Beta oscillations are critical for semantic processing and predict behavioral performance

Poster Session B - Sunday, April 14, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Maggie Rempe^1,2 (maggie.rempe@boystown.org), Christine Embury¹, Yasra Arif¹, Seth Bashford¹, Grant Garrison¹, Ryan Glesinger¹, Hannah Okelberry¹, Chloe Casagrande¹, Elizabeth Heinrichs-Graham^1,3, Tony Wilson^1,3; ¹Boys Town National Research Hospital, ²University of Nebraska Medical Center (UNMC), ³Creighton University

The neural mechanisms underlying automatic facilitation in the setting of semantic priming are well characterized, however, most studies have focused on tasks during which semantic processing is implicit. Few studies have investigated neural processing during explicit semantic relatedness judgements. Here, 33 participants (18 females; Mage: 27.16) completed a semantic relatedness judgement task during magnetoencephalography (MEG). MEG data were transformed into the time-frequency domain and significant task-related oscillatory responses were source-imaged using a beamformer. Whole-brain paired-sample t-tests were conducted to evaluate conditional differences in neural recruitment. Further, whole-brain subtraction maps were computed and correlated with conditional differences in reaction time (RT). Behaviorally, participants had significantly shorter RT in related trials compared to unrelated trials (t[32]=-8.90, p<.001). Regarding the MEG data, we observed robust neural responses in alpha and beta frequency bands in bilateral occipital, and left temporo-parietal cortices. Whole-brain condition-wise analyses revealed significant differences in alpha activity in bilateral temporoparietal cortices (p<.005, corrected), as well as significant conditional differences in beta activity in the left temporal and medial occipital regions (p<.005, corrected). These differences were such that stronger decreases in power were observed in related trials as compared to unrelated trials. Further, we found that conditional differences in beta oscillatory activity in the left inferior frontal gyrus (IFG) significantly predicted RT differences (p<.001). These data suggest that there is bilateral recruitment of temporoparietal cortices and medial occipital regions during judgements of semantic relatedness. Additionally, these data promote the role of left IFG beta activity in the executive control of semantic judgements.

Topic Area: LANGUAGE: Semantic