Procedural Memory Consolidation Research Articles

Memory stabilization and enhancement following music practice

Procedural memory consolidation has been shown to enhance a variety of perceptual and motor skills during sleep, but only recently has this effect been investigated in trained musicians performing music. I tested the extent to which expected music performance skill improves over a night of sleep and to what extent the new skill memory may be fragile following initial learning. Musicians ( N = 60) learned a 13-note piano melody in individual evening training sessions under one of four practice conditions. Performance of the target melody was tested the next morning following a night of sleep. In line with previous research findings, subjects showed evidence of overnight gains in performance speed and accuracy. However, these results reveal, for the first time with musicians, that additional practice on a second, similar melody seems to inhibit these overnight gains, perhaps indicating that the overnight consolidation of new skill memories is susceptible to interference from similar tasks.

Alpha Activity during Rem Sleep Contributes to Overnight Improvement in Performance on a Visual Discrimination Task

The purpose of this preliminary study was to clarify the association between cortical and subcortical activities during REM and non-REM sleep with overnight improvement of performance on a procedural memory task. Eleven healthy volunteers (M age = 23.8 yr., SD = 3.1) participated in this study which was conducted over two consecutive nights: an adaptation night and the experimental night. They underwent a visual discrimination task before and after the experimental night. A positive correlation was observed between overnight performance improvement on the visual discrimination task and EEG alpha band power during REM sleep, while no significant correlation was observed between the performance and either the amount of Stage REM sleep, REM activity, or other sleep variables. The findings corroborate other studies and suggest that cortical activity during REM sleep contributed to procedural memory consolidation and highlights the importance of measuring quantitative REM sleep components to elucidate the role of physiological sleep on memory consolidation in humans.

The timing of learning before night-time sleep differentially affects declarative and procedural long-term memory consolidation in adolescents.

Sleep after learning has been shown to foster the consolidation of new memories. However, fundamental questions on the best timing of learning before night-time sleep persist. We tested the hypothesis that learning directly prior to night-time sleep compared to 7.5 hrs prior to night-time sleep provides better conditions for the consolidation of declarative and procedural memories. Fifty healthy female adolescents (aged 16–17 years) were trained on a declarative word-pair and a procedural finger-tapping task at 3 pm (afternoon group, n = 25) or at 9 pm (evening group, n = 25), followed by a sleep laboratory night. Retrieval was assessed 24 hours and 7 days after initial training. Subjects trained in the afternoon showed a significantly elevated retention rate of word-pairs compared to subjects trained in the evening after 24 hours, but not after 7 days. In contrast, off-line gains in finger-tapping performance were significantly higher in subjects trained in the evening compared to those trained in the afternoon after both retention intervals. The observed enhanced consolidation of procedural memories after training in the evening fits to current models of sleep-related memory consolidation. In contrast, the higher retention of declarative memories after encoding in the afternoon is surprising, appeared to be less robust and needs further investigation.

Effects of Daytime Food Intake on Memory Consolidation during Sleep or Sleep Deprivation

Sleep enhances memory consolidation. Bearing in mind that food intake produces many metabolic signals that can influence memory processing in humans (e.g., insulin), the present study addressed the question as to whether the enhancing effect of sleep on memory consolidation is affected by the amount of energy consumed during the preceding daytime. Compared to sleep, nocturnal wakefulness has been shown to impair memory consolidation in humans. Thus, a second question was to examine whether the impaired memory consolidation associated with sleep deprivation (SD) could be compensated by increased daytime energy consumption. To these aims, 14 healthy normal-weight men learned a finger tapping sequence (procedural memory) and a list of semantically associated word pairs (declarative memory). After the learning period, standardized meals were administered, equaling either ∼50% or ∼150% of the estimated daily energy expenditure. In the morning, after sleep or wakefulness, memory consolidation was tested. Plasma glucose was measured both before learning and retrieval. Polysomnographic sleep recordings were performed by electroencephalography (EEG). Independent of energy intake, subjects recalled significantly more word pairs after sleep than they did after SD. When subjects stayed awake and received an energy oversupply, the number of correctly recalled finger sequences was equal to those seen after sleep. Plasma glucose did not differ among conditions, and sleep time in the sleep conditions was not influenced by the energy intake interventions. These data indicate that the daytime energy intake level affects neither sleep’s capacity to boost the consolidation of declarative and procedural memories, nor sleep’s quality. However, high energy intake was followed by an improved procedural but not declarative memory consolidation under conditions of SD. This suggests that the formation of procedural memory is not only triggered by sleep but is also sensitive to the fluctuations in the energy state of the body.

