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Dreaming and lucidity in synesthesia.
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Lucid dreaming refers to the phenomenon of becoming aware of the fact that one is dreaming during ongoing sleep. Despite having been physiologically validated for decades, the neurobiology of lucid dreaming is still incompletely characterized. Here we review the neuroscientific literature on lucid dreaming, including electroencephalographic, neuroimaging, brain lesion, pharmacological and brain stimulation studies. Electroencephalographic studies of lucid dreaming are mostly underpowered and show mixed results. Neuroimaging data is scant but preliminary results suggest that prefrontal and parietal regions are involved in lucid dreaming. A focus of research is also to develop methods to induce lucid dreams. Combining training in mental set with cholinergic stimulation has shown promising results, while it remains unclear whether electrical brain stimulation could be used to induce lucid dreams. Finally, we discuss strategies to measure lucid dreaming, including best-practice procedures for the sleep laboratory. Lucid dreaming has clinical and scientific applications, and shows emerging potential as a methodology in the cognitive neuroscience of consciousness. Further research with larger sample sizes and refined methodology is needed.
The aim of the present study was to test the relationship between different types of synaesthesia and their involvement in art, creative, and visual abilities. We tested 20 grapheme‐colour, 18 sound‐colour, 19 grapheme‐colour‐and‐sound‐colour, 20 sequence‐space synaesthetes, and the same number of controls matched by age, gender, and education. We assessed the number of artistic professions, involvement in art, and the performance in psychometric tests of divergent and convergent creativity, as well as visual and visuo‐spatial abilities. Results show a higher prevalence of artists among synaesthetes, especially sound‐colour synaesthetes. Sound‐colour synaesthetes also showed a higher involvement in artistic activities overall while sequence‐space synaesthetes showed higher involvement in visual art. Only grapheme‐colour‐and‐sound‐colour synaesthetes showed significantly higher divergent creativity compared to matched controls. Additionally, overall, synaesthetes scored higher in visuo‐spatial abilities (i.e., mental rotation). For synaesthetes and controls, visuo‐spatial abilities correlated with divergent creativity. We discuss that synaesthetes’ higher involvement in art is not necessarily reflected in their basic creative abilities.
Grapheme–color synesthesia is a condition in which objectively achromatic graphemes induce concurrent color experiences. While it was long thought that the colors emerge during perception, there is growing support for the view that colors are integral to synesthetes’ cognitive representations of graphemes. In this work, we review evidence for two opposing theories positing either a perceptual or cognitive origin of concurrent colors: the cross-activation theory and the conceptual-mediation model. The review covers results on inducer and concurrent color processing as well as findings concerning the brain structure and grapheme–color mappings in synesthetes and trained mappings in nonsynesthetes. The results support different aspects of both theories. Finally, we discuss how research on memory colors could provide a new perspective in the debate about the level of processing at which the synesthetic colors occur.
Dreams are sometimes described as an intensified form of spontaneous waking thought. Lucid dreams may seem to be a counterexample, because metacognitive insight into the fact that one is now dreaming is often associated with the ability to deliberately control the ongoing dream. This chapter uses conceptual considerations and empirical research findings to argue that lucid dreaming is in fact a promising and rich target for the future investigation of spontaneous thought. In particular, the investigation of dream lucidity can shed light on the relationship between metacognitive insight and control, on the one hand, and the spontaneous, largely imagistic cognitive processes that underlie the formation of dream imagery, on the other hand. In some cases, even lucid insight itself can be described as the outcome of spontaneous processes, rather than as resulting from conscious and deliberate reasoning. This raises new questions about the relationship
between metacognitive awareness and spontaneous thought.
Synesthesia occurs when the activation of one sense modality elicits an experience in another modality. Synesthetic experiences are often referred to as imagery, and indeed both mental imagery and synesthesia occur in many sense modes and can represent forms of internally generated sensory experiences. However, they differ in prevalence, effects on perception, how voluntary they are, and probably in sites of brain activation; moreover, imagery and synesthesia are clearly differentiated by synesthetes themselves. We conclude that they are best considered as related but distinct mental processes. © 2013 Springer Science+Business Media, LLC. All rights reserved.
Synesthesia has historically been linked with enhanced creativity, but this had never been demonstrated in a systematically recruited sample. The current study offers a broad examination of creativity, personality, cognition, and mental imagery in a small sample of systematically recruited synesthetes and controls (n = 65). Synesthetes scored higher on some measures of creativity, personality traits of absorption and openness, and cognitive abilities of verbal comprehension and mental imagery. The differences were smaller than those reported in the literature, indicating that previous studies may have overestimated group differences, perhaps due to biased recruitment procedures. Nonetheless, most of our results replicated literature findings, yielding two possibilities: (1) our study was influenced by similar biases, or (2) differences between synesthetes and controls, though modest, are robust across recruitment methods. The covariance among our measures warrants interpretation of these differences as a pattern of associations with synesthesia, leaving open the possibility that this pattern could be explained by differences on a single measured trait, or even a hidden, untested trait. More generally, this study highlights the difficulty of comparing groups of people in psychology, not to mention neuropsychology and neuroimaging studies. The requirements discussed here - systematic recruitment procedures, large battery of tests, and large cohorts - are best fulfilled through collaborative efforts and cumulative science.
