Several studies have suggested a link between aphantasia (reduced or absent visual mental imagery) and alexithymia (difficulty identifying and describing one's feelings, together with an externally oriented thinking style), but results and interpretations differ across studies, and no consensus has emerged. We pooled data from five independent studies (N = 1478: 147 complete aphantasics, 141 hypophantasics, 1115 typical imagers, 75 hyperphantasics) who completed the Vividness of Visual Imagery Questionnaire and the twenty-item Toronto Alexithymia Scale, and compared six candidate models, from linear and categorical baselines to several non-linear alternatives (GAM, Segmented and Floor-group models), to determine the shape of the relationship between visual imagery vividness and alexithymia, rather than assuming it in advance. The best fitting and most interpretable model (floor-group) showed that among all participants capable of some degree of visual imagery (from hypo- to hyperphantasics), alexithymia declined as visual imagery vividness increased, consistent across all three TAS-20 sub-scales. Complete aphantasics broke this linear relationship entirely: rather than showing the highest level of alexithymia, as the linear relationship would predict, their scores were lower than that of hypophantasics and did not meaningfully differ from those of typical imagers. This discontinuity, specific to the total absence of visual imagery, was corroborated by an equally well-fitting segmented model, held up across all five studies individually, and is inconsistent with prior work treating any degree of reduced imagery as equivalent. Our results support the idea that some components of alexithymia are related to the level of visual imagery vividness in people that experience visual imagery. However, in people with complete aphantasia, alexithymia levels may depend on other processes. In other words, having no visual imagery at all does not seem to be associated with increased alexithymia levels, while having very weak visual imagery does.

Working memory and attention are jointly needed in most everyday life tasks and activities. They have however mostly been studied separately. Here we investigate how auditory working memory-in a delayed-matching-to-sample task-and selective attention interact using a recently introduced paradigm (MEMAT, for MEMory and ATtention) and MEG (Magneto-encephalographic) recordings in twenty-two participants. We manipulate the difficulty of the memory task and attentional filtering. When memory task difficulty increases, accuracy decreases, CNV (Contingent Negative Variation) amplitude in anticipation of the melody to encode increases, and the decrease in alpha power during encoding and maintenance in a left fronto-temporal network is reduced. When attentional filtering difficulty increases, accuracy decreases, the amplitude of the sustained evoked response during encoding increases, whereas the differential processing of relevant and irrelevant sounds in auditory areas is less pronounced, and frontal theta power during encoding and maintenance is higher. In the left auditory cortex, we directly observe the result of the interaction between auditory memory and attention: the facilitation of relevant sound processing in the easy filtering condition reduces when the memory task difficulty increases. This pattern mirrors the observed behavioural effects: a smaller difference in accuracy between attention conditions when the memory task difficulty increases. Overall brain dynamics highlight reciprocal influences of working memory and selective attention processes, in keeping with shared cognitive resources between them.

Epilepsy impacts cognition during wakefulness. As epileptic activity is present and even augmented during sleep, epilepsy could also influence sleep-related cognitive processes. However, whether epilepsy modulates sleep-related experiences like dreaming remains poorly known. Here, we prospectively investigated the characteristics and determinants of dreaming in patients with epilepsy. Consecutive adult patients with epilepsy and no major cognitive deficit were recruited in an epilepsy outpatient clinic. They completed a questionnaire about their dreams, sleep and epilepsy over the past year. Medical data on epilepsy characteristics were gathered from the medical file. A generalised linear model was used to explore the determinants of dream recall frequency (DRF). We included 300 patients, with a mean (standard deviation [SD]) age of 40.4 (13.4) years and 51.3% female; 28.6% had more than one seizure/month, and 34.7% already had seizures during sleep. Patients recalled dreams on an average of 1.6 (1.5) days/week and 11% had one or more nightmare/week. Younger age, higher number of nocturnal awakenings, and lower seizures frequency predicted a higher DRF. In patients with focal epilepsy (65.3%), the localisation of the epileptic focus in the parieto-occipital area was negatively associated with DRF. Regarding dream content, 34.0% of patients reported having already dreamt about epilepsy. Dreams of seizures were associated with sleep-related seizures (p = 0.034) and dreams of epilepsy were associated with nightmare frequency (p = 0.004). Our results show that patients with epilepsy share several determinants of DRF (age, awakenings, role of the parieto-occipital area) with healthy subjects. In addition, epilepsy-related factors (seizure frequency, focus localisation) also impact DRF. Investigating dreams in patients with epilepsy can provide information on their epilepsy and their sleep.

