Wakeful Rest Research Articles

Wakeful rest benefits before and after encoding in anterograde amnesia.

Objective: Studies have shown that patients with anterograde amnesia forget less episodic information after a delay if encoding is immediately followed by an unfilled period of wakeful rest. This benefit has been attributed to the reduced interference with the consolidation process. However, this account cannot directly explain improved retention in healthy adults resulting from pre-encoding rest. While benefits resulting from pre- and post-encoding rest can be alternatively explained via improved distinctiveness at retrieval, it has yet to be established whether both benefits are observable in amnesics. The aim of the current study was to assess whether amnesic patients showed improved retention of prose material after 10 min following both pre- and post-encoding unfilled intervals of wakeful rest. Method: Twelve patients with anterograde amnesia were recruited. Participants completed four conditions. A short prose passage was aurally presented in each condition. Prose presentation was preceded and followed by a 9-min delay interval. Delay intervals were either filled (spot-the-difference task) or unfilled (wakeful rest). Prose retention was assessed immediately after presentation and after 10 min. Results: Prose retention was consistently better when wakeful rest followed prose encoding in comparison to a condition where an effortful task was encountered both before and after encoding. Conclusions: Post-encoding wakeful rest alone substantially improves retention in amnesic patients. While pre-encoding wakeful rest elicits inconsistent benefits in amnesics, reduced retention following both pre- and post-encoding task engagement suggests that pre-encoding activity may still be relevant. Overall, our findings support consolidation interference explanations of forgetting in anterograde amnesia. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Functional imaging evidence for task-induced deactivation and disconnection of a major default mode network hub in the mouse brain

The default mode network (DMN) has been defined in functional brain imaging studies as a set of highly connected brain areas, which are active during wakeful rest and inactivated during task-based stimulation. DMN function is characteristically impaired in major neuropsychiatric diseases, emphasizing its interest for translational research. However, in the mouse, a major preclinical rodent model, there is still no functional imaging evidence supporting DMN deactivation and deconnection during high-demanding cognitive/sensory tasks. Here we have developed functional ultrasound (fUS) imaging to properly visualize both activation levels and functional connectivity patterns, in head-restrained awake and behaving mice, and investigated their modulation during a sensory-task, whisker stimulation. We identified reproducible and highly symmetric resting-state networks, with overall connectivity strength directly proportional to the wakefulness level of the animal. We show that unilateral whisker stimulation leads to the expected activation of the contralateral barrel cortex in lightly sedated mice, while interhemispheric inhibition reduces activity in the ipsilateral barrel cortex. Whisker stimulation also leads to elevated bilateral connectivity in the hippocampus. Importantly, in addition to functional changes in these major hubs of tactile information processing, whisker stimulation during genuine awake resting-state periods leads to highly specific reductions both in activation and interhemispheric correlation within the restrosplenial cortex, a major hub of the DMN. These results validate an imaging technique for the study of activation and connectivity in the lightly sedated awake mouse brain and provide evidence supporting an evolutionary preserved function of the DMN, putatively improving translational relevance of preclinical models of neuropsychiatric diseases.

The claustrum coordinates cortical slow-wave activity.

During sleep and awake rest, the neocortex generates large-scale slow-wave (SW) activity. Here, we report that the claustrum coordinates neocortical SW generation. We established a transgenic mouse line that enabled the genetic interrogation of a subpopulation of claustral glutamatergic neurons. These neurons received inputs from and sent outputs to widespread neocortical areas. The claustral neuronal firings mostly correlated with cortical SW activity. In vitro optogenetic stimulation of the claustrum induced excitatory postsynaptic responses in most neocortical neurons, but elicited action potentials primarily in inhibitory interneurons. In vivo optogenetic stimulation induced a synchronized down-state featuring prolonged silencing of neural activity in all layers of many cortical areas, followed by a down-to-up state transition. In contrast, genetic ablation of claustral neurons attenuated SW activity in the frontal cortex. These results demonstrate a crucial role of claustral neurons in synchronizing inhibitory interneurons across wide cortical areas for the spatiotemporal coordination of SW activity.

