scholarly journals Task-related activity in human visual cortex

PLoS Biology ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. e3000921
Author(s):  
Zvi N. Roth ◽  
Minyoung Ryoo ◽  
Elisha P. Merriam
Keyword(s):  
Visual Cortex ◽  
Optical Imaging ◽  
Visual Stimulation ◽  
Field Of View ◽  
Imaging Studies ◽  
Related Activity ◽  
Temporal Precision ◽  
Human Participants ◽  
Visual Cortical ◽  
The Brain

The brain exhibits widespread endogenous responses in the absence of visual stimuli, even at the earliest stages of visual cortical processing. Such responses have been studied in monkeys using optical imaging with a limited field of view over visual cortex. Here, we used functional MRI (fMRI) in human participants to study the link between arousal and endogenous responses in visual cortex. The response that we observed was tightly entrained to task timing, was spatially extensive, and was independent of visual stimulation. We found that this response follows dynamics similar to that of pupil size and heart rate, suggesting that task-related activity is related to arousal. Finally, we found that higher reward increased response amplitude while decreasing its trial-to-trial variability (i.e., the noise). Computational simulations suggest that increased temporal precision underlies both of these observations. Our findings are consistent with optical imaging studies in monkeys and support the notion that arousal increases precision of neural activity.

scholarly journals Focal Electrical Stimulation of Cortical Functional Networks

2020 ◽  
Vol 30 (10) ◽  
pp. 5532-5543 ◽  
Author(s):  
Jia Ming Hu ◽  
Mei Zhen Qian ◽  
Hisashi Tanigawa ◽  
Xue Mei Song ◽  
Anna Wang Roe
Keyword(s):  
Electrical Stimulation ◽  
Visual Cortex ◽  
Functional Organization ◽  
Visual Stimulation ◽  
Prosthetic Design ◽  
Single Feature ◽  
Selective Targeting ◽  
Visual Cortical ◽  
The Brain ◽  
Stimulation Of

Abstract Traditional electrical stimulation of brain tissue typically affects relatively large volumes of tissue spanning multiple millimeters. This low spatial resolution stimulation results in nonspecific functional effects. In addition, a primary shortcoming of these designs was the failure to take advantage of inherent functional organization in the cerebral cortex. Here, we describe a new method to electrically stimulate the brain which achieves selective targeting of single feature-specific domains in visual cortex. We provide evidence that this paradigm achieves mesoscale, functional network-specificity, and intensity dependence in a way that mimics visual stimulation. Application of this approach to known feature domains (such as color, orientation, motion, and depth) in visual cortex may lead to important functional improvements in the specificity and sophistication of brain stimulation methods and has implications for visual cortical prosthetic design.

Predictability-dependent encoding of statistical regularities in the early visual cortex

2022 ◽  
Author(s):  
Andrea Kóbor ◽  
Karolina Janacsek ◽  
Petra Hermann ◽  
Zsofia Zavecz ◽  
Vera Varga ◽  
...  
Keyword(s):  
Visual Cortex ◽  
The Other ◽  
Block Type ◽  
Statistical Knowledge ◽  
Early Visual Cortex ◽  
Statistical Regularities ◽  
Visual Cortical ◽  
Increased Activity ◽  
The Brain ◽  
Subsequent Task

Previous research recognized that humans could extract statistical regularities of the environment to automatically predict upcoming events. However, it has remained unexplored how the brain encodes the distribution of statistical regularities if it continuously changes. To investigate this question, we devised an fMRI paradigm where participants (N = 32) completed a visual four-choice reaction time (RT) task consisting of statistical regularities. Two types of blocks involving the same perceptual elements alternated with one another throughout the task: While the distribution of statistical regularities was predictable in one block type, it was unpredictable in the other. Participants were unaware of the presence of statistical regularities and of their changing distribution across the subsequent task blocks. Based on the RT results, although statistical regularities were processed similarly in both the predictable and unpredictable blocks, participants acquired less statistical knowledge in the unpredictable as compared with the predictable blocks. Whole-brain random-effects analyses showed increased activity in the early visual cortex and decreased activity in the precuneus for the predictable as compared with the unpredictable blocks. Therefore, the actual predictability of statistical regularities is likely to be represented already at the early stages of visual cortical processing. However, decreased precuneus activity suggests that these representations are imperfectly updated to track the multiple shifts in predictability throughout the task. The results also highlight that the processing of statistical regularities in a changing environment could be habitual.