Lucid dreaming is the ability of a dreamer to become aware that he is dreaming and to possibly change some
aspects of his current dream. This ability is associated with higher creativity and a proclivity for divergent thinking. Between subjects, dreams have different structural characteristics, such as the incorporation of daytime events, aversive dream content, or dream recall frequency (DRF). This study aimed to investigate the relationship between lucid dreaming, creativity and dream characteristics like aversive dream content, personal significance, dream recall, incorporation of daytime events and great dreams. A total of 334 participants took part in an online study. The results show that lucid dreamers scored higher on the creative personality scale of the Adjective Checklist and reported a higher DRF than non-lucid dreamers. As to the dream structure, lucid dreamers were more likely to incorporate daytime events into their dreams, and their dreams had a higher personal significance than those of non-lucid dreamers. Furthermore, substantial gender differences were found in DRF and other dream characteristics. The results confirm the relationship between lucid dreaming and creativity and indicate that lucid dreamers differ from non-lucid dreamers in their general dream structure.
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 having had at least one lucid dream. As hypothesized, incidence of lucid dreams was most strongly associated with the preference for reading fantasy/science-fiction. Whether lucid dreaming might be beneficial for children in skills training or coping with nightmares are interesting topics for future research.
Synesthesia is a neurological condition that gives rise to unusual secondary sensations (e.g., reading letters might trigger the experience of colour). Testing the consistency of these sensations over long time intervals is the behavioural gold standard assessment for detecting synesthesia (e.g., Simner, Mulvenna et al., 2006). In 2007 however, Eagleman and colleagues presented an online 'Synesthesia Battery' of tests aimed at identifying synesthesia by assessing consistency but within a single test session. This battery has been widely used but has never been previously validated against conventional long-term retesting, and with a randomly recruited sample from the general population. We recruited 2847 participants to complete The Synesthesia Battery and found the prevalence of grapheme-colour synesthesia in the general population to be 1.2%. This prevalence was in line with previous conventional prevalence estimates based on conventional long-term testing (e.g., Simner, Mulvenna et al., 2006). This reproduction of similar prevalence rates suggests that the Synesthesia Battery is indeed a valid methodology for assessing synesthesia.
Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.
Lucid dreaming is a state of awareness that one is dreaming, without leaving the sleep state. Dream reports show that self-reflection and volitional control are more pronounced in lucid compared with nonlucid dreams. Mostly on these grounds, lucid dreaming has been associated with metacognition. However, the link to lucid dreaming at the neural level has not yet been explored. We sought for relationships between the neural correlates of lucid dreaming and thought monitoring. Human participants completed a questionnaire assessing lucid dreaming ability, and underwent structural and functional MRI. We split participants based on their reported dream lucidity. Participants in the high-lucidity group showed greater gray matter volume in the frontopolar cortex (BA9/10) compared with those in the low-lucidity group. Further, differences in brain structure were mirrored by differences in brain function. The BA9/10 regions identified through structural analyses showed increases in blood oxygen level-dependent signal during thought monitoring in both groups, and more strongly in the high-lucidity group. Our results reveal shared neural systems between lucid dreaming and metacognitive function, in particular in the domain of thought monitoring. This finding contributes to our understanding of the mechanisms enabling higher-order consciousness in dreams.
Copyright © 2015 the authors 0270-6474/15/351082-07$15.00/0.
Synesthesia based in visual modalities has been associated with reports of vivid visual imagery. We extend this finding to consider whether other forms of synesthesia are also associated with enhanced imagery, and whether this enhancement reflects the modality of synesthesia. We used self-report imagery measures across multiple sensory modalities, comparing synesthetes’ responses (with a variety of forms of synesthesia) to those of non-synesthete matched controls. Synesthetes reported higher levels of visual, auditory, gustatory, olfactory and tactile imagery and a greater level of imagery use. Furthermore, their reported enhanced imagery is restricted to the modalities involved in the individual’s synesthesia. There was also a relationship between the number of forms of synesthesia an individual has, and the reported vividness of their imagery, highlighting the need for future research to consider the impact of multiple forms of synesthesia. We also recommend the use of behavioral measures to validate these self-report findings.
In lucid dreams the dreamer is aware that he or she is dreaming. Although such dreams are not that uncommon, many aspects of lucid dream phenomenology are still unclear. An online survey was conducted to gather data about lucid dream origination, duration, active or passive participation in the dream, planned actions for lucid dreams, and other phenomenological aspects. Among the 684 respondents who filled out the questionnaire, there were 571 lucid dreamers (83.5%). According to their reports, lucid dreams most often originate spontaneously in adolescence. The average lucid dream duration is about 14 minutes. Lucid dreamers are likely to be active in their lucid dreams and plan to accomplish different actions (e.g., flying, talking with dream characters, or having sex), yet they are not always able to remember or successfully execute their intentions (most often because of awakening or hindrances in the dream environment). The frequency of lucid dream experience was the strongest predictor of lucid dream phenomenology, but some differences were also observed in relation to age, gender, or whether the person is a natural or self-trained lucid dreamer. The findings are discussed in light of lucid dream research, and suggestions for future studies are provided.
