Elizaveta Solomonova

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 ± 4.3 years) and control (n = 18; mean age 23.7 ± 4.4 years) groups underwent a partial REMD and control nights in the laboratory, respectively. In the evening preceding and morning following REMD, subjects rated neutral and negative pictures on scales of valence and arousal and EA scores were calculated. Subjects also rated dream emotions using the same scales and a 10‐item emotions list. REMD was relatively successful in decreasing REM% on the experimental night, although a mean split procedure was applied to better differentiate subjects high and low in REM%. High and low groups differed – but in a direction contrary to expectations. Subjects high in REMD% showed greater adaptation to negative pictures on arousal ratings than did those low in REMD% (P < 0.05), even after statistically controlling sleep efficiency and awakening times. Subjects above the median on EAvalence had less intense overall dream negativity (P < 0.005) and dream sadness (P < 0.004) than subjects below the median. A correlation between the emotional intensities of the morning dream and the morning picture ratings supports a possible emotional carry‐over effect. REM sleep may enhance morning reactivity to negative emotional stimuli. Further, REM sleep and dreaming may be implicated in different dimensions of cross‐night adaptation to negative emotions.

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. METHODS A preliminary study of 14 subjects with frequent NMs (> or = 1 NM/week; 27.6+/-9.9 years) and 11 healthy control subjects (<1 NM/month; 24.3+/-5.3 years) was undertaken. Subjects completed home sleep/dream logs and underwent three nights of polysomnographic recording with REM sleep deprivation on night 2. Group differences were assessed for a battery of REM sleep and dream measures on nights 1 and 3. RESULTS Several measures, including #skipped early-night REM periods, REM latency, REM/NREM cycle length, early/late REM density, REM rebound, late-night REM% and dream vividness, suggested that REM sleep propensity was abnormally low for the frequent NM group throughout the 3-day study. CONCLUSIONS Findings raise the possibility that REM anomalies recorded from NM sufferers sleeping in the laboratory environment reflect a disruption of one or more endogenous regulators of REM sleep propensity.

Sensed presence as a correlate of sleep paralysis distress, social anxiety and waking state social imagery.

Isolated sleep paralysis (ISP) is a common parasomnia characterized by an inability to move or speak and often accompanied by hallucinations of a sensed presence nearby. Recent research has linked ISP, and sensed presence more particularly, with social anxiety and other psychopathologies. The present study used a large sample of respondents to an internet questionnaire (N=193) to test whether these associations are due to a general personality factor, affect distress, which is implicated in nightmare suffering and hypothesized to involve dysfunctional social imagery processes. A new measure, ISP distress, was examined in relation to features of ISP experiences, to self-reported psychopathological diagnosis, to scores on the Leibowitz Social Anxiety Scale and to scores on a new questionnaire subscale assessing social imagery in a variety of waking states. Three main results were found: (1) ISP experiences are only weakly associated with a prior diagnosis of mental disorder, (2) sensed presence during ISP is associated preferentially with ISP distress, and (3) ISP distress is associated with dysfunctional social imagery. A general predisposition to affective distress may influence the distress associated with ISP experiences; overly passive social imagery may, in turn, be implicated in this affect distress influence.

Methodological considerations for the neurophenomenology of dreaming: commentary on Windt's "Reporting dream experience"

Windt (2013) eloquently and compellingly presents an anti-skeptical approach to the use of subjective dream reports in empirical research (the “transparency view”). On this view, dream reports are “trustworthy sources of evidence about the occurrence and phenomenal character of experience during sleep, at least when gathered under ideal reporting conditions.” Her paper is an example of the changing tides in the cognitive neuroscience of consciousness, and is a welcome valorization of the utility of subjective reports. The long-standing distrust of verbal reports of private mental processes is gradually giving way to realization of the necessity for incorporating first-person reports into objective, third-person paradigms in mutually informing ways (Varela and Shear, 1999)—a methodology often embraced by the term “neurophenomenology” (Lutz and Thompson, 2003). But what are “ideal reporting conditions?” Taking Windts “transparency view” as a starting point, we discuss a number of methodological considerations for neurophenomenological research on dreaming. We agree with Windt that it is crucial for empirical dream research to establish the extent to which dream reports are “transparent” accounts of subjective experiences; indeed, such transparency is the sine qua non for conducting meaningful qualitative and quantitative research on dream content. However, whereas dream experiences may be disclosed to the dreamer—or at least appear in the dreamers memory—in a transparent way, important individual differences exist in introspective skills and in ability to articulate the breadth or depth of experience accurately in verbal or written form (Fleming et al., 2010; Sze et al., 2010; Fox et al., 2012). We may need to ask then, on both practical and epistemological levels, whether we wish to uncover what is “typical” in dreams of a certain socio-cultural population (the “breadth” of dreaming), or what is “possible” in the dream state (the “depth” of dreaming). In light of this distinction, the “ideal conditions” for reporting dreams may well be different depending on whether the purpose of a study is to assess breadth or depth of dream experience. Accordingly, and to further integrate dream studies within the nascent neurophenomenological framework, we outline two methodological elements that support more reliable elicitation, collection and analysis of dream reports: (1) specific and rigorous laboratory conditions for dream collection; and (2) introspective training and/or solicitation of “expert” participants.

