Neural responses in the inferior colliculus of albino rat to binaural stimuli

Abstract

The responses of units in the inferior colliculus of rats were recorded while noise, tone, and click stimuli were presented binaurally. The interaural time and intensity disparities were varied; time to a maximum of 180 μsec in 30−μsec steps and intensity to a maximum of 20 dB in 4−dB steps. Total spike count, probability of firing, and average latency indicated that for most cells contralateral stimuli leading in time or of greater intensity relative to the ipsilateral ear produced increased spike counts and probability of firing and decreased latency of firing. While support is apparent for the influence of both time and intensity cues, the intensity cue would seem to predominate under naturally occuring conditions. A population model for the utilization of these two cues is supported by the data. Subject Classification: 65.44, 65.62.