Objectif L’activité épileptique étant activée par le sommeil, elle pourrait influencer les processus cognitifs associés au sommeil, comme le rêve. L’objectif de cette étude prospective était de décrire les caractéristiques des rêves des personnes souffrant d’épilepsie, et d’investiguer les facteurs, associés au sommeil et à l’épilepsie, modulant la fréquence de rappel de rêve (FRR) et le contenu des rêves. Méthodes Des patients de 18 à 65 ans souffrant d’épilepsie et sans déficit cognitif majeur ont été recrutés consécutivement à leur consultation de suivi épileptologique. Ils ont rempli un questionnaire sur leurs rêves, leur sommeil, et leur épilepsie au cours de l’année passée. Les informations concernant l’épilepsie ont été recueillies dans leur dossier médical. Un modèle linéaire généralisé a été utilisé pour explorer les déterminants de la FRR. Résultats Trois cent patients (40,4±13,4 ans, 51,3 % de femmes, 66,4 % avec une épilepsie focale, 48,3 % pharmacorésistants) ont été inclus. Parmi eux, 28,6 % faisaient plus d’une crise épileptique par mois, et 34,7 % avaient déjà présenté des crises pendant le sommeil. La FRR moyenne observée était de 1,6±1,5 rêves/semaine et 11 % des patients faisaient au moins un cauchemar/semaine. Un âge plus jeune (p<0,001), davantage de réveils nocturnes (p=0,019), et une fréquence de crises épileptique moindre (p=0,035) étaient associés à une FRR plus élevée. Chez les patients souffrant d’épilepsie focale, la localisation pariéto-occipitale du foyer épileptique était négativement associé avec la FRR (p=0,034). Concernant le contenu des rêves, 34,0 % des patients rapportaient avoir déjà rêvé d’épilepsie (crises/symptômes de crise/épilepsie en général), et les rêves de crise étaient associés au fait de faire des crises pendant le sommeil (p=0,034). Conclusion Les facteurs prédictifs positifs de la FRR tels qu’un jeune âge et des réveils nocturnes sont similaires à ceux observés dans la population générale. La FRR plus faible associée aux épilepsies pariéto-occipitales est cohérente avec le rôle critique de cette région dans la formation et/ou le rappel des rêves. De plus, la fréquence des crises d’épilepsie impacte négativement la FRR, et la thématique épileptique est incorporée dans le contenu des rêves de nombreux patients, ce qui suggère que l’épilepsie influence la cognition pendant le sommeil.

Sleep inertia refers to the transient physiological state of hypoarousal upon awakening, associated with various degrees of impaired neurobehavioral performance, confusion, a desire to return to sleep and often a negative emotional state. Scalp and intracranial electro-encephalography as well as functional imaging studies have provided evidence that the sleep inertia phenomenon is underpinned by an heterogenous cerebral state mixing local sleep and local wake patterns of activity, at the neuronal and network levels. Sleep inertia is modulated by homeostasis and circadian processes, sleep stage upon awakening, and individual factors; this translates into a huge variability in its intensity even under physiological conditions. In sleep disorders, especially in hypersomnolence disorders such as idiopathic hypersomnia, sleep inertia may be a daily, serious and long-lasting symptom leading to severe impairment. To date, few tools have been developed to assess sleep inertia in clinical practice. They include mainly questionnaires and behavioral tests such as the psychomotor vigilance task. Only one neurophysiological protocol has been evaluated in hypersomnia, the forced awakening test which is based on an event-related potentials paradigm upon awakening. This contrasts with the major functional consequences of sleep inertia and its potentially dangerous consequences in subjects required to perform safety-critical tasks soon after awakening. There is a great need to identify reproducible biomarkers correlated with sleep inertia-associated cognitive and behavioral impairment. These biomarkers will aim at better understanding and measuring sleep inertia in physiological and pathological conditions, as well as objectively evaluating wake-promoting treatments or non-pharmacological countermeasures to reduce this phenomenon.

