Awakening Latency From Sleep For Meaningful and Non‐Meaningful Stimuli

Abstract
Personally significant and non‐significant low intensity sound stimuli were used to determine awakening latencies from sleep stages REM and 2. Latency was measured from stimulus onset to a) the sleeper's own acknowledgement of waking, and b) alpha rhythm onset. Both stimuli were presented twice, once in each sleep stage, to 8 Ss. Voluntary response latencies in REM were shorter than in stage 2 (p <.025) but no difference was found for the latency of alpha rhythm onset. The personally significant stimulus, however, caused a significantly shorter awakening latency using both criteria. The results suggest that perceptual thresholds are low in both sleep stages 2 and REM but that the ability or willingness to organize a response is greater in REM sleep.