Pontine projection from striate and prestriate visual cortex in the macaque monkey: An anterograde study

1990 ◽  
Vol 4 (3) ◽  
pp. 205-216 ◽  
Author(s):  
W. Fries
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Striate Cortex ◽  
Macaque Monkey ◽  
Field Of View ◽  
Central Visual Field ◽  
Tracer Techniques ◽  
Visual Areas ◽  
Visual Cortical ◽  
Anterograde Tracer

AbstractThe projection from striate and prestriate visual cortex to the pontine nuclei has been studied in the macaque monkey by means of anterograde tracer techniques in order to assess the contribution of anatomically and functionally distinct visual cortical areas to the cortico-ponto-cerebellar loop. No projection to the pons was found from central or paracentral visual-field representations of V1 (striate cortex) or prestriate visual areas V2, and V4. Small patches of terminal labeling occurred after injections of tracer into more peripheral parts of V1, V2 and V3, and into V3A. The terminal fields were located most dorsolaterally in the anterior to middle third of the pons and were quite restricted in their rostro-caudal extent. Injections of V5, however, yielded substantial terminal labeling, stretching longitudinally throughout almost the entire pons. This projection could be demonstrated to arise from parts of V5 receiving input from central visual-field representations of striate cortex, whereas parts of V4 receiving similarly central visual-field input had no detectable projection to the pons. Its distribution may overlap to a large extent with the termination of tecto-pontine fibers and with the termination of fibers from visual areas in the medial bank (area V6 or P0) and lateral bank (area LIP) of the intraparietal sulcus, as well as from frontal eye fields (FEF). It appears that the main information relayed to the cerebellum by the visual corticopontine projection is related to movement in the field of view.

scholarly journals Saccade-based termination responses in macaque V1 and visual perception

2018 ◽  
Vol 35 ◽  
Author(s):  
JAMES E. NIEMEYER ◽  
MICHAEL A. PARADISO
Keyword(s):  
Visual Cortex ◽  
Visual Perception ◽  
Firing Rate ◽  
Visual Stimulation ◽  
Saccadic Eye Movement ◽  
Perceptual Sensitivity ◽  
Neural Correlate ◽  
Visual Areas ◽  
Natural Situation ◽  
The Brain

AbstractNeurons in visual areas of the brain are generally characterized by the increase in firing rate that occurs when a stimulus is flashed on in the receptive field (RF). However, neurons also increase their firing rate when a stimulus is turned off. These “termination responses” or “after-discharges” that occur with flashed stimuli have been observed in area V1 and they may be important for vision as stimulus terminations have been shown to influence visual perception. The goal of the present study was to determine the strength of termination responses in the more natural situation in which eye movements move a stimulus out of an RF. We find that termination responses do occur in macaque V1 when termination results from a saccadic eye movement, but they are smaller in amplitude compared to flashed-off stimuli. Furthermore, there are termination responses even in the absence of visual stimulation. These findings demonstrate that termination responses are a component of naturalistic vision. They appear to be based on both visual and nonvisual signals in visual cortex. We speculate that the weakening of termination responses might be a neural correlate of saccadic suppression, the loss of perceptual sensitivity around the time of saccades.

scholarly journals Regions of Mid-level Human Visual Cortex Sensitive to the Global Coherence of Local Image Patches

2014 ◽  
Vol 26 (8) ◽  
pp. 1764-1774 ◽  
Author(s):  
Damien J. Mannion ◽  
Daniel J. Kersten ◽  
Cheryl A. Olman
Keyword(s):  
Visual Cortex ◽  
Visual Stimulation ◽  
Signal Amplitude ◽  
Global Coherence ◽  
Image Patches ◽  
Left And Right ◽  
Global Coordination ◽  
Coherent Condition ◽  
The Brain ◽  
Local Image

