Thresholds of auditory sensitivity and binaural localization during sleep.

Abstract

The hypothesis that one function of REM sleep might be indirectly to innervate the auditory system was tested. Sensitivity and spatial localization thresholds were measured in 16 Ss prior to sleep, alternately at the onset and end of REM periods, and upon morning awakening, and 15 min. later. Sensitivity thresholds of the left ear were lower and difference limens (DL) greater at the onset compared to the end of REM periods. Left ear thresholds were also lower and DLs greater for both ears in the morning than prior to sleep. Localization thresholds did not differ at the onset and end of REM periods or prior to and following sleep. The results were contrary to the hypothesis that REM sleep innervates the auditory system. Greater changes in the left ear than the right ear probably reflect lateral differences in the brain.