Faculty Opinions recommendation of Neural activity in early visual cortex reflects behavioral experience and higher-order perceptual saliency.

2002 ◽  
Author(s):  
Shimon Ullman
Keyword(s):  
Visual Cortex ◽  
Neural Activity ◽  
Higher Order ◽  
Early Visual Cortex

Neural activity in early visual cortex reflects behavioral experience and higher-order perceptual saliency

2002 ◽  
Vol 5 (6) ◽  
pp. 589-597 ◽  
Author(s):  
Tai Sing Lee ◽  
Cindy F. Yang ◽  
Richard D. Romero ◽  
David Mumford
Keyword(s):  
Visual Cortex ◽  
Neural Activity ◽  
Higher Order ◽  
Early Visual Cortex

scholarly journals Active Ignoring in Early Visual Cortex

2011 ◽  
Vol 23 (8) ◽  
pp. 2046-2058 ◽  
Author(s):  
Helen E. Payne ◽  
Harriet A. Allen
Keyword(s):  
Visual Cortex ◽  
Selective Attention ◽  
Primary Visual Cortex ◽  
Neural Activity ◽  
Irrelevant Information ◽  
Subsequent Stage ◽  
Mental Processes ◽  
Initial Stage ◽  
Early Visual Cortex ◽  
Attentional Mechanisms

Selective attention is critical for controlling the input to mental processes. Attentional mechanisms act not only to select relevant stimuli but also to exclude irrelevant stimuli. There is evidence that we can actively ignore irrelevant information. We measured neural activity relating to successfully ignoring distracters (using preview search) and found increases in both the precuneus and primary visual cortex during preparation to ignore distracters. We also found reductions in activity in fronto-parietal regions while previewing distracters and a reduction in activity in early visual cortex during search when a subset of items was successfully excluded from search, both associated with precuneus activity. These results are consistent with the proposal that actively excluding distractions has two components: an initial stage where distracters are encoded, and a subsequent stage where further processing of these items is inhibited. Our findings suggest that it is the precuneus that controls this process and can modulate activity in visual cortex as early as V1.

scholarly journals Early Numerosity Encoding in Visual Cortex Is Not Sufficient for the Representation of Numerical Magnitude

2018 ◽  
Vol 30 (12) ◽  
pp. 1788-1802 ◽  
Author(s):  
Michele Fornaciai ◽  
Joonkoo Park
Keyword(s):  
Visual Cortex ◽  
Neural Activity ◽  
Stimulus Onset ◽  
Neural Representation ◽  
Numerical Magnitude ◽  
Sensory Representation ◽  
Area V2 ◽  
Early Visual Cortex ◽  
Multivariate Pattern ◽  
Number Perception

Recent studies have demonstrated that the numerosity of visually presented dot arrays is represented in low-level visual cortex extremely early in latency. However, whether or not such an early neural signature reflects the perceptual representation of numerosity remains unknown. Alternatively, such a signature may indicate the raw sensory representation of the dot-array stimulus before becoming the perceived representation of numerosity. Here, we addressed this question by using the connectedness illusion, whereby arrays with pairwise connected dots are perceived to be less numerous compared with arrays containing isolated dots. Using EEG and fMRI in two independent experiments, we measured neural responses to dot-array stimuli comprising 16 or 32 dots, either isolated or pairwise connected. The effect of connectedness, which reflects the segmentation of the visual stimulus into perceptual units, was observed in the neural activity after 150 msec post stimulus onset in the EEG experiment and in area V3 in the fMRI experiment using a multivariate pattern analysis. In contrast, earlier neural activity before 100 msec and in area V2 was strictly modulated by numerosity regardless of connectedness, suggesting that this early activity reflects the sensory representation of a dot array before perceptual segmentation. Our findings thus demonstrate that the neural representation for numerosity in early visual cortex is not sufficient for visual number perception and suggest that the perceptual encoding of numerosity occurs at or after the segmentation process that takes place later in area V3.

scholarly journals Computational measures of perceived image complexity correspond to neural activity in early visual cortex

2020 ◽  
Vol 20 (11) ◽  
pp. 870
Author(s):  
Elizabeth Yue Zhou ◽  
Claudia Damiano ◽  
John Wilder ◽  
Dirk B. Walther
Keyword(s):  
Visual Cortex ◽  
Neural Activity ◽  
Image Complexity ◽  
Early Visual Cortex

Higher-Order Visual Cortex Shows Stronger Neural Correlates of Visual and Multisensory Detection Behavior Compared to Primary Visual Cortex

2019 ◽  
Author(s):  
Guido Meijer ◽  
Pietro Marchesi ◽  
Jorge Mejias ◽  
Jorrit Montijn ◽  
Carien Lansink ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Neural Correlates ◽  
Higher Order

scholarly journals Alzheimer’s Disease Progressively Reduces Visual Functional Network Connectivity

2021 ◽  
pp. 1-14
Author(s):  
Jie Huang ◽  
Paul Beach ◽  
Andrea Bozoki ◽  
David C. Zhu
Keyword(s):  
Visual Cortex ◽  
Lower Order ◽  
Resting State ◽  
Visual Processing ◽  
Network Connectivity ◽  
Higher Order ◽  
Functional Network ◽  
Functional Networks ◽  
The Face ◽  
Processing Network

Background: Postmortem studies of brains with Alzheimer’s disease (AD) not only find amyloid-beta (Aβ) and neurofibrillary tangles (NFT) in the visual cortex, but also reveal temporally sequential changes in AD pathology from higher-order association areas to lower-order areas and then primary visual area (V1) with disease progression. Objective: This study investigated the effect of AD severity on visual functional network. Methods: Eight severe AD (SAD) patients, 11 mild/moderate AD (MAD), and 26 healthy senior (HS) controls undertook a resting-state fMRI (rs-fMRI) and a task fMRI of viewing face photos. A resting-state visual functional connectivity (FC) network and a face-evoked visual-processing network were identified for each group. Results: For the HS, the identified group-mean face-evoked visual-processing network in the ventral pathway started from V1 and ended within the fusiform gyrus. In contrast, the resting-state visual FC network was mainly confined within the visual cortex. AD disrupted these two functional networks in a similar severity dependent manner: the more severe the cognitive impairment, the greater reduction in network connectivity. For the face-evoked visual-processing network, MAD disrupted and reduced activation mainly in the higher-order visual association areas, with SAD further disrupting and reducing activation in the lower-order areas. Conclusion: These findings provide a functional corollary to the canonical view of the temporally sequential advancement of AD pathology through visual cortical areas. The association of the disruption of functional networks, especially the face-evoked visual-processing network, with AD severity suggests a potential predictor or biomarker of AD progression.

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