Cocaine use and the mid-latency auditory evoked responses.

To examine the effects of chronic cocaine use on the mid-latency auditory evoked responses (MLAERs), we recorded the evoked responses of 15 cocaine-dependent subjects and 13 age-matched healthy control subjects. Two evoked response paradigms were used: a trains paradigm with four different inter-stimulus intervals (ISIs) and a paired-click paradigm. Our data suggest that cocaine-dependent subjects generate smaller P50 components when long ISIs are used with multiple repetitions (in the trains paradigm). In a single repetition paradigm (paired clicks), a significant decrease in the ability to attenuate the N100 component was seen in the cocaine-dependent subjects.