Mark Blagrove

Swansea University | SWAN · Department of Psychology

Limited research has examined the effect of meal composition on sleep. Based on previous research, we hypothesized that a low glycemic index (LGI) drink containing 50g isomaltulose (Palatinose™, GI = 32) would result in more N3 sleep, less rapid eye movement (REM) sleep, and better memory consolidation than a high glycemic index (HGI) drink contain...

This study investigated whether sensory processing sensitivity (SPS) is associated with a perceptual advantage, above just heightened brain, emotional and behavioural reactivity. Participants (N = 222) were tested on detection and identification of visually degraded words at three levels of difficulty, and completed the Highly Sensitive Person Scal...

Electroencephalography (EEG) studies of dreaming are an integral paradigm in the study of neurocognitive processes of human sleep and consciousness, but they are limited by the number of observations that can be collected per study. Dream studies also involve substantial methodological and conceptual variability which poses problems for the integra...

This investigation tested the effect of priming on pareidolia (the hearing of illusory words in ambiguous stimuli). Participants (41 women, 20 men, mean age 29.95 years) were assigned to primed (n = 30) or unprimed (n = 31) groups: the former were told the study was of ‘purported ghosts voices’, the latter ‘voices in noisy environments.’ Participan...

During sleep, emotional memories are preferentially strengthened. However, most studies on sleep and emotional memory focus on comparing negative valence with neutral valence stimuli. This study compared the sleep‐dependent memory effects for stories and images, each comprising negative, neutral, and positive stimuli. It was hypothesized that a sle...

There are many theories of the function of dreams, such as memory consolidation, emotion processing, threat simulation and social simulation. In general, such theories hold that the function of dreams occurs within sleep, occurs for unrecalled dreams as well as for dreams that are recalled on awakening, and that conscious recall of dreams is not ne...

While material from waking life is often represented in dreams, it is less clear whether and how dreams impact waking life. Here, we assessed whether dream mood and content from home diaries predict subsequent waking mood using both subjective self-reports and an objective automated word detection approach. Subjective ratings of dream and morning m...

There are differences in Sensory Processing Sensitivity (SPS) within many species. In humans high SPS refers to greater responsivity to stimuli, slower, deeper processing, aesthetic sensitivity, and low threshold for sensory discomfort. This study tested whether SPS is associated with the accurate recognition of degraded auditory stimuli and suscep...

This study replicated and extended a previous finding that the discussion of dreams increases the level of empathy toward the dreamer from those with whom the dream is discussed. The study addressed mediating variables for the empathy effect. Participants who already knew each other were recruited in dyads and were assigned dream-sharer and discuss...

While material from waking life is often represented in dreams, it is less clear whether and how dreams impact waking life in return. Here, we assessed whether dream mood and content from home diaries predict subsequent waking mood using both subjective self-report and an objective automated word detection approach. Subjective ratings of dream and...

Animal dreams have fascinated mankind for ages. Empirical research indicated that children dream more often about animals than adults and dogs, cats, and horses are the most frequent animals that appear within dreams. Moreover, most dreamer-animal interactions are negative. The present study included 4849 participants (6 to 90 yrs. old) reporting 2...

Nightmares are intensely negative dreams that awaken the dreamer. Frequent nightmares are thought to reflect an executive deficit in regulating arousal. Within a diathesis-stress framework, this arousal is specific to negative contexts, though a differential susceptibility framework predicts elevated arousal in response to both negative and positiv...

Propensity to have nightmares has been theorised in terms of diathesis-stress models, with this propensity being seen as negative or even pathological. In contrast, a recent model proposes that nightmare propensity is due to Differential Susceptibility to stimuli, where high susceptibility can be beneficial in positive environments but detrimental...

This chapter argues that the two dreams of ‘Dora’, told as part of her analysis with Sigmund Freud at the end of 1900, are poignant depictions of the distress, abuse and hopes in her life. The argument is that this can be seen clearly from Dora’s free associations to her dreams. Unfortunately, these interpretations of her dreams, although present i...

