Enhancement of sound motion detection in acallosal individuals.

It has been proposed that the corpus callosum may play an important role in spectral cue processing that allows vertical auditory movement perception. The purpose of the present study was to assess the contribution of the corpus callosum to this type of auditory processing. Noise bursts were presented to 10 control and two callosal agenesis individuals from different positions located within midsagittal and coronal planes. Although acallosal participants were comparable with controls in their ability to correctly identify the trajectory direction or its length, they showed greater capability in detecting motion per se when the task was difficult. These results suggest that in the absence of the corpus callosum, compensatory reorganization of the brain allowed for superior auditory spectral cue processing.