Effects of Learning on Neural Representations of Rhythm and Beat

Poster Session E - Monday, April 15, 2024, 2:30 – 4:30 pm EDT, Sheraton Hall ABC

Joshua D. Hoddinott^1,2 (jhoddin@uwo.ca), Jessica A. Grahn^1,2; ¹Brain and Mind, University of Western Ontario, ²Western Institute of Neuroscience, University of Western Ontario

Listening to rhythmic sounds elicits activity in the basal ganglia, cerebellum, and motor cortices, including supplementary motor area and premotor cortex. Rhythms with musical structure that give rise to a steady underlying pulse, or 'beat', elicit increased activity in the SMA and basal ganglia, suggesting these areas are involved in beat perception. However, because people hear music regularly, rhythms eliciting a strong beat are necessarily more predictable than amusical, irregularly-timed rhythms that are often used as control stimuli. Thus, neural correlates of beat perception may be confounded by the relative experience-driven predictability of strong-beat rhythms. To address this confound, we will equalize the predictability of a subset of rhythms that vary in beat strength, and measure BOLD activity associated with the rhythms before and after predictability is equalized. Across 4 sessions, participants train on 12 unique rhythms (4 strong-beat, 4 weak-beat, and 4 non-beat) in finger-tapping tasks. In pre- and post-training fMRI sessions, we measure BOLD responses while participants listen to the rhythms during a rhythm discrimination task. Brain regions that are truly sensitive to the beat will maintain activity differences between beat strength conditions in both pre- and post-training scans. However, predictability-sensitive regions will show no difference between beat strength conditions in the post-training scan only, as all rhythms will be equally predictable. Data collection is currently ongoing (~15% of sample collected), preliminary results will be presented.

Topic Area: PERCEPTION & ACTION: Audition