Description of Research Expertise

Speech comprehension is facilitated by neuronal coding schemes that impart precision in the detection and discrimination of the highly variable acoustic patterns of speech signals. At the same time the coding schemes must be flexible enough to retain comprehension through wide ranges of loudness, contrast and speech production rates. While sound encoding by individual neurons in the primary auditory cortex (A1) has been extensively characterized, how A1 neurons act in concert as a population to encode acoustic information, and how this multi-neuronal representation of the sound is transformed as statistical properties of complex sounds, such as speech, dynamically change, is presently unknown. The overarching goal of our research is to understand the neuronal mechanisms by which ensembles of neurons in the auditory cortex construct a precise yet adaptable representation of the acoustic environment. Using chronic recordings of activity in neuronal ensembles from awake rats, and applying innovative computational tools to analyze these populations, we identify unique properties of multi-neuronal interactions in A1 that underlie precise sound representations, tolerant to changes in contrast and temporal scale. We also use optogenetic tools to isolate the function of specific subpopulations of neurons in auditory scene segregation. Another line of research in the laboratory deals with investigating the effect of emotional learning on auditory perception.

For more information, please visit http://www.med.upenn.edu/hearing.