The varieties of experience during dreamless sleep: conceptual and methodological considerations

Jennifer Windt (Monash University)

The varieties of experience during dreamless sleep: conceptual and methodological considerations

Dreaming is increasingly recognized as a relevant topic for philosophy of mind and interdisciplinary consciousness research. Experience occurring during dreamless sleep has, by contrast, received very little attention. Often, conscious experience itself is defined as that which appears in waking and dreaming, but is lost in dreamless sleep, suggesting that the very notion of dreamless sleep experience is contradictory. Recent philosophical work and empirical findings suggest that this view is oversimplified. To begin with, NREM sleep is not, as occasionally assumed, synonymous with dreamless sleep. Dreaming is not restricted to REM sleep and occurs in all stages of sleep. Moreover, different types of subjective experience, mostly occurring during sleep onset and the stages of NREM sleep, cannot be classified as dreaming. In this talk, I will introduce a conceptual framework for describing the varieties of dreamless sleep experience. I will then discuss several consequences and predictions for investigating their sleep-stage and neural correlates, as well as their relation to memory consolidation and stimulus processing during sleep, sleep behaviour, and sleep (mis)perception, as in insomnia.