Presentation Title

Neural Activity in the Visual Cortex Predicts Semantic Decisions

Faculty Mentor

Jesse J. Bengson PhD

Start Date

18-11-2017 11:00 AM

End Date

18-11-2017 11:15 AM

Location

15-1808

Session

Social Science 1

Type of Presentation

Oral Talk

Subject Area

behavioral_social_sciences

Abstract

Categorizing incoming visual information from our environment is essential for deciding how to react to situations. Visual search tasks provide evidence that early semantic categorization in the visual cortex occurs soon after the presentation of an image, biasing visual processing in favor of a specific category (Peelen, Fei-Fei & Kastner, 2009). Considering those findings, we incorporated an attentional control paradigm using an arbitrary cue to generate semantic expectancies. Using EEG recording, our results suggest that different magnitudes of activation in thevisual cortex soon after the presentation of the arbitrary cue predict decisions to expect a broad semantic category.

Keywords: decisions-making, visual perception, vision, attention, EEG, semantic categorization

Summary of research results to be presented

At a time interval of 150-200ms, ERP analysis revealed that the sensory response of the visual cortex upon the presentation of the arbitrary cue is significantly larger when participants later decided to expect an image of a human as opposed to an animal. This suggest that the magnitude of activation in the visual cortex can influence subsequent semantic, categorical decisions.

Semantic categorization and decision-making are commonly thought of as top-down higher level cognitive functions occurring in the frontal lobes (Thorpe et al. 1996). In contrast, our results provide emerging evidence that attentional control and decision-making are influenced by bottom-up mechanisms initiated at the early stages of the visual processing stream.

Unlike most of the pre-existing studies that have investigated semantic categorization in the visual cortex as a response to an already semantically charged stimulus, our findings suggest that the way an arbitrary stimulus is represented in the visual cortex can bias high-level volitional processes involving the decision to expect a semantic category. Further implications of our findings might suggest top-down cognitive processes are heavily influenced by bottom-up, sensory processing areas. This interaction could introduce the possibility of manipulating incoming visual stimuli in order to yield and predict decisional outcomes in the decision-making process.

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Nov 18th, 11:00 AM Nov 18th, 11:15 AM

Neural Activity in the Visual Cortex Predicts Semantic Decisions

15-1808

Categorizing incoming visual information from our environment is essential for deciding how to react to situations. Visual search tasks provide evidence that early semantic categorization in the visual cortex occurs soon after the presentation of an image, biasing visual processing in favor of a specific category (Peelen, Fei-Fei & Kastner, 2009). Considering those findings, we incorporated an attentional control paradigm using an arbitrary cue to generate semantic expectancies. Using EEG recording, our results suggest that different magnitudes of activation in thevisual cortex soon after the presentation of the arbitrary cue predict decisions to expect a broad semantic category.

Keywords: decisions-making, visual perception, vision, attention, EEG, semantic categorization