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 Selective Modulation of Early Visual Cortical Activity by Movement Intention

2019 ◽  
Vol 29 (11) ◽  
pp. 4662-4678 ◽  
Author(s):  
Jason P Gallivan ◽  
Craig S Chapman ◽  
Daniel J Gale ◽  
J Randall Flanagan ◽  
Jody C Culham
Keyword(s):  
Visual Cortex ◽  
Activity Patterns ◽  
Action Planning ◽  
Cortical Activity ◽  
Target Object ◽  
Movement Planning ◽  
Dependent Manner ◽  
Related Information ◽  
Early Visual Cortex ◽  
Visual Cortical

Abstract The primate visual system contains myriad feedback projections from higher- to lower-order cortical areas, an architecture that has been implicated in the top-down modulation of early visual areas during working memory and attention. Here we tested the hypothesis that these feedback projections also modulate early visual cortical activity during the planning of visually guided actions. We show, across three separate human functional magnetic resonance imaging (fMRI) studies involving object-directed movements, that information related to the motor effector to be used (i.e., limb, eye) and action goal to be performed (i.e., grasp, reach) can be selectively decoded—prior to movement—from the retinotopic representation of the target object(s) in early visual cortex. We also find that during the planning of sequential actions involving objects in two different spatial locations, that motor-related information can be decoded from both locations in retinotopic cortex. Together, these findings indicate that movement planning selectively modulates early visual cortical activity patterns in an effector-specific, target-centric, and task-dependent manner. These findings offer a neural account of how motor-relevant target features are enhanced during action planning and suggest a possible role for early visual cortex in instituting a sensorimotor estimate of the visual consequences of movement.

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.

Motion-defined Surface Segregation in Human Visual Cortex

2014 ◽  
Vol 26 (11) ◽  
pp. 2479-2489 ◽  
Author(s):  
Gabriel J. Vigano ◽  
Ryan T. Maloney ◽  
Colin W. G. Clifford
Keyword(s):  
Visual Cortex ◽  
Surface Segregation ◽  
Multivariate Analyses ◽  
Perceptual Analysis ◽  
Rotation Direction ◽  
Motion Display ◽  
Early Visual Cortex ◽  
Visual Cortical ◽  
Multivariate Pattern ◽  
Psychophysical Task

Surface segregation provides an efficient way to parse the visual scene for perceptual analysis. Here, we investigated the segregation of a bivectorial motion display into transparent surfaces through a psychophysical task and fMRI. We found that perceptual transparency correlated with neural activity in the early areas of the visual cortex, suggesting these areas may be involved in the segregation of motion-defined surfaces. Two oppositely rotating, uniquely colored random dot kinematograms (RDKs) were presented either sequentially or in a spatially interleaved manner, displayed at varying alternation frequencies. Participants reported the color and rotation direction pairing of the RDKs in the psychophysical task. The spatially interleaved display generated the percept of motion transparency across the range of frequencies tested, yielding ceiling task performance. At high alternation frequencies, performance on the sequential display also approached ceiling, indicative of perceived transparency. However, transparency broke down in lower alternation frequency sequential displays, producing performance close to chance. A corresponding pattern mirroring the psychophysical data was also evident in univariate and multivariate analyses of the fMRI BOLD activity in visual cortical areas V1, V2, V3, V3AB, hV4, and V5/MT+. Using gray RDKs, we found significant presentation by frequency interactions in most areas; differences in BOLD signal between presentation types were significant only at the lower alternation frequency. Multivariate pattern classification was similarly unable to discriminate between presentation types at the higher frequency. This study provides evidence that early visual cortex may code for motion-defined surface segregation, which in turn may enable perceptual transparency.

scholarly journals Preparatory Activity in Posterior Temporal Cortex Causally Contributes to Object Detection in Scenes

2015 ◽  
Vol 27 (11) ◽  
pp. 2117-2125 ◽  
Author(s):  
Reshanne R. Reeder ◽  
Francesca Perini ◽  
Marius V. Peelen
Keyword(s):  
Visual Cortex ◽  
Object Detection ◽  
Activity Patterns ◽  
Temporal Cortex ◽  
Relevant Information ◽  
Visual Selective Attention ◽  
Object Categories ◽  
Preparatory Attention ◽  
Preparatory Activity ◽  
Early Visual Cortex

