2aPP29. The unit responses to various complex sounds in the auditory cortex of the Japanese monkey.

Session: Tuesday Morning, December 3


Author: Tsutomu Kamada
Location: Dept. of Oral Physiol., Hokkaido Univ. School of Dentistry, Sapporo, 060 Japan


It is well investigated in the mammalian cortex that physiological parameters like tonotopicity and binaural response properties are represented in the primary auditory cortex, while the coding mechanism of complex sounds is not always understood in the primary as well as secondary cortex. In these circumstances it is still necessary to examine the response properties of neurons in a wide area of auditory cortices. The author has examined the neuronal responses to monkey vocalizations as well as pure tones, white noise, and synthetic sounds in the auditory cortex of the Japanese monkey in the chronic condition. More than 200 hundreds of units were recorded, most of which responded to either of the sound stimuli while the specific response to a sound was rare. Sharp tuning units with clear characteristic frequencies were located mainly in the primary cortex, while broad tuning ones were in periphery of the koniocortex. Some neurons responded, like the frequency analyzer when examined, to ``coo'' vocalizations and to synthetic harmonic components of the vocalization. Other responses were compared to acoustic structures of the stimuli. The correlations between stimuli and neural responses were discussed in association with the location of the neurons in the cortex.

ASA 132nd meeting - Hawaii, December 1996