Neurophysiological Consequence of Auditory Training: Subcortical and Cortical Structures

Abstract

Earlier studies have shown that auditory system has capacity to reorganize and show plastic changes with auditory training. The changes have been demonstrated in both brainstem as well as cortical areas. However, the However, studies on the effect of training on brainstem structures are equivocal and fail to show any conclusive findings. One possible reason for this could be lesser number of sessions of training. Hence, the present study was aimed to see the effect of long term auditory discrimination training on brainstem and cortical responses to speech. To examine this, late latency and brainstem responses were recorded for speech stimulus before, during and after a stipulated period of auditory training in ten normal hearing subjects. Subjects were trained for frequency discrimination, intensity discrimination and temporal modulation identification for 33 sessions. Late latency and brainstem responses were recorded 5 times during the course of training. The results showed training related improvement in both brainstem and cortical responses evidencing neural plasticity secondary to auditory training in adulthood. However, plastic changes are slow in the brainstem compared to cortical areas.