Atypical Neuronal Oscillatory Synchrony of the Auditory Steady State Response in Down Syndrome

The mechanisms by which the brain coordinates a constant flood of information to provide a unified perception of reality remains poorly understood. Mounting evidence suggests that information integration is closely related to oscillatory activity in the gamma frequency band. Individuals with Down Syndrome (DS) reportedly struggle with higher cognitive processes, but existing knowledge representing the neuronal oscillatory dynamics of the DS brain remains limited. Cortical circuit dysfunction can be probed by the examination of phase coherence of the Auditory Steady State Response (ASSR). Using a measure of phase coherence to assess oscillatory synchrony in the auditory cortices, results show evidence of reduced inter-hemispheric phase locking in the gamma band at the group level (N=12) for DS individuals (p < 0.01) compared to control participants. These findings indicate the DS brain does not integrate information as effectively as non-DS individuals do, contributing to a deeper understanding of the neurophysiological correlates of DS symptomology.