Search Papers | Poster Sessions | All Posters
Poster B136 in Poster Session B - Thursday, August 8, 2024, 1:30 – 3:30 pm, Johnson Ice Rink
Hippocampal versus cortical language processing: Similar selectivity profile, difference in tuning axis
Elizabeth Jiachen Lee1 (), Idan A. Blank2, Evelina Fedorenko1, Greta Tuckute1; 1Massachusetts Institute of Technology, 2University of California Los Angeles
The role of the medial temporal lobe structures, including the hippocampus, in language processing remains largely unknown. In a large-scale fMRI dataset (>600 participants), we identified a language-responsive region (LangHippoc) in the anterior left hippocampus. This region responds to meaningful linguistic inputs and is engaged in semantic processing, but is not engaged during cognitively demanding spatial memory and arithmetic tasks. Critically, by performing an encoding-model-guided search procedure on another fMRI dataset of responses to 1,000 diverse sentences, we searched for sentences that maximally differentiate responses in LangHippoc and the cortical language network (LangCortex). We found that the tuning axes of LangCortex and LangHippoc can be teased apart: LangCortex is more modulated by linguistic processing difficulty, whereas LangHippoc shows a preference towards particular kinds of content: descriptions of places and objects.
Keywords: Language Hippocampus Selectivity LLM