Practice Makes Imperfect: Restorative Effects of Sleep on Motor Learning

Emerging evidence suggests that sleep plays a key role in procedural learning, particularly in the continued development of motor skill learning following initial acquisition. We argue that a detailed examination of the time course of performance across sleep on the finger-tapping task, established as the paradigm for studying the effect of sleep on motor learning, will help distinguish a restorative role of sleep in motor skill learning from a proactive one. Healthy subjects rehearsed for 12 trials and, following a night of sleep, were tested. Early training rapidly improved speed as well as accuracy on pre-sleep training. Additional rehearsal caused a marked slow-down in further improvement or partial reversal in performance to observed levels below theoretical upper limits derived on the basis of early pre-sleep rehearsal. This decrement in learning efficacy does not occur always, but if and only if it does, overnight sleep has an effect in fully or partly restoring the efficacy and actual performance to the optimal theoretically achieveable level. Our findings re-interpret the sleep-dependent memory enhancement in motor learning reported in the literature as a restoration of fatigued circuitry specialized for the skill. In providing restitution to the fatigued brain, sleep eliminates the rehearsal-induced synaptic fatigue of the circuitry specialized for the task and restores the benefit of early pre-sleep rehearsal. The present findings lend support to the notion that latent sleep-dependent enhancement of performance is a behavioral expression of the brain's restitution in sleep

Sleep-dependent memory consolidation is related to perceived value of learned material

Although many types of newly encoded information can be consolidated during sleep, an enhanced effect has been found for memories tagged as relevant to the future, such as through knowledge of future testing or payment for successful recall. In the current study, participants (n = 80) learned Welsh and Breton translations of English words, and intrinsic relevance of learned material was operationalized as perceived value of the Welsh and Breton languages. Participants were non-Welsh native English speakers who had recently arrived in Wales. Memory for the words was tested immediately and 12 h later, after either a period of wake or a period of sleep. An increase in recall for both languages was found after sleep, but not after wake. Importantly, for the sleep condition, overnight improvement in Welsh word recall was associated with participants’ level of valuing the Welsh language. This association was not found for the wake period condition. These findings support previous indications of an active role of sleep in the consolidation of memories relevant for the future, and demonstrate that this effect may be modulated by individual differences in perceived value of the learned material. It remains to be established whether this association is mediated by an emotional attachment to the language or a cognitive facility with it, or both

Complementary roles of slow-wave sleep and rapid eye movement sleep in emotional memory consolidation

Although rapid eye movement sleep (REM) is regularly implicated in emotional memory consolidation, the role of slow-wave sleep (SWS) in this process is largely uncharacterized. In the present study, we investigated the relative impacts of nocturnal SWS and REM upon the consolidation of emotional memories using functional magnetic resonance imaging (fMRI) and polysomnography (PSG). Participants encoded emotionally positive, negative, and neutral images (remote memories) before a night of PSG-monitored sleep. Twenty-four hours later, they encoded a second set of images (recent memories) immediately before a recognition test in an MRI scanner. SWS predicted superior memory for remote negative images and a reduction in right hippocampal responses during the recollection of these items. REM, however, predicted an overnight increase in hippocampal–neocortical connectivity associated with negative remote memory. These findings provide physiological support for sequential views of sleep-dependent memory processing, demonstrating that SWS and REM serve distinct but complementary functions in consolidation. Furthermore, these findings extend those ideas to emotional memory by showing that, once selectively reorganized away from the hippocampus during SWS, emotionally aversive representations undergo a comparably targeted process during subsequent REM

A technique for determining pump injector settings for an on-table CT or 3D DSA in interventional radiology