L’ivresse de sommeil au réveil et le « brouillard mental » pendant la journée sont des symptômes fréquents et invalidants de l’hypersomnie idiopathique (HI). Leurs corrélats neurophysiologiques restent peu connus, mais pourraient impliquer la microstructure de l’éveil. Notre objectif était d’explorer la transition sommeil-veille et la veille diurne en quantifiant les micro-sommeils (MS). Quarante sujets (10 HI, 10 narcolepsies de type 1, 10 narcolepsies de type 2, et 10 hypersomnolences subjectives – CT) ayant bénéficié d’une polysomnographie ad libitum sur 24 h ont été inclus. Le sommeil a été scoré et les MS pendant la veille ont été marqués manuellement. La durée du réveil matinal spontané calculé comme le délai entre sommeil stable (10 époques contiguës de sommeil) et veille stable (10 époques contiguës de veille) et les MS dans différents intervalles suivant le réveil et pendant la veille diurne ont été comparés entre les quatre groupes (Kruskall-Wallis et test de permutation de Fisher-Pitman). La durée du réveil matinal ne différait pas entre les 4 groupes. En revanche, le nombre médian (IQR) de MS pendant les 2 premières heures post-réveil était plus élevé chez les HI que chez les CT : 16,5 (5,7–25,4) vs 3,0 (2,5–4,8), p = 0,018. L’index de MS (nb/heure) pendant toute la période de veille diurne était également plus élevé chez les HI que chez les CT : 1,7 (6,4–19,7) vs 3,0 (2,3-3,9), p = 0,043. Nos résultats suggèrent que l’analyse des micro-états pourrait permettre d’évaluer objectivement l’inertie du sommeil et l’altération de la qualité de l’éveil dans l’HI.

Understanding the complex relationship between sleep and memory consolidation is a major challenge in cognitive neuroscience and psychology. Many studies suggest that sleep triggers off-line memory processes, resulting in less forgetting of declarative memory and performance stabilization in non-declarative memory. However, the role of sleep in human memory consolidation is still under considerable debate, and numerous contradictory and non-replicable findings have been reported. Methodological issues related to experimental designs, task characteristics and measurements, and data-analysis practices all influence the effects that are observed and their interpretation. In this Perspective, we review methodological issues in sleep and memory studies and suggest constructive solutions to address them. We believe that implementing these solutions in future sleep and memory research will substantially advance the field and improve understanding of the specific role of sleep in memory consolidation. Studies of the effect of sleep on learning and memory sometimes reveal conflicting or unreliable results. In this Perspective, Nemeth and colleagues review methodological challenges and make recommendations for improving the reliability of research in this field.

Objective: Early functional evaluation and prognosis of patients with disorders of consciousness is a major challenge that clinical assessments alone cannot solve. Objective measures of brain activity could help resolve this uncertainty. We used electroencephalogram at bedside to detect voluntary attention with a paradigm previously validated in healthy subjects. Methods: Using auditory-oddball sequences, our approach rests on detecting known attentional modulations of Event Related Potentials that reflect compliance with verbal instructions. Sixty-eight unresponsive patients were tested in their first year after coma onset (37 coma and 31 first year post-coma patients). Their evolution 6 months after the test was considered. Results: Fourteen of the 68 patients, showed a positive response. Nine were in a coma and 5 in a minimally conscious state (MCS). Except for one who died early, all responders evolved to exit-MCS within 6 months (93%), while 35 (65%) among non-responders only. Conclusions: Among those patients for whom the outcome is highly uncertain, 21% responded positively to this simple but cognitively demanding test. Strikingly, some coma patients were among responders. Significance: The proposed paradigm revealed cognitive-motor dissociation in some coma patients. This ability to sustain attention on demand predicted awakening within 6 months and represents an immediately useful information for relatives and caregivers. (c) 2022 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Même s’il est très difficile d’étudier les rêves des enfants de manière expérimentale, les études réalisées suggèrent que le rêve se développe en parallèle des capacités cognitives, et notamment des aptitudes visuo-spatiales et de symbolisation. Les récits de rêve des petits sont courts et simples et se complexifient et s’allongent quand ils grandissent. Le contenu des rêves montre typiquement des éléments de la vie vécue, et les préoccupations notamment émotionnelles. La fréquence de cauchemars la plus élevée est observée chez les 5-10 ans, elle diminue ensuite et se stabilise à des valeurs basses à l’âge adulte (moins d’un par mois). En termes de fonction, les résultats chez l’enfant et chez l’adulte suggèrent que le rêve participe à la régulation émotionnelle et que l’activité onirique aboutit à une diminution de l’intensité émotionnelle des souvenirs. La recherche expérimentale sur le rêve converge donc vers les pratiques et conclusions de la psychologie clinique qui voit dans le rêve un outil utile pour la thérapie.

