Nature and Science of Sleep
January 1, 2021
Eirin Fränkl, Serena Scarpelli, Michael R Nadorff et al.
Dream recall frequency increased during the COVID-19 pandemic compared to pre-pandemic levels across four continents. In a cross-sectional web survey of 19,355 individuals from 14 countries, high dream recall (three or more nights per week) was associated with female gender, nightmares, sleep talking, sleep maintenance problems, symptoms of REM sleep behavior disorder, and repeated disturbing thoughts indicative of PTSD. Older adults aged 55-64 reported less high dream recall than younger participants. While unadjusted analyses showed associations between depression, anxiety, and dream recall, adjusted analyses revealed negative associations: depression and anxiety were linked to lower odds of high dream recall. The findings suggest that the pandemic's emotional intensity is reflected in dreams.
Brain Sciences
June 3, 2020
Serena Scarpelli, Aurora D'Atri, Chiara Bartolacci et al.
Among older adults, those who recall dreams show higher cortical arousal during NREM sleep than those who do not. In a study of 20 elders, dream recallers had lower delta power over parietal areas and higher activation index (delta/beta power) in fronto-temporal and parieto-occipital regions compared to non-recallers. No differences appeared in the last five minutes before awakening. Visual vividness and dream length correlated positively with arousal level. The findings support the activation hypothesis, which links dream recall to brain arousal, and highlight the temporo-parietal-occipital zone as crucial for storing dream content.
Nature and Science of Sleep
January 1, 2020
Serena Scarpelli, Chiara Bartolacci, Aurora D'Atri et al.
Dream recall is associated with higher brain activation during REM sleep, regardless of the time of night. Theta, delta, and beta EEG bands were analyzed in 10 subjects who underwent multiple awakenings during REM sleep across the night. Results showed no significant effect of time of night or interaction, but significant differences in beta band activity over the occipital area and in the delta/beta activation index over the parietal area. These findings support the activation-hypothesis, which links dream recall to desynchronized EEG activity, and suggest that such recall is related to state-like factors rather than homeostatic pressure.
Sleep Medicine Reviews
April 1, 2019
Valentina Alfonsi, Aurora D'Atri, Serena Scarpelli et al.
Sleep talking is a common, non-pathological behavior involving unaware vocalizations during sleep. Despite increased knowledge about sleep cognition, research on sleep talking remains outdated. Verbal utterances often reflect ongoing dream content, offering a direct window into dreamlike mental experiences. The phenomenon is discussed within a cognitive framework, considering atypical activation of psycholinguistic circuits during sleep and the role of verbal 'replay' in memory consolidation. Analyzing sleep talking episodes could help address fundamental questions about dreaming and information processing during sleep, though further systematic polysomnographic and neuroimaging studies are needed.
Annals of Clinical and Translational Neurology
March 1, 2019
Aurora D'Atri, Serena Scarpelli, Cinzia Schiappa et al.
In drug-free adults with narcolepsy type 1, successful dream recall after naps is linked to a more activated brain state during both REM and NREM sleep. Using scalp EEG, the study found that recall was associated with lower delta power over centro-parietal areas in both sleep stages, higher beta power in those areas during NREM, and a lower delta/beta ratio across most scalp locations during NREM. These results suggest that a more desynchronized, activated electrophysiological milieu promotes dream recall, and that parietal areas are important not only for generating dream experiences but also for the memory processes that enable recall.
Frontiers in Psychology
January 1, 2019
Serena Scarpelli, Chiara Bartolacci, Aurora D'Atri et al.
Dream experience is linked to emotional processes and the inner world. REM sleep plays a key role in processing emotional waking-life experiences and consolidating emotional memories. Neuroimaging studies show that neural substrates regulating dreaming and emotional salience in sleep mentation overlap with those controlling emotions during wakefulness. REM theta oscillations are crucial for emotional re-processing and memory processes during REM sleep, while gamma activity relates to emotional processes, dream recall, and lucid dreams. In clinical samples, similar EEG correlates appear with nightmares or dreams. Rehearsing frightening content to change it is a promising treatment for nightmares, and lucid dreams attenuate nightmares.
Frontiers in Neurology
January 1, 2019
Serena Scarpelli, Aurora D'Atri, Chiara Bartolacci et al.
Frontal theta oscillations during the last five minutes of REM sleep predict whether older adults will recall a dream upon waking, replicating a pattern previously established in young adults. In a study of 21 healthy older volunteers (mean age 69.2) and 20 young adults (mean age 23.4), dream recall occurred when REM sleep showed rhythmic frontal theta activity. No interaction between age and recall status was found, indicating the same brain activity supports dream recall in both age groups. Theta oscillations were more abundant in young participants, and the authors distinguish this rhythmic theta from non-rhythmic theta linked to sleepiness or clinical cortical slowing.
Brain Topography
September 1, 2017
Serena Scarpelli, Aurora D'Atri, Anastasia Mangiaruga et al.
Dream recall upon awakening from NREM sleep is predicted by reduced delta activity in left frontal and temporo-parietal areas during the final segment of sleep. This finding suggests that increased cortical activation is a prerequisite for remembering dreams from NREM sleep, challenging the traditional view that dreaming is unique to REM sleep. The study used a multiple nap protocol and within-subjects design to collect dream reports after stage 2 NREM sleep awakenings. The results indicate that the brain mechanisms underlying dream recall during NREM sleep may share features with those involved in encoding episodic memories during wakefulness, though they also depend on the specific electrophysiological state of sleep.
Human Brain Mapping
March 1, 2016
Luigi De Gennaro, Olimpia Lanteri, Fabrizio Piras et al.
Patients with Parkinson's Disease (PD) show no substantial differences from healthy controls in sleep, dream, or neuroanatomical measures. Higher dopamine agonist dosages in PD patients are associated with qualitatively impoverished dreams—lower bizarreness and emotional load. Visual vividness of dream reports positively correlates with amygdala volume and left medial prefrontal cortex thickness, while emotional load correlates with hippocampal volume. These findings support the hypothesis that a dopamine network involving the amygdala and medial prefrontal cortex plays a key role in dream generation, though causal relations cannot be established due to limitations in using dopamine agonist dosage as a proxy for hypodopaminergic state.
Frontiers in Psychology
January 1, 2015
Serena Scarpelli, Aurora D'Atri, Maurizio Gorgoni et al.
Dream recall is predicted by theta (5-8 Hz) EEG oscillations over frontal regions just before awakening, paralleling the role of theta activity in successful episodic memory retrieval during wakefulness. This continuity suggests shared neurophysiological mechanisms between encoding and retrieval of episodic memories across sleep and wakefulness. REM sleep shows limbic activation and prefrontal deactivation, which may explain emotional dream content. Amygdala and hippocampus morphoanatomical measures predict dream bizarreness, vividness, and emotional load. Existing evidence cannot definitively determine whether this theta-dream recall relation reflects state- or trait-like differences.
Frontiers in Psychology
January 1, 2015
Serena Scarpelli, Cristina Marzano, Aurora D'Atri et al.
Dream recall after REM sleep is linked to higher frontal theta oscillations, a brain rhythm also involved in encoding memories while awake. In six healthy subjects awakened from afternoon naps, theta activity in the frontal cortex was greater before a remembered dream than before a forgotten one, though only the measure of sustained theta oscillations reached statistical significance. The findings support the idea that dream recall depends on the momentary brain state during sleep rather than on a fixed individual trait.