EEG sigma and slow‐wave activity during NREM sleep correlate with overnight declarative and procedural memory consolidation

Previous studies suggest that sleep-specific brain activity patterns such as sleep spindles and electroencephalographic slow-wave activity contribute to the consolidation of novel memories. The generation of both sleep spindles and slow-wave activity relies on synchronized oscillations in a thalamo-cortical network that might be implicated in synaptic strengthening (spindles) and downscaling (slow-wave activity) during sleep. This study further examined the association between electroencephalographic power during non-rapid eye movement sleep in the spindle (sigma, 12-16 Hz) and slow-wave frequency range (0.1-3.5 Hz) and overnight memory consolidation in 20 healthy subjects (10 men, 27.1 ± 4.6 years). We found that both electroencephalographic sigma power and slow-wave activity were positively correlated with the pre-post-sleep consolidation of declarative (word list) and procedural (mirror-tracing) memories. These results, although only correlative in nature, are consistent with the view that processes of synaptic strengthening (sleep spindles) and synaptic downscaling (slow-wave activity) might act in concert to promote synaptic plasticity and the consolidation of both declarative and procedural memories during sleep.

Sleep‐dependent consolidation of procedural motor memories in children and adults: the pre‐sleep level of performance matters

In striking contrast to adults, in children sleep following training a motor task did not induce the expected (offline) gain in motor skill performance in previous studies. Children normally perform at distinctly lower levels than adults. Moreover, evidence in adults suggests that sleep dependent offline gains in skill essentially depend on the pre-sleep level of performance. Against this background, we asked whether improving children's performance on a motor sequence learning task by extended training to levels approaching those of adults would enable sleep-associated gains in motor skill in this age group also. Children (4-6 years) and adults (18-35 years) performed on the motor sequence learning task (button-box task) before and after ~2-hour retention intervals including either sleep (midday nap) or wakefulness. Whereas one group of children and adults, respectively, received the standard amount of 10 blocks of training before retention intervals of sleep or wakefulness, a further group of children received an extended training on 30 blocks (distributed across 3 days). A further group of adults received a restricted training on only two blocks before the retention intervals. Children after standard training reached lowest performance levels, whereas in adults performance after standard training was highest. Children with extended training and adults after reduced training reached intermediate performance levels. Only at these intermediate performance levels did sleep induce significant gains in motor sequence skill, whereas performance did not benefit from sleep in the low-performing children or in the high-performing adults. Spindle counts in the post-training nap were correlated with performance gains at retrieval only in the adults benefitting from sleep. We conclude that, across age groups, sleep induces the most robust gain in motor skill at an intermediate pre-sleep performance level. In low-performing children sleep-dependent improvements in skill may be revealed only after enhancing the pre-sleep performance level by extended training.