La discordance entre perception subjective du sommeil et enregistrements objectifs est fréquente. Elle reposerait sur la présence de micro-états (micro-éveils ou micro-sommeils). L’objectif est d’identifier les déterminants de la perception du sommeil dans les hypersomnies centrales en analysant la microstructure du sommeil. Nous avons analysé les tests itératifs de latence d’endormissement (TILE) de patients présentant une narcolepsie de type 1 (NT1, n = 17), de type 2 (NT2, n = 16), une hypersomnie idiopathique (HSI, n = 17) ou une hypersomnolence subjective (CT, n = 22). Les sujets étaient interrogés sur leur perception du sommeil à la fin des tests. La macrostructure du sommeil était codée selon les recommandations de l’AASM et la microstructure en continu au travers des époques. La perception du sommeil a été comparée entre les groupes, et des modèles linéaires généralisés ont été appliqués sur différentes variables de structure du sommeil pour prédire la perception du sommeil. Nous avons analysé 232 TILE. Les patients NT1, NT2 et HSI percevaient mieux leur sommeil que les CT. Les paramètres les mieux corrélés à la perception du sommeil étaient la durée de sommeil ininterrompu par des micro-éveils (seuil de perception à 75 % atteint pour 4 minutes de ce sommeil) et la présence de sommeil paradoxal. La durée du sommeil, sa continuité et la présence de sommeil paradoxal sont associées à la perception subjective d’avoir dormi, expliquant potentiellement une meilleure perception dans les hypersomnies centrales.

Working memory and attention are jointly needed in most everyday life tasks and activities. They have however mostly been studied separately. Here we investigate how auditory working memory and selective attention interact using a recently introduced paradigm (MEMAT) that combines a classic working memory paradigm, the delayed-matching-to-sample task, and selective attention, with distractors presented during the encoding phase. All stimuli are four-tone melodies. Twenty-two participants performed the MEMAT task during MEG recordings. We manipulate the difficulty of the memory task and of attentional filtering. When memory task difficulty increases , the amplitude of the CNV in anticipation of the melody to encode increases and the decrease in alpha power during encoding and maintenance in a left fronto-temporal network is reduced. When attentional filtering difficulty increases , the amplitude of the sustained evoked response during encoding increases, whereas the differential processing of relevant and irrelevant sounds in auditory areas is less pronounced, and frontal theta power during encoding and maintenance is higher. In the left auditory cortex, we could directly observe the result of the interaction between auditory memory and attention: the facilitation of relevant sound processing in the easy filtering condition was reduced when the memory task difficulty increased. This pattern mirrors the observed behavioral effects. Overall brain dynamics highlight reciprocal influences of working memory and selective attention processes, in keeping with shared cognitive resources between them.

Understanding the complex relationship between sleep and memory is a major challenge in neuroscience. Many studies on memory consolidation in humans suggest that sleep triggers offline memory processes, resulting in less forgetting of declarative memory and performance stabilization in non-declarative memory. However, an increasing number of contradictory findings reveal potential issues with how research is conducted in this field and call into question the reliability and interpretation of the results. All scientific disciplines face similar challenges. In this regard, research on the relationship between sleep and memory is still very fortunate. Yet, there is a constant need to fine-tune the methodology. In this article, we describe four behavioral methodological issues in human sleep and memory research that should be improved: non-optimal experimental designs, task complexity, fatigue effects in repetitive tasks, and inappropriate data analysis practices. We then offer solutions to each of these issues. We believe that implementing these solutions in future sleep and memory research will lead to more reliable results and significantly advance our understanding in this field.