Is Resting-State EEG Longitudinally Associated With Recovery of Clinical Neurological Impairments Early Poststroke? A Prospective Cohort Study

Background. The time course of cortical activation and its relation with clinical measures may elucidate mechanisms underlying spontaneous neurobiological recovery after stroke. Objective. We aimed to investigate (1) the time course of cortical activation as revealed by EEG-based spectral characteristics during awake rest and (2) the development of these spectral characteristics in relation to global neurological and upper-limb motor recovery in the first 6 months poststroke. Methods. Resting-state EEG was measured serially in 41 patients after a first-ever ischemic stroke, within 3 and at 5, 12, and 26 weeks poststroke. We computed the brain symmetry index (BSI) and directional BSI (BSIdir) over different frequency bands (1-25 Hz, delta, theta) and delta/alpha ratio (DAR). The National Institutes of Health Stroke Scale (NIHSS) and Fugl-Meyer motor assessment of the upper extremity (FM-UE) were determined as clinical reflections of spontaneous neurobiological recovery. Longitudinal changes in spectral characteristics and within- and between-subject associations with NIHSS and FM-UE were analyzed with linear mixed models. Results. Spectral characteristics showed a gradual normalization over time, within and beyond 12 weeks poststroke. Significant within- and between-subject associations with NIHSS were found for DAR of the affected hemisphere (DARAH) and BSIdirdelta. BSIdirdelta also demonstrated significant within- and between-subject associations with FM-UE. Conclusions. Changes in spectral characteristics are not restricted to the time window of recovery of clinical neurological impairments. The present study suggests that decreasing DARAH and BSIdirdelta reflect improvement of global neurological impairments, whereas BSIdirdelta was also specifically associated with upper-limb motor recovery early poststroke.

Effects of wakeful resting versus social media usage after learning on the retention of new memories

SummaryCommunication and information sharing via social media platforms is a common and popular activity. The majority of existing studies indicate that social media usage has detrimental effects on learning and memory. However, it is an open question as to whether social media usage affects memory even after learning. To test this, healthy young adults learned and immediately recalled a vocabulary list. Subsequent to recall, participants either wakefully rested for 8 min or used social media for 8 min. A delayed recall test took place after the wakeful resting condition and the social media condition and again after 1 day. Our results showed that social media usage, compared with wakeful resting, had detrimental effects on memory performance over both retention intervals. We assume that social media usage interfered with memory consolidation of learned vocabularies and suggest that learners opt for wakeful resting over social media usage as a learning‐break activity.

Comparing the Effects of Sleep and Rest on Memory Consolidation.

IntroductionThere is ample evidence that overnight sleep and daytime naps benefit memory retention, compared to comparable amounts of active wakefulness. Yet recent evidence also suggests that a period of post-training rest (eg, quiet wakefulness with eyes closed) provides a similar memory benefit compared to wake. However, the relative benefits of sleep vs quiet waking rest on memory remain poorly understood. Here, we assessed the extent to which sleep provides a unique memory benefit, above and beyond that conferred by quiet waking rest.MethodsIn a sample of healthy undergraduate students (N=83), we tested the effect of 30 mins of post-learning sleep, rest, or active wake on concept learning (dot pattern classification) and declarative memory (word pair associates) across a 4-hr daytime training-retest interval.Results and ConclusionsContrary to our hypotheses, we found no differences in performance between the three conditions for either task. The findings are interpreted with reference to methodological considerations including the length of the experimental interval, the nature of the tasks used, and challenges inherent in creating experimental conditions that can be executed by participants.

Electrophysiological dynamics of antagonistic brain networks reflect attentional fluctuations

Neuroimaging evidence suggests that the default mode network (DMN) exhibits antagonistic activity with dorsal attention (DAN) and salience (SN) networks. Here we use human intracranial electroencephalography to investigate the behavioral relevance of fine-grained dynamics within and between these networks. The three networks show dissociable profiles of task-evoked electrophysiological activity, best captured in the high-frequency broadband (HFB; 70–170 Hz) range. On the order of hundreds of milliseconds, HFB responses peak fastest in the DAN, at intermediate speed in the SN, and slowest in the DMN. Lapses of attention (behavioral errors) are marked by distinguishable patterns of both pre- and post-stimulus HFB activity within each network. Moreover, the magnitude of temporally lagged, negative HFB coupling between the DAN and DMN (but not SN and DMN) is associated with greater sustained attention performance and is reduced during wakeful rest. These findings underscore the behavioral relevance of temporally delayed coordination between antagonistic brain networks.

