The Relationship Between Dreams and Subsequent Morning Mood Using Self-Reports and Text Analysis.

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 mood were highly correlated within participants for both negative and positive valence, suggesting that dream mood persists into waking. Text analyses revealed similar relationships between affect words in dreams and morning mood. Moreover, dreams referencing death or the body were related to worse morning mood, as was first-person singular pronoun usage (e.g., "I"). Dreams referencing leisure or ingestion, or including first-person plural pronouns (e.g., "we"), were related to better morning mood. Together, these results suggest that subjective experiences during sleep, while often overlooked, may be an important contributor to waking mood. Supplementary Information: The online version contains supplementary material available at 10.1007/s42761-021-00080-8.

Working Memory Swap Errors Have Identifiable Neural Representations.

Working memory is an essential component of cognition that facilitates goal-directed behavior. Famously, it is severely limited and performance suffers when memory load exceeds an individual's capacity. Modeling of visual working memory responses has identified two likely types of errors: guesses and swaps. Swap errors may arise from a misbinding between the features of different items. Alternatively, these errors could arise from memory noise in the feature dimension used for cueing a to-be-tested memory item, resulting in the wrong item being selected. Finally, it is possible that so-called swap errors actually reflect informed guessing, which could occur at the time of a cue, or alternatively, at the time of the response. Here, we combined behavioral response modeling and fMRI pattern analysis to test the hypothesis that swap errors involve the active maintenance of an incorrect memory item. After the encoding of six spatial locations, a retro-cue indicated which location would be tested after memory retention. On accurate trials, we could reconstruct a memory representation of the cued location in both early visual cortex and intraparietal sulcus. On swap error trials identified with mixture modeling, we were able to reconstruct a representation of the swapped location, but not of the cued location, suggesting the maintenance of the incorrect memory item before response. Moreover, participants subjectively responded with some level of confidence, rather than complete guessing, on a majority of swap error trials. Together, these results suggest that swap errors are not mere response-phase guesses, but instead result from failures of selection in working memory, contextual binding errors, or informed guesses, which produce active maintenance of incorrect memory representations.

Benefits and concerns of seeking and experiencing lucid dreams: benefits are tied to successful induction and dream control.

Therapies focused on lucid dreaming could be useful for treating various sleep disorders and other conditions. Still, one major roadblock is the paucity of systematic information on the consequences of attempting these sorts of dreams. The current study sought to quantify positive and negative aspects of seeking lucid dreams, describe their phenomenology in detail, and identify features associated with positive or negative experiences. Observational data from a massive lucid-dream discussion forum were analyzed to capture lucid-dreaming themes. Forum posts were independently rated on multiple dimensions hypothesized to contribute to the valence of lucidity-related phenomena. Our results revealed that lucid dreams can end nightmares and prevent their recurrence, but they can also induce harrowing dysphoric dreams. The realization of dreaming (lucidity) and dreams with high-control were both associated with positive experiences. We translated our results into a process model that describes the progression from lucid dream induction to waking benefit, identifying potential areas of concern. Our results and model suggest that negative outcomes primarily result from failed induction attempts or lucid dreams with low dream control, and that successfully inducing high-control lucid dreams poses low risk for negative outcomes. Lucid dreaming has valuable therapeutic and recreational potential, but a better understanding of the risks is required. Our findings provide new insights into possible negative repercussions and how to avoid them in future applications.

Real-time dialogue between experimenters and dreamers during REM sleep.

Dreams take us to a different reality, a hallucinatory world that feels as real as any waking experience. These often-bizarre episodes are emblematic of human sleep but have yet to be adequately explained. Retrospective dream reports are subject to distortion and forgetting, presenting a fundamental challenge for neuroscientific studies of dreaming. Here we show that individuals who are asleep and in the midst of a lucid dream (aware of the fact that they are currently dreaming) can perceive questions from an experimenter and provide answers using electrophysiological signals. We implemented our procedures for two-way communication during polysomnographically verified rapid-eye-movement (REM) sleep in 36 individuals. Some had minimal prior experience with lucid dreaming, others were frequent lucid dreamers, and one was a patient with narcolepsy who had frequent lucid dreams. During REM sleep, these individuals exhibited various capabilities, including performing veridical perceptual analysis of novel information, maintaining information in working memory, computing simple answers, and expressing volitional replies. Their responses included distinctive eye movements and selective facial muscle contractions, constituting correctly answered questions on 29 occasions across 6 of the individuals tested. These repeated observations of interactive dreaming, documented by four independent laboratory groups, demonstrate that phenomenological and cognitive characteristics of dreaming can be interrogated in real time. This relatively unexplored communication channel can enable a variety of practical applications and a new strategy for the empirical exploration of dreams.

Distraction in Visual Working Memory: Resistance is Not Futile.

Over half a century of research focused on understanding how working memory is capacity constrained has overshadowed the fact that it is also remarkably resistant to interference. Protecting goal-relevant information from distraction is a cornerstone of cognitive function that involves a multifaceted collection of control processes and storage mechanisms. Here, we discuss recent advances in cognitive psychology and neuroscience that have produced new insights into the nature of visual working memory and its ability to resist distraction. We propose that distraction resistance should be an explicit component in any model of working memory and that understanding its behavioral and neural correlates is essential for building a comprehensive understanding of real-world memory function.

Partial memory reinstatement while (lucid) dreaming to change the dream environment.

