Dream recall and visual memory

Targeted dream incubation at sleep onset increases post-sleep creative performance

The link between dreams and creativity has been a topic of intense speculation. Recent scientific findings suggest that sleep onset (known as N1) may be an ideal brain state for creative ideation. However, the specific link between N1 dream content and creativity has remained unclear. To investigate the contribution of N1 dream content to creative performance, we administered targeted dream incubation (a protocol that presents auditory cues at sleep onset to introduce specific themes into dreams) and collected dream reports to measure incorporation of the selected theme into dream content. We then assessed creative performance using a set of three theme-related creativity tasks. Our findings show enhanced creative performance and greater semantic distance in task responses following a period of N1 sleep as compared to wake, corroborating recent work identifying N1 as a creative sweet spot and offering novel evidence for N1 enabling a cognitive state with greater associative divergence. We further demonstrate that successful N1 dream incubation enhances creative performance more than N1 sleep alone. To our knowledge, this is the first controlled experiment investigating a direct role of incubating dream content in the enhancement of creative performance.

The route to recall a dream: theoretical considerations and methodological implications

The goal of this paper is to shed new light on the relation between dream recall and dream experiences by providing a thorough analysis of the process that leads to dream reports. Three crucial steps of this process will be distinguished: dream production (the generation of a conscious experience during sleep), dream encoding (storing a trace of this experience in memory) and dream retrieval (accessing the memory trace upon awakening). The first part of the paper will assess how major theories think about the relationship between dream reports and these distinct steps. The second part will systematise how trait and state factors affecting dream recall-given different theoretical assumptions-might interact with dream production, encoding and retrieval. Understanding how the distinct steps of dream recall can be modulated by different factors is crucial for getting a better grip on how to acquire information about these steps empirically and for drawing methodological conclusions with regard to the tools dream research relies on to collect subjective data about dream experiences. The third part of the paper will analyse how laboratory reports, logs and retrospective scales interact with the different factors that affect the distinct steps leading to dream reports and will argue that prospective methods provide more direct access to data regarding dream production and encoding than retrospective methods, which-due to their inability to provide systematic control over the factors affecting the retrieval stage-screen-off the variability in the production and the encoding of dreams.

Dream recall frequency is associated with attention rather than with working memory abilities

Several factors influencing dream recall frequency (DRF) have been identified, but some remain poorly understood. One way to study DRF is to compare cognitive processes in low and high dream recallers (LR and HR). According to the arousal-retrieval model, long-term memory encoding of a dream requires wakefulness while its multisensory short-term memory is still alive. Previous studies showed contradictory results concerning short-term memory differences between LR and HR. It has also been found that extreme DRFs are associated with different electrophysiological traits related to attentional processes. However, to date, there is no evidence for attentional differences between LR and HR at the behavioural level. To further investigate attention and working memory in HR and LR, we used a newly-developed challenging paradigm called "MEMAT" (for MEMory and ATtention), which allows the study of selective attention and working memory interaction during memory encoding of non-verbal auditory stimuli. We manipulated the difficulties of the distractor to ignore and of the memory task. The performance of the two groups were not differentially impacted by working memory load. However, HR were slower and less accurate in the presence of a hard rather than easy to-ignore distractor, while LR were much less impacted by the distractor difficulty. Therefore, we show behavioural evidence towards less resistance to hard-to-ignore distractors in HR. Using a challenging task, we show for the first time, attentional differences between HR and LR at the behavioural level. The impact of auditory attention and working memory on dream recall is discussed.

Dream Recall: State or Trait Variable? Part I: Model, Theories, Methodology and Trait Factors

The aim of the present article is to carefully review the research carried out hitherto regarding factors influencing dream recall. With respect to the hypotheses explaining the variation in dream recall frequency (DRF) and a model of the dream recall process, the empirical data has been divided into two groups, trait factors and state factors. In the first part of the article the studies on the influence of trait factors are reviewed. The second part incudes data concerning state factors, new empirical data and some final conclusions. State factors such as nocturnal awakening and focusing on dreams in the morning and trait factors such as fantasy life, creativity and visual memory play a major role in explaining variability in dream recall.