Info-Relational Cognitive Operability of the Posterior Cingulate Cortex According to the Informational Model of Consciousness

Based on the analysis of the accumulated experimental data and on the informational concepts of the Informational Model of Consciousness (IMC), in this article is presented an informational modeling of the operability of the posterior cingulate cortex (PCC). Examination of the experimental results obtained with the modern non-destructive, high spatial resolution investigation tools to study the functional characteristics of the PCC and associate metabolic processes, shows mainly that this is involved in the large scale default mode network (DMN), composed primarily by PCC, medial prefrontal cortex (MPFC), and the inferior parietal lobe (IPL), displaying an increased activity under passive task conditions (i.e. negative mode). This operability mode is in an opposing balance with attention and task performances mode, acting thus as a disruption process. One of the main conclusions is that the PCC cognitive orientation is primarily focused on the self person or on the “self” (I) projected from others, in “daydreaming” or “mind-wandering" wakeful rest, involved in present or future virtual projects. In spite of these advances, the particular role and specific functions of PCC are not yet fully understood, PCC remaining an enigmatic/contradictory structure of the brain, not included up to date in any brain model, so the PCC informational modeling presented here in terms of IMC covers this lack. IMC assigns to the brain the fundamental role of informational processor, composed by various operating structures according to specific objectives synthetically expressed by seven main cognitive centers of “self" (I) as: Iknow (memory), Iwant (decision), Ilove (emotions), Iam (self-status), Icreate (genetic transmission), Icreated (genetic inheritance), Ibelive (info-selection), assuring the info-connectivity with the body and external/internal world, the adaptability (learning process) and survival. It is deduced in this way that the specific behavior of PCC according to its intermediary architectural position between the vital central region of the brain, connecting the mind with the external/internal reality, is that of a moderator/integrator hub/informational YES/NO switcher from the external/awake captured focusing information to the internal accumulated experience of life, used as a valid reference. Therefore, the specific operability of PCC in terms of cognitive centers is that of an informational switcher, mainly operating with Iknow/Iwant to explore the self-status reflected in Iam, within day-dreaming/imaginary virtual sceneries.

The key role of daytime sleepiness in cognitive functioning of adults with attention deficit hyperactivity disorder

Adults with attention deficit hyperactivity disorder (ADHD) frequently suffer from sleep problems and report high levels of daytime sleepiness compared to neurotypical controls, which has detrimental effect on quality of life. We evaluated daytime sleepiness in adults with ADHD compared to neurotypical controls using an observer-rated sleepiness protocol during the Sustained Attention Response Task as well as electroencephalogram (EEG) slowing, a quantitative electroencephalographic measure collected during a short period of wakeful rest. We found that adults with ADHD were significantly sleepier than neurotypical controls during the cognitive task and that this on-task sleepiness contributed to cognitive performance deficits usually attributed to symptoms of ADHD. EEG slowing predicted severity of ADHD symptoms and diagnostic status, and was also related to daytime sleepiness. Frontal EEG slowing as well as increased frontal delta were especially prominent in adults with ADHD. We have validated and adapted an objective observer-rated measure for assessing on-task sleepiness that will contribute to future sleep research in psychology and psychiatry. These findings indicate that the cognitive performance deficits routinely attributed to ADHD and often conceptualized as cognitive endophenotypes of ADHD are largely due to on-task sleepiness and not exclusively due to ADHD symptom severity. Daytime sleepiness plays a major role in cognitive functioning of adults with ADHD.

Supplemental Material for Wakeful Rest Benefits Before and After Encoding in Anterograde Amnesia

Supplemental Material for Wakeful Rest Benefits Before and After Encoding in Anterograde Amnesia

Translating for Practice: A Case Study of Recommendations From the Wakeful Rest Literature

Translational research—a bridge between research in more controlled settings and application in more complex contexts—is an essential step in developing effective evidence-based practices. Yet, it is rare. Previous lab-based research has recommended wakeful rest (WR)—a relaxed state of mind in the absence of activity—as a classroom intervention to promote memory consolidation and improve both short- and long-term memory. We implemented the proposed WR intervention in a simulated classroom context. The results did not support the recommendations from studies in more controlled settings: WR did not improve participants’ short- or long-term memory. We discuss the importance of translational research in applying promising principles to classroom settings before making recommendations for practice.

Sensory and Cognitive Components of Auditory Processing in Individuals With Tinnitus.

