Neural Bases of Auditory Processing Disorders in Adults

DESCRIPTION (provided by applicant): Auditory Processing Disorders (APD), also known as Central Auditory Processing Disorders, is characterized by deficits in processing complex verbal and nonverbal acoustic signals. The diagnosis, treatment, and even the very existence of APD are controversial. Little is known about the pathophysiology of APD. The National Institute of Deafness and Other Communication Disorders stated that much research is still needed to understand this disorder (NIH Pub. No. 01-4949, 2004). Despite the lack of evidence on many fronts, as well as difficulty with third-party payment reimbursements, individuals with APD symptoms are being diagnosed and treated everyday, and students in clinical audiology are taught to provide services to this population. This proposed research aims at building evidence for APD, with particular attention to exploring the common belief that APD is associated with neurophysiologic and possibly neuroanatomic anomalies in the central auditory nervous system. Functional Magnetic Resonance Imaging will be utilized as APD individuals process complex acoustic signals, as well as high-resolution anatomical imaging. Although APD is often discussed in children, this first research will focus on the more ontogenetically developed brain (ages 25 to 40) for ease of comparison with existing auditory fMRI data. Future experiments will include both children and adults. Specifically, the proposed research aims at investigating the following: 1) Whether neuroanatomic anomalies exist in adults diagnosed with APD based on behavioral testing, and whether it is feasible to use MRI to identify them. 2) Whether it is feasible to use MRI to identify neurophysiologic anomalies in APD adults. If so, whether APD is associated with a collection of unifying or diverse neurophysiologic anomalies.