Theories of visual selective attention propose that top–down preparatory attention signals mediate the selection of task-relevant information in cluttered scenes. Neuroimaging and electrophysiology studies have provided correlative evidence for this hypothesis, finding increased activity in target-selective neural populations in visual cortex in the period between a search cue and target onset. In this study, we used online TMS to test whether preparatory neural activity in visual cortex is causally involved in naturalistic object detection. In two experiments, participants detected the presence of object categories (cars, people) in a diverse set of photographs of real-world scenes. TMS was applied over a region in posterior temporal cortex identified by fMRI as carrying category-specific preparatory activity patterns. Results showed that TMS applied over posterior temporal cortex before scene onset (−200 and −100 msec) impaired the detection of object categories in subsequently presented scenes, relative to vertex and early visual cortex stimulation. This effect was specific to category level detection and was related to the type of attentional template participants adopted, with the strongest effects observed in participants adopting category level templates. These results provide evidence for a causal role of preparatory attention in mediating the detection of objects in cluttered daily-life environments.

scholarly journals Shared and Independent Neural Representation Between Visual Perception and Mental Imagery

2021 ◽  
Author(s):  
Yingying Huang ◽  
Frank Pollick ◽  
Ming Liu ◽  
Delong Zhang
Keyword(s):  
Visual Perception ◽  
Mental Imagery ◽  
Activity Patterns ◽  
Neural Representation ◽  
Gabor Features ◽  
Visual Areas ◽  
Neural Substrate ◽  
Early Visual Cortex ◽  
Human Participants ◽  
Insight Into

Abstract Visual mental imagery and visual perception have been shown to share a hierarchical topological visual structure of neural representation. Meanwhile, many studies have reported a dissociation of neural substrate between mental imagery and perception in function and structure. However, we have limited knowledge about how the visual hierarchical cortex involved into internally generated mental imagery and perception with visual input. Here we used a dataset from previous fMRI research (Horikawa & Kamitani, 2017), which included a visual perception and an imagery experiment with human participants. We trained two types of voxel-wise encoding models, based on Gabor features and activity patterns of high visual areas, to predict activity in the early visual cortex (EVC, i.e., V1, V2, V3) during perception, and then evaluated the performance of these models during mental imagery. Our results showed that during perception and imagery, activities in the EVC could be independently predicted by the Gabor features and activity of high visual areas via encoding models, which suggested that perception and imagery might share neural representation in the EVC. We further found that there existed a Gabor-specific and a non-Gabor-specific neural response pattern to stimuli in the EVC, which were shared by perception and imagery. These findings provide insight into mechanisms of how visual perception and imagery shared representation in the EVC.

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.

scholarly journals Early cross-modal interactions and adult human visual cortical plasticity revealed by binocular rivalry

2015 ◽  
Author(s):  
Claudia Lunghi
Keyword(s):  
Visual Cortex ◽  
Binocular Rivalry ◽  
Visual Processing ◽  
Cortical Plasticity ◽  
Monocular Deprivation ◽  
Homeostatic Plasticity ◽  
Multisensory Perception ◽  
Modal Interactions ◽  
Early Visual Cortex ◽  
Visual Cortical

In this research binocular rivalry is used as a tool to investigate different aspects of visual and multisensory perception. Several experiments presented here demonstrated that touch specifically interacts with vision during binocular rivalry and that the interaction likely occurs at early stages of visual processing, probably V1 or V2. Another line of research also presented here demonstrated that human adult visual cortex retains an unexpected high degree of experience-dependent plasticity by showing that a brief period of monocular deprivation produced important perceptual consequences on the dynamics of binocular rivalry, reflecting a homeostatic plasticity. In summary, this work shows that binocular rivalry is a powerful tool to investigate different aspects of visual perception and can be used to reveal unexpected properties of early visual cortex.

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 Perceptual Learning of Simple Stimuli Modifies Stimulus Representations in Posterior Inferior Temporal Cortex

2014 ◽  
Vol 26 (10) ◽  
pp. 2187-2200 ◽  
Author(s):  
Hamed Zivari Adab ◽  
Ivo D. Popivanov ◽  
Wim Vanduffel ◽  
Rufin Vogels
Keyword(s):  
Visual Cortex ◽  
Perceptual Learning ◽  
Single Unit ◽  
Brain Plasticity ◽  
Temporal Cortex ◽  
Adult Brain ◽  
Orientation Discrimination ◽  
Area V4 ◽  
Early Visual Cortex ◽  
Visual Cortical

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 recordings 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 orthogonal 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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