Previous experiments combining cognitive techniques and sleep disruption have been relatively successful in inducing at-home lucid dreams (LD) over training periods of 1 week or more. Here, we induce LD in a single laboratory nap session by pairing cognitive training with external stimulation. Participants came to the laboratory at 7:30 a.m. or 11:...

Introduction Sleep inertia (SI) can negatively affect cognitive functions including time perception. Accurate time perception is important for evaluating wakefulness at night. Overestimating wakefulness can be anxiety-provoking for individuals with insomnia. Here we present data from three studies testing the impact of SI on time perception after w...

Although gender differences in the dreams of adults have been studied extensively, large-scale studies in children and adolescents are scarce. The UK Library Study collected 1,995 most recent dreams of children and adolescents. Boys reported more physical aggression and fewer female characters in their dreams, whereas indoor settings were more prom...

In general, dreams are a novel but realistic simulation of waking social life, with a mixture of characters, motivations, scenarios, and positive and negative emotions. We propose that the sharing of dreams has an empathic effect on the dreamer and on significant others who hear and engage with the telling of the dream. Study 1 tests three correlat...

Incorporation of details from waking life events into Rapid Eye Movement (REM) sleep dreams has been found to be highest on the two nights after, and then 5-7 nights after events. These are termed, respectively, the day-residue and dream-lag effects. This study is the first to categorize types of waking life experiences and compare their incorporat...

Throughout history, there have been reports and claims that consideration of dreams can produce personal realizations and insight. We assessed Exploration–Insight scores associated with discussing REM and non-REM dreams in connection with recent waking life experiences. Thirty-one participants were cued in the sleep laboratory for a daydream report...

Rapid Eye Movement (REM) sleep and its main oscillatory feature, frontal theta, have been related to the processing of recent emotional memories. As memories constitute much of the source material for our dreams, we explored the link between REM frontal theta and the memory sources of dreaming, so as to elucidate the brain activities behind the for...

Nightmares are defined as disturbing mental experiences that generally occur during REM sleep and often result in awakening. The continuity hypothesis of dreaming would predict that media consumption arousing anxious feelings might increase nightmare frequency. Whereas there is some research on the effect of watching TV and playing computer games o...

[This corrects the article DOI: 10.1371/journal.pone.0185262.].

This study investigates the time course of incorporation of waking life experiences into daydreams. Thirty-one participants kept a diary for 10 days, reporting major daily activities (MDAs), personally significant events (PSEs) and major concerns (MCs). They were then cued for daydream, Rapid Eye Movement (REM) and N2 dream reports in the sleep lab...

Several studies have demonstrated that dream content is related to the waking life of the dreamer. However, the characteristics of the memory sources incorporated into dreams are still unclear. We designed a new protocol to investigate remote memories and memories of trivial experiences, both relatively unexplored in dream content until now. Upon a...

Characteristics of the WLEs incorporated into dreams that happened 6 to 9 days before the dreams (n = 36). (DOCX)

Concerns reported in the initial questionnaire. Concerns were distributed in 7 thematic categories. The number of concerns per categories are represented in pink. Red bars illustrate the percentage of concerns from one category that were incorporated into dreams during the 7-days experiment. (TIF)

Distribution of the scores for all the WLEs incorporated into dreams and day-residues only (see S2 Table for the figures). (TIF)

Examples of waking life elements incorporated into dreams. (DOCX)

Distribution (%) of mundane WLEs incorporated into dreams according to their temporal remoteness. (DOCX)

Distribution of the score given to WLEs incorporated into dreams, for all WLEs (bold) and day-residues only. (DOCX)

Background: Sleep difficulties might be a contributory causal factor in the occurrence of mental health problems. If this is true, improving sleep should benefit psychological health. We aimed to determine whether treating insomnia leads to a reduction in paranoia and hallucinations. Methods: We did this single-blind, randomised controlled trial...

Sleep contributes to the consolidation of memories. This process may involve extracting the gist of learned material at the expense of details. It has thus been proposed that sleep might lead to false memory formation. Previous research examined the effect of sleep on false memory using the Deese-Roediger-McDermott (DRM) paradigm. Mixed results wer...

