Differential hemispheric and visual stream contributions to ensemble coding of crowd emotion

AbstractThe visual system takes advantage of redundancies in the scene by extracting summary statistics from a set of items. Similarly, in many social situations where scrutinizing each individual’s expression is inefficient, human observers make snap judgments of crowds of people by reading “crowd emotion” to avoid danger (e.g., mass panic or violent mobs) or to seek help. However, how the brain accomplishes this feat remains unaddressed. Here we report a set of behavioral and fMRI studies in which participants made avoidance or approach decisions by choosing between two facial crowds presented in the left and right visual fields (LVF/RVF). Participants were most accurate for crowds containing task-relevant cues: avoiding angry crowds and approaching happy crowds. This effect was amplified by sex-linked facial cues (angry male/happy female crowds) and highly lateralized, with better recognition of the task-congruent facial crowd when presented in LVF. fMRI results showed that the dorsal visual stream was preferentially activated in crowd emotion processing, with intraparietal sulcus and superior frontal gyrus predicting behavioral crowd emotion efficiency, whereas the ventral visual stream showed greater involvement in individual face emotion processing, with fusiform cortex activity predicting the accuracy of decisions about individual face emotion. Our results shed new light on the distinction between global vs. local processing of face stimuli, revealing differential involvement of the left and right hemispheres and the dorsal and ventral pathways in reading crowd vs. individual emotion.

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Integration and segmentation conflict during ensemble coding of shape.

Journal of Experimental Psychology Human Perception & Performance ◽

10.1037/xhp0000733 ◽

2020 ◽

Vol 46 (6) ◽

pp. 593-609 ◽

Cited By ~ 3

Author(s):

Elric Elias ◽

Timothy D. Sweeny

Keyword(s):

Ensemble Coding

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Using Convolutional Neural Networks to measure the contribution of visual features to the representation of object animacy in the brain

10.31237/osf.io/fxz4q ◽

2019 ◽

Cited By ~ 1

Author(s):

Sushrut Thorat

Keyword(s):

Neural Networks ◽

Convolutional Neural Networks ◽

Temporal Cortex ◽

Large Degree ◽

Visual Features ◽

Visual Feature ◽

Visual Stream ◽

Feature Information ◽

Ventral Visual Stream ◽

Animal Images

A mediolateral gradation in neural responses for images spanning animals to artificial objects is observed in the ventral temporal cortex (VTC). Which information streams drive this organisation is an ongoing debate. Recently, in Proklova et al. (2016), the visual shape and category (“animacy”) dimensions in a set of stimuli were dissociated using a behavioural measure of visual feature information. fMRI responses revealed a neural cluster (extra-visual animacy cluster - xVAC) which encoded category information unexplained by visual feature information, suggesting extra-visual contributions to the organisation in the ventral visual stream. We reassess these findings using Convolutional Neural Networks (CNNs) as models for the ventral visual stream. The visual features developed in the CNN layers can categorise the shape-matched stimuli from Proklova et al. (2016) in contrast to the behavioural measures used in the study. The category organisations in xVAC and VTC are explained to a large degree by the CNN visual feature differences, casting doubt over the suggestion that visual feature differences cannot account for the animacy organisation. To inform the debate further, we designed a set of stimuli with animal images to dissociate the animacy organisation driven by the CNN visual features from the degree of familiarity and agency (thoughtfulness and feelings). Preliminary results from a new fMRI experiment designed to understand the contribution of these non-visual features are presented.

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“Real-time” obstacle avoidance in the absence of primary visual cortex

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0905549106 ◽

2009 ◽

Vol 106 (37) ◽

pp. 15996-16001 ◽

Cited By ~ 27

Author(s):

Christopher L. Striemer ◽

Craig S. Chapman ◽

Melvyn A. Goodale

Keyword(s):

Visual Cortex ◽

Real Time ◽

Obstacle Avoidance ◽

Primary Visual Cortex ◽

Posterior Parietal Cortex ◽

Dorsal Stream ◽

Visual Pathways ◽

Visual Stream ◽

Reaching Task ◽

Visual Inputs

When we reach toward objects, we easily avoid potential obstacles located in the workspace. Previous studies suggest that obstacle avoidance relies on mechanisms in the dorsal visual stream in the posterior parietal cortex. One fundamental question that remains unanswered is where the visual inputs to these dorsal-stream mechanisms are coming from. Here, we provide compelling evidence that these mechanisms can operate in “real-time” without direct input from primary visual cortex (V1). In our first experiment, we used a reaching task to demonstrate that an individual with a dense left visual field hemianopia after damage to V1 remained strikingly sensitive to the position of unseen static obstacles placed in his blind field. Importantly, in a second experiment, we showed that his sensitivity to the same obstacles in his blind field was abolished when a short 2-s delay (without vision) was introduced before reach onset. These findings have far-reaching implications, not only for our understanding of the time constraints under which different visual pathways operate, but also in relation to how these seemingly “primitive” subcortical visual pathways can control complex everyday behavior without recourse to conscious vision.

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Visuopathy of prematurity: is retinopathy just the tip of the iceberg?

Pediatric Research ◽

10.1038/s41390-021-01625-0 ◽

2021 ◽

Author(s):

Sigrid Hegna Ingvaldsen ◽

Tora Sund Morken ◽

Dordi Austeng ◽

Olaf Dammann

Keyword(s):

Visual Processing ◽

Structural Changes ◽

Developmental Trajectories ◽

Visual Pathway ◽

Visual Stream ◽

Visual Deficits ◽

Cortical Areas ◽

Cellular Architecture ◽

Increased Risk ◽

Dorsal Visual Stream

AbstractResearch on retinopathy of prematurity (ROP) focuses mainly on the abnormal vascularization patterns that are directly visible for ophthalmologists. However, recent findings indicate that children born prematurely also exhibit changes in the retinal cellular architecture and along the dorsal visual stream, such as structural changes between and within cortical areas. Moreover, perinatal sustained systemic inflammation (SSI) is associated with an increased risk for ROP and the visual deficits that follow. In this paper, we propose that ROP might just be the tip of an iceberg we call visuopathy of prematurity (VOP). The VOP paradigm comprises abnormal vascularization of the retina, alterations in retinal cellular architecture, choroidal degeneration, and abnormalities in the visual pathway, including cortical areas. Furthermore, VOP itself might influence the developmental trajectories of cerebral structures and functions deemed responsible for visual processing, thereby explaining visual deficits among children born preterm.

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