CONSOLIDATION THROUGH THE LOOKING-GLASS: SLEEP-DEPENDENT PROACTIVE INTERFERENCE ON PROCEDURAL LEARNING IN CHILDREN

Event Abstract Back to Event CONSOLIDATION THROUGH THE LOOKING-GLASS: SLEEP-DEPENDENT PROACTIVE INTERFERENCE ON PROCEDURAL LEARNING IN CHILDREN Charline Urbain1, 2*, Emeline Houyoux1, Genevieve Albouy3 and Philippe Peigneux1 1 Université Libre de Bruxelles, UR2NF - Neuropsychology and Functional Neuroimaging Research Unit, Université Libre de Bruxelles , Belgium 2 Université Libre de Bruxelles, LCFC - Laboratoire de Cartographie Fonctionnelle du Cerveau, Hôpital Érasme, Belgium 3 University of Montreal, Centre de recherche, Institut Universitaire de Gériatrie de Montréal, Canada Although a beneficial role of post-training sleep for declarative memory has been consistently evidenced in children like in adults, available data suggest that procedural memory consolidation does not benefit from sleep in children. We surmised that despite a possible absence of sleep-dependent changes in performance in children, sleep-dependent plasticity processes involved in procedural memory consolidation might be expressed through differential interference effects on the learning of novel but related procedural material. To do so, thirty-two 10-12 years old children were trained to the rotation adaptation task then retested after either a sleep or a wake period on the same rotation applied at learning, thus assessing offline sleep-dependent changes in performance. We then presented at retest the opposite (unlearned) rotation to assess sleep-dependent modulations in proactive interference of the consolidated visuomotor memory trace against learning of the new rotation. Results show that children gradually improve performance over the learning session, showing effective adaptation to the imposed rotation. Notwithstanding, besides a conspicuous absence of sleep-dependent changes in performance for the learned rotations, the presentation of the opposite, unlearned deviation elicited significantly worse performance (i.e. higher interference effects) after post-training sleep than wakefulness in children. Considering that a definite feature of procedural memory and skill acquisition is the implementation of highly automatized motor behaviour, thus lacking flexibility, our results suggest a better integration and/or automation or motor adaptation skills after post-training sleep, eventually resulting in higher proactive interference effects on untrained material. Consequently, our results suggest that sleep contributes in the consolidation of a procedural adaptation memory in children. Acknowledgements CU is supported by a grant of the ULB-ARC project "Pathophysiology of Memory Consolidation Processes“ and the Fondation Vigneron. GA is supported by a Canadian Institutes of Health Research (CIHR) postdoctoral grant. Keywords: Children, visuomotor adaptation, procedural learning, interference, Sleep, memory consolidation Conference: Belgian Brain Council, Liège, Belgium, 27 Oct - 27 Oct, 2012. Presentation Type: Poster Presentation Topic: Other basic/clinical neurosciences topic Citation: Urbain C, Houyoux E, Albouy G and Peigneux P (2012). CONSOLIDATION THROUGH THE LOOKING-GLASS: SLEEP-DEPENDENT PROACTIVE INTERFERENCE ON PROCEDURAL LEARNING IN CHILDREN. Conference Abstract: Belgian Brain Council. doi: 10.3389/conf.fnhum.2012.210.00019 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 10 Sep 2012; Published Online: 12 Sep 2012. * Correspondence: Dr. Charline Urbain, Université Libre de Bruxelles, UR2NF - Neuropsychology and Functional Neuroimaging Research Unit, Université Libre de Bruxelles, Bruxelles, 1050, Belgium, curbain@ulb.ac.be Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Charline Urbain Emeline Houyoux Genevieve Albouy Philippe Peigneux Google Charline Urbain Emeline Houyoux Genevieve Albouy Philippe Peigneux Google Scholar Charline Urbain Emeline Houyoux Genevieve Albouy Philippe Peigneux PubMed Charline Urbain Emeline Houyoux Genevieve Albouy Philippe Peigneux Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Representations in a recurrent network model of motor sequence learning reveal unified view of procedural memory consolidation and structure learning

Event Abstract Back to Event Representations in a recurrent network model of motor sequence learning reveal unified view of procedural memory consolidation and structure learning Quan Wang1*, Constantin A. Rothkopf1 and Jochen Triesch1 1 Johann Wolfgang Goethe University, Frankfurt Institute for Advanced Studies (FIAS), Germany Humans can improve their performance in procedural movement tasks through practice, but such motor learning has shown puzzling and seemingly contradictory results. On the one hand, a wide variety of proactive and retroactive interference effects have been observed when multiple tasks have to be learned. On the other hand, some studies have reported facilitation and transfer of learning between different tasks, sometimes based on abstract structure similarities. Here we show how these different phenomena can all be understood based on generic learning principles in a recurrent neural network model. Specifically, we consider a self-organizing recurrent neural network model whose activity and connectivity is shaped by three plasticity mechanisms: spike timing-dependent plasticity (STDP), intrinsic plasticity, and synaptic scaling [1]. The network receives stimulus-specific input and is connected to a layer of motor neurons mediating the movement sequences through a winner-take-all mechanism. We use this network to model a series of experiments on movement sequence learning using a single set of parameters in all simulations. The network learns to carry out the correct movement sequences over trials and reproduces differences in behavior between training schedules such as blocked vs. random training. The network also shows striking similarity to human performance in tasks with similar training sequences but different training times. Previously we have shown the agreement between the output of the network and psychophysical performance across several tasks and training schedules with a single set of parameters for the recurrent network. The current work presents a detailed analysis of the underlying changes in the neuronal representations of the motor sequences across learning. Mutual information, PCA analysis of network activity, and measures of neuronal selectivity for parts of the motor sequences reveal how input representations and the trajectories of neural activity change with training. Finally, we provide testable experimental predictions. Thus, we show how training schedule and task similarity interact to produce a rich set of interference and facilitation effects thereby unifying procedural memory consolidation and structure learning in a recurrent network model with multiple plasticity mechanisms. Acknowledgements First authorship is shared between QW and CR. This research was funded in part by the BMBF through the Bernstein Focus: Neurotechnology in Frankfurt and by the European Union through FP7 project IM-CLeVeR.