Although many types of newly encoded information can be consolidated during sleep, an enhanced effect has been found for memories tagged as relevant to the future, such as through knowledge of future testing or payment for successful recall. In the current study, participants (n = 80) learned Welsh and Breton translations of English words, and intr...

Memories constitute much of the source material for our dreams. Although waking life events are not faithfully replayed in dreams, dream content arises from recent daily experiences. Numerous empirical studies and theoretical accounts highlight the key function of sleep in the consolidation of newly learned memories, raising the question how refere...

Research that has focused on the relationship between the Big Five personality dimensions and lucid dreaming frequency has been restricted to student samples. The present study included adolescents and adults (N = 1375). i.e., the sample included a large range of ages. Lucid dreaming was more strongly related to openness to experiences compared to...

Although dreams are very private experiences, they are often shared with others. The findings of the present study (N = 1,375) indicate that sharing dreams is indeed very common and that dream sharing frequency is related to gender (only in adolescents, with girls sharing dreams more often than boys), extraversion, dream recall frequency, and night...

Edwards et al. (2013, 2015) found that most participants declared that they had experienced insight in dream discussions following Ullman’s (2006) procedure. Pennebaker, Colder & Sharpe (1990) found that expression of thoughts and feelings about a particular experience produced insight for most participants. In the present paper, we wish to address...

Edwards et al. (2013; 2015) have previously shown that a majority of participants experience insight as a result of discussing recent dreams following the Dream Appreciation procedure of Ullman (1996). These findings were based on participant’s responses to the “Exploration-Insight” subscale of the Gains from Dream Interpretation (Heaton et al. 199...

There have been suggestions that the deliberate alteration of sleep-related behaviors, such as briefly going back to sleep after waking, can be used to induce lucid dreams. The current study extends this work by investigating the association between lucid dream frequency and alarm clock use. Eighty-four participants (44 females, 39 males, 1 not sta...

There have been reports and claims in the psychotherapeutic literature that the consideration of recent dreams can result in personal realizations and insight. There is theoretical support for these claims from work on rapid eye movement (REM) sleep having a function of the consolidation of emotional memories and the creative formation of connectio...

This paper presents the findings of a study of insight gained from discussions of recent dreams and recent events.

In the study, participants shared a description of a dream and an event and discussed them with a small group. Researchers calculated the amount of words within dream descriptions that participants connected with their own waking experience prior to the dream during dream discussions. The researchers also calculated the amount of words in event des...

This paper reviews work that addresses the degree to which waking life is continuous with dream content. It addresses the issue of how much of the dream is not related to recent or past waking life experiences of the dreamer, and whether assessment methods for continuity do not include an assessment of the amount of non-continuity text. It reports...

Incorporation of details from waking life events into Rapid Eye Movement (REM) sleep dreams has been found to be highest on the night after, and then 5-7 nights after events (termed, respectively, the day-residue and dream-lag effects). In experiment 1, 44 participants kept a daily log for 10 days, reporting major daily activities (MDAs), personall...

Several studies have found a high incorporation of waking life events into dreams that occur during the following night (day-residue effect), then a decrease in incorporation into dreams over the next 2 to 4 nights, followed by a resurgence of incorporation into dreams 5 to 7 days after events (dream-lag effect). These studies involve dream diary a...

This paper addresses claims that dreams can be a source of personal insight. Whereas there has been anecdotal backing for such claims, there is now tangential support from findings of the facilitative effect of sleep on cognitive insight, and of REM sleep in particular on emotional memory consolidation. Furthermore, the presence in dreams of metaph...

Llewellyn's claim that rapid eye movement (REM) dream imagery may be related to the processes involved in memory consolidation during sleep is plausible. However, whereas there is voluntary and deliberate intention behind the construction of images in the ancient art of memory (AAOM) method, there is a lack of intentionality in producing dream imag...

The ability to recall a dream upon waking up in the morning has been linked to a broad variety of factors such as personality, creativity, sleep behaviour and cognitive function. There have been conflicting findings as to whether dream recall is related more to the right or to the left hemisphere, and conflicting findings regarding the relationship...

