Human brain areas involved in the analysis of auditory movement

This work tests the hypothesis that a network of areas involving bilateral premotor cortex and right parietal cortex subserves the analysis of sound movement. The components of this network have been examined at the level of individual subjects in a study where 720 fMRI scans were acquired per subject. Additionally, the effect of movement direction was investigated by varying this property systematically. Linear sound ramps that are perceived as movement toward one side of the head or the other were used in an experiment in which the principal contrast was between movement, and a stationary control stimulus made up of identical component interaural phase and amplitude cues. In a group analysis, the network of bifrontal and right parietal areas suggested by previous work was confirmed. The frontal activation included both dorsal premotor activity in the region of the frontal eye fields and discrete ventral premotor activation in an area corresponding to primate areas for multimodal spatial analysis and motor planning. The right parietal activation included both superior and inferior parietal cortex. Analysis of the individual data showed a similar pattern of activation in each subject, with the greatest variability within the right parietal area. The pattern of activation did not vary when the direction of movement was varied, suggesting that both directions of movement are represented in the network we have demonstrated.