Distributed Practice and Procedural Memory Consolidation in Musicians’ Skill Learning

This research was designed to determine whether musicians’ learning is affected by the time intervals interposed between practice sessions. Twenty-nine non-pianist musicians learned a 9-note sequence on a piano keyboard in three practice sessions that were separated by 5 min, 6 hr, or 24 hr. Significant improvements in performance accuracy were observed in Session 2 only in the group whose sessions were separated by 24 hr. There were significant increases in performance speed in Session 2 in all three practice conditions, results which likely were attributable to the inclusion of all Session 1 data in the analysis. Additional significant speed increases were observed in Session 3 only in the groups whose sessions were separated by 6 and 24 hr. These results suggest that sleep-based procedural memory consolidation may enhance performance accuracy in music skill learning, whereas enhancements in performance speed may be attributable to both wake- and sleep-based consolidation processes.

Reduced Sleep Spindles and Spindle Coherence in Schizophrenia: Mechanisms of Impaired Memory Consolidation?

Sleep spindles are thought to induce synaptic changes and thereby contribute to memory consolidation during sleep. Patients with schizophrenia show dramatic reductions of both spindles and sleep-dependent memory consolidation, which may be causally related. To examine the relations of sleep spindle activity to sleep-dependent consolidation of motor procedural memory, 21 chronic, medicated schizophrenia outpatients and 17 healthy volunteers underwent polysomnography on two consecutive nights. On the second night, participants were trained on the finger-tapping motor sequence task (MST) at bedtime and tested the following morning. The number, density, frequency, duration, amplitude, spectral content, and coherence of stage 2 sleep spindles were compared between groups and examined in relation to overnight changes in MST performance. Patients failed to show overnight improvement on the MST and differed significantly from control participants who did improve. Patients also exhibited marked reductions in the density (reduced 38% relative to control participants), number (reduced 36%), and coherence (reduced 19%) of sleep spindles but showed no abnormalities in the morphology of individual spindles or of sleep architecture. In patients, reduced spindle number and density predicted less overnight improvement on the MST. In addition, reduced amplitude and sigma power of individual spindles correlated with greater severity of positive symptoms. The observed sleep spindle abnormalities implicate thalamocortical network dysfunction in schizophrenia. In addition, the findings suggest that abnormal spindle generation impairs sleep-dependent memory consolidation in schizophrenia, contributes to positive symptoms, and is a promising novel target for the treatment of cognitive deficits in schizophrenia.

A Role for Central Nervous Growth Hormone-Releasing Hormone Signaling in the Consolidation of Declarative Memories

Contributions of somatotropic hormonal activity to memory functions in humans, which are suggested by clinical observations, have not been systematically examined. With previous experiments precluding a direct effect of systemic growth hormone (GH) on acute memory formation, we assessed the role of central nervous somatotropic signaling in declarative memory consolidation. We examined the effect of intranasally administered growth hormone releasing-hormone (GHRH; 600 µg) that has direct access to the brain and suppresses endogenous GHRH via an ultra-short negative feedback loop. Twelve healthy young men learned word-pair associates at 2030 h and were administered GHRH and placebo, respectively, at 2100 h. Retrieval was tested after 11 hours of wakefulness. Compared to placebo, intranasal GHRH blunted GH release within 3 hours after substance administration and reduced the number of correctly recalled word-pairs by ∼12% (both P<0.05). The impairment of declarative memory consolidation was directly correlated to diminished GH concentrations (P<0.05). Procedural memory consolidation as examined by the parallel assessment of finger sequence tapping performance was not affected by GHRH administration. Our findings indicate that intranasal GHRH, by counteracting endogenous GHRH release, impairs hippocampal memory processing. They provide first evidence for a critical contribution of central nervous somatotropic activity to hippocampus-dependent memory consolidation.

