Abstract Mkid 114

The time course of ‘sleep inertia’ was studied with a semantic priming paradigm. With this automatic spreading activation task it was found that longer reaction times on target words after an awakening from sleep, as compared to those obtained after a period of wakefulness, appeared only during the first 2.5 minutes. Thus, sleep inertia could be observed but dissipated in a fast way. Moreover, no differences in sleep inertia could be found after forced awakenings from deep slow wave sleep compared to light slow wave sleep as well as to REM sleep. Characteristics of sleep inertia are discussed in terms of task difficulty in relation to awakenings from a particular sleep-wake state. It is suggested that the semantic priming task is an automatic and easy one, which is expressed in a relatively short period of sleep inertia.