The Anatomy of Speech Perception

Language comprehension is an everyday phenomenon which we all accept, yet nobody knows what it means in terms of brain activity. This review will not resolve the matter. It purports only to mention the methods which are used in approaching the problem and to summarize the results to date. Since I try to synthesize clinical, histological, and neurolinguistic findings, as well as relevant results from animal experiments, the treatment of each individual field of research must of necessity be very compact. Due to my own training and inclinations, the emphasis is on the anatomy and physiology of language “centers” in the brain, and, as the title indicates, mainly on the sensory language regions. In these respects this review differs from other recent reviews (Caramazza and Berndt, 1978; Zurif and Blumstein, 1978; Saffran, 1982) which were written from the neurolinguistic point of view and make a more “high-level” attack on the problem of language. In the speculative part of the chapter I shall attempt to interpret neurolinguistic findings in anatomical/physiological terms. The models proposed there are not intended to be final explanations of cortical speech processing but ideas which will be modified by future research. Finally, I shall point out the obvious gaps in our current knowledge—for future investigation.