Dream recall and Dream Content in Children with Attention Deficit/Hyperactivity Disorder

Although sleep is widely investigated in children with ADHD, dream studies in this group are completely lacking. The continuity hypothesis of dreaming stating that waking life is reflected in dreams would predict that waking-life symptoms are reflected in the dreams of such children. 103 children with ADHD and 100 controls completed a dream questionnaire eliciting dream recall frequency and the most recent dream. The dreams of the children with ADHD did not show a heightened occurrence of activities but were more negatively toned and included more misfortunes/threats, negative endings, and physical aggression towards the dreamer. Dream recall frequency and general dream characteristics like dream length and dream bizarreness did not differ from children without ADHD. The dreams seem to reflect the inner world of the child with ADHD. From a clinical point of view, it would be very interesting to study whether the negatively toned dreams change during treatment (pharmacological and/or psychotherapeutic) in a way similar to how sleep quality improves.     

Do all mammals dream?

The presence of dreams in human sleep, especially in REM sleep, and the detection of physiologically similar states in mammals has led many to ponder whether animals experience similar sleep mentation. Recent advances in our understanding of the anatomical and physiological correlates of sleep stages, and thus dreaming, allow a better understanding of the possibility of dream mentation in nonhuman mammals. Here, we explore the potential for dream mentation, in both non-REM and REM sleep across mammals. If we take a hard-stance, that dream mentation only occurs during REM sleep, we conclude that it is unlikely that monotremes, cetaceans, and otariid seals while at sea, have the potential to experience dream mentation. Atypical REM sleep in other species, such as African elephants and Arabian oryx, may alter their potential to experience REM dream mentation. Alternatively, evidence that dream mentation occurs during both non-REM and REM sleep, indicates that all mammals have the potential to experience dream mentation. This non-REM dream mentation may be different in the species where non-REM is atypical, such as during unihemispheric sleep in aquatic mammals (cetaceans, sirens, and Otariid seals). In both scenarios, the cetaceans are the least likely mammalian group to experience vivid dream mentation due to the morphophysiological independence of their cerebral hemispheres. The application of techniques revealing dream mentation in humans to other mammals, specifically those that exhibit unusual sleep states, may lead to advances in our understanding of the neural underpinnings of dreams and conscious experiences.     

EEG activities during elicited sleep onset REM and NREM periods reflect different mechanisms of dream generation. Electroencephalograms. Rapid eye movement.

OBJECTIVE: To be the first to compare EEG power spectra during sleep onset REM periods (SOREMP) and sleep onset NREM periods (NREMP) in normal individuals and relate this to dream appearance processes underlying these different types of sleep periods. METHODS: Eight healthy undergraduates spent 7 consecutive nights in the sleep lab including 4 nights for SOREMP elicitation using the Sleep Interruption Technique. This enabled us to control preceding sleep processes between SOREMP and NREMP. EEG power spectra when participants did and did not report 'dreams' were compared between both types of sleep. Sleep stages, subjective measurements including dream property scores, sleepiness, mood, and tiredness after awakenings were also examined to determine their consistency with EEG findings. RESULTS: Increased alpha EEG activities (11.72-13.67 Hz) observed mainly in the central area were related to the absence of SOREMP dreams and appearance of NREMP dreams. Analyses of sleep stages combining two studies (16 participants) also supported the Fast Fourier Transform findings, showing that when dreams were reported there were decreased amounts of stage 2 and increased stage REM in SOREMP and increased stage W in NREMP. SOREMP dreams were more bizarre than NREMP dreams. Participants felt more tired after SOREMP with dreams than without dreams, while the opposite was observed after NREMP episodes. CONCLUSIONS: EEG power spectra patterns reflected different physiological mechanisms underlying generation of SOREMP and NREMP dreams. The same relationships were also reflected by sleep stage analyses as well as subjective measurements including dream properties and tiredness obtained after awakenings. This study not only supports the hypothesized relationships between REM mechanisms and REM dreams as well as arousal processes and NREM dreams, it also provides a new perspective to dream research due to its unique techniques to awaken participants and collect REM dreams during experimentally induced SOREMP.     

