Description
The perception of beat, while seeming easy and intuitive, is a rather complex cognitive and sensorimotor achievement that at times can manifest as a visceral sensation. Deficits in beat perception also appear to positively correlate with increased impairment in movement disorders such Parkinson's disease. Neuroimaging has shown findings like these are likely due to rhythm perception and production relying on a complex interaction of auditory and motor regions, in association with a supportive network that includes prefrontal, parietal, and deep striatal areas of the brain. This study therefore aimed (I) to use traditional task-based activation techniques (fMRI) to define the critical regions of the rhythm network under both a beat rating (BR) and beat production/maintenance (BPM) cognitive task; and (II) employ task-based functional connectivity (fcMRI) methods, to map the most important connections within this network, highlighting how they may change dependent on task behavior and stimuli. Activation results for 14 normal right handed participants (4F : 10M, 24 yrs ± 4.54) confirmed much of the current literature and indicated that both beat perception and production recruit neural resources from predominantly overlapping regions of a single network. Functional connectivity analyses described a network whose connectivity is relatively stable regardless of stimuli or task. Differences between perception and production of rhythm appear to stem from specific, subtle changes in the synchronicity between particular regions. To our knowledge, the correlation matrices and connectivity maps derived from our fMRI-fcMRI data are the first comprehensive representations of the rhythm network as a whole.