Introduction Several results suggest that the frequency of dream recall is positively correlated with personality traits such as creativity and openness to experience. In addition, neuroimaging results have evidenced different neurophysiological profiles in high dream recallers (HR) and low dream recallers (LR) during both sleep and wakefulness, specifically within regions of the default mode network (DMN). These findings are consistent with the emerging view that dreaming and mind wandering pertain to the same family of spontaneous mental processes, subserved by the DMN. Methods To further test this hypothesis, we measured the DMN functional connectivity during resting wakefulness, together with personality and cognitive abilities (including creativity) in 28 HR and 27 LR. Results As expected, HR demonstrated a greater DMN connectivity than LR, higher scores of creativity, and no significant difference in memory abilities. However, there was no significant correlation between creativity scores and DMN connectivity. Discussion These results further demonstrate that there are trait neurophysiological and psychological differences between individuals who frequently recall their dreams and those who do not. They support the forebrain and the DMN hypotheses of dreaming and leave open the possibility that increased activity in the DMN promotes creative-thinking during both wakefulness and sleep. Further work is needed to test whether activity in the DMN is causally associated with creative-thinking.

Event-related potentials (ERPs) associated with the involuntary orientation of (bottom-up) attention toward an unexpected sound are of larger amplitude in high dream recallers (HR) than in low dream recallers (LR) during passive listening, suggesting different attentional functioning. We measured bottom-up and top-down attentional performance and their cerebral correlates in 18 HR (11 women, age = 22.7 years, dream recall frequency = 5.3 days with a dream recall per week) and 19 LR (10 women, age = 22.3, DRF = 0.2) using EEG and the Competitive Attention Task. Between-group differences were found in ERPs but not in behavior. The results show that HR present larger ERPs to distracting sounds than LR even during active listening, arguing for enhanced bottom-up processing of irrelevant sounds. HR also presented larger contingent negative variation during target expectancy and P3b to target sounds than LR, speaking for an enhanced recruitment of top-down attention. The attentional balance seems preserved in HR since their performances are not altered, but possibly at a higher resource cost. In HR, increased bottom-up processes would favor dream recall through awakening facilitation during sleep and enhanced top-down processes may foster dream recall through increased awareness and/or short-term memory stability of dream content.

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.

Abstract Introduction During the COVID-19 pandemic, individuals have faced unprecedented events, which are often stressful. Stress has an important impact on dreams, and stress-induced sleep difficulties may also impact dream recall. The present study evaluated associations between sleep, stress and dream content on dream recall during the pandemic. Methods A sample of N=419 US adults completed online surveys about sleep and COVID-19 experiences. Participants were asked if they remember more, fewer or about the same amount of dreams as before the pandemic. They were also asked whether the pandemic was associated with more stress, a more regular schedule, improved sleep, worse sleep, more early insomnia, more middle-of-the-night insomnia, more sleepiness, and more naps. They also completed the Insomnia Severity Index, Fatigue Severity Scale, Epworth Sleepiness Scale, Brief Index of Sleep Control, Assessment of Sleep Environment, GAD-7 anxiety scale, and PHQ9 depression scale. Multinomial logistic regressions examined correlates of increased or decreased recall (versus same), adjusted for age, sex, and race/ethnicity. Results Those who experienced greater schedule regularity were less likely to report decreased recall (RRR=0.50,p<0.0005), as were those who reported sleep improvement (RRR=0.48,p=0.006). Those whose sleep worsened were more likely to report both increased (RRR=1.64,p=0.003) and decreased (RRR=2.16,p<0.0005) recall. Those suffering maintenance insomnia were more likely to report both increased (RRR=1.70,p=0.001) and decreased (RRR=2.68,p<0.0005) recall, as did those who reported more daytime sleepiness (Increased RRR=1.57,p=0.006; Decreased RRR=1.94,p=0.001). Those whose dream content was more negative were more likely to report both increased (RRR=4.05,p<0.005) and decreased (RRR=3.35,p<0.0005) recall, as did those who reported less negative content (Increased RRR=4.20,p<0.0005; Decreased RRR=5.05,p<0.0005). Similarly, those who reported more positive dream content reported both increased (RRR=17.37,p<0.0005) and decreased (RRR=7.14,p=0.02) recall, as did those who reported less positive content (Increased RRR=4.49,p<0.0005; Decreased RRR=5.59,p<0.0005). Less recall was associated with greater insomnia severity (RRR=1.08,p=0.001), fatigue (RRR=1.04,p=0.001), sleepiness (RRR=1.09,p=0.01), COVID stress (RRR=1.67,p=0.03), anxiety (RRR=1.08,p=0.01), and depression (RRR=1.06,p=0.007), worse sleep environment (RRR=1.06,p=0.005), and less sleep control (RRR=0.56,p=0.001). Conclusion The results of this survey suggest that a sudden decrease in dream recall in reaction to a new stress could be considered as a pejorative indicator regarding sleep quality and mental health. Support (if any) R01MD011600, R01DA051321

