Tempo representation in the basal ganglia and its role in sensorimotor synchronization

Poster Session D - Monday, April 15, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Jacob Duda¹ (dudaj@mcmaster.ca), Jonathan Cannon¹; ¹McMaster University

Activation of segregated cortico-nigro-striatal-thalamic-cortical (CSNTC) loops is thought to encode the initiation of specific actions or to be involved in controlling action “vigour.” We propose that the loops could also be encoding the tempo with which rhythmic actions (ex. finger tapping) are performed. In this way, switching which CSNTC loops are activated would act as a mechanism for tempo correction in sensorimotor synchronization tasks (classically, tapping along to a metronome). As a proof of concept, we represent parallel CSNTC loops as a bump attractor where the activity of units represents the activity of CSNTC loops. This architecture captures the excitation/inhibition patterns of CSNTC loops as well as observations of overlapping striatal representations of similar movements. We use this model to demonstrate how a continuous mapping of actions on the striatum, the proposed role of dopamine in reward prediction error and action switching, and a representation of action frequency in CSNTC loops can explain results of various tapping studies. Specifically, our model explains the observed differences in corrections to large and small tempo changes in synchronization tasks, as well as the increased variation in tapping intervals seen in patients with Parkinson’s disorder. Alterations to the basal ganglia and dopamine are experimentally seen to effect movement, synchronization, and temporal and rhythm perception. This research attempts to further our understanding said relationship and may have implications regarding RAS therapy for Parkinson’s or perception of rhythm and music.

Topic Area: PERCEPTION & ACTION: Motor control