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NJIT Mathematical Biology Seminar

Tuesday, April 21, 2009, 4:00pm
Cullimore Hall 611
New Jersey Institute of Technology

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A Model of the primary auditory cortex response to auditory streaming sound sequences

Ernest Montbrio

Center for Neural Science, NYU

The neurons in the medial geniculate body (MGB) provide the main input to the primary auditory cortex (A1) via layers III/IV. While neurons in MGB are able to sustain responses to tones repeated at rates up to 200 Hz, A1 fails to respond when the repetition rate is much beyond 20 Hz. However, even for repetition rates below 20 Hz, there is a frequency-selective filtering known as differential suppression. This filtering produces a refinement of the A1 neuron's receptive fields, in such a way that the neurons become more selective to the tone's frequency as the tone's repetition rate is increased. This phenomenon is thought to play a fundamental role in auditory grouping (or auditory stream segregation) phenomena, i.e. in the organization of sequential sounds into perceptual streams reflecting individual environmental sound sources. Here we propose a simple model of the A1 which can account for the differential suppression phenomenon. The implications of our study for the auditory streaming phenomenon are discussed.