Responses of cells in the auditory cortex of awake squirrel monkeys to normal and reversed species-specific vocalizations.

Natural vocalizations and their artificial counterparts were found to be equally effective in evoking responses in auditory cortex units of awake squirrel monkeys. Neural responsiveness was presumably based primarily on the sensitivity of the units to acoustic transients embedded in the stimuli. For the left hemisphere, a significantly higher percentage of responding units was found in the primary compared to the secondary auditory cortex. However, the difference in the percentage of responding units between the primary and secondary auditory cortices was not significant for the right hemisphere.