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.
The threat simulation theory (TST) proposes that dreaming evolved as a biological defense mechanism to rehearse threat perception and avoidance, enhancing reproductive success. A key prediction is that real-life threats should increase the frequency and severity of threatening dreams. Analyzing dream reports from severely traumatized Kurdish children, less traumatized Kurdish children, and non-traumatized Finnish children supported most TST predictions. Severely traumatized children reported significantly more dreams, a higher number of threatening dream events, and threats that were more severe in nature compared to less traumatized or non-traumatized children.