Sleep and dreams in Korsakoff's amnesia due to alcoholism

Sleep and dreams in 15 chronic alcoholic patients with amnesia were compared with sleep and dreams of 15 age- and sex-adjusted normal subjects. The patients were subjected to psychological tests in order to determine their I.Q. and their memory disturbances. All subjects had two nights of polygraphic recordings; the first tested the natural sleep organization. During the second night, they were awakened 7 min after the onset of each REM sleep episode, and, at least once, 20 min after the onset of a stage II episode, in order to record on a tape their dream reports according to a standardized protocol. The sleep patterns of the amnesic patients did not show any significant alteration. However, after wakening during the night, patients exhibited a higher tendency to return to REMS than controls. There was still some dream activity in those patients, although noticeably less frequently, and their dream activity had a very poor verbal expression. However, there was no change with respect to the spatio-temporal organization, sensorial perceptions, motor activity and verbalizations during their dreams.     

REM dream activity of insomnia sufferers: a systematic comparison with good sleepers

Background and ObjectiveThe dream activity of patients with primary insomnia (PI) has rarely been studied, especially using in-laboratory dream collection, although dreams could be linked to their state of hyperarousal and their negative waking experiences. The objective of the study was to compare patients with PI and good sleeper controls (GSCs) in terms of dream recall frequency and dream content.Patients/MethodsPolysomnography was recorded in 12 patients with PI and 12 GSCs (aged between 30 and 45 years) for five consecutive nights. Rapid eye movement (REM) sleep awakenings were enforced on nights 3 and 5 for dream collections.ResultsThe REM dream collections revealed that the groups were similar in terms of dream recall frequency (p ≤ 0.7). With respect to dream content variables, the dreams of GSCs tended to comprise more positive emotions (p = 0.06), whereas the dreams of patients with PI were characterized by more negative elements than positive ones (p = 0.001). Subjectively, GSCs characterized their dreams as being more pleasant and containing more joy, happiness, and vividness (p ≤ 0.03) than patients with PI. Finally, elevated negative dream content was associated with lower sleep efficiencies in insomnia (p = 0.004).ConclusionThese results suggest that less positive emotions and greater negative content characterize the dreams of patients with PI, which is in line with their waking experiences. One potential explanation could be hyperarousal exacerbating presleep negative mentation, thus contributing to poorer sleep quality. The lack of difference in dream recall frequency is most likely due to the forced awakening “dream collection” procedure. The study of dream activity seems a promising avenue for understanding the 24-h experience of insomnia better and exploring the potential benefits of dream management techniques.     

Dream experience during REM and NREM sleep of patients with complex partial seizures

This study examined the effectiveness of the cognitive processes underlying dreaming in patients with complex partial seizures (CPS), by assessing the frequency of recall and the structural organization of dreams reported after awakenings provoked alternately during REM and stage 2 NREM sleep on 12 cognitively unimpaired CPS-patients (six with epileptic focus in the right hemisphere and six in the left one). Each patient was recorded for three consecutive nights, respectively, for adaptation to the sleep laboratory context, for polysomnography and for dream collection. The frequency of dream recall was lower after stage 2 NREM sleep than REM sleep, regardless of the side of epileptic focus, while the length and structural organization of dreams did not significantly differ in REM and NREM sleep. However, the length of story-like dreams was influenced by global cognitive functioning during REM sleep. These findings indicate that in CPSs-patients the elaboration of dream experience is maintained in both REM and NREM sleep, while the access to information for conversion into dream contents and the consolidation of dream contents is much less effective during NREM rather than during REM sleep. Further studies may distinguish between these two possibilities and enlighten us as to whether the impaired memory functioning during NREM sleep is a side effect of anticonvulsant treatment.     

