Daniel Polley, Ph.D.

 

Assistant Professor of Otology and Laryngology

Eaton-Peabody Laboratory
243 Charles Street
Boston, MA 02114
Tel: 617-391-5952
Fax: 617-720-4408
Email: daniel_polley@meei.harvard.edu
Visit my lab page here.




Research in our 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 through study of the auditory cortex. The auditory cortex is powerfully influenced by experience during finite windows of development known as critical periods, after which time significant changes can only be brought about through learned associations between sounds and behaviorally relevant consequences. We study the mechanisms and perceptual correlates of cortical plasticity using a variety of neurophysiological, genetic, behavioral and computational approaches. We also record from subcortical auditory nuclei such as the inferior colliculus and auditory thalamus to better understand more about features that are relayed to the cortex versus constructed there de novo.

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 apply what we’ve learned about the dynamic interplay between plasticity and stability towards improving auditory processing in individuals that have been reconnected to the auditory world following a period of prolonged hearing loss.

Ongoing work in our group is directed towards three broad questions:

1. What aspects of thalamocortical circuit physiology distinguish normally hearing subjects from subjects with a history of compromised hearing?
2. What are the biological signals that transition thalamocortical circuits between states of stability versus plasticity?
3. How can we design adult auditory learning protocols that will bring about effective and long-lasting improvements in auditory perceptual acuity?


For a complete listing of publications click here.



Last Update: 10/30/2013