The Neural Processing of Phonetic Information: The Role of the Superior Temporal Gyrus

Abstract

Speech is a complex acoustic stimulus. According to the earliest observations of Wernicke, deficits in the perceptual processing of speech were associated with damage to the left superior temporal gyrus. Wernicke’s observations were acute, since the dorsolateral temporal lobes (including the superior temporal gyri) contain primary auditory cortex and auditory association cortex. Though speech is the primary mode for linguistic expression in humans, its perception relies predominantly on auditory cortical fields. Considerable work in the neuroanatomy of primate auditory cortex, in parallel with functional and anatomical studies of human auditory processing has indicated that there is considerable complexity in the ways that sound and speech is processed in the primate brain. The chapter reviews some of the evidence for this from human functional imaging studies.