MODELLING RESPONSES OF THE PRIMARY AUDITORY CORTEX TO FREQUENCY-MODULATED TONES IN AWAKE CATS

摘要

Responses of primary auditory cortex (A1) neurons tornfrequency-modulated (FM) tones are heterogenic in awakerncats. These neurons include tonic and phasic cells, whichrnshow sustained and phasic responses, respectively. FM responsesrnof phasic cells increase as the sweep speed duringrnthe frequency modulation increases. In contrast, tonic cellrnresponses decrease with an increase in the sweep speed.rnTo explain the FM responses of A1 neurons, we developedrnan auditory model with a multichannel neural pathway.rnThe model consists of seven blocks: the basilar membranern(BM), the inner hair cell (IHC), the primary auditory nervern(AN), the ventral cochlear nucleus (VCN), the inferior colliculusrn(IC), the medial geniculate body (MGB), and the A1rnneuron. Weighted summations across the channels were introducedrnto the VCN, IC, MGB, and A1 blocks because lateralrninhibition is observed in these connections. The modelrnoutput successfully replicated physiological data of the responsernpatterns and the peak–speed relationship in the FMrnresponses. This model can be used to convert acousticalrnsignals into electrical stimuli as part of an auditory brain–rnmachine interface for individuals with severe hearing impairments.