Neural dynamics of event processing under reduced uncertainty.

Poster Session D - Monday, April 15, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC
Also presenting in Data Blitz Session 3 - Saturday, April 13, 2024, 1:00 – 2:30 pm EDT, Ballroom West.

Karen Sasmita¹ (ss3837@cornell.edu), Khena M. Swallow¹; ¹Cornell University

Processing everyday experience may involve monitoring errors in predictions made by working memory representations of the current situation (event models) at points of uncertainty (e.g. when the situation changes, event boundaries). How does event processing change when uncertainty at event boundaries is reduced? To answer this question, we used EEG to examine changes in neural activity during the viewing of two ~7-minute long movie clips. We manipulated uncertainty along two dimensions: familiarity with the movie clips (which were viewed twice and then segmented into events), and by allowing participants to sample visual information in a restricted (by asking participants to maintain central fixation; n = 20) or unrestricted (by allowing participants to freely move their eyes; n = 20) manner. Restricted and unrestricted viewing groups identified boundaries at similar times. However, theta (4-8 Hz), alpha (8-12 Hz), and gamma (30 - 100 Hz) band power was modulated around event boundaries encountered during the first movie viewing, particularly when eye movements were unrestricted. In contrast, during the second viewing, power in these frequency bands was reduced around event boundaries in the unrestricted condition and temporally shifted in the restricted condition. These observations are consistent with uncertainty contributing to event processing, both through knowledge about what is happening when and by the ability to develop that knowledge through active sampling of visual information.

Topic Area: PERCEPTION & ACTION: Multisensory