scholarly journals On the role of expectation in visual perception: A top-down view of early visual cortex

2015 ◽  
Vol 9 ◽  
Author(s):  
Kok Peter ◽  
De Lange Floris
Keyword(s):  
Visual Cortex ◽  
Visual Perception ◽  
Top Down ◽  
Early Visual Cortex

The role of early visual cortex (V1/V2) in conscious and unconscious visual perception

NeuroImage ◽  
2010 ◽  
Vol 51 (2) ◽  
pp. 828-834 ◽  
Author(s):  
Mika Koivisto ◽  
Teemu Mäntylä ◽  
Juha Silvanto
Keyword(s):  
Visual Cortex ◽  
Visual Perception ◽  
Early Visual Cortex

scholarly journals Top-down control of visual cortex by the frontal eye fields through oscillatory realignment

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Domenica Veniero ◽  
Joachim Gross ◽  
Stephanie Morand ◽  
Felix Duecker ◽  
Alexander T. Sack ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Visual Perception ◽  
Magnetic Stimulation ◽  
Single Pulse ◽  
Frontal Eye Fields ◽  
Phase Reset ◽  
Top Down ◽  
Visual Areas ◽  
Beta Frequency

AbstractVoluntary allocation of visual attention is controlled by top-down signals generated within the Frontal Eye Fields (FEFs) that can change the excitability of lower-level visual areas. However, the mechanism through which this control is achieved remains elusive. Here, we emulated the generation of an attentional signal using single-pulse transcranial magnetic stimulation to activate the FEFs and tracked its consequences over the visual cortex. First, we documented changes to brain oscillations using electroencephalography and found evidence for a phase reset over occipital sites at beta frequency. We then probed for perceptual consequences of this top-down triggered phase reset and assessed its anatomical specificity. We show that FEF activation leads to cyclic modulation of visual perception and extrastriate but not primary visual cortex excitability, again at beta frequency. We conclude that top-down signals originating in FEF causally shape visual cortex activity and perception through mechanisms of oscillatory realignment.

scholarly journals Layer-dependent multiplicative effects of spatial attention on contrast responses in human early visual cortex

2020 ◽  
Author(s):  
Fanhua Guo ◽  
Chengwen Liu ◽  
Chencan Qian ◽  
Zihao Zhang ◽  
Kaibao Sun ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Spatial Attention ◽  
Middle Layer ◽  
Additive Effect ◽  
List Type ◽  
Strong Nonlinearity ◽  
Top Down ◽  
Contrast Gain ◽  
Early Visual Cortex ◽  
Deep Layers

AbstractAttention mechanisms at different cortical layers of human visual cortex remain poorly understood. Using submillimeter-resolution fMRI at 7T, we investigated the effects of top-down spatial attention on the contrast responses across different cortical depths in human early visual cortex. Gradient echo (GE) T2* weighted BOLD signal showed an additive effect of attention on contrast responses across cortical depths. Compared to the middle cortical depth, attention modulation was stronger in the superficial and deep depths of V1, and also stronger in the superficial depth of V2 and V3. Using ultra-high resolution (0.3mm in-plane) balanced steady-state free precession (bSSFP) fMRI, a multiplicative scaling effect of attention was found in the superficial and deep layers, but not in the middle layer of V1. Attention modulation of low contrast response was strongest in the middle cortical depths, indicating baseline enhancement or contrast gain of attention modulation on feedforward input. Finally, the additive effect of attention on T2* BOLD can be explained by strong nonlinearity of BOLD signals from large blood vessels, suggesting multiplicative effect of attention on neural activity. These findings support that top-down spatial attention mainly operates through feedback connections from higher order cortical areas, and a distinct mechanism of attention may also be associated with feedforward input through subcortical pathway.HighlightsResponse or activity gain of spatial attention in superficial and deep layersContrast gain or baseline shift of attention in V1 middle layerNonlinearity of large blood vessel causes additive effect of attention on T2* BOLD

scholarly journals Layer-specific modulation of top-down spatial attention in human early visual cortex

2019 ◽  
Vol 19 (10) ◽  
pp. 169
Author(s):  
Peng Zhang ◽  
Chengwen Liu ◽  
chencan Qian ◽  
Zihao Zhang ◽  
Sheng He ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Spatial Attention ◽  
Top Down ◽  
Early Visual Cortex

Determinants of motion response anisotropies in human early visual cortex: The role of configuration and eccentricity

