Cognitive Aspects of Mental Activity during Sleep

Abstract

Upon nighttime experimental awakening of 27 subjects in four sleep conditions (sleep onset early; sleep onset late; Stage 2; and rapid eye movement, REM, sleep), 108 dream reports and their association reports were collected. Dream reports were analyzed for length (temporal units) and content categories (continuity; implausibility; presence of the dreamer [i.e., "the self"], a setting, characters). Associations were classified as episodic, abstract self-referred, and semantic memories. The two sets of results tend to show a basic homogeneity among mentation reports in the four sleep conditions considered. These findings are interpreted as supporting the hypothesis that the same cognitive mechanisms operate, at different levels of engagement, in dream generation rather than the hypothesis of multiple dream-generation systems dependent upon the physiological characteristics of the various sleep stages.

Emotion and Cognition: Feeling and Character Identification in Dreaming

“…As a result, dream characters may very well be seen differently and elicit different feelings than those in waking life where the DLPFC is in communication with these areas. When the DLPFC is in poor communication with these areas as in REM sleep, the ability to perform logical inference, to recall accurately, and to discern whether a premise is fact or fiction may very well be compromised (MujicaParodi et al, 2000;Barbas, 1995;Barbas et al, 1999;Bosinelli, 1995;Cicogna et al, 1991;Cummings, 1993;Duncan et al, 1996).…”

“…Previous reviews and studies were done by eliciting dream reports and analyzing cognitive differences that occur in dreams and in waking (in, for example, Blick & Howe, 1984;Bosinelli, 1995;Cartwright et al, 1998;Cicogna et al, 1991;Domhoff, 1996Domhoff, , 1999Foulkes et al, 1988;Hall & Van de Castle, 1966;Hobson, 1988Hobson, , 1997Kahn et al, 1997;Kramer, 1993;Nielsen et al, 1991;Schredl & Doll, 1998). We have recently undertaken a study of how characters that appear in dreams are recognized (Kahn et al, 2000).…”

Consciousness during Dreams

“…In our opinion, and in terms of mental processes, what may differ at the psychological level is the ''engagement amount'' of the cognitive system which is influenced by the modulation of the physiological background. This may explain the occurrence of dreams of different lengths and with different amounts of imagery, bizarreness, emotions, and so on (Antrobus, 1991(Antrobus, , 1999Cavallero et al, 1992;Cicogna et al, 1991Cicogna et al, , 1998Cicogna et al, , 2000Foulkes, 1985Foulkes, , 1996. Our viewpoint also includes the hypothesis of a single dream generator for both REM and NREM mental experiences.…”

As we fall asleep we forget about the future: A quantitative linguistic analysis of mentation reports from hypnagogia

“…In how far hypnagogic imagery draws from memory input has previously been studied by systematic self-observation procedures in which the investigator observed and analysed his own hypnagogic imagery in spontaneous drowsy episodes during the day (Nielsen, 1995): According to this investigation, four types of memory sources (immediate-, short-, medium-, and long-term) appear to feed into hypnagogic imagery (Nielsen, 1995). Content of sleep onset mentation is believed to draw from episodic memory, as participants afterwards (once awake) tended to associate the content of sleep onset mentation with specific personal events (Cicogna, Cavallero, & Bosinelli, 1991;Cicogna et al, 1998).…”