Neural correlates of sound-learning experiences in the auditory system: Translational candidates for hearing rehabilitation

A major disconnect between traditional auditory perception research and recent neuroscience is the high propensity in the auditory system for neuroplasticity. Altered processing of reward-associated sound stimuli can contribute to adaptive behavior, such as hearing, listening, and attending appropriately to sound cues. I will the present work from animal models of learning-induced neuroplasticity in the cortical and subcortical auditory system. The data show how receptive fields and tonotopic maps in primary auditory cortex (A1) as well as the auditory brainstem response (ABR) can change when adult animals trained by pairing a tone with the availability to obtain reward alters sound coding in the auditory system. Over the course of conditioning, increases and reductions, respectively, in ABR amplitude and peak latencies predict how well animals can pick out the learned sound-frequency acoustic cue from other frequencies following conditioning. Furthermore, receptive fields in A1 have narrower tuning for a remembered sound frequency—and only in animals who successfully remember that frequency over others assessed by behavioral test. Therefore, learned sounds are preferentially processed over novel and distractor sounds following conditioning. Significant behavioral preferences for learned tones may be due, in part, to the observed changes in auditory processing across the auditory system.