Synaesthesia is a phenomenon in which stimulation in one sensory modality triggers involuntary experiences typically not associated with that stimulation. Inducing stimuli (inducers) and synaesthetic experiences (concurrents) may occur within the same modality (e.g., seeing colours while reading achromatic text) or span across different modalities (e.g., tasting flavours while listening to music). Although there has been considerable progress over the last decade in understanding the cognitive and neural mechanisms of synaesthesia, the focus of current neurocognitive models of synaesthesia does not encompass many crucial psychophysical characteristics documented in behavioural research. Prominent theories of the neurophysiological basis of synaesthesia construe it as a perceptual phenomenon and hence focus primarily on the modality-specific brain regions for perception. Many behavioural studies, however, suggest an essential role for conceptual-level information in synaesthesia. For example, there is evidence that synaesthetic experience arises subsequent to identification of an inducing stimulus, differs substantially from real perceptual events, can be akin to perceptual memory, and is susceptible to lexical/semantic contexts. These data suggest that neural mechanisms lying beyond the realm of the perceptual cortex (especially the visual system), such as regions subserving conceptual knowledge, may play pivotal roles in the neural architecture of synaesthesia. Here we discuss the significance of non-perceptual mechanisms that call for a re-evaluation of the emphasis on synaesthesia as a perceptual phenomenon. We also review recent studies which hint that some aspects of synaesthesia resemble our general conceptual knowledge for object attributes, at both psychophysical and neural level. We then present a conceptual-mediation model of synaesthesia in which the inducer and concurrent are linked within a conceptual-level representation. This ‘inducer-to-concurrent’ n
One of the main problems in understanding synaesthesia is determining whether it is a sensory or semantic phenomenon-a problem also known as the distinction between ‘low-’ vs. ‘high-level’ synaesthesia. Recently, it has been reported that in grapheme-colour synaesthesia, the colour associated to a letter is chosen by similarity to other letters. Letters of similar shapes tend to elicit similar colours. The authors explained this result by low-level cross-wiring between grapheme and colour brain areas. In the present study we show that when new graphemes are learned, they also associate synaesthetic colours based on shape- and colour similarity. Importantly, these novel associations between graphemes and colors are created within minutes, which is too rapid to be accounted for by cross-wiring. In addition, the dimensions of similarity used to create these associations were more abstract than what would be expected from elementary features processed in the grapheme area. Therefore, we conclude that the result is better explained by high-level conceptual mechanisms that guide the choices and creation of synaesthetic concurrents.
In this study we investigated whether synaesthesia is associated with a particular cognitive style. Cognitive style refers to preferred modes of information processing, such as a verbal style or a visual style. We reasoned that related to the enriched world of experiences created by synaesthesia, its association with enhanced verbal and visual memory, higher imagery and creativity, synaesthetes might show enhanced preference for a verbal as well as for a visual cognitive style compared to non-synaesthetes. In Study 1 we tested a large convenience sample of 1046 participants, who classified themselves as grapheme-color, sound-color, lexical-gustatory, sequence-space, or as non-synaesthetes. To assess cognitive style, we used the revised verbalizer-visualizer questionnaire (VVQ), which involves three independent cognitive style dimensions (verbal style, visual-spatial style, and vivid imagery style). The most important result was that those who reported grapheme-color synaesthesia showed higher ratings on the verbal and vivid imagery style dimensions, but not on the visual-spatial style dimension. In Study 2 we replicated this finding in a laboratory study involving 24 grapheme-color synaesthetes with objectively confirmed synaesthesia and a closely matched control group. Our results indicate that grapheme-color synaesthetes prefer both a verbal and a specific visual cognitive style. We suggest that this enhanced preference, probably together with the greater ease to switch between a verbal and a vivid visual imagery style, may be related to cognitive advantages associated with grapheme color synaesthesia such as enhanced memory performance and creativity.
Mental practice is the cognitive rehearsal of a motor task in the absence of overt physical movement. A different and rather unknown kind of mental rehearsal is practice in lucid dreams. Within lucid dreams, the dreamer is able to control the ongoing dream content and for athletes it is possible to use the dream state to deliberately practice sport skills while physically asleep. In this study, 840 German athletes from various sports were asked about their experience with lucid dreams. About 57% of the athletes stated that they experienced a lucid dream at least once in their lives, 24% are frequent lucid dreamers (having one or more lucid dreams per month) and 9% of the lucid dreamers used this dream state to practice sport skills and the majority of those athletes had the impression that the rehearsal within the lucid dream improved their performance in wakefulness. The prevalence rate of lucid dreaming in professional athletes is similar as in general population, however the rough estimate of the percentage of lucid dreams compared to all dreams in athletes was found to be nearly twice as high as in general population (14.5% vs. 7.5%). The possibilities of lucid dream practice for professional sports will be discussed.
This article is founded on the bold claim that mental imagery is a basic building block of all consciousness. Conscious mental imagery is reported in association with waking, dreaming and intermediate states of consciousness. Meta-cognitive theory claims that the individual may be treated as an imperfect measuring device of his or her own consciousness. This is supported by the evidence on the psychological correlates of imagery vividness reported using the Vividness of Visual Imagery Questionnaire (VVIQ) (Marks, 1973). Meta-analysis of 150 studies has demonstrated high levels of reliability, content validity and criterion validity (McKelvie, 1995 a, b). This analysis demonstrates that under controlled conditions, verbal reports provide reliable and valid measures of conscious experience. The activity cycle theory of conscious imagery claims that a primary function of consciousness is the mental rehearsal of adaptive, goal-directed action through the experimental manipulation of perceptual-motor imagery. As predicted by this theory, the meta-analysis shows that the vividness of conscious mental imagery is strongly associated with precisely those performances most likely to benefit from the use of perceptual-motor imagery and mental practice. The theory helps to explain the existence and function of conscious experience.