Sleep restores daytime deficits in procedural memory in children with attention-deficit/hyperactivity disorder

Sleep supports the consolidation of declarative and procedural memory. While prefrontal cortex (PFC) activity supports the consolidation of declarative memory during sleep, opposite effects of PFC activity are reported with respect to the consolidation of procedural memory during sleep. Patients with attention-deficit/hyperactivity disorder (ADHD) are characterised by a prefrontal hypoactivity. Therefore, we hypothesised that children with ADHD benefit from sleep with respect to procedural memory more than healthy children. Sixteen children with ADHD and 16 healthy controls (aged 9-12) participated in this study. A modification of the serial-reaction-time task was conducted. In the sleep condition, learning took place in the evening and retrieval after a night of sleep, whereas in the wake condition learning took place in the morning and retrieval in the evening without sleep. Children with ADHD showed an improvement in motor skills after sleep compared to the wake condition. Sleep-associated gain in reaction times was positively correlated with the amount of sleep stage 4 and REM-density in ADHD. As expected, sleep did not benefit motor performance in the group of healthy children. These data suggest that sleep in ADHD normalizes deficits in procedural memory observed during daytime. It is discussed whether in patients with ADHD attenuated prefrontal control enables sleep-dependent gains in motor skills by reducing the competitive interference between explicit and implicit components within a motor task.

Sleep-related memory consolidation in primary insomnia

It has been suggested that healthy sleep facilitates the consolidation of newly acquired memories and underlying brain plasticity. The authors tested the hypothesis that patients with primary insomnia (PI) would show deficits in sleep-related memory consolidation compared to good sleeper controls (GSC). The study used a four-group parallel design (n=86) to investigate the effects of 12 h of night-time, including polysomnographically monitored sleep ('sleep condition' in PI and GSC), versus 12 h of daytime wakefulness ('wake condition' in PI and GSC) on procedural (mirror tracing task) and declarative memory consolidation (visual and verbal learning task). Demographic characteristics and memory encoding did not differ between the groups at baseline. Polysomnography revealed a significantly disturbed sleep profile in PI compared to GSC in the sleep condition. Night-time periods including sleep in GSC were associated with (i) a significantly enhanced procedural and declarative verbal memory consolidation compared to equal periods of daytime wakefulness in GSC and (ii) a significantly enhanced procedural memory consolidation compared to equal periods of daytime wakefulness and night-time sleep in PI. Across retention intervals of daytime wakefulness, no differences between the experimental groups were observed. This pattern of results suggests that healthy sleep fosters the consolidation of new memories, and that this process is impaired for procedural memories in patients with PI. Future work is needed to investigate the impact of treatment on improving sleep and memory.

Sleep Selectively Enhances Memory Expected to Be of Future Relevance

The brain encodes huge amounts of information, but only a small fraction is stored for a longer time. There is now compelling evidence that the long-term storage of memories preferentially occurs during sleep. However, the factors mediating the selectivity of sleep-associated memory consolidation are poorly understood. Here, we show that the mere expectancy that a memory will be used in a future test determines whether or not sleep significantly benefits consolidation of this memory. Human subjects learned declarative memories (word paired associates) before retention periods of sleep or wakefulness. Postlearning sleep compared with wakefulness produced a strong improvement at delayed retrieval only if the subjects had been informed about the retrieval test after the learning period. If they had not been informed, retrieval after retention sleep did not differ from that after the wake retention interval. Retention during the wake intervals was not affected by retrieval expectancy. Retrieval expectancy also enhanced sleep-associated consolidation of visuospatial (two-dimensional object location task) and procedural motor memories (finger sequence tapping). Subjects expecting the retrieval displayed a robust increase in slow oscillation activity and sleep spindle count during postlearning slow-wave sleep (SWS). Sleep-associated consolidation of declarative memory was strongly correlated to slow oscillation activity and spindle count, but only if the subjects expected the retrieval test. In conclusion, our work shows that sleep preferentially benefits consolidation of memories that are relevant for future behavior, presumably through a SWS-dependent reprocessing of these memories.