The global structural arrangement and spatial layout of the visual environment must be derived from the integration of local signals represented in the lower tiers of the visual system. This interaction between the spatially local and global properties of visual stimulation underlies many of our visual capacities, and how this is achieved in the brain is a central question for visual and cognitive neuroscience. Here, we examine the sensitivity of regions of the posterior human brain to the global coordination of spatially displaced naturalistic image patches. We presented observers with image patches in two circular apertures to the left and right of central fixation, with the patches drawn from either the same (coherent condition) or different (noncoherent condition) extended image. Using fMRI at 7T (n = 5), we find that global coherence affected signal amplitude in regions of dorsal mid-level cortex. Furthermore, we find that extensive regions of mid-level visual cortex contained information in their local activity pattern that could discriminate coherent and noncoherent stimuli. These findings indicate that the global coordination of local naturalistic image information has important consequences for the processing in human mid-level visual cortex.

scholarly journals Intact extrastriate visual network without primary visual cortex in a Rhesus macaque with naturally occurring Blindsight

2018 ◽  
Author(s):  
Holly Bridge ◽  
Andrew Bell ◽  
Matt Ainsworth ◽  
Jerome Sallet ◽  
Elsie Premereur ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Rhesus Macaque ◽  
Primary Visual Cortex ◽  
Visual Stimulation ◽  
Brain Structures ◽  
Macaque Monkey ◽  
Full Field ◽  
Visual Cortical ◽  
And Control ◽  
Temporally Correlated

AbstractLesions of primate primary visual cortex (V1) lead to loss of conscious visual perception, and are often devastating to those affected. Understanding the neural consequences of such damage may aid the development of rehabilitation methods. In this rare case of a Rhesus macaque (monkey S), likely born without V1, we investigated the brain structures underlying residual visual abilities using multimodal magnetic resonance imaging. In-group behaviour was unremarkable. Compared to controls, visual structures outside of monkey S’s lesion appeared normal. Visual stimulation under anaesthesia with checkerboards activated lateral geniculate nucleus of monkey S, but not the pulvinar, while full-field moving dots activated the pulvinar. Functional connectivity analysis revealed a network of bilateral dorsal visual areas temporally correlated with V5/MT, consistent across lesion and control animals. Overall, we found an intact network of visual cortical areas even without V1, but little evidence for strengthened subcortical input to V5/MT supporting residual visual function.

scholarly journals Contextual expectations shape cortical reinstatement of sensory representations

2021 ◽  
Author(s):  
Alex Clarke ◽  
Jordan E Crivelli-Decker ◽  
Charan Ranganath
Keyword(s):  
Visual Cortex ◽  
Activity Patterns ◽  
Medial Cortex ◽  
Pattern Similarity ◽  
Early Visual Cortex ◽  
Animal Images ◽  
Human Participants ◽  
Visual Cortical ◽  
Multivariate Pattern ◽  
Perceptual Systems

When making a turn at a familiar intersection, we know what items and landmarks will come into view. These perceptual expectations, or predictions, come from our knowledge of the context, however it is unclear how memory and perceptual systems interact to support the prediction and reactivation of sensory details in cortex. To address this, human participants learned the spatial layout of animals positioned in a cross maze. During fMRI, participants navigated between animals to reach a target, and in the process saw a predictable sequence of five animal images. Critically, to isolate activity patterns related to item predictions, rather than bottom-up inputs, one quarter of trials ended early, with a blank screen presented instead. Using multivariate pattern similarity analysis, we reveal that activity patterns in early visual cortex, posterior medial regions, and the posterior hippocampus showed greater similarity when seeing the same item compared to different items. Further, item effects in posterior hippocampus were specific to the sequence context. Critically, activity patterns associated with seeing an item in visual cortex and posterior medial cortex, were also related to activity patterns when an item was expected, but omitted, suggesting sequence predictions were reinstated in these regions. Finally, multivariate connectivity showed that patterns in the posterior hippocampus at one position in the sequence were related to patterns in early visual cortex and posterior medial cortex at a later position. Together, our results support the idea that hippocampal representations facilitate sensory processing by modulating visual cortical activity in anticipation of expected items.

scholarly journals Head Movements Control the Activity of Primary Visual Cortex in a Luminance Dependent Manner

2020 ◽  
Author(s):  
Guy Bouvier ◽  
Yuta Senzai ◽  
Massimo Scanziani
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Head Movements ◽  
Inhibitory Neurons ◽  
Dependent Manner ◽  
Ambient Light ◽  
Cortical Circuits ◽  
Cortical Layers ◽  
Visual Cortical ◽  
The Brain

