DESCRIBING AND MODELING HYPNAGOGIC IMAGERY USING A SYSTEMATIC SELF-OBSERVATION PROCEDURE

The published literature suggests that systematic self-observation may be a suitable method for clarifying the nature and correlates of hypn agogic imagery and thus a useful adjunct to psychophysiological and co gnitive studies of sleep onset. The potential applicability of one rec ently proposed self-observation procedure (Nielsen, 1992) to such stud ies is demonstrated in the present work. The procedure permits numerou s hypnagogic images to be collected during spontaneous drowsy periods occurring during the day. The observer sits in an upright, head-unsupp orted position, fixes an observational intent, and pays attention to i nternal events; images are observed, transcribed and then assessed for their likely memory sources. The procedure has been pilot-tested by t he author in four exploratory studies comprising over 250 hypnagogic i mages. Neuromuscular events accompanying these images (e.g., head nods , leg jerks) and EEG correlates of the images are described. Certain d istinctions among imagery types are suggested, e.g., fleeting vs. full y-formed, images with self movement vs. images with non-self movement. Silberer's conclusions regarding the 'autosymbolic' function of hypna gogic images are supported and extended by the results. Four types of memory element (immediate, short-, medium-, and long-term) appear to h ave contributed causally to the formation of these hypnagogic images a nd are illustrated. To demonstrate how the self-observational method m ay be used to model the formation of hypnagogic imagery from such memo ry sources, a single sample image and its multiple memory sources are described and analyzed in detail.