Introduction On-Table computed tomography (CT) or 3D digital subtraction angiography (DSA) in interventional radiology (IR) has become a valuable diagnostic tool. Methods A review of the literature found a poor evidential base supporting the technical parameters for iodinated contrast delivery during these acquisition sequences. Results and conclusion This technical note presents an easy method of estimating the parameters needed to reliably obtain diagnostic on-table CT or 3D DSA images, whilst attempting minimising contrast dose. Implications for practice A systematic approach to estimating contrast delivery regimes during on-table CT and 3D DSA can help ensure diagnostic quality images are obtained. Further clinical studies are now required to rigorously evaluate this protocol

Initial single centre experiences of a radiographer advanced practitioner led nephrostomy exchange programme

PURPOSE: To evaluate the technical success, radiation dose, complications and costs from the introduction of a radiographer-led nephrostomy exchange service. METHODS: Post-graduate qualified interventional radiographers with several years’ experience in performing other interventional procedures began performing nephrostomy exchanges. Training was provided by an interventional radiologist. Each radiographer performed ten procedures under direct supervision followed by independent practice with remote supervision. Each radiographer was then responsible for the radiological report, discharge, re-referral for further exchange and, where indicated, sending urine samples for culture and sensitivity. Data extraction included the time interval between exchanges, radiation dose/screening time and complications. RESULTS: Thirty-eight long-term nephrostomy patients had their histories interrogated back to the time of the initial insertion. The mean (range) age at nephrostomy insertion was 67 (35-93) years and 65% were male. Indications for nephrostomy were prostatic or gynaecological malignancy, ureteric injury, bulky lymphoma and post-transplant ureteric stricture. A total of 170 nephrostomy exchanges were performed with no statistically differences in the radiation dose, fluoroscopy time nor complication rates between consultants and radiographers. There was, however, a statistical reduction in the time interval between nephrostomy exchanges for the radiographer group (P=0.022). CONCLUSION: Interventional radiographers can provide a safe, technically successful nephrostomy exchange program with radiation doses equivalent to radiologists. This is a cost-effective solution to the capacity issues faced in many departments, whilst providing career progression, job satisfaction and possibly improved care. IMPLICATIONS FOR PRACTICE: Radiographer-led interventional services should be considered by other institutions as a means of providing effective nephrostomy exchanges

Does Sleep Improve Your Grammar? : Preferential Consolidation of Arbitrary Components of New Linguistic Knowledge

We examined the role of sleep-related memory consolidation processes in learning new form-meaning mappings. Specifically, we examined a Complementary Learning Systems account, which implies that sleep-related consolidation should be more beneficial for new hippocampally dependent arbitrary mappings (e.g. new vocabulary items) relative to new systematic mappings (e.g. grammatical regularities), which can be better encoded neocortically. The hypothesis was tested using a novel language with an artificial grammatical gender system. Stem-referent mappings implemented arbitrary aspects of the new language, and determiner/suffix+natural gender mappings implemented systematic aspects (e.g. tib scoiffesh + ballerina, tib mofeem + bride; ked jorool + cowboy, ked heefaff + priest). Importantly, the determiner-gender and the suffix-gender mappings varied in complexity and salience, thus providing a range of opportunities to detect beneficial effects of sleep for this type of mapping. Participants were trained on the new language using a word-picture matching task, and were tested after a 2-hour delay which included sleep or wakefulness. Participants in the sleep group outperformed participants in the wake group on tests assessing memory for the arbitrary aspects of the new mappings (individual vocabulary items), whereas we saw no evidence of a sleep benefit in any of the tests assessing memory for the systematic aspects of the new mappings: Participants in both groups extracted the salient determiner-natural gender mapping, but not the more complex suffix-natural gender mapping. The data support the predictions of the complementary systems account and highlight the importance of the arbitrariness/systematicity dimension in the consolidation process for declarative memories

Wake Up and Talk with Me! In-the-Field Study of an Autonomous Interactive Wake Up Robot

12th International Conference, ICSR 2020, Golden, CO, USA, November 14–18, 2020In this paper, we present a robot that is designed to smoothly wake up a user in the morning. We created an autonomous interactive wake up robot that implements a wake up behavior that was selected through preliminary experiments. We conducted a user study to test the interactive robot and compared it to a baseline robot that behaves like a conventional alarm clock. We recruited 22 participants that agreed to bring the robot to their home and test it for two consecutive nights. The participants felt significantly less sleepy after waking up with the interactive robot, and reported significantly more intention to use the interactive robot

Does Sleep Really Influence Face Recognition Memory?