The interactions between epilepsy and sleep are numerous and the impact of epilepsy on cognition is well documented. Epilepsy is therefore likely to influence dreaming as one sleep-related cognitive activity. The frequency of dream recall is indeed decreased in patients with epilepsy, especially in those with primary generalized seizures. The content of dreams is also disturbed in epilepsy patients, being more negative and with more familiar settings. While several confounding factors (anti-seizure medications, depression and anxiety disorders, cognitive impairment) may partly account for these changes, some observations suggest an effect of seizures themselves on dreams. Indeed, the incorporation of seizure symptoms in dream content has been described, concomitant or not with a focal epileptic discharge during sleep, suggesting that epilepsy might directly or indirectly interfere with dreaming. These observations, together with current knowledge on dream neurophysiology and the links between epilepsy and sleep, suggest that epilepsy may impact not only wake- but also sleep-related cognition.

Understanding the complex relationship between sleep and memory is a major challenge in neuroscience. Thousands of studies on memory consolidation in humans suggest that sleep triggers offline memory processes, resulting in less forgetting of declarative memory and performance stabilization in non-declarative memory. However, an increasing number of contradictory findings reveal potential issues with how research is conducted in this field and call into question the reliability and interpretation of the results. In this consensus paper, we describe four sets of prevalent methodological pitfalls in human sleep and memory research: (i) non-optimal experimental designs, (ii) task complexity, (iii) fatigue effects in repetitive tasks, and (iv) inappropriate data analysis practices. We then offer solutions to each of these pitfalls. We believe that implementing these solutions in future research of sleep and memory will lead to more reliable results and significantly advance our understanding in this field.

Abstract Introduction In 2020, a global pandemic impacted sleep for many people in the US, which was also experiencing an extremely contentious election season. These overlapped somewhat, as the liberal/left side of the political spectrum was more vocal about the dangers of COVID-19 and the pandemic, while the conservative/right frequently expressed less concern about COVID-related risks. Perhaps this confluence was borne out in sleep quality and dreams. Methods A sample of N=419 US adults completed online surveys about sleep and COVID-19 experiences. Participants rated their political affiliation on a scale of 0 (Very Conservative/Right) to 6 (Very Liberal/Left). Participants were also asked whether, since the pandemic, their sleep improved or worsened, whether their dream content has become more positive (more or less positive content, versus same) or negative (more or less negative content, versus same), the number of nightmares they recall, and whether their dreams included themes of politics and/or COVID. Regression analyses examined political affiliation as independent variable with ordinal logistic analyses for sleep improvement/worsening, multinomial logistic analyses for positive/negative content, linear regression analyses for nightmare frequency, and binary logistic analyses for presence of political/COVID themes in dreams. All analyses were adjusted for age, sex, and race/ethnicity. Results Greater liberal/left affiliation was associated with a greater likelihood of worsened sleep (oOR=1.20, p=0.002), but no difference in likelihood of sleep improvement. Greater liberal/left affiliation was associated with a greater likelihood of decreased positive dream content (RRR=1.29, p=0.001) but no different in likelihood of increased positive content. In addition, greater liberal/left affiliation was associated with an increased likelihood of more negative dream content (RRR=1.33, p<0.0005) but no difference in the experience of less negative content. Liberal/left affiliation was also associated with more frequent nightmares during the pandemic (B=1.55, p=0.019), and more political dreams (OR=1.29, p=0.010) but no difference in COVID-related dreams. Conclusion During the COVID-19 pandemic, more liberal/left individuals reported a greater degree of worsening sleep and dream content that was less positive and more negative in nature. Though there was no difference in COVID-related dream content, there was a difference in political content in dreams. Support (if any) None