Implications of a sensory-motor theory for the representation and segregation of speech
Neil P. McAngus Todd · The Journal of the Acoustical Society of America · 1999
Discussed is a computational model which attempts to simulate the principal brain structures involved in sensory-motor sequencing, including auditory cortex, posterior parietal cortex, cerebellum, motor cortex, and the motor output system. A particular focus in this presentation is on the auditory cortical component responsible for computing a 3-D spatio-temporal power spectrum of the auditory image flow [N. Todd, Proc. 16th ICA (1998)], which captures information topographically on three levels, roughly corresponding to timbre, pitch, and rhythm, and reflects the temporal resolution of the cochlea, inferior colliculus, and auditory cortex, respectively. By considering the spatio-temporal orientations of cortical receptive fields (RFs), it is possible to delineate a set of stationary and moving primitive features upon which the higher-order constructs of pitch and timbre are built. A separate model population of secondary auditory cortical neurons, which receive inputs from the population of primary RFs, provides a potential means of accounting for a number of important phonological and melodic processes. Implications of this model are discussed for the development of new algorithms for the representation and segregation of speech via self-organization of primary and secondary RFs by means of the principle of information maximization.