Pharmacological inactivation does not support a unique causal role for intraparietal sulcus in the discrimination of visual number Journal Article

PLoS ONE, 12 (12), pp. 1–23, 2017.

Abstract | Links | BibTeX

Kacie Dougherty; Michele A Cox; Taihei Ninomiya; David A Leopold; Alexander Maier

Ongoing alpha activity in V1 regulates visually driven spiking responses Journal Article

Cerebral Cortex, 27 (2), pp. 1113–1124, 2017.

Abstract | Links | BibTeX

Ilse Van C Dromme; Elsie Premereur; Bram-Ernst Verhoef; Wim Vanduffel

Posterior parietal cortex drives inferotemporal activations during three- dimensional object vision Journal Article

PloS Biology, 14 (4), pp. 1–26, 2016.

Abstract | Links | BibTeX

Caroline B Drucker; Monica L Carlson; Koji Toda; Nicholas K DeWind; Michael L Platt

Non-invasive primate head restraint using thermoplastic masks. Journal Article

Journal of Neuroscience Methods, 253 , pp. 90–100, 2015.

Abstract | Links | BibTeX

Jacob Duijnhouwer; Bart Krekelberg

Evidence and counterevidence in motion perception Journal Article

Cerebral Cortex, 26 , pp. 4602–4612, 2016.

Abstract | Links | BibTeX

S L Eagleman; V Dragoi

Image sequence reactivation in awake V4 networks Journal Article

Proceedings of the National Academy of Sciences, 109 (47), pp. 19450–19455, 2012.

Abstract | Links | BibTeX

Becket R Ebitz; Karli K Watson; Michael L Platt

Oxytocin blunts social vigilance in the rhesus macaque Journal Article

Proceedings of the National Academy of Sciences, 110 (28), pp. 11630–11635, 2013.

Abstract | Links | BibTeX

Becket R Ebitz; John M Pearson; Michael L Platt

Pupil size and social vigilance in rhesus macaques Journal Article

Frontiers in Neuroscience, 8 (8 MAY), pp. 1–13, 2014.

Abstract | Links | BibTeX

@article{Ebitz2014,
title = {Pupil size and social vigilance in rhesus macaques},
author = {Becket R Ebitz and John M Pearson and Michael L Platt},
doi = {10.3389/fnins.2014.00100},
year = {2014},
date = {2014-01-01},
journal = {Frontiers in Neuroscience},
volume = {8},
number = {8 MAY},
pages = {1--13},
abstract = {Complex natural environments favor the dynamic alignment of neural processing between goal-relevant stimuli and conflicting but biologically salient stimuli like social competitors or predators. The biological mechanisms that regulate dynamic changes in vigilance have not been fully elucidated. Arousal systems that ready the body to respond adaptively to threat may contribute to dynamic regulation of vigilance. Under conditions of constant luminance, pupil diameter provides a peripheral index of arousal state. Although pupil size varies with the processing of goal-relevant stimuli, it remains unclear whether pupil size also predicts attention to biologically salient objects and events like social competitors, whose presence interferes with current goals. Here we show that pupil size in rhesus macaques both reflects the biological salience of task-irrelevant social distractors and predicts vigilance for these stimuli. We measured pupil size in monkeys performing a visual orienting task in which distractors-monkey faces and phase-scrambled versions of the same images-could appear in a congruent, incongruent, or neutral position relative to a rewarded target. Baseline pupil size under constant illumination predicted distractor interference, consistent with the hypothesis that pupil-linked arousal mechanisms regulate task engagement and distractibility. Notably, pupil size also predicted enhanced vigilance for social distractors, suggesting that pupil-linked arousal may adjust the balance of processing resources between goal-relevant and biologically important stimuli. The magnitude of pupil constriction in response to distractors closely tracked distractor interference, saccade planning and the social relevance of distractors, endorsing the idea that the pupillary light response is modulated by attention. These findings indicate that pupil size indexes dynamic changes in attention evoked by both the social environment and arousal.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

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