The main goal of the present study was to explore electrophysiological differences between lucid and nonlucid dreams in REM sleep. Seven men and four women experienced in lucid dreaming underwent polysomnographic recordings in the sleep laboratory on two consecutive nights. EEG signals were subjected to spectral analysis to obtain five different frequency bands between 1 and 20 Hz. Lucidity was determined by both subjective dream reports and eye-movement signals made by the subjects in response to light stimuli indicating a REM period. The main discrimination factor between lucid and nonlucid dreaming was found in the beta-1 frequency band (13–19 Hz), which in lucid dreaming was increased in both parietal regions. The ratio of frontal to parietal beta-1 activity was 1 to 1.16 in nonlucid and 1 to 1.77 in lucid dreaming. A tendency towards the greatest increase was observed in the left parietal lobe (P3), an area of the brain considered to be related to semantic understanding and self-awareness. Lucid dreaming refers to a specific dream state characterized by the dreamer's awareness of being in a dream and the ability to volitionally control its content. Lucid dreamers report being in possession of all their cognitive faculties: they are able to reason clearly, to remember the conditions of waking life, and to act voluntarily within the dream upon reflection or in accordance with plans decided upon before sleep (Carskadon, 1995). The dream state can be experienced very vividly, and thus lucid dreams are often described as peak experiences or "high" dreams (Tart, 1990).
Synaesthesia is a condition in which one property of a stimulus induces a conscious experience of an additional attribute. For example, in grapheme-colour synaesthesia, a visually presented grapheme results in synaesthetic experiences of colour. These experiences occur in approximately 4% of the population (Simner et al., 2006) and the authenticity of the condition is well established (Cohen Kadosh and Henik, 2007). Despite this, our understanding of the neuropsychiatric profiles of synaesthetes remains limited and surprisingly few studies have addressed whether synaesthesia is linked to more widespread abnormalities in perception that extend beyond the synaesthetic experience itself. There is, however, growing evidence to suggest that synaesthesia may be linked to a broader phenotype. For example, synaesthetes who experience colour show early processing differences to stimuli which do not evoke synaesthesia (Barnett et al., 2008); and the presence of synaesthesia has been linked with other phenotypic manifestations including out-of-body experiences (Terhune, 2009), creativity (Ward et al., 2008), mental imagery (Barnett and Newell, 2008), and mitempfindung (Burrack et al., 2006). Here, we examined the relationship between synaesthesia involving colour and the abnormal perceptions observed in schizophrenia by assessing levels of schizotypy in synaesthetes and non-synaesthetes. We report that synaesthesia for colour is associated with greater levels of positive and disorganised schizotypy (Fig. 1A), suggesting widespread perceptual differences in synaesthesia that extend beyond the synaesthetic concurrent.
Little is known about how the properties of our private mental world relate to the physical and functional properties of our brain. Studying synesthesia, where a particular experience evokes a separate additional sensory experience, offers the unique opportunity to study phenomenological experiences as a stable trait in healthy subjects. A common form of synesthesia is grapheme-color synesthesia, where a particular letter or number evokes a particular color experience. We studied the neural basis of qualitative different properties of the synesthetic experience by using individual differences in grapheme-color synesthesia. Specifically, the synesthetic color can be experienced "in the mind" (associator synesthetes) or "in the outside world" (projector synesthetes). Gray matter structure and functioning (imaged using voxel-based morphometry and functional magnetic resonance imaging, respectively) were examined in grapheme-color synesthetes (N = 42, 16 projectors and 26 associators) and nonsynesthetes. Results indicated partly shared mechanisms for all grapheme-color synesthetes, particularly in posterior superior parietal lobe, which is involved in the integration of sensory information. In addition, the nature of synesthetic experience was found to be mediated by distinct neural mechanisms. The outside-world experience is related to brain areas involved in perceiving and acting in the outside world (visual cortex, auditory cortex, motor cortex) as well as frontal brain areas. In contrast, the in-the-mind experience is related to the hippocampus and parahippocampal gyrus, known for their role in memory. Thus, the different subjective experiences are related to distinct neural mechanisms. Moreover, the properties of subjective experiences are in accordance with functional properties of the mediating brain mechanisms.
Although a considerable amount of research has addressed psychopathological and personality correlates of creativity, the relationship between these characteristics and the phenomenology of creativity has been neglected. Relating these characteristics to the phenomenology of creativity may assist in clarifying the precise nature of the relationship between psychopathology and creativity. The current article reports on an empirical study of the relationship between the phenomenology of the creative process and psychopathological and personality characteristics in a sample of artists.
A total of 100 artists (43 males, 57 females, mean age = 34.69 years) from a range of disciplines completed the Experience of Creativity Questionnaire and measures of "positive" schizotypy, affective disturbance, mental boundaries, and normal personality.
The sample of artists was found to be elevated on "positive" schizotypy, unipolar affective disturbance, thin boundaries, and the personality dimensions of Openness to Experience and Neuroticism, compared with norm data. Schizotypy was found to be the strongest predictor of a range of creative experience scales (Distinct Experience, Anxiety, Absorption, Power/Pleasure), suggesting a strong overlap of schizotypal and creative experience.
These findings indicate that "positive" schizotypy is associated with central features of "flow"-type experience, including distinct shift in phenomenological experience, deep absorption, focus on present experience, and sense of pleasure. The neurologically based construct of latent inhibition may be a mechanism that facilitates entry into flow-type states for schizotypal individuals. This may occur by reduced latent inhibition providing a "fresh" awareness and therefore a greater absorption in present experience, thus leading to flow-type states.