Mounting evidence implicates sleep in the consolidation of various kinds of memories. We investigated the effect of sleep on memory for face identity, a declarative form of memory that is indispensable for nearly all social interaction. In the acquisition phase, observers viewed faces that they were required to remember over a variable retention period (0–36 hours). In the test phase, observers viewed intermixed old and new faces and judged seeing each before. Participants were classified according to acquisition and test times into seven groups. Memory strength (d′) and response bias (c) were evaluated. Substantial time spent awake (12 hours or more) during the retention period impaired face recognition memory evaluated at test, whereas sleep per se during the retention period did little to enhance the memory. Wakefulness during retention also led to a tightening of the decision criterion. Our findings suggest that sleep passively and transiently shelters face recognition memory from waking interference (exposure) but does not actively aid in its long-term consolidation

Sleep patterns and school performance of Korean adolescents assessed using a Korean version of the pediatric daytime sleepiness scale

PurposeKorean adolescents have severe nighttime sleep deprivation and daytime sleepiness because of their competitive educational environment. However, daytime sleep patterns and sleepiness have never been studied using age-specific methods, such as the pediatric daytime sleepiness scale (PDSS). We surveyed the daytime sleepiness of Korean adolescents using a Korean translation of the PDSS.MethodsWe distributed the 27-item questionnaire, including the PDSS and questions related to sleep pattern, sleep satisfaction, and emotional state, to 3,370 students in grades 5-12.ResultsThe amount of nighttime sleep decreased significantly with increasing age. During weekday nights, 5-6th graders slept for 7.95±1.05 h, 7-9th graders for 7.57±1.05 h, and 10-12th graders for 5.78±1.13 h. However, the total amounts of combined daytime and nighttime sleep during weekdays were somewhat greater, 8.15±1.12 h for 5-6th graders, 8.17±1.20 h for 7-9th graders, and 6.87±1.40 h for 10-12th graders. PDSS scores increased with age, 11.89±5.56 for 5-6th graders, 16.57±5.57 for 7-9th graders, and 17.71±5.24 for 10-12th graders. Higher PDSS scores were positively correlated with poor school performance and emotional instability.ConclusionKorean teenagers sleep to an unusual extent during the day because of nighttime sleep deprivation. This negatively affects school performance and emotional stability. A Korean translation of the PDSS was effective in evaluating the severity of daytime sleepiness and assessing the emotional state and school performance of Korean teenagers

Right hemisphere advantage in statistical learning: evidence from a probabilistic sequence learning task

Picking up statistical regularities of patterns from the environment is essential for predictive and adaptive behavior. One of the most important challenges is to understand how statistical learning occurs and how the acquired information consolidates and stabilizes in the brain. Evidence suggests that the prefrontal cortex (PFC) has a critical role in these processes; the division of labor between hemispheres, however, is less characterized. The aim of the present study was to directly investigate the causal role of the right and left PFC in statistical learning and its consolidation. Healthy, young adults were trained on a probabilistic sequence learning task. Anodal transcranial direct current stimulation (tDCS) over the right or left dorsolateral PFC (DLPFC) was applied during the training in order to modify learning-related cortical plasticity in the targeted brain regions by increasing neural excitability. Performance was tested during and immediately after the stimulation, 2-hour and 24-hour later. We found that the anodal tDCS over the right DLPFC led to enhanced learning performance both after the 2-hour and 24-hour retention periods, suggesting the causal role of this area in statistical learning. In contrast, we did not find any effect of left DLPFC stimulation on learning. These results highlight the role of the right fronto-striatal network in statistical learning and its consolidation