Sleep restriction over several days does not affect long-term recall of declarative and procedural memories in adolescents

Objectives There is broad evidence that sleep as opposed to waking facilitates the consolidation of both declarative and procedural memory. The current study addressed the question whether different extents of sleep restriction after learning would impair long-term memory consolidation in adolescents. Methods Eighty-eight healthy adolescents were randomized to five different sleep protocols with 9, 8, 7, 6 or 5 h of time in bed for four consecutive nights under controlled conditions that excluded daytime sleep. Declarative (word-pair task) and procedural memory (mirror tracing task) encoding was assessed prior to the sleep restriction protocol. Recall was assessed after two recovery nights following the sleep protocol and 4 weeks later. Results Sleep diaries and actigraphy data demonstrated that the participants closely followed the sleep protocols. There were no differences in demographic parameters or memory encoding at baseline. In contrast to the initial prediction, restriction of nocturnal sleep over four consecutive nights had no significant impact on declarative or procedural memory consolidation. Polysomnographic monitoring after sleep restriction demonstrated a high preservation of the amount of slow wave sleep in the restricted conditions. Conclusions The results suggest that adolescents show a high resilience of memory consolidation to substantial sleep curtailment across four nights that might be promoted by increased sleep intensity under conditions of sleep restriction.

Unifying procedural memory consolidation and structure learning in a recurrent network model of motor control

Unifying procedural memory consolidation and structure learning in a recurrent network model of motor control

Sleep-dependent memory consolidation of a new task is inhibited in psychiatric patients

Schizophrenic and depressive patients show impeded sleep-dependent procedural memory consolidation. But this has been shown mainly for tasks testing the adaptation of old skills. This study tested the overnight memory consolidation of a new task and the transfer of this new skill to a similar task. Using an adapted version of the sequential finger tapping task, keyboard-naïve Ethiopian depressive ( n = 8) and schizophrenic ( n = 15) patients and healthy controls ( n = 11 and n = 17) were tested twice, 24 h apart. In addition the subjects underwent training in a second sequence after the retest of the first sequence. Both schizophrenic and depressive patients did not show a significant overnight change in performance (1% and 4% improvement respectively) in the task and differed significantly from the healthy control groups who did show significant improvement (16% and 22%). Further in contrast to the healthy controls both patients groups showed no significant transfer of the newly acquired skill to the second sequence. This study shows that depressive and schizophrenic patients are not only deficient in the overnight memory consolidation of a new task, but also fail to show a transfer of this new skill to similar tasks.

Off-line memory consolidation impairments in multiple sclerosis patients receiving high-dose corticosteroid treatment mirror consolidation impairments in depression

Sleep supports the consolidation of procedural memory, however patients with major depression show impaired motor memory performance after a night of sleep. It was hypothesized that this impairment is related to hypothalamic-pituitary-adrenal (HPA) axis dysfunction. We tested if high-dose administration of corticosteroids impairs off-line motor memory consolidation in patients with multiple sclerosis (MS). Nine patients with MS receiving high-dose corticosteroid therapy (methylprednisolone) and nine MS patients receiving alternative therapy (mitoxantrone) were assessed using a sequential finger tapping task before and after a night with polysomnography. In addition, nine patients with major depression (MD) receiving antidepressants and nine healthy controls were assessed. Although the four groups did not differ in practice-dependent learning, healthy subjects and MS patients receiving mitoxantrone showed markedly overnight-improvements in tapping performance of 17% and 24% while MS patients receiving high-dose corticosteroid therapy and depressed patients showed -9% and -10% overnight decrease. MS patients with and without corticosteroid therapy did not differ in their amount of REM sleep, nor did MD patients and healthy controls. In addition, we did not find any correlation between REM sleep and memory consolidation. Our results show that a strong intervention into the HPA system like in MS high-dose corticosteroid therapy impairs off-line motor memory consolidation comparable to the impairments seen in depressed patients. We propose therefore that depression-related changes in plasma corticosteroid levels rather than in sleep per se underlie off-line memory consolidation impairments in MD.

Impaired off-line memory consolidation in depression

Sleep is critically involved in the consolidation of procedural memory. In major depression (MD) and during antidepressant pharmacotherapy, changes in sleep EEG are well documented. Here, we test if off-line motor memory consolidation is impaired in MD. 50 medicated patients with an acute episode of MD, 50 normal controls and 12 patients with a remitted episode of MD were assessed using a sequential finger tapping task before and after a night of sleep. Although depressed patients and control subjects did not differ in practice-dependent learning, healthy subjects showed markedly overnight improvements in tapping performance of 18% while patients failed to show any improvement. This pattern became even more striking when the subjects were divided by an age threshold of 30years: In the 30+yrs group the healthy subjects showed 16% overnight increase in motor performance, whereas the patients showed -10% overnight decrease. In contrast, patients and controls in the </=30yrs group showed virtually the same motor performance, as well as remitted patients and controls in the 30+yrs group. In addition, the younger controls showed stronger overnight improvements than the older controls. This pattern might be interpreted as a synergistic interaction between age and depression: Off-line motor memory consolidation is not affected in young patients, but severely impaired in older patients with an acute episode of MD. This impairment seems to recover after remission from depression.

