Poster Session E, Monday, March 25, 2:30 – 4:30 pm, Pacific Concourse
Time-frequency characteristics of neural responses to perturbations during sensorimotor synchronization to auditory and visual rhythms
Daniel Comstock1, Ramesh Balasubramaniam1; 1University of California Merced
Timing mechanisms play a crucial role in detection and correction of errors sensorimotor synchronization (SMS) tasks. Given that existing research suggests there are multiple context dependent neural timing mechanisms, we expect to find different timing mechanisms between auditory and visual SMS and for detecting and correcting errors of different types. We investigated these mechanisms by using time frequency measures, including event related spectral perturbations (ERSP) and inter-trial coherence (ITC) to reanalyze EEG data from a previous event related perturbation (ERP) study looking at auditory and visual error correction (Comstock & Balasubramaniam 2018). In the study, subjects tapped in synchrony to auditory and to visual flashing metronomes with occasional step perturbations, where a tone or flash came either earlier or later than expected. We found measures of error detection most strongly in the theta and alpha bands with strongest responses to auditory late perturbations. Phase coherence over the motor region contralateral to the tapping hand showed a relative increase in the visual condition following a late perturbation and a relative decrease following an early perturbation. The auditory condition showed a double peak in coherence only following an early perturbation, with the peaks corresponding with the timing of the expected tone onset and actual tone onset. Ipsilateral motor phase coherence showed reduced coherence for both perturbations only in the auditory condition. These results show both differences in mechanisms for both error detection and in correction in both modality and in direction, confirming the presence of multiple context dependent timing mechanisms.
Topic Area: PERCEPTION & ACTION: Motor control