Lucid dreams often coincide with having control over dream events in real-time, although the limitations of dream control are not completely understood. The current study probed the ability of lucid dreamers to reinstate waking scene memories while dreaming. After brief exposure to an experimental scene, participants were asked to reinstate the scene while lucid dreaming (i.e., change dream scenery to match real-world scene). Qualitative analysis revealed that successful dream scene reinstatements were overwhelmingly inaccurate with respect to the original experimental scene. Importantly, reinstatement inaccuracies held even when the dreamer was aware of them during the dream, suggesting a dissociation between memory access while dreaming and dream imagery. The ability to change the environment of a dream speaks to the high amount of lucid dream control, yet the inaccuracies speak to a lack of detailed control. Reinstating context during lucid sleep offers an experimental method to investigate sleep, dreams, and memory.

Dream lucidity is associated with positive waking mood.

Lucid dreaming is a unique phenomenon with potential applications for therapeutic interventions. Few studies have investigated the effects of lucidity on an individual's waking mood, which could have valuable implications for improving psychological wellbeing. The current experiment aims to investigate whether the experience of lucidity enhances positive waking mood, and whether lucidity is associated with dream emotional content and subjective sleep quality. 20 participants were asked to complete lucid dream induction techniques along with an online dream diary for one week, which featured a 19-item lucidity questionnaire, and subjective ratings of sleep quality, dream emotional content, and waking mood. Results indicated that higher lucidity was associated with more positive dream content and elevated positive waking mood the next day, although there was no relationship with sleep quality. The results of the research and suggestions for future investigations, such as the need for longitudinal studies of lucidity and mood, are discussed.

Distraction biases working memory for faces.

Working memory persists in the face of distraction, yet not without consequence. Previous research has shown that memory for low-level visual features is systematically influenced by the maintenance or presentation of a similar distractor stimulus. Responses are frequently biased in stimulus space towards a perceptual distractor, though this has yet to be determined for high-level stimuli. We investigated whether these influences are shared for complex visual stimuli such as faces. To quantify response accuracies for these stimuli, we used a delayed-estimation task with a computer-generated "face space" consisting of 80 faces that varied continuously as a function of age and sex. In a set of three experiments, we found that responses for a target face held in working memory were biased towards a distractor face presented during the maintenance period. The amount of response bias did not vary as a function of distance between target and distractor. Our data suggest that, similar to low-level visual features, high-level face representations in working memory are biased by the processing of related but task-irrelevant information.

Functional Connectivity Fingerprints at Rest Are Similar across Youths and Adults and Vary with Genetic Similarity.

Distinguishing individuals from brain connectivity, and studying the genetic influences on that identification across different ages, improves our basic understanding of functional brain network organization. We applied support vector machine classifiers to two datasets of twins (adult, pediatric) and two datasets of repeat-scan individuals (adult, pediatric). Classifiers were trained on resting state functional connectivity magnetic resonance imaging (rs-fcMRI) data and used to predict individuals and co-twin pairs from independent data. The classifiers successfully identified individuals from a previous scan with 100% accuracy, even when scans were separated by months. In twin samples, classifier accuracy decreased as genetic similarity decreased. Our results demonstrate that classification is stable within individuals, similar within families, and contains similar representations of functional connections over a few decades of life. Moreover, the degree to which these patterns of connections predict siblings' data varied by genetic relatedness, suggesting that genetic influences on rs-fcMRI connectivity are established early in life.

Working memory prioritization impacts neural recovery from distraction.

The ability to protect goal-relevant information from disruption over short intervals is a hallmark of working memory. Recent behavioral data suggest that high-priority items in working memory are more vulnerable to disruption. We used functional magnetic resonance imaging to evaluate the hypothesis that prioritization of working memories might impact the recovery of their neural representation(s) after distraction. A delay-period retrospective cue informed participants which of two memory items (a face or a scene) to prioritize during a first delay period. Consistent with prior work, and confirming successful prioritization, multivoxel pattern classifier evidence in perceptual brain regions was higher for cued versus uncued memory items. A distraction task was then imposed before a second retrospective cue informed participants to either "stay" remembering the previously cued item or "switch" to the previously uncued item. This allowed for the evaluation of recovery for high-priority items (on stay trials) and also low-priority items (on switch trials). Classifiers showed successful reinstatement of both high- and low-priority items after distraction, but only low-priority items recovered to their pre-distraction representational levels. Moreover, the degree of prioritization before distraction predicted the amount of disruption for high-priority items after distraction, suggesting that the more a participant prioritized the cued item, the greater the impact of distraction. Our data provide neural evidence that prioritizing working memory information in perceptual regions makes that information more vulnerable to disruption.

Behavioral decoding of working memory items inside and outside the focus of attention.

How we attend to our thoughts affects how we attend to our environment. Holding information in working memory can automatically bias visual attention toward matching information. By observing attentional biases on reaction times to visual search during a memory delay, it is possible to reconstruct the source of that bias using machine learning techniques and thereby behaviorally decode the content of working memory. Can this be done when more than one item is held in working memory? There is some evidence that multiple items can simultaneously bias attention, but the effects have been inconsistent. One explanation may be that items are stored in different states depending on the current task demands. Recent models propose functionally distinct states of representation for items inside versus outside the focus of attention. Here, we use behavioral decoding to evaluate whether multiple memory items-including temporarily irrelevant items outside the focus of attention-exert biases on visual attention. Only the single item in the focus of attention was decodable. The other item showed a brief attentional bias that dissipated until it returned to the focus of attention. These results support the idea of dynamic, flexible states of working memory across time and priority.