Sleep Induced Mu-Beta Rhythm Modulations in Motor Sequence Memory Consolidation

Event Abstract Back to Event Sleep Induced Mu-Beta Rhythm Modulations in Motor Sequence Memory Consolidation Genevieve Albouy1*, Francoise Lecaignard2, Jeremie Mattout1, Claude Delpuech3, Pierre-Emmanuel Aguera1, Pierre-Herve Luppi4, Alain Nicolas4, Pierre Maquet5 and Olivier Bertrand1 1 University of Lyon, INSERM U821, France 2 CERMEP, Imagerie du Vivant, MEG Dept, France 3 CERMEP/INSERM U821, France 4 University of Lyon, CNRS UMR 5167, France 5 University of Liège, Cyclotron Research Centre, Belgium The neural correlates of motor sequence memory consolidation have already been studied but its electrophysiological correlates remain scarcely described. The aim of the present study was to determine the influence of sleep on the electrophysiological correlates of motor sequence memory consolidation, using magnetoencephalography (275-channel MEG). Subjects were scanned during training on a sequential finger tapping task (FTT). After training, they were divided in two groups whether they slept (N=15) or were totally sleep-deprived (N=16) on the following night. Three days after training, a second MEG session consisted in the retest on the FTT for the two groups. Using ELAN software package (INSERM U821, Lyon), both sessions were analysed in the time frequency (TF) domain, during practice and inter-tapping rest periods. Subsequent group source reconstruction analyses of significant effects during training were performed using SPM8 (Wellcome Department of Imaging Neuroscience, London, UK). TF analyses on the training session show a progressive desynchronization, i.e. a power decrease, of mu (10-15 Hz) and beta (20-25 Hz) oscillations over bilateral and medial central areas during practice of the learned sequence. The anatomical sources of this effect in the beta band were localised in bilateral sensorimotor cortices (pre- and post-central gyri). An overall sleep-dependent increase in the amplitude of mu-beta oscillations was observed over controlateral and medial central areas during both practice periods and inter-tapping rest periods following practice of the learned sequence. Interestingly, in sleepers, a beta power increase was observed specifically for the learned sequence during inter-tapping rest periods. In contrast, no changes in mu-beta oscillatory activity were observed after sleep deprivation. These results provide the first electrophysiological evidence of sleep-dependent reorganisation of motor cortex activity during procedural sequence memory consolidation. Conference: Biomag 2010 - 17th International Conference on Biomagnetism , Dubrovnik, Croatia, 28 Mar - 1 Apr, 2010. Presentation Type: Poster Presentation Topic: Neurocognition and Functional Connectivity Citation: Albouy G, Lecaignard F, Mattout J, Delpuech C, Aguera P, Luppi P, Nicolas A, Maquet P and Bertrand O (2010). Sleep Induced Mu-Beta Rhythm Modulations in Motor Sequence Memory Consolidation. Front. Neurosci. Conference Abstract: Biomag 2010 - 17th International Conference on Biomagnetism . doi: 10.3389/conf.fnins.2010.06.00393 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 08 Apr 2010; Published Online: 08 Apr 2010. * Correspondence: Genevieve Albouy, University of Lyon, INSERM U821, Bron, France, gmalbouy@club-internet.fr Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Genevieve Albouy Francoise Lecaignard Jeremie Mattout Claude Delpuech Pierre-Emmanuel Aguera Pierre-Herve Luppi Alain Nicolas Pierre Maquet Olivier Bertrand Google Genevieve Albouy Francoise Lecaignard Jeremie Mattout Claude Delpuech Pierre-Emmanuel Aguera Pierre-Herve Luppi Alain Nicolas Pierre Maquet Olivier Bertrand Google Scholar Genevieve Albouy Francoise Lecaignard Jeremie Mattout Claude Delpuech Pierre-Emmanuel Aguera Pierre-Herve Luppi Alain Nicolas Pierre Maquet Olivier Bertrand PubMed Genevieve Albouy Francoise Lecaignard Jeremie Mattout Claude Delpuech Pierre-Emmanuel Aguera Pierre-Herve Luppi Alain Nicolas Pierre Maquet Olivier Bertrand Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.