Purpose The main purpose of the study is to explore the auditory selective attention abilities (using event-related potentials) and the neuronal oscillatory activity in the default mode network sites (using electroencephalogram [EEG]) in individuals with tinnitus. Method Auditory selective attention was measured using P300, and the resting state EEG was assessed using the default mode function analysis. Ten individuals with continuous and bothersome tinnitus along with 10 age- and gender-matched control participants underwent event-related potential testing and 5 min of EEG recording (at wakeful rest). Results Individuals with tinnitus were observed to have larger N1 and P3 amplitudes along with prolonged P3 latency. The default mode function analysis revealed no significant oscillatory differences between the groups. Conclusion The current study shows changes in both the early sensory and late cognitive components of auditory processing. The change in the P3 component is suggestive of selective auditory attention deficit, and the sensory component (N1) suggests an altered bottom-up processing in individuals with tinnitus.

Resting States and Memory Consolidation: A Preregistered Replication and Meta-Analysis

While several recent studies have found that a post-encoding period of quiet, eyes-closed waking rest benefits memory consolidation, others have reported null effects. To more precisely estimate this effect, we conducted a quasi-exact behavioural replication of a recent study from our lab, which found that post-training eyes-closed waking rest improved declarative memory relative to a distractor task. Contrary to our hypothesis, the observed effect was not significant; however, it did fall within the 95% confidence interval of our previous finding. Furthermore, a meta-analytic effect summarizing n = 10 similar studies indicates a moderately sized and significant benefit of waking rest for verbal memory (d = 0.38, p < 0.001). We argue that the apparently conflicting results in this literature are most parsimoniously explained by variability due to sampling and/or measurement error, in a group of studies often underpowered to detect a smaller-than-expected effect of rest. Additionally, exploratory analyses revealed that increased trait daydreaming frequency negatively correlated with memory retention during eyes-closed rest. Together with our replication and meta-analysis, these studies suggest that waking rest confers a small but significant benefit on memory consolidation, and that this benefit requires the mind to be free from attention to either external tasks or spontaneous thought.

Wakeful rest promotes the viewpoint-invariance, but not the fine discriminability, of entities mnemonic representations for subsequent familiarity-based recognition

Wakeful rest promotes the viewpoint-invariance, but not the fine discriminability, of entities mnemonic representations for subsequent familiarity-based recognition

The effects of different protocols of physical exercise and rest on long-term memory.

Whilst there are many studies comparing the different effects of exercise on long-term memory, these typically adopt varying intensities, durations, and behavioural measures. Furthermore, few studies provide direct comparisons between exercise and different types of rest. Therefore, by providing a standardised methodological design, this study will ascertain the most effective intensity and protocol of exercise for the modulation of long-term memory, whilst directly comparing it to different types rest. This was achieved using the same old/new recognition memory test and an 80-90min retention interval. Three experiments were performed (total N=59), each with a three-armed crossover design measuring the extent to which physical exercise and wakeful rest can influence long-term memory performance. In Experiment 1, the effects of continuous moderate intensity exercise (65-75% HRmax), passive rest (no cognitive engagement) and active rest (cognitively engaged) were explored. In Experiment 2, continuous moderate intensity exercise was compared to a type of high-intensity interval training (HIIT) and passive rest. Experiment 3 observed the effects of low- (55-65% HRmax), moderate- and high-intensity (75-85% HRmax) continuous exercise. Across the three experiments moderate intensity exercise had the greatest positive impact on memory performance. Although not significant, HIIT was more effective than passive-rest, and passive rest was more effective than active rest. Our findings suggest that it is not necessary to physically overexert oneself in order to achieve observable improvements to long-term memory. By also investigating wakeful rest, we reaffirmed the importance of the cognitive engagement during consolidation for the formation of long-term memories.

Factors modulating the effects of waking rest on memory

Study results indicate that moments of unoccupied rest immediately after learning serve an essential cognitive function: memory consolidation. However, there also are findings suggesting that waking rest after learning has similar effects on delayed memory performance as an active wake condition, where participants work on a cognitive distractor task. Based on these studies, we highlight several potentially modulating factors of the so-called resting effect.

