Coding In The Auditory Cortex

Publisher Summary This chapter provides an overview of basic auditory parameters, some anatomical considerations, and the coding in the auditory cortex. Studies on sound stimulation showed that the stimulation of basal auditory fibers gave rise to an evoked response in the anterior part of the corresponding region in the cat. It is fairly clear that an area of cortex lying (in the cat) in the middle ectosylvian gyrus and designated variously as AI, primary auditory cortex, or primary projection area is unequivocally auditory cortex. In addition to these cochleotopic projections, there are other auditory projection systems that reach the cortex from the thalamus and are not organized in a cochleotopic manner. From evidence, the hypothesis that the auditory cortex consists wholly or even largely of a set of feature detectors does not receive much encouragement. The untransformed input—the harmonic series—appears in several parts of the auditory cortex. The input has been transformed, and the units responded to the features of objectness.