NeuroImage ◽  
2014 ◽  
Vol 100 ◽  
pp. 564-579 ◽  
Author(s):  
Ryan T. Maloney ◽  
Tamara L. Watson ◽  
Colin W.G. Clifford
Keyword(s):  
Visual Cortex ◽  
Motion Response ◽  
Early Visual Cortex

scholarly journals Feedback contribution to surface motion perception in the human early visual cortex

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Ingo Marquardt ◽  
Peter De Weerd ◽  
Marian Schneider ◽  
Omer Faruk Gulban ◽  
Dimo Ivanov ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Motion Perception ◽  
Depth Distribution ◽  
Ultra High Field ◽  
Surface Perception ◽  
Surface Motion ◽  
Surface Segmentation ◽  
Early Visual Cortex ◽  
Illusory Perception

Human visual surface perception has neural correlates in early visual cortex, but the role of feedback during surface segmentation in human early visual cortex remains unknown. Feedback projections preferentially enter superficial and deep anatomical layers, which provides a hypothesis for the cortical depth distribution of fMRI activity related to feedback. Using ultra-high field fMRI, we report a depth distribution of activation in line with feedback during the (illusory) perception of surface motion. Our results fit with a signal re-entering in superficial depths of V1, followed by a feedforward sweep of the re-entered information through V2 and V3. The magnitude and sign of the BOLD response strongly depended on the presence of texture in the background, and was additionally modulated by the presence of illusory motion perception compatible with feedback. In summary, the present study demonstrates the potential of depth-resolved fMRI in tackling biomechanical questions on perception.

scholarly journals The essential role of feedback processing for figure-ground perception in mice

2018 ◽  
Author(s):  
Lisa Kirchberger ◽  
Sreedeep Mukherjee ◽  
Ulf H. Schnabel ◽  
Enny H. van Beest ◽  
Areg Barsegyan ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Visual Perception ◽  
Essential Role ◽  
Pyramidal Cells ◽  
Neuronal Responses ◽  
Feedback Processing ◽  
Visual Areas ◽  
Higher Visual Areas ◽  
Delayed Phase

AbstractThe segregation of figures from the background is an important step in visual perception. In primary visual cortex, figures evoke stronger activity than backgrounds during a delayed phase of the neuronal responses, but it is unknown how this figure-ground modulation (FGM) arises and whether it is necessary for perception. Here we show, using optogenetic silencing in mice, that the delayed V1 response phase is necessary for figure-ground segregation. Neurons in higher visual areas also exhibit FGM and optogenetic silencing of higher areas reduced FGM in V1. In V1, figures elicited higher activity of vasoactive intestinal peptide-expressing (VIP) interneurons than the background, whereas figures suppressed somatostatin-positive interneurons, resulting in an increased activation of pyramidal cells. Optogenetic silencing of VIP neurons reduced FGM in V1, indicating that disinhibitory circuits contribute to FGM. Our results provide new insight in how lower and higher areas of the visual cortex interact to shape visual perception.

scholarly journals Gestalts at threshold could reveal Gestalts as predictions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thiago Leiros Costa ◽  
Johan Wagemans
Keyword(s):  
Predictive Processing ◽  
Top Down ◽  
Visual Neurons ◽  
Chance Performance ◽  
Response Profile ◽  
Early Visual Cortex ◽  
Feedback Connections ◽  
And Control ◽  
Contrast Response

AbstractWe review and revisit the predictive processing inspired “Gestalts as predictions” hypothesis. The study of Gestalt phenomena at and below threshold can help clarify the role of higher-order object selective areas and feedback connections in mid-level vision. In two psychophysical experiments assessing manipulations of contrast and configurality we showed that: (1) Gestalt phenomena are robust against saliency manipulations across the psychometric function even below threshold (with the accuracy gains and higher saliency associated with Gestalts being present even around chance performance); and (2) peak differences between Gestalt and control conditions happened around the time where responses to Gestalts are starting to saturate (mimicking the differential contrast response profile of striate vs. extra-striate visual neurons). In addition, Gestalts are associated with steeper psychometric functions in all experiments. We propose that these results reflect the differential engagement of object-selective areas in Gestalt phenomena and of information- or percept-based processing, as opposed to energy- or stimulus-based processing, more generally. In addition, the presence of nonlinearities in the psychometric functions suggest differential top-down modulation of the early visual cortex. We treat this as a proof of principle study, illustrating that classic psychophysics can help assess possible involvement of hierarchical predictive processing in Gestalt phenomena.

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