title: Recalling and forgetting dreams: theta and alpha oscillations during sleep predict subsequent dream recall.
abstract: Under the assumption that dream recall is a peculiar form of declarative memory, we have hypothesized that (1) the encoding of dream contents during sleep should share some electrophysiological mechanisms with the encoding of episodic memories of the awake brain and (2) recalling a dream(s) after awakening from non-rapid eye movement (NREM) and rapid eye movement (REM) sleep should be associated with different brain oscillations. Here, we report that cortical brain oscillations of human sleep are predictive of successful dream recall. In particular, after morning awakening from REM sleep, a higher frontal 5-7 Hz (theta) activity was associated with successful dream recall. This finding mirrors the increase in frontal theta activity during successful encoding of episodic memories in wakefulness. Moreover, in keeping with the different EEG background, a different predictive relationship was found after awakening from stage 2 NREM sleep. Specifically, a lower 8-12 Hz (alpha) oscillatory activity of the right temporal area was associated with a successful dream recall. These findings provide the first evidence of univocal cortical electroencephalographic correlates of dream recall, suggesting that the neurophysiological mechanisms underlying the encoding and recall of episodic memories may remain the same across different states of consciousness.
authors.affiliation: Department of Psychology, University of Rome Sapienza, 00185 Rome, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Marzano
authors.forename: Michele
authors.initials: M
authors.lastname: Ferrara
authors.forename: Federica
authors.initials: F
authors.lastname: Mauro
authors.forename: Fabio
authors.initials: F
authors.lastname: Moroni
authors.forename: Maurizio
authors.initials: M
authors.lastname: Gorgoni
authors.forename: Daniela
authors.initials: D
authors.lastname: Tempesta
authors.forename: Carlo
authors.initials: C
authors.lastname: Cipolli
authors.forename: Luigi
authors.initials: L
authors.lastname: De Gennaro
mesh_terms: D000328:Adult; D000513:Alpha Rhythm / Q000502:physiology*; D000704:Analysis of Variance; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology; D004325:Dreams / Q000502:physiology*; D004569:Electroencephalography; D004585:Electrooculography; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D013826:Theta Rhythm / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology