Daniel B. Polley, Ph.D.
Assistant Professor of Otology and Laryngology, Harvard Medical School
Research in the Neural Plasticity group focuses on the mechanisms and therapeutic potential of auditory brain plasticity. Brain plasticity (or neuroplasticity) is the science of brain change. Of all the organs in our body, the brain possesses a unique capacity to change its basic composition in response to our experiences, be they catastrophic, such as injury, or subtle and natural, such as infant learning. This remarkable plasticity is offset by an equally remarkable capacity for maintaining constancy in the face of a fluctuating and unpredictable sensory world. How do brain circuits maintain this critical balance between plasticity and stability? Can the brain’s ability to change itself be harnessed and directed for therapeutic benefit?
We address these questions by studying higher levels of the central auditory pathways such as the auditory cortex, auditory thalamus and inferior colliculus. We are interested in rapid physiological changes that unfold on the scale of seconds and minutes (e.g., changes that accompany heighted auditory attention or auditory learning) as well as plasticity that develops over the course of weeks or months (e.g., influences of early developmental experience on receptive fields and topographic maps). We study the mechanisms and perceptual correlates of cortical plasticity using a variety of neurophysiological, genetic, behavioral and computational approaches.
We believe this class of study will contribute towards a richer understanding of normal function, but might also hold the key for remediating abnormal auditory signal processing following a history of compromised hearing or deafness in early life. As with any communicative system, hearing arises through the interaction of an emitter (the cochlea) and a receiver (the central auditory system). In the context of hearing loss, a great deal of work is directed towards improving or reinstating outgoing signals from the emitter through amplification devices, cochlear implants and even hair cell replacement. Far less is known about the flip side of the coin: whether additional recovery of function might be possible by “tuning up” the receiver. A major goal for our group is to understand how brain plasticity can be utilized to improve auditory sensitivity and acuity in individuals with subnormal hearing.