Role of REM sleep and dream variables in the prediction of remission from depression

To test the hypothesis that REM sleep and/or dreams contribute to overnight mood regulation, 61 subjects were tested on the Beck Depression Inventory (BDI), and for 3 nights of monitored sleep on two occasions, once close to, and 1 year after, a marital separation. Forty-nine percent of the variance in the follow-up BDI could be accounted for by the initial BDI score, and three sleep and dream variables associated with the mood regulatory hypothesis: eye movement density in the first REM, strength of the affect in the first dream and total number of negative dreams recalled from REM awakenings. Among the 39 who met BDI depression criteria initially, 71.8% could be classified correctly as remitted or not remitted at follow-up by discriminant function analysis based on the presence of negative dreams the first vs. second half of the night. Subjects reporting more negative dreams at the beginning and fewer at the night's end were more likely to be in remission 1 year later than were those with fewer negative dreams at the beginning and more at the end of the night. Early negative dreams may reflect a within-sleep mood regulation process taking place, while those that occur later may indicate a failure in the completion of this process.     

The capacity of stroke patients to report dreams

We studied the capacity of stroke patients to report dreams following awakening from REM sleep. Four left-hemisphere aphasia and two right-hemisphere visuospatial deficit patients reported dreams. The expression of ideas in dreams appeared normal despite the patients' waking difficulties. Given their similar rules of grammar, both dream and phonetic language modalities could emanate from common sites.     

La motricité redevient-elle normale en sommeil paradoxal ? Le trouble comportemental en sommeil paradoxal

Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by violent, or potentially violent, movements during REM sleep, corresponding to enacted dreams. During sleep monitoring, there is a partial or total loss of the normal muscle atonia during REM sleep. REM sleep behavior disorder predominantly affects elderly subjects without any other disease (idiopathic RBD, a precursor of Parkinson disease and Lewy body dementia) or suffering from various neurological and neurodegenerative diseases, mainly synucleinopathies. In addition to being a treatable cause of nocturnal injury of the patients or their bed-partners, RBD is a fantastic window into motor and cognitive control during REM sleep. Notably, parkinsonism transiently disappears during RBD. The patient's voice is louder and better articulated than when awake, and movements are rapid (but jerky) suggesting that the deleterious message from the basal ganglia to the primary motor cortex is reduced or bypassed. As we observed culturally-acquired behaviors, retired patients practicing their former work with mastered gestures, as well as sentences pronounced with appropriate prosody, gesturing, fluency, and syntax during the RBD, we suggest that these behaviors are generated by the same cortical areas as during wakefulness. This model also enables the demonstration that REM during REM sleep are coded in the same direction as the arm and hand movements, as if the dreamer were scanning the dream images. This online access to the motor and verbal dream scenario (through the video and audio monitoring), and the physiological measures (via the EEG, eye movements, muscle tone, respiration, heart rate), together with the offline access to the mental content (dream report after the awakening) constitute a triangulation for validating new hypotheses about REM sleep and dreams.     

Phenomenology of dreams in Parkinson's disease.

Rapid eye movement sleep behavior disorder (RBD) occurs in approximately one third of patients with Parkinson's disease (PD) and is associated with a loss of muscle atonia during REM sleep and aggressive dream content. We examined the dream characteristics of PD patients to determine whether dream content differed between patients with RBD and without RBD, men and women with RBD, and men and women with PD. One hundred-twenty patients with a diagnosis of idiopathic PD were consecutively recruited from a movement disorders clinic and were assessed for RBD using clinical diagnostic criteria of the International Classification of Sleep Disorders Revised (2001). Verbatim dream content was obtained from each patient and categorized into dream themes that were coded into nominal categories. Fisher's exact tests determined whether particular dreams were correlated with RBD versus non-RBD, men and women with RBD, and men and women with PD. RBD patients had a higher percentage of violent dreams compared to non-RBD patients. There were no significant sex differences in the dream content of RBD patients. Men with PD had more aggressive dreams compared to females with PD. Aggressive dream content was characteristic of RBD patients and sex differences exist in the dream content of the PD population.     

