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Right hemisphere sensitivity to speed, structure and emotion during narrative processing
Poster Session C, Saturday, September 13, 11:00 am - 12:30 pm, Field House
This poster is part of the Sandbox Series.
Aline-Priscillia Messi1, Abir Bhuyain1, Liina Pylkkanen1; 1New York University
Introduction: The role of the right hemisphere in language remains controversial. Current models suggest different degrees of right hemisphere involvement from simple homologous activity to specialization: the right hemisphere integrates information on a slower timescale than the left (Oderbolz, Poeppel, & Meyer, 2025), right hemisphere lesions lead to social, emotional and pragmatic impairments (Younes et al., 2022), and discourse level processing preferentially engages the right hemisphere (Thye, Hoffman, & Mirman, 2024) suggesting its importance in the creation and updating of a situation model (Kurby and Zacks, 2015). These findings lead us to three distinct and mutually compatible hypotheses of the right hemisphere’s contribution to narrative processing: (i) if the right hemisphere integrates slower temporal windows, then the speed at which a stimulus is presented should modulate right hemisphere activity; (ii) if it is sensitive only to discourse-level information then contrasting complete stories with lists of words or phrases should modulate right hemisphere activity and (iii) if it is sensitive to emotional content, then the right hemisphere should more accurately track the emotional evolution of a narrative. Methods: Data collection for this project is ongoing. MEG responses to two personal essays are being collected. We manipulated both the structure and speed at which the stories are being presented in a blocked design. Stories were chunked into small phrases and then flashed for 300ms per chunk in rapid parallel visual presentation (RPVP) either as Intact stories, as SentenceLists (order of the sentences was shuffled), or as WordLists (with all the words shuffled and then organized into chunks suitable for RPVP). The three levels of structure were then crossed with a speed manipulation with a 150ms gap between chunk offset and onset in the fast speed and a 500ms gap in the slow speed. Comprehension was assessed through self-reports at the end of each block as well as a chunk recognition task. In a separate behavioral experiment, 80 participants were asked to rate the emotional valence, intensity and their overall engagement for both stories at the two presentation speeds. We will fit a regression model that predicts the ratings using MEG source time courses to identify the network that is tracking the emotional engagement of the essays. Preliminary Results: Results from the Ratings study showed that self-reported comprehension was lower for the faster than the slower speed. However, there was no effect of Speed on emotional valence, intensity or overall engagement suggesting that regardless of perceived comprehension, the emotional processing of the essays remained the same. Pilot MEG data shows that responses to the stimuli overall dampen when the stories are presented at a faster speed. This effect does not seem to be more prominent in the right hemisphere over the left. BA22 and 44 show a higher amplitude for trials in the Intact condition in the right hemisphere while there is no such distinction in the left.
Topic Areas: Reading, Meaning: Discourse and Pragmatics