Cortical representations of pitch: theories and experiments

Abstract

Pitch perception is one of the most important auditory perceptual phenomena. Its underlying neural mechanisms have not been well understood. Recent human imaging studies and neurophysiology experiments in non-human primate have begun to reveal possible neural coding mechanisms in the cerebral cortex. These studies have pointed to a specialized area in the rostral region of primate auditory cortex where harmonic pitch is extracted. How pitch-selective neurons in this cortical area extract harmonic pitch at the cellular level, however, is yet known. Moreover, it remained to be explored whether other auditory cortical areas process aspects of pitch that are not processed by this rostral pitch-region. An important issue in the study of cortical representations of pitch is whether pitch embedded in harmonic complex sounds is extracted and uniquely represented by a specific cortical area or a subset of neurons in that area. Simply showing that pitch information exists in neural firing in a cortical area is not an adequate demonstration of pitch processing mechanisms. (Research supported by NIH grant R01-DC003180)