Synesthesia is an atypical perceptual phenomenon that has been associated with generalized differences in other cognitive and perceptual domains. Given similarities in the qualitative nature of synesthetic experiences to visual imagery perceptions, several studies have sought to examine whether synesthetes demonstrate increased visual imagery abilities. Using subjective imagery questionnaires, some studies have identified superior imaging abilities in synesthetes, while others have not. However, because most research on synesthesia uses un-blinded group membership prior to data collection, such methods for studying group differences may be prone to participant and experimenter biases (e.g., a motivated synesthete may rate themselves as having stronger visual imagery abilities due to their own bias and perceived experimenter expectations). To address this issue, we demonstrate the feasibility of double-blind designs in synesthesia research, applied here to examine differences in subjectively reported levels of imagery usage and intensity. Prior to identifying synesthetes' and non-synesthetes' group membership (in order to eliminate the potential for bias), subjects completed two common measures of visual imagery experiences. Using this approach, we replicated findings of greater visual imagery usage in synesthetes on the Spontaneous Use of Imagery Scale (SUIS) measure, but not of enhanced imagery abilities on the standardized Vividness of Visual Imagery Questionnaire (VVIQ) measure. The present study strengthens prior evidence that synesthesia is associated with heightened visual imagery and demonstrates the utility of double-blind designs in order to limit biases and promote further replicability of other findings in research on synesthesia.
Strong conceptual and theoretical connections have been made between meditation practice, mindfulness, and lucid dreaming. However, only a handful of empirical studies have evaluated the relationship between lucid dreaming and meditation, and conclusions remain tempered by methodological limitations. In this study, we evaluated the relationship between meditation, mindfulness, and lucid dream frequency using several complementary methods. First, using a cross-sectional design, we evaluated differences in lucid dream frequency between long-term meditators and meditation-naïve individuals. Second, we evaluated the relationship between lucid dream frequency and specific facets of trait mindfulness in both meditators and nonmeditators. Third, using a blinded, randomized controlled design, we evaluated the effect of an 8-week mindfulness course on lucid dreaming frequency. Our results show that lucid dreaming is more frequent in long-term meditators than in meditation-naïve individuals. In addition, lucid dream frequency in meditation-naïve individuals was associated with a tendency to verbalize experience, whereas lucid dream frequency in long-term meditators was associated with observational and decentering facets of trait mindfulness. However, an 8-week mindfulness course did not increase the frequency of lucid dreams. Together, these results support a continuity between increased awareness of waking and sleeping states, provide a novel form of evidence linking meditation training to meta-awareness, and support an association between meditation practice and lucid dreaming, but leave open the specific nature of this connection.
We report a quality effects meta-analysis on studies from the period 1966–2016 measuring
either (a) lucid dreaming prevalence (one or more lucid dreams in a lifetime); (b) frequent
lucid dreaming (one or more lucid dreams in a month) or both. A quality effects
meta-analysis allows for the minimisation of the influence of study methodological quality
on overall model estimates. Following sensitivity analysis, a heterogeneous lucid dreaming
prevalence data set of 34 studies yielded a mean estimate of 55%, 95% C. I. [49%, 62%] for
which moderator analysis showed no systematic bias for suspected sources of variability.
A heterogeneous lucid dreaming frequency data set of 25 studies yielded a mean estimate
of 23%, 95% C. I. [20%, 25%], moderator analysis revealed no suspected sources of variability.
These findings are consistent with earlier estimates of lucid dreaming prevalence and
frequent lucid dreaming in the population but are based on more robust evidence.
The universal quest to create cosmologies to comprehend the relationship between mind and world - is inevitably limited by the social, cultural and historical perspective of the observer, in this instance western psychoanalysis. in this book Michael Robbins attempts to transcend such contextual limitations by putting forward a primordial form of mental activity that co-exists alongside thought and is of equal importance in human affairs.
Lucid dreaming has been said to be within the capability of all individuals (LaBerge, 1985). Based on analyses of the incidence of this dream experience among university students and among persons with an expressed interest in dreaming, a majority have reported experiencing at least one lucid dream during their lifetime, and about 20% have reported experiencing lucid dreams with relative frequency. Our goal in this chapter is to describe and to integrate what has been learned through research about individuals who experience lucid dreams. To this end we will present data derived from the study of four separable but not unrelated functional domains for which subject differences associated with lucid dreaming, or lucidity, have been found. These functional domains are (1) oculomotor/equilibratory; (2) visual/imaginal; (3) intellectual/creative, and (4) personal/interpersonal. The extent of individual differences in lucid dreaming and the methods by which these differences have been investigated will also be discussed. Because methodology is an integral part of research into individual differences, methodological considerations will first be presented.
The author was the subject in an investigation of the feasibility of learning to dream lucidly, i.e., while knowing that one is dreaming. During the 3-yr. study, the subject recorded a total of 389 lucid dreams and developed a mnemonic technique for the voluntary induction of lucid dreams (MILD). Without using any induction procedure, the subject reported less than 1 lucid dream per month. Using auto-suggestion resulted in a range of 1 to 13 lucid dreams per month (M = 5.4), with at most 2 per night. MILD yielded 18 to 26 lucid dreams per month (M = 21.5), with up to 4 per night.
Introduction
The present paper introduces the three most common methods for measuring dream recall: laboratory awakenings, dream diaries and questionnaire scales. An easy applicable seven-point scale, its retest reliability and validity analyses will be presented.
Patients and Methods
Within several studies, 941 healthy persons rated their dream recall frequency using the scale. The retest sample (70 days retest interval) consisted of 42 patients with sleep disorders.
Results
The data of the healthy persons replicated the previous significant findings of gender differences (women tend to recall their dreams more often than men) and the decline of dream recall frequency with age. Retest relibility was high.
