Limited Discriminability of REM and Sleep Onset Reports and Its Psychiatric Implications

Eyelid Movements and Mental Activity at Sleep Onset

“…On the one hand, our results support the conclusions of previous studies that hypnagogic dreams can show all of the features of REM-period dreams (e.g., Foulkes & Vogel, 1965;Foulkes, Spear, & Symonds, 1966;Vogel, Barrowclough, & Giesler, 1972;Foulkes & Schmidt, 1983). They can be hallucinatory, delusional, emotional, bizarre, and organized around narrative plots (for review, see Schacter, 1976).…”

What subjective experiences determine the perception of falling asleep during sleep onset period?

“…Foulkes and Vogel concluded that hypnagogic experience -defined as a state of intermediate consciousness that precedes sleep -was quite similar to REM dream experience. This same pattern of changes in subjective experience was confirmed in other studies by the same research group (Vogel, Barrowclough, & Giesler, 1972;Vogel, Foulkes, & Trosman, 1966). Similarly, Gibson and his colleagues investigated subjective experiences associated with judgments that corresponded to physiological sleep states during the sleep onset period.…”

Mammalian sleep

“…Dream reports have been obtained from various stages of NREM sleep. The dreams occurring at sleep onset may be vivid and indistinguishable from REM reports (Foulkes and Vogel 1965;Foulkes et al 1966;Vogel et al 1972;Cicogna et al 1991;Cicogna 1994); similarly with Stage 2 sleep (Cicogna et al 1991). Broadly similar findings have been described with slow wave sleep (Stages 3-4) (Pivik and Foulkes 1968;Cavallero et al 1992).…”