Recalling and forgetting dreams: theta and alpha oscillations during sleep predict subsequent dream recall.
The Journal of neuroscience : the official journal of the Society for Neuroscience May 4, 2011 Cristina Marzano, Michele Ferrara, Federica Mauro et al.
Dream recall after awakening is linked to specific brain oscillations that differ between REM and NREM sleep. After REM sleep, higher frontal theta activity (5-7 Hz) predicts successful dream recall, mirroring the brain activity seen when encoding episodic memories while awake. After stage 2 NREM sleep, lower alpha activity (8-12 Hz) in the right temporal area predicts successful recall. These findings suggest that the neurophysiological mechanisms for encoding and recalling episodic memories may be consistent across different states of consciousness.