Conclusions
The introduced scale is well qualified for measuring interindividual differences and permits—by breaking down of the data into four age groups—comparisons with samples stemming from different settings, e. g. patient groups.
Normal perception involves experiencing objects within perceptual scenes as real, as existing in the world. This property of "perceptual presence" has motivated "sensorimotor theories" which understand perception to involve the mastery of sensorimotor contingencies. However, the mechanistic basis of sensorimotor contingencies and their mastery has remained unclear. Sensorimotor theory also struggles to explain instances of perception, such as synesthesia, that appear to lack perceptual presence and for which relevant sensorimotor contingencies are difficult to identify. On alternative "predictive processing" theories, perceptual content emerges from probabilistic inference on the external causes of sensory signals, however, this view has addressed neither the problem of perceptual presence nor synesthesia. Here, I describe a theory of predictive perception of sensorimotor contingencies which (1) accounts for perceptual presence in normal perception, as well as its absence in synesthesia, and (2) operationalizes the notion of sensorimotor contingencies and their mastery. The core idea is that generative models underlying perception incorporate explicitly counterfactual elements related to how sensory inputs would change on the basis of a broad repertoire of possible actions, even if those actions are not performed. These "counterfactually-rich" generative models encode sensorimotor contingencies related to repertoires of sensorimotor dependencies, with counterfactual richness determining the degree of perceptual presence associated with a stimulus. While the generative models underlying normal perception are typically counterfactually rich (reflecting a large repertoire of possible sensorimotor dependencies), those underlying synesthetic concurrents are hypothesized to be counterfactually poor. In addition to accounting for the phenomenology of synesthesia, the theory naturally accommodates phenomenological differences between a range of experiential states including dreaming, hallucination, and the like. It may also lead to a new view of the (in)determinacy of normal perception.
People with synaesthesia not only have – by definition – unusual experiences (e.g., numbers triggering colour), they also have a different cognitive profile (e.g., in terms of their memory and perceptual abilities) and a bias towards certain interests and activities (e.g., towards the arts). However, virtually nothing is known about whether synaesthetes have an atypical personality profile. In this study, a standard measure of personality was administered (Big Five Inventory) along with two questionnaire measures of empathy. Synaesthetes, relative to demographically matched controls, reported higher levels of ‘Openness to Experience’ which is known to be related to imagination and artistic tendencies. They also reported higher levels of ‘Fantasizing’ on one of the empathy measures, which is conceptually related to Openness, although their self-reported empathy did not differ in other respects. In addition, synaesthetes reported lower levels of Agreeableness which we did not predict in advance.
There is emerging evidence that the encoding of visual information and the maintenance of this information in a temporarily accessible state in working memory rely on the same neural mechanisms. A consequence of this overlap is that atypical forms of perception should influence working memory. We examined this by investigating whether having grapheme-color synesthesia, a condition characterized by the involuntary experience of color photisms when reading or representing graphemes, would confer benefits on working memory. Two competing hypotheses propose that superior memory in synesthesia results from information being coded in two information channels (dual-coding) or from superior dimension-specific visual processing (enhanced processing). We discriminated between these hypotheses in three n-back experiments in which controls and synesthetes viewed inducer and non-inducer graphemes and maintained color or grapheme information in working memory. Synesthetes displayed superior color working memory than controls for both grapheme types, whereas the two groups did not differ in grapheme working memory. Further analyses excluded the possibilities of enhanced working memory among synesthetes being due to greater color discrimination, stimulus color familiarity, or bidirectionality. These results reveal enhanced dimension-specific visual working memory in this population and supply further evidence for a close relationship between sensory processing and the maintenance of sensory information in working memory.
This book is designed to advance both theory and practice in the psychological preparation of high-level sports performers. Seven aspects of psychological preparation are considered. Each discussion ends with a summary of the implications for future research and best practice. The authors explore the links between the practices elite athletes use during competition and theories which underlie psychological preparation for performance.
This book develops a model of psychological preparation for elite sports performers incorporating research-to-practice orientation and a global perspective using evidence derived from North American, European, Australian and other research literatures in both general and sport psychology. This book is intended for sport psychologists, students and professionals with an interest in sport or high-level performance. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Reviews psychological and psychophysiological frameworks for understanding the experience of lucid dreaming (knowing you are dreaming while the dream is ongoing). Several of the psychological approaches take an information processing view of lucid dreaming. One approach sees lucidity in sleep as a cognitive tool whereas others put more emphasis on a model of self awareness. Psychophysiological perspectives show that lucidity is a significantly more aroused REM sleep experience than nonlucid REM sleep. The EEG and lucidity work is based on the association of lucidity to meditation. This sleep experience is also viewed from the framework of spatial skills especially as implicated in vestibular system functioning. The connectionist view of neural nets is another explanatory vehicle. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
The current study focused on the distribution of lucid dreams in school children and young adults. The survey was conducted on a large sample of students aged 6-19 years. Questions distinguished between past and current experience with lucid dreams. Results suggest that lucid dreaming is quite pronounced in young children, its incidence rate drops at about age 16 years. Increased lucidity was found in those attending higher level compared with lower level schools. Taking methodological issues into account, we feel confident to propose a link between the natural occurrence of lucid dreaming and brain maturation.
