Auditory processing for contrast enhancement of salient communication vocalizations.

In a natural acoustic environment, coherent representations of auditory objects and sources are streamed from the myriad sounds that enter our ears. Features of those sounds that are familiar and behaviorally salient to us are detected and discriminated into invariant precepts that inform us about our external world. Research into how this occurs is increasingly converging on the idea that there is a transformation from the auditory periphery wherein an initial acoustically faithful representation by neurons becomes progressively altered to enhance the population neural representation of perceptually relevant aspects of the sound. How this occurs may vary for sounds whose meanings are acquired in different ways, perhaps depending on what actions and decisions must be executed upon recognition. We have investigated this process in a natural social context in which mouse mothers "learn" about the meaning of pup ultrasound vocalizations through their maternal care. Here we discuss our recent studies in awake mice using electrophysiological, behavioral, immunohistochemical and computational methods. Our results suggest that experience with natural vocalizations may alter core auditory cortical neural responses so that the contrast in activity across the neural population enhances the detection and discrimination of salient calls.