The properties of acoustically responsive cells in the anterior suprasylvian gyrus of the cat.

The properties of acoustically responsive neurons were studied in the anterior part of the suprasylvian gyrus ( ASG ) of cats anaesthetized with pentobarbital or chloralose-urethan. The acoustic responsiveness of the cells was screened with click stimuli. Whenever an acoustic response occurred, its properties were further analysed with the aid of spectrally pure tone pulses. The most important features of the responses given to pure tones of different frequencies were (a) short latency and (b) sharp tuning to well defined frequencies. In this respect the cells showed a close resemblance to those in the primary acoustic area (AI) and differed considerably from neurons of the middle suprasylvian association field (AMSA), which lacked well defined best frequency (BF) and responded with longer latencies. At the same time the ASG neurons showed responses to somatosensory stimuli thus representing a transition between neurons of primary sensory and association areas.