scholarly journals The influence of surround suppression on adaptation effects in primary visual cortex

2011 ◽  
Vol 11 (11) ◽  
pp. 2-2
Author(s):  
A. Kohn
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Surround Suppression ◽  
Adaptation Effects

Parallel Advantage: Further Evidence for Bottom-up Saliency Computation by Human Primary Visual Cortex

Perception ◽  
2022 ◽  
Vol 51 (1) ◽  
pp. 60-69
Author(s):  
Li Zhaoping
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Surround Suppression ◽  
Bottom Up ◽  
Black Disk ◽  
V1 Neurons ◽  
Behavioral Observations ◽  
White Disk ◽  
Special Case

Finding a target among uniformly oriented non-targets is typically faster when this target is perpendicular, rather than parallel, to the non-targets. The V1 Saliency Hypothesis (V1SH), that neurons in the primary visual cortex (V1) signal saliency for exogenous attentional attraction, predicts exactly the opposite in a special case: each target or non-target comprises two equally sized disks displaced from each other by 1.2 disk diameters center-to-center along a line defining its orientation. A target has two white or two black disks. Each non-target has one white disk and one black disk, and thus, unlike the target, activates V1 neurons less when its orientation is parallel rather than perpendicular to the neurons’ preferred orientations. When the target is parallel, rather than perpendicular, to the uniformly oriented non-targets, the target’s evoked V1 response escapes V1’s iso-orientation surround suppression, making the target more salient. I present behavioral observations confirming this prediction.

scholarly journals Nonuniform surround suppression of visual responses in mouse V1

2017 ◽  
Vol 118 (6) ◽  
pp. 3282-3292 ◽  
Author(s):  
Jason M. Samonds ◽  
Berquin D. Feese ◽  
Tai Sing Lee ◽  
Sandra J. Kuhlman
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Primary Visual Cortex ◽  
Surround Suppression ◽  
Visual Responses ◽  
Neural Basis ◽  
Global Features ◽  
Perceptual Inference ◽  
Inference Problems ◽  
Local And Global Features

Complex receptive field characteristics, distributed across a population of neurons, are thought to be critical for solving perceptual inference problems that arise during motion and image segmentation. For example, in a class of neurons referred to as “end-stopped,” increasing the length of stimuli outside of the bar-responsive region into the surround suppresses responsiveness. It is unknown whether these properties exist for receptive field surrounds in the mouse. We examined surround modulation in layer 2/3 neurons of the primary visual cortex in mice using two-photon calcium imaging. We found that surround suppression was significantly asymmetric in 17% of the visually responsive neurons examined. Furthermore, the magnitude of asymmetry was correlated with orientation selectivity. Our results demonstrate that neurons in mouse primary visual cortex are differentially sensitive to the addition of elements in the surround and that individual neurons can be described as being either uniformly suppressed by the surround, end-stopped, or side-stopped. NEW & NOTEWORTHY Perception of visual scenes requires active integration of both local and global features to successfully segment objects from the background. Although the underlying circuitry and development of perceptual inference is not well understood, converging evidence indicates that asymmetry and diversity in surround modulation are likely fundamental for these computations. We determined that these key features are present in the mouse. Our results support the mouse as a model to explore the neural basis and development of surround modulation as it relates to perceptual inference.

scholarly journals Distinct Laminar Processing of Local and Global Context in Primate Primary Visual Cortex

2017 ◽  
Author(s):  
Maryam Bijanzadeh ◽  
Lauri Nurminen ◽  
Sam Merlin ◽  
Alessandra Angelucci
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Space ◽  
Spatial Context ◽  
Surround Suppression ◽  
Cortical Layers ◽  
Global Context ◽  
Global Signal ◽  
Deep Layers ◽  
Contextual Stimuli

Visual perception is profoundly affected by spatial context. In visual cortex, neuronal responses to stimuli inside their receptive field (RF) are suppressed by contextual stimuli in the RF surround (surround suppression). How do neuronal RFs integrate information across visual space, and what role do different cortical layers play in the processing of spatial context? By recording simultaneously across all layers of macaque primary visual cortex, while presenting visual stimuli at increasing distances from the recorded cells RF, we find that near vs. far stimuli activate distinct layers. Stimuli in the near-surround evoke the earliest subthreshold responses in superficial and deep layers, and cause the earliest surround suppression of spiking responses in superficial layers. Instead, far-surround stimuli evoke the earliest subthreshold responses in feedback-recipient layers, i.e. 1 and the lower half of the deep layers, and suppress visually-evoked spiking responses almost simultaneously in all layers, except 4C, where suppression emerges latest. Our results reveal unique contributions of the cortical layers to the processing of local and global spatial context, and suggest distinct underlying circuits for local and global signal integration.

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