ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

3aPP5. A bridge between place and time. II. Its significance for theories of pitch.

Steven Greenberg

Int. Comput. Sci. Inst., 1947 Center St., Berkeley, CA 94704

The opposition between ``place'' and ``time'' perspectives in auditory function finds its fullest theoretical expression in the long-standing controversy over the neural basis of pitch. Traditionally, the two perspectives have been viewed as mutually exclusive, with pitch derived from either place or temporal cues, but not both. The controversy persists, in large part, because neither perspective, by itself, can fully account for the full range of perceptual experience associated with the pitch of complex signals [E. F. Evans, Audiology 17, 369--420 (1978)]. It is proposed that pitch stems from the interplay of place and time information, bound together into a coherent representation through the operation of central coincidence-sensitive neural populations. This framework provides a principled basis for understanding the neural mechanisms underlying the major properties of pitch (such as the ``dominance'' and ``existence'' regions, the first and second effects of the pitch shift, phase-insensitivity and dichotically mediated pitch) and illustrates the manner in which both frequency selectivity and synchrony are required for computing a signal's periodicity with precision and reliability.