Dream process in asthmatic subjects with nocturnal attacks

Polygraphic sleep recordings were made and dream reports collected over 3 consecutive nights for 12 asthmatic subjects with nocturnal attacks and 12 matched normal control subjects. The asthmatic group 1) had more episodes of a vivid impression of dreaming without recollection of dream content ("white dreams") after awakening spontaneously in the morning (nights 1 and 2) and after awakening immediately following REM sleep (night 3), 2) used shorter sentences in dream narrations, and 3) had no dream recall when awakened during nocturnal asthma attacks. The authors suggest that conflictual material emerging during REM or other sleep stages may contribute to the occurrence of nocturnal attacks but is repressed on awakening.     

The 'dream-lag' effect: a 6-day temporal delay in dream content incorporation

The temporal relationship between daily events and their incorporation into dreams was studied. In two experiments, a 6-day delay between event occurrence and dream incorporation was found. Moreover, variations in incorporation across a 7-day-period were found to follow a sinusoidal pattern. These results implicate dream incorporation in the learning consolidation functions of REM sleep.     

Change in the mental contents in the paradoxical stage and in stage 2 under the effects of a benzodiazepine, flunitrazepam]

In some insomniacs under flunitrazepam treatment is noted on one hand a global increase of dream memories, and on the other hand an increase of dreams with unpleasant or anxious contents. The present investigation is intended first to test the hypothesis of a possible increase of mental contents in sleep outside the paradoxical phases, to account for the increase of dream memories without concomitant increase of paradoxical stage. Second it intends to investigate if the increase of unpleasant dreams may be found in the normal subject in laboratory.     

The incidence and significance of perceptual qualities in the reported dreams of patients with anorexia nervosa

The dreams of anorexic patients' were recorded using a standardized sleep questionnaire concerning the perceptual qualities and affects remembered from their dreams. The anorexic subjects consistently had less frequent dream recall, fewer dreams in colour and fewer pleasurable themes than was noted in the normal controls. Anorexics frequently saw themselves in their dreams as having a distorted body (especially an enlarged belly), a younger appearance, and experienced food and hunger dysphoria. The evaluation of an anorexic patient's dreams and their subsequent changes in both sensations and the frequency of reported dreaming may have diagnostic and as well as prognostic importance for the therapeutic assessment of anorexia nervosa.     

Story-like organization of REM-dreams in patients with narcolepsy-cataplexy

Narcolepsy with cataplexy (NC) is a neurological disorder characterized by excessive daytime sleepiness and an altered architecture of sleep. Previous laboratory studies have shown that frightening, bizarre and visually vivid contents are more frequent in dream experiences developed during the first period of REM sleep by NC patients than healthy subjects. As the structural organization of dream experiences of NC patients has not been yet examined, we compared its indicators in dream reports collected from a sample of NC patients and their matched controls. During an experimental night two awakenings were provoked after 8min of REM sleep in the first and third sleep cycle. Dream reports were analyzed using the rules of story grammars, capable of identifying units larger than single contents and describing their story-like organization. While dream recall (about 85%) was comparable in NC patients and controls, 1st-REM dream reports were longer in NC patients. Statistical analyses on the 12 NC patients and their matched controls who reported dreams after both REM periods showed that dream experiences occurring in 1st-REM reports of NC patients were longer and had a more complex organization than those of controls. These findings suggest that the cognitive processes underlying dream generation reach their optimal functioning earlier in the night in NC patients than in normal subjects.     