The term lucid dream designates a dream in which the dreamer is––while dreaming––aware that she/he is dreaming. Within an unselected student sample, 82% of the participants reported the occurrence of at least one lucid dream. In this sample, lucid dreaming frequency was not associated with the Big Five personality factors and, thus, theories linking lucid dreaming with introversion or well-being, that is, low neuroticism scores have not been supported. However, substantial but small correlations have been found for two openness facts (“fantasy”, “ideas”) and for dimensions which are associated with the openness to experience factor: Thin boundaries, Absorption and Imagination. Since these correlations are similar to corresponding correlations to dream recall frequency and the relationships between lucid dreaming frequency and these personality dimensions are mediated by dream recall frequency, it might be concluded that the direct relationship between lucid dreaming frequency and personality is rather small. Other variables such as meditation experience, field independence on a perceptual level, performance of the vestibular system should be included in future models explaining interindividual differences in lucid dreaming frequency. Nightmare frequency was moderately associated with lucid dreaming frequency. Although partialling out dream recall frequency reduced the magnitude of the correlation, the still significant partial correlation supports the reports of lucid dreamers that nightmares can trigger lucidity. Controlled studies investigating the effect of training the technique of lucid dreaming on nightmare frequency have not yet been carried out.
Many studies have reported gender differences in nightmare frequency. In order to study this difference systematically, data from 111 independent studies have been included in the meta-analysis reported here. Overall, estimated effect sizes regarding the gender difference in nightmare frequency differed significantly from zero in three age groups of healthy persons (adolescents, young adults, and middle-aged adults), whereas for children and older persons no substantial gender difference in nightmare frequency could be demonstrated. There are several candidate variables like dream recall frequency, depression, childhood trauma, and insomnia which might explain this gender difference because these variables are related to nightmare frequency and show stable gender differences themselves. Systematic research studying the effect of these variables on the gender difference in nightmare frequency, though, is still lacking. In the present study it was found that women tend to report nightmares more often than men but this gender difference was not found in children and older persons. Starting with adolescence, the gender difference narrowed with increasing age. In addition, studies with binary coded items showed a markedly smaller effect size for the gender difference in nightmare frequency compared to the studies using multiple categories in a rating scale. How nightmares were defined did not affect the gender difference. In the analyses of all studies and also in the analysis for the children alone the data source (children vs. parents) turned out to be the most influential variable on the gender difference (reporting, age). Other results are also presented. Investigating factors explaining the gender difference in nightmare frequency might be helpful in deepening the understanding regarding nightmare etiology and possibly gender differences in other mental disorders like depression or posttraumatic stress disorder.
Dreaming has fascinated and mystified humankind for ages: the bizarre and evanescent qualities of dreams have invited boundless speculation about their origin, meaning and purpose. For most of the twentieth century, scientific dream theories were mainly psychological. Since the discovery of rapid eye movement (REM) sleep, the neural underpinnings of dreaming have become increasingly well understood, and it is now possible to complement the details of these brain mechanisms with a theory of consciousness that is derived from the study of dreaming. The theory advanced here emphasizes data that suggest that REM sleep may constitute a protoconscious state, providing a virtual reality model of the world that is of functional use to the development and maintenance of waking consciousness.
Synesthesia, a neurological condition affecting between 0.05%-1% of the population, is characterized by anomalous sensory perception and associated alterations in cognitive function due to interference from synesthetic percepts. A stimulus in one sensory modality triggers an automatic, consistent response in either another modality or a different aspect of the same modality. Familiality studies show evidence of a strong genetic predisposition; whereas initial pedigree analyses supported a single-gene X-linked dominant mode of inheritance with a skewed F:M ratio and a notable absence of male-to-male transmission, subsequent analyses in larger samples indicated that the mode of inheritance was likely to be more complex. Here, we report the results of a whole-genome linkage scan for auditory-visual synesthesia with 410 microsatellite markers at 9.05 cM density in 43 multiplex families (n = 196) with potential candidate regions fine-mapped at 5 cM density. Using NPL and HLOD analysis, we identified four candidate regions. Significant linkage at the genome-wide level was detected to chromosome 2q24 (HLOD = 3.025, empirical genome-wide p = 0.047). Suggestive linkage was found to chromosomes 5q33, 6p12, and 12p12. No support was found for linkage to the X chromosome; furthermore, we have identified two confirmed cases of male-to-male transmission of synesthesia. Our results demonstrate that auditory-visual synesthesia is likely to be an oligogenic disorder subject to multiple modes of inheritance and locus heterogeneity. This study comprises a significant step toward identifying the genetic substrates underlying synesthesia, with important implications for our understanding of the role of genes in human cognition and perception.
We show that the neurological condition of synaesthesia--which causes fundamental differences in perception and cognition throughout a lifetime--is significantly represented within the childhood population, and that it manifests behavioural markers as young as age 6 years. Synaesthesia gives rise to a merging of cognitive and/or sensory functions (e.g. in grapheme-colour synaesthesia, reading letters triggers coloured visual photisms) and adult synaesthesia is characterized by a fixed pattern of paired associations for each synaesthete (e.g. if a is carmine red, it is always carmine red). We demonstrate that the onset of this systematicity can be detected in young grapheme-colour synaesthetes, but is an acquired trait with a protracted development. We show that grapheme-colour synaesthesia develops in a way that supersedes the cognitive growth of non-synaesthetic children (with both average and superior abilities) in a comparable paired association task. With methodology based on random sampling and behavioural tests of genuineness, we reveal the prevalence of grapheme-colour synaesthesia in children (over 170,000 grapheme-colour synaesthetes ages 0-17 in the UK, and over 930,000 in the US), the progression of the condition in longitudinal testing, and the developmental differences between synaesthetes and non-synaesthetes in matched tasks. We tested 615 children age 6-7 years from 21 primary schools in the UK. Each child was individually assessed with a behavioural test for grapheme-colour synaesthesia, which first detects differences between synaesthetes and non-synaesthetes, and then tracks the development of each group across 12 months (from ages 6/7 to 7/8 years). We show that the average UK primary school has 2-3 grapheme-colour synaesthetes at any time (and the average US primary school has five) and that synaesthetic associations (e.g. a = carmine red) develop from chaotic pairings into a system of fixed, consistent cogno-sensory responses over time. Our study represents the first assessment of synaesthesia in a randomly sampled childhood population demonstrating the real-time development of the condition. We discuss the complex profile of benefits and costs associated with synaesthesia, and our research calls for a dialogue between researchers, clinicians and educators to highlight the prevalence and characteristics of this unusual condition.
