Stimulus coding by medial superior olivary neurons.

Abstract

Results were obtained from neurons located within or near the medial superior olivary (MSO) nucleus of cat, to low frequency (3.0 kc and below) and click stimulation. Some of the response characteristics of these neurons to monotic, diotic, and dichotic acoustic signals were described. The interspike interval histograms for some neurons to monaural tonal stimuli showed recurring peaks at multiples of the tonal period. Other neurons discharged consistently with but 1 interval regardless of the frequency of stimulation. Click stimulation produced, in most binaural neurons, an inhibitory interaction that centers near a zero-time difference, suggesting that the contralateral input traveled with a greater velocity than the ipsilateral one. Direct evidence was presented for this conclusion. Inhibitory interactions also occurred upon tonal stimulation. At some interaural phase angles, the inhibitory interactions showed maxima that were unchanged when intensive differences are introduced to the ears.