Srivatsun Sadagopan
| We
hear sounds such as speech in a wide range of listening conditions, of which
few parameters are under our control. For example, sounds might emanate from
different locations, at different intensities, in the presence of other noise
or distracting sounds, and in echoing settings. For a given sound, each of
these environmental variables alters the physical pressure waveform that
impinges on our eardrums; yet, we are able to interpret these varied physical
waveforms as arising from the same underlying sound. In other words, our
perception of sounds is perceptually invariant to a large number of nuisance
parameters, and one of the primary functions of the ascending auditory system
is to develop this perceptual invariance. The research thrust of our laboratory
is to study the mechanisms by which such invariance properties are generated
in the neural responses of primary and higher auditory cortex. In particular,
we focus on one behaviorally important set of sounds - vocal communication
sounds. We use a range of techniques to answer these questions, including in-vivo array and multi-electrode extracellular recordings and in-vivo whole-cell intracellular recordings from awake (and eventually behaving) animals. We expect to add in-vivo two-photon imaging, inducible genetics and viral tract-tracing to this suite of techniques in the near future. Realistic listening conditions pose a significant challenge to patients with communication disorders such as dyslexia, some sensory aphasias, to the hearing impaired, and to the elderly with age-related decline in hearing. We hope to provide fundamental insights into these disorders by understanding the circuit mechanisms by which the brain extracts meaningful signals from noise. |
| Neural mechanisms underlying real-world auditory perception |