Non-dreamers

OBJECTIVE: Assess incidence and clarify whether diagnostic correlates exist for sleep laboratory patients reporting a lack of dream recall. To awaken, during polysomnographically defined sleep including rapid eye movement (REM) sleep, individuals reporting never having experienced a dream, and determine whether they report dreaming. METHODS: Study # 1 - Incidence and polysomnographic correlates of sleep lab patients responding on questionnaire that they had never experienced dreaming. Study # 2 - Phone interviews with those individuals reporting non-dreaming on questionnaire to reassess incidence. Study # 3 - After reassessment, individuals (non-dreamers - # 16) are awakened during polysomnographic defined sleep (including REM sleep) and queried about dream recall. This group is compared statistically to a group (rare-dreamers - # 12) that reported dreaming as an extremely rare occurrence (mean dream recall latency - 13.5 years). RESULTS: Study # 1: Incidence of questionnaire reported non-dreaming in this sleep laboratory population is 6.5% (N=534) and is associated with the diagnosis of obstructive sleep apnea (specificity 95.6% for respiratory disturbance index >15). Study # 2 - Individuals who report after interview to have never experienced dreaming are more unusual (0.38% of this sleep laboratory population). Study # 3 - None of the non-dreamers (# 16) reported dream recall after waking in the sleep laboratory (36 awakenings in total for this group). This group does not differ, based on polysomnographic, clinical, or demographic variables, from the rare-dreaming group that occasionally reported dreams when awakened (3/12 patients, 3/32 awakenings) - a finding consistent with the reports of previous studies. CONCLUSION: The experience of dreaming may not be as ubiquitous as generally accepted. The group of non-dreamers evaluated in this study reports never having recalled a dream and reports no dreams when awakened during polysomnographicly defined sleep. These individuals might not experience dreaming.     

Language learning efficiency, dreams and REM sleep

As a follow-up from a previous study, four subjects taking a 6-week French language immersion program maintained a dream diary starting 2 weeks before until 2 weeks after the course. They also slept in the laboratory during four series of nights: one before the course, two during the course and one after the course. Confirming previous observations, it was observed that those subjects who made significant progress in French learning, experienced French incorporations into dreams earlier and had more verbal communication in their dreams during the language training than those who made little progress. Combining these results with those of the earlier study revealed significant positive correlations between language learning efficiency and both increases in REM sleep percentages, and verbal communication in dreams, as well as a negative correlation with latency to the first French incorporation in dreams. These results support the notion that REM sleep and dreaming are related to waking cognitive processes.     

Dreaming and episodic memory: a functional dissociation?

The activity that takes place in memory systems during sleep is likely to be related to the role of sleep in memory consolidation and learning, as well as to the generation of dream hallucinations. This study addressed the often-stated hypothesis that replay of whole episodic memories contributes to the multimodal hallucinations of sleep. Over a period of 14 days, 29 subjects kept a log of daytime activities, events, and concerns, wrote down any recalled dreams, and scored the dreams for incorporation of any waking experiences. While 65% of a total of 299 sleep mentation reports were judged to reflect aspects of recent waking life experiences, the episodic replay of waking events was found in no more than 1-2% of the dream reports. This finding has implications for understanding the unique memory processing that takes place during the night and is consistent with evidence that sleep has no role in episodic memory consolidation.     

Pandemic dreams: quantitative and qualitative features of the oneiric activity during the lockdown due to COVID-19 in Italy

ObjectiveThe lockdown due to COVID-19 pandemic had a strong impact on daily habits, emotional experience, mental health and sleep. A large body of evidence suggests that dreams are affected by both waking experiences and sleep pattern. In this view, the lockdown should have induced intense modifications in dreaming activity. The aim of the study was to assess dream features during the lockdown in Italy.MethodsWe used an online survey to collect self-reported demographic, clinical, sleep and dream data. Our sample included 1091 participants.ResultsResults point to an increased dream frequency, emotional load, vividness, bizarreness and length during the lockdown, compared to a pre-lockdown period. Higher dream frequency and specific qualitative features were found in females and subjects with poor sleep quality, nocturnal disruptive behaviours and depressive symptoms. Most of the dream features assessed during the lockdown were predicted by age, gender, depressive symptoms, presence/absence of other people at home, and territorial area. A specific focus on sleep features revealed that sleep duration and several sleep quality indexes were the best predictors of dream variables. During the lockdown, dreams were also characterized by increased negative emotions, which were particularly frequent in females, younger adults, and participants with poor sleep quality, nocturnal disruptive behaviours, anxiety and depressive symptoms.ConclusionsOur results confirm the hypothesis of a strong influence of the pandemic on dreaming, supporting both the hypothesis of continuity between wake and sleep mental processes and the view of a crucial influence of sleep quality and duration on dreaming activity.