The effects of sleep on objective measures of gap detection using a time-efficient multi-deviant paradigm.

Auditory temporal resolution, measured through gap detection, is critical for the perception of speech. A time-efficient multi-deviant paradigm has previously been developed for gap detection. The purpose of the present study was to determine if this multi-deviant paradigm could be used for gap detection during NREM sleep. ERPs were recorded in 10 young adults while awake and during the first two hours of NREM sleep. A multi-deviant paradigm was employed with six different deviants varying in gap duration, ranging from 2 to 40 ms. During waking, a DRN was observed for the 10, 20, 30 and 40 ms gaps. The DRN was absent during sleep. A P2 was present in NREM for the 20, 30 and 40 ms gaps followed by a P3a to the 30 and 40 ms gaps. An N350 was observed following the 10, 20, 30 and 40 ms gaps. Previous studies have reported significant ERPs to gaps having shorter durations than the present study. The multi-deviant paradigm may not be suitable for the determination of gap threshold during sleep. Nevertheless, it provides an exquisite means to determine perceptibility and the extent of processing of longer duration, supra-threshold gaps during sleep.