Felt presence: the uncanny encounters with the numinous Other

Felt presence, a sensation that “someone is there”, is an integral part of our everyday experience. It can manifest itself in a variety of forms ranging from most subtle fleeting impressions to intense hallucinations of demonic assault or visions of the divine. Felt presence phenomenon outside of the context of neurological disorders is largely neglected and not well understood by contemporary science. This paper focuses on the experiential and expressive qualities of the phenomenon and attempts to bring forth the complexity and the richness of possibilities for inter- and intrasubjective awareness represented by these experiences. Are these simply misperceptions and hallucinations heightened and enforced by the mystical or superstitious mind? Or are these entities projections of our own “selves”, elements of self-estrangement? How are such experiences shaping our understanding of ourselves and of others? And finally, what is the interplay between intersubjective, private experiences and private or public spaces of dwelling?

Extra-personal awareness through the media-rich environment

The richness and subtlety of the felt presence phenomenon introduced by “Felt Presence: the uncanny encounters with the numinous Other” (Solomonova et al., this issue) offers a challenge to the emerging field of new media. How to create a computer-mediated environment which can engender a spontaneous, creative, and individualized experience such as felt presence? The Other experiment described in this paper explores the possibility of unfolding phenomenological and poetic aura of felt presence experience in a media-rich environment with liminal stimulation, dosed carefully, and open to interpretation.

Sleep‐dependent consolidation of face recognition and its relationship to REM sleep duration, REM density and Stage 2 sleep spindles

Face recognition is a highly specialized capability that has implicit and explicit memory components. Studies show that learning tasks with facial components are dependent on rapid eye movement and non‐rapid eye movement sleep features, including rapid eye movement sleep density and fast sleep spindles. This study aimed to investigate the relationship between sleep‐dependent consolidation of memory for faces and partial rapid eye movement sleep deprivation, rapid eye movement density, and fast and slow non‐rapid eye movement sleep spindles. Fourteen healthy participants spent 1 night each in the laboratory. Prior to bed they completed a virtual reality task in which they interacted with computer‐generated characters. Half of the participants (REMD group) underwent a partial rapid eye movement sleep deprivation protocol and half (CTL group) had a normal amount of rapid eye movement sleep. Upon awakening, they completed a face recognition task that contained a mixture of previously encountered faces from the task and new faces. Rapid eye movement density and fast and slow sleep spindles were detected using in‐house software. The REMD group performed worse than the CTL group on the face recognition task; however, rapid eye movement duration and rapid eye movement density were not related to task performance. Fast and slow sleep spindles showed differential relationships to task performance, with fast spindles being positively and slow spindles negatively correlated with face recognition. The results support the notion that rapid eye movement and non‐rapid eye movement sleep characteristics play complementary roles in face memory consolidation. This study also raises the possibility that fast and slow spindles contribute in opposite ways to sleep‐dependent memory consolidation.

Dream content and procedural learning in Vipassana meditators and controls.

Vipassana meditation is characterized by observing bodily sensations, developing emotional and attentional stability, and promoting prosocial qualities. Whether these characteristics are also reflected in meditators’ dream content is not currently known. Evidence relating dream content with sleep-dependent learning is mixed: Some studies suggest that dreaming of a task is beneficial for improvement, whereas others find no such effect. This study aimed at investigating whether meditators have qualitatively different dreams than do controls, whether meditators incorporate a procedural learning task more often than do controls, and whether dreaming about the task is related to better postsleep performance on the task. Twenty meditators and 20 controls slept for a daytime nap in the laboratory. Before sleeping and upon awakening, they completed a procedural learning task. Dream reports were collected at sleep onset and upon awakening (REM or N2 sleep). Dreams were then scored for qualities associated with meditation practice and for incorporations of the procedural task and the laboratory. Meditators had longer dreams, slightly more references to the body, and friendlier and more compassionate interactions with dream characters. Dreams of meditation practitioners were not more lucid than those of controls. Meditators did not incorporate the learning task or laboratory into dream content more often than did controls, and no relationship was found between dream content and performance on the procedural task. In control participants, in contrast, incorporating the task or laboratory in REM/N2 dreams was associated with improvement on the task, but incorporations at sleep onset were associated with slightly worse task performance.