Wakeful rest compared to vigilance reduces intrusive but not deliberate memory for traumatic videos

Intrusive memories are prominent features of post-traumatic stress disorder, but the mechanisms supporting their development, and their relationship to deliberate memories, are subject to competing theories. Are they strengthened examples of a unitary memory system, or fragmented representations lacking aspects of healthy memories? Given the importance of post-encoding processing in memory consolidation, we investigated the effects of a brief wakeful rest compared to a vigilance task immediately after the encoding of traumatic material on subsequent intrusive and deliberate memory. Across two experiments, participants watched emotionally negative film clips immediately followed by a brief wakeful rest or a simple vigilance (0-back) task. Brief wakeful rest had distinct effects on memory compared to the 0-back task, reducing intrusive memory frequency but not changing deliberate memory performance. These differential effects suggest that intrusive memory and deliberate memory reflect dissociable systems, arguing against unitary accounts. Our findings highlight the importance of post-encoding processing in the consolidation of traumatic material and the development of intrusive memories and provide a new perspective for interpreting mechanisms of therapeutic intervention.

The psychology of rest in athletes: An empirical study and initial model

ObjectivesTo better understand the psychology of rest in athletes. Rest is central to an understanding of recovery, skill learning, and expertise development in athletes, yet extant conceptualizations of rest seldom extend beyond rest as inactivity. DesignA qualitative design was used to build an initial descriptive model of the psychology of rest in athletes. Method18 athletes and 4 staff members comprising a highly-ranked women’s university field hockey squad were interviewed about meanings and experiences of rest. An inductive content analysis was undertaken to identify concepts within the interview data. ResultsAn initial descriptive model of the psychology of rest in athletes was proposed. Within this model, being well rested is considered to be a psychological state involving feeling fresh, and valuing, being motivating toward, and enjoying one’s sport. Athletes become well rested by engaging in a resting process, which includes sleeping and wakeful resting. Wakeful resting involves key resting experiences including not thinking about one’s sport. These experiences are obtained by engaging in specific activities (e.g., watching television) and within specific physical and social environments (e.g., being out of town). Obtaining resting experiences during in-season rest days is challenging due to limited time but more time is available to obtain these experiences during the off-season. ConclusionThe initial descriptive model proposed may offer analytical generalizability by having significance and utility within research with different sport contexts and populations that is concerned with recovery, skill learning, and expertise development.

Increased Thalamocortical Connectivity in Schizophrenia Correlates With Sleep Spindle Deficits: Evidence for a Common Pathophysiology

BackgroundConverging evidence implicates abnormal thalamocortical interactions in the pathophysiology of schizophrenia. This evidence includes consistent findings of increased resting-state functional connectivity of the thalamus with somatosensory and motor cortex during wake and reduced spindle activity during sleep. We hypothesized that these abnormalities would be correlated, reflecting a common mechanism: reduced inhibition of thalamocortical neurons by the thalamic reticular nucleus (TRN). The TRN is the major inhibitory nucleus of the thalamus and is abnormal in schizophrenia. Reduced TRN inhibition would be expected to lead to increased and less filtered thalamic relay of sensory and motor information to the cortex during wake and reduced burst firing necessary for spindle initiation during sleep. MethodsOvernight polysomnography and resting-state functional connectivity magnetic resonance imaging were performed in 26 outpatients with schizophrenia and 30 demographically matched healthy individuals. We examined the relations of sleep spindle density during stage 2 non–rapid eye movement sleep with connectivity of the thalamus to the cortex during wakeful rest. ResultsAs in prior studies, patients with schizophrenia exhibited increased functional connectivity of the thalamus with bilateral somatosensory and motor cortex and reduced sleep spindle density. Spindle density inversely correlated with thalamocortical connectivity, including in somotosensory and motor cortex, regardless of diagnosis. ConclusionsThese findings link two biomarkers of schizophrenia—the sleep spindle density deficit and abnormally increased thalamocortical functional connectivity—and point to deficient TRN inhibition as a plausible mechanism. If TRN-mediated thalamocortical dysfunction increases risk for schizophrenia and contributes to its manifestations, understanding its mechanism could guide the development of targeted interventions.

Benefit of wakeful resting on gist and peripheral memory retrieval in healthy younger and older adults

Retrieval is greater if new learning is followed by a period of wakeful rest, minimising the likelihood of retroactive interference. It is not known if this benefit extends to recollection of both gist and peripheral details, nor whether age affects the benefit of wakeful resting in either of these types of recollection. Forty-five younger and forty older adults were presented with prose passages for later recall followed by a period of either interference or wakeful resting. Younger participants outperformed older participants in remembering peripheral details, but not on gist memory. Wakeful resting led to higher overall recollection in both age groups, both for gist and for peripheral details. Also, wakeful resting was more beneficial for gist than peripheral memory in older but not younger adults. We discuss these novel findings and their theoretical implications for a memory consolidation account of the benefits of wakeful resting.