REM sleep characteristics of nightmare sufferers before and after REM sleep deprivation.

Objectives: To examine whether disrupted regulation of REM sleep propensity is implicated in nightmare (NM) pathophysiology.

Background: Heightened REM propensity induced by REM sleep deprivation is belied by increases in REM %, REM density and the dream-like quality of dream mentation during post-deprivation recovery sleep. Compromised regulation of REM sleep propensity may be a contributing factor in the pathophysiology of frequent NMs.

Overnight emotional adaptation to negative stimuli is altered by REM sleep deprivation and is correlated with intervening dream emotions.

Rapid eye movement (REM) sleep and dreaming may be implicated in cross-night adaptation to emotionally negative events. To evaluate the impact of REM sleep deprivation (REMD) and the presence of dream emotions on a possible emotional adaptation (EA) function, 35 healthy subjects randomly assigned to REMD (n = 17; mean age 26.4 +/- 4.

Longitudinal study of preschool sleep disturbance: the predictive role of maladaptive parental behaviors, early sleep problems, and child/mother psychological factors.

Objective: To determine if maladaptive parental behaviors (at age 29-41 months) and mother/child psychological characteristics predict future sleep disturbances in 50-month-old to 6-year-old preschoolers, while controlling for early (age 5-17 months) sleep and sociodemographic factors.

Design: Randomized survey; children assessed annually from 5 months to 6 years of age.

Setting: Participants' homes.

Longitudinal study of bad dreams in preschool-aged children: prevalence, demographic correlates, risk and protective factors.

Study Objectives: To (1) clarify the epidemiology of bad dreams in children and investigate risk and protective factors related to (2) the child's sleep, (3) parental sleep-enabling practices, and (4) the child's temperament.

Design: Longitudinal with 6 time points from 5 months to 6 years.

Setting: Subjects' homes.

Disturbed dreaming, posttraumatic stress disorder, and affect distress: a review and neurocognitive model.

Nightmares are common, occurring weekly in 4%-10% of the population, and are associated with female gender, younger age, increased stress, psychopathology, and dispositional traits. Nightmare pathogenesis remains unexplained, as do differences between nontraumatic and posttraumatic nightmares (for those with or without posttraumatic stress disorder) and relations with waking functioning. No models adequately explain nightmares nor have they been reconciled with recent developments in cognitive neuroscience, fear acquisition, and emotional memory.

What are the memory sources of dreaming?

Investigators since Freud have appreciated that memories of the people, places, activities and emotions of daily life are reflected in dreams but are typically so fragmented that their predictability is nil. The mechanisms that translate such memories into dream images remain largely unknown. New research targeting relationships between dreaming, memory and the hippocampus is producing a new theory to explain how, why and when we dream of waking life events.

Immediate and delayed incorporations of events into dreams: further replication and implications for dream function.

The incorporation of memories into dreams is characterized by two types of temporal effects: the day-residue effect, involving immediate incorporations of events from the preceding day, and the dream-lag effect, involving incorporations delayed by about a week. This study was designed to replicate these two effects while controlling several prior methodological problems and to provide preliminary information about potential functions of delayed event incorporations. Introductory Psychology students were asked to recall dreams at home for 1 week.

Chronobiological features of dream production.

A review of the scientific literature clarifies several chronobiological features of dreaming. The literature supports the conclusions that dreaming 'intensity' and, to a lesser extent dream-like quality, is modulated by (1) a sinusoidal, 90-min ultradian oscillation, (2) a 'switch-like' circadian oscillation, (3) a 12-h circasemidian rhythm, and (4) a 28-day circatrigintan rhythm (for women). Further, access to dream memory sources appears to be modulated by (5) a 7-day circaseptan rhythm.

Reduced Alpha power associated with the recall of mentation from Stage 2 and Stage REM sleep.

Relationships between Alpha (8-12 Hz) activity and cognitive processes during wakefulness raise the possibility of similar relationships between Alpha and cognitive activity during sleep. We hypothesized that Alpha power decreases during both Stage 2 and REM sleep would index the presence of sleep mentation in these stages. Absolute power for six classical EEG bands and three Alpha subbands was calculated for Stage 2 and REM sleep awakenings both with and without mentation recall.

Sleep pathophysiology in posttraumatic stress disorder and idiopathic nightmare sufferers.

Background: Nightmares are common in posttraumatic stress disorder (PTSD), but they also frequently occur in idiopathic form. Findings associated with sleep disturbances in these two groups have been inconsistent, and sparse for idiopathic nightmares. The aim of the present study was to investigate whether sleep anomalies in PTSD sufferers with frequent nightmares (P-NM) differ from those observed in non-PTSD, idiopathic nightmare (I-NM) sufferers and healthy individuals.

Incorporation of pain in dreams of hospitalized burn victims.

It has been shown that realistic, localized painful sensations can be experienced in dreams either through direct incorporation or from past memories of pain. Nevertheless, the frequency of pain dreams in healthy subjects is low. This prospective study was designed to evaluate the occurrence and frequency of pain in the dreams of patients suffering from burn pain.

Quality of sleep and its daily relationship to pain intensity in hospitalized adult burn patients.

Sleep disturbances are frequently reported in victims following burn injuries. This prospective study was designed to assess sleep quality and to examine its daily relationship to pain intensity within the first week of hospitalization. Twenty-eight non-ventilated patients were interviewed during 5 consecutive mornings (number of observations=140) to collect information about perceived quality of sleep (visual analogue scale, number of hours, number of awakenings, presence of nightmares).