Early-night serial awakenings as a new paradigm for studies on NREM dreaming.
International journal of psychophysiology : official journal of the International Organization of Psychophysiology October 1, 2009 Valdas Noreika, Katja Valli, Hetti Lahtela et al.
A new experimental paradigm called Early-Night Serial Awakenings (ENSA) was tested to assess its usefulness for studying NREM sleep dreaming. Five participants spent 20 nights in a sleep laboratory and were awakened every 24 minutes during Stages 2 and 3 of NREM sleep. Out of 164 awakenings, 30% produced dream reports, 39% reports of white dreaming, and 31% reports of dreamless sleep. Sleep EEG power, dream recall frequency, and dream complexity remained stable across sessions. The authors conclude that ENSA yields static, content-limited dreams and could help reveal the psychophysiological mechanisms of simple early-night NREM dreaming.