Auditory deprivation during the development of the nervous system can induce numerous perceptual deficits, as well as impeded speech and language acquisition. To understand the perceptual deficits in the deprived auditory system, past studies focused primarily on determining the sensitivity of single neuron responses to acoustic stimuli in a passive or anesthetized preparation. While these neurophysiological studies have firmly established impairment of encoding of sensory stimuli as a characteristic deficit in hearing loss (HL) populations, a quantitative relationship between sensory encoding and perceptual outcome is absent. This proposal seeks to establish a direct relationship between neural encoding and perceptual performance in populations with developmental (HL). Another undetermined component of auditory processing in previous studies of hearing loss is the contribution of non-sensory processes (e.g. attention, decision-making) present during behavior that act to enhance sensory coding properties. It has been established that auditory cortex neurons become more sensitive to acoustic stimuli during task performance, however it is unknown if this process is disrupted in the case of HL. Using an awake-behaving preparation, behaviorally driven changes to auditory response properties in both normal and HL populations will be assessed. The primary goal of this proposal is to determine the relationship between neural responses and behavioral output on a trial by trial basis in HL populations. The secondary goal of this proposal is to quantify behaviorally driven changes in stimulus processing in a control population and make a direct comparison in a HL population.
Sensory deprivation can have profound and long lasting effects on the developing central nervous system, for individuals with prolonged hearing loss this includes both cognitive and perceptual deficits. This project is aimed at understanding the neural basis of perceptual deficits displayed in individuals with prolonged hearing loss. This relationship will be quantified by concurrently assessing neural responses and animal behavior during a perceptual task, thus allowing the additional measurement of task-related (e.g. decision making, attention) contributions to sensory processing.