In synaesthesia, ordinary stimuli elicit extraordinary experiences. For
example when C., who is a digit-colour synaesthete, views black digits,
each number elicits a photism - a visual experience of a specific
colour. It has been proposed that synaesthetic experiences differ from
imagery in their consistency, automaticity and reliance on external
stimuli to induce them. Here we demonstrate that C.'s photisms are both
consistent and automatic, but we find that an externally presented
inducing stimulus is not necessary to trigger a photism and that simply
activating the concept of a digit is sufficient.
Synesthesia is a conscious experience of systematically induced sensory attributes that are not experienced by most people under comparable conditions. Recent findings from cognitive psychology, functional brain imaging and electrophysiology have shed considerable light on the nature of synesthesia and its neurocognitive underpinnings. These cognitive and physiological findings are discussed with respect to a neuroanatomical framework comprising hierarchically organized cortical sensory pathways. We advance a neurobiological theory of synesthesia that fits within this neuroanatomical framework.
For individuals with synaesthesia, stimuli in one sensory modality elicit anomalous experiences in another modality. For example, the sound of a particular piano note may be 'seen' as a unique colour, or the taste of a familiar food may be 'felt' as a distinct bodily sensation. We report a study of 192 adult synaesthetes, in which we administered a structured questionnaire to determine the relative frequency and characteristics of different types of synaesthetic experience. Our data suggest the prevalence of synaesthesia in the adult population is approximately 1 in 1150 females and 1 in 7150 males. The incidence of left-handedness in our sample was within the normal range, contrary to previous claims. We did, however, find that synaesthetes are more likely to be involved in artistic pursuits, consistent with anecdotal reports. We also examined responses from a subset of 150 synaesthetes for whom letters, digits and words induce colour experiences ('lexical-colour' synaesthesia). There was a striking consistency in the colours induced by certain letters and digits in these individuals. For example, 'R' elicited red for 36% of the sample, 'Y' elicited yellow for 45%, and 'D' elicited brown for 47%. Similar trends were apparent for a group of non-synaesthetic controls who were asked to associate colours with letters and digits. Based on these findings, we suggest that the development of lexical-colour synaesthesia in many cases incorporates early learning experiences common to all individuals. Moreover, many of our synaesthetes experienced colours only for days of the week, letters or digits, suggesting that inducers that are part of a conventional sequence (e.g. Monday, Tuesday, Wednesday...; A, B, C...; 1, 2, 3...) may be particularly important in the development of synaesthetic inducer-colour pairs. We speculate that the learning of such sequences during an early critical period determines the particular pattern of lexical-colour links, and that this pattern then generalises to other words.
Synesthesia is an unusual condition in which stimulation of one modality evokes sensation or experience in another modality. Although discussed in the literature well over a century ago, synesthesia slipped out of the scientific spotlight for decades because of the difficulty in verifying and quantifying private perceptual experiences. In recent years, the study of synesthesia has enjoyed a renaissance due to the introduction of tests that demonstrate the reality of the condition, its automatic and involuntary nature, and its measurable perceptual consequences. However, while several research groups now study synesthesia, there is no single protocol for comparing, contrasting and pooling synesthetic subjects across these groups. There is no standard battery of tests, no quantifiable scoring system, and no standard phrasing of questions. Additionally, the tests that exist offer no means for data comparison. To remedy this deficit we have devised the Synesthesia Battery. This unified collection of tests is freely accessible online (http://www.synesthete.org). It consists of a questionnaire and several online software programs, and test results are immediately available for use by synesthetes and invited researchers. Performance on the tests is quantified with a standard scoring system. We introduce several novel tests here, and offer the software for running the tests. By presenting standardized procedures for testing and comparing subjects, this endeavor hopes to speed scientific progress in synesthesia research.
The authors studied the self-rated effect of dreams on creativity in participants who were not selected for creative abilities. Students (N = 444) and online respondents (N = 636) answered a questionnaire about dreams and creative dreams. In addition, the students completed several personality measures and creativity scales. Results indicated that dreams that stimulated waking-life creativity played a considerable role in the lives of ordinary people (about 8% of all dreams). Examples reported by the online participants fell into 4 categories: (a) dream images used for art, work, or similar areas; (b) dreams that solved a problem; (c) dreams that provided the impetus to do something that the dreamer otherwise had difficulty doing; and (d) dreams containing emotional insights. The main factors influencing frequency of creative dreams were dream recall frequency and the thin boundaries personality dimension. Future researchers should use diary techniques to study the effects of dreams on waking life and should develop techniques to increase the frequency of creative dreams that might be valuable as aids for people in creative jobs.