Dream recall frequency: impact of prospective measures and motivational factors

Significant individual differences exist in dream recall frequency (DRF) but some variance is likely attributable to instrument choice in measuring DRF. Three hundred and fifty eight participants estimated their weekly DRF and recorded their dreams in either a narrative log (n = 165) or checklist log (n = 193) for 2-5 weeks. There was an early peak in DRF within the first week of both types of prospective logs after which DRF remained relatively stable. Although the two groups did not differ in their estimated DRF, significantly fewer dreams were reported per week on the narrative logs and only checklist logs yielded significantly higher DRF than participants' questionnaire estimates. The interactions between DRF measures did not vary across groups with low, medium or high baseline levels of DRF. Keeping a dream log does not necessarily increase DRF and narrative logs' time consuming nature can impact subjects' motivation to report all of their dreams over time.

Experimental research on dreaming: state of the art and neuropsychoanalytic perspectives

Dreaming is still a mystery of human cognition, although it has been studied experimentally for more than a century. Experimental psychology first investigated dream content and frequency. The neuroscientific approach to dreaming arose at the end of the 1950s and soon proposed a physiological substrate of dreaming: rapid eye movement sleep. Fifty years later, this hypothesis was challenged because it could not explain all of the characteristics of dream reports. Therefore, the neurophysiological correlates of dreaming are still unclear, and many questions remain unresolved. Do the representations that constitute the dream emerge randomly from the brain, or do they surface according to certain parameters? Is the organization of the dream's representations chaotic or is it determined by rules? Does dreaming have a meaning? What is/are the function(s) of dreaming? Psychoanalysis provides hypotheses to address these questions. Until now, these hypotheses have received minimal attention in cognitive neuroscience, but the recent development of neuropsychoanalysis brings new hopes of interaction between the two fields. Considering the psychoanalytical perspective in cognitive neuroscience would provide new directions and leads for dream research and would help to achieve a comprehensive understanding of dreaming. Notably, several subjective issues at the core of the psychoanalytic approach, such as the concept of personal meaning, the concept of unconscious episodic memory and the subject's history, are not addressed or considered in cognitive neuroscience. This paper argues that the focus on singularity and personal meaning in psychoanalysis is needed to successfully address these issues in cognitive neuroscience and to progress in the understanding of dreaming and the psyche.

Demographic and psychological features of déjà vu experiences in a nonclinical Japanese population

The authors investigated the frequency and correlates of déjà vu experiences in 386 healthy adult volunteers recruited from several areas in Japan. Déjà vu experiences and related experiences were evaluated using the Inventory of Déjà vu Experiences Assessment. Déjà vu experiences were observed by 294 (76.2%) of the 386 participants. Persons who experienced déjà vu were younger and more educated than persons who had not experienced it. There were no differences in the frequency of déjà vu experiences based on sex, hand preference, or area of residence. Subsequent factor analysis associated déjà vu with precognitive dreams and remembering dreams as dream- and memory-related factors rather than with the dissociation-related factors of depersonalization, derealization, jamais vu, and daydreams or with mental activity-related factors such as paranormal quality and travel frequency. Results suggest that déjà vu experiences are associated with good memory function.

The Multidimensional Dream Inventory: preliminary evidence for validity and reliability

The present study focused on the development of the Multidimensional Dream Inventory, an individual difference measure of dimensions of dreams. Items were administered to 151 college students. Consistent with expectations, results of an exploratory factor analysis of intercorrelations among items indicated a four-factor solution was appropriate. As a result, four dream-relevant scales were constructed, viz, Dream Importance, Dream Vividness, Dream Usefulness, and Dream Recall. In addition, these scales showed good internal consistency for research. Implications and uses for the Multidimensional Dream Inventory were discussed.

Autogenic training and dream recall

The present study has investigated the relationship between Autogenic Training and dream recall for 112 participants in 16 beginning courses of 10 wk. Analyses confirmed the hypothesis that learning and practicing this relaxation technique enhanced dream recall.