The ability to recall a dream upon waking up in the morning has been linked to a broad variety of factors such as personality, creativity, sleep behavior, and cognitive function. As dreaming has been associated with the right hemisphere, it has been proposed that left-handed persons would have easier access to their dreams. However, previous empiri...

The continuity hypothesis of dreaming states that our daily activities like reading books and watching films, movies and shows should be represented in our dreams. The majority of participants in the UK library study (N = 1375) stated that their dreams are affected by their reading and TV consumption, and by their daily activities. The more time th...

Since watching TV represents a considerable constituent of children’s waking-life, TV content should hence have a great influence on dream content. The present study in children (N = 3167) clearly indicates that most children stated that watching TV affect their dreams. Whereas the amount of TV watching is weakly associated with nightmare frequency...

This study evaluates gender differences in dream recall frequency, dream sharing frequency, dream listening frequency and nightmare frequency in childhood and adolescence. The sample included 3534 children for the ages from 6 to 18 who completed a brief questionnaire distributed in libraries. We were able to show that overall girls recalled dreams...

There have been proposals for REM to have a function of emotional memory consolidation, and also for REM sleep to be involved in the promotion of attachment behaviour. The hormones cortisol and oxytocin, respectively, may be involved in these proposed REM sleep functions. However, there are conflicting reports on whether levels of cortisol differ b...

The term lucid dream designates a dream in which the dreamer, while dreaming, is aware he or she is dreaming. Whereas lucid dreaming has been studied in adults, large-scaled surveys in children are scarce. The sample here included 3579 children for the ages from 6 to 18 who completed a brief questionnaire distributed in UK libraries. 43.5% reported...

This commentary argues firstly that we are so far from an account of what causes dream content that we should be cautious in linking that partial knowledge to a quest for function. Secondly, that it may be that all current data on the causes of dream content allow for the null hypothesis of dream function, that is, dreams do not have a function and...

This study investigates evidence, from dream reports, for memory consolidation during sleep. It is well-known that events and memories from waking life can be incorporated into dreams. These incorporations can be a literal replication of what occurred in waking life, or, more often, they can be partial or indirect. Two types of temporal relationshi...

The dream-lag effect refers to there being, after the frequent incorporation of memory elements from the previous day into dreams (the day-residue), a lower incorporation of memory elements from 2 to 4 days before the dream, but then an increased incorporation of memory elements from 5 to 7 days before the dream. Participants (n=8, all female) kept...

Ecstasy/MDMA use has been associated with various memory deficits. This study assessed declarative and procedural memory in ecstasy/MDMA users. Participants were tested in two sessions, 24 h apart, so that the memory consolidation function of sleep on both types of memory could also be assessed. Groups were: drug-naive controls (n = 24); recent ecs...

To assess prospectively the emotional content of dreams in individuals with the obstructive sleep apnea hypopnea syndrome (OSAHS) and sleepy snorers. Prospective observational study. Forty-seven patients with sleepiness and snoring attending a sleep-disordered breathing clinic, completed a morning diary concerning pleasantness/unpleasantness of the...

Individuals differ greatly in their dream recall frequency, in their incidence of recalling types of dreams, such as nightmares, and in the content of their dreams. This chapter reviews work on the waking life correlates of these differences between people in their experience of dreaming and reviews some of the neurobiological correlates of these i...

Lucid dreaming involves the attentional skill of having metacognition about the dreamer's state of consciousness at the same time as being engaged in the dream scenario. A combination of two levels of cognition also occurs in the incongruent condition of the Stroop task, where there is interference between the attentional demands of a relatively di...

There are reports of lucid dreaming being cued by the recognition that a dream event is bizarre from the point of view of waking life. However, for dreams in general, there is a lack of ability to notice or question bizarre occurrences. A waking-life analog of this inability is here proposed to be change blindness. In change blindness tasks, a prom...

This study investigated the associations between chronic cannabis and Ecstasy/MDMA use and one objective and two subjective measure of creativity. Fifteen abstinent Ecstasy users, 15 abstinent cannabis users, and 15 nondrug-user controls, completed three measures of creativity: the Consequences behavioral test of creativity, self-assessed performan...