AbstractThe vestibular system broadcasts head-movement related signals to sensory areas throughout the brain, including visual cortex. These signals are crucial for the brain’s ability to assess whether motion of the visual scene results from the animal’s head-movements. How head-movements impact visual cortical circuits remains, however, poorly understood. Here, we discover that ambient luminance profoundly transforms how mouse primary visual cortex (V1) processes head-movements. While in darkness, head movements result in an overall suppression of neuronal activity, in ambient light the same head movements trigger excitation across all cortical layers. This light-dependent switch in how V1 processes head-movements is controlled by somatostatin expressing (SOM) inhibitory neurons, which are excited by head movements in dark but not in light. This study thus reveals a light-dependent switch in the response of V1 to head-movements and identifies a circuit in which SOM cells are key integrators of vestibular and luminance signals.

Early Human Visual Cortex Encodes Surface Brightness Induced by Dynamic Context

2012 ◽  
Vol 24 (2) ◽  
pp. 367-377 ◽  
Author(s):  
Vincent van de Ven ◽  
Bert Jans ◽  
Rainer Goebel ◽  
Peter De Weerd
Keyword(s):  
Visual Cortex ◽  
Surface Brightness ◽  
Scene Perception ◽  
Neural Mechanisms ◽  
Surface Perception ◽  
Brightness Perception ◽  
Early Visual Cortex ◽  
Human Participants ◽  
Visual Cortical ◽  
Early Human

Visual scene perception owes greatly to surface features such as color and brightness. Yet, early visual cortical areas predominantly encode surface boundaries rather than surface interiors. Whether human early visual cortex may nevertheless carry a small signal relevant for surface perception is a topic of debate. We induced brightness changes in a physically constant surface by temporally modulating the luminance of surrounding surfaces in seven human participants. We found that fMRI activity in the V2 representation of the constant surface was in antiphase to luminance changes of surrounding surfaces (i.e., activity was in-phase with perceived brightness changes). Moreover, the amplitude of the antiphase fMRI activity in V2 predicted the strength of illusory brightness perception. We interpret our findings as evidence for a surface-related signal in early visual cortex and discuss the neural mechanisms that may underlie that signal in concurrence with its possible interaction with the properties of the fMRI signal.

Ocular Dominance Peaks at Pinwheel Center Singularities of the Orientation Map in Cat Visual Cortex

1997 ◽  
Vol 77 (6) ◽  
pp. 3381-3385 ◽  
Author(s):  
Michael C. Crair ◽  
Edward S. Ruthazer ◽  
Deda C. Gillespie ◽  
Michael P. Stryker
Keyword(s):  
Visual Cortex ◽  
Visual Stimulation ◽  
Ocular Dominance ◽  
Normal Function ◽  
Functional Link ◽  
Orientation Map ◽  
Cat Visual Cortex ◽  
Visual Cortical ◽  
Continuous Orientation ◽  
Stimulation Of

Crair, Michael C., Edward S. Ruthazer, Deda C. Gillespie, and Michael P. Stryker. Ocular dominance peaks at pinwheel center singularities of the orientation map in cat visual cortex. J. Neurophysiol. 77: 3381–3385, 1997. In the primary visual cortex of monkey and cat, ocular dominance and orientation are represented continuously and simultaneously, so that most neighboring neurons respond optimally to visual stimulation of the same eye and orientation. Maps of stimulus orientation are punctuated by singularities referred to as “pinwheel centers,” around which all orientations are represented. Given that the orientation map is mostly continuous, orientation singularities are a mathematical necessity unless the map consists of perfectly parallel rows, and there is no evidence that the singularities play a role in normal function or development. We report here that in cats there is a strong tendency for peaks of ocular dominance to lie on the pinwheel center singularities of the orientation map. This relationship predicts but is not predicted by the tendencies, previously reported, for pinwheels to lie near the center lines of ocular dominance bands and for iso-orientation bands to cross ocular dominance boundaries at right angles. The coincidence of ocular dominance peaks with orientation singularities is likely to reflect a strong underlying functional link between the two visual cortical maps.

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