Motor Sequence Task Research Articles

The Relative Impact of Sleep and Circadian Drive on Motor Skill Acquisition and Memory Consolidation.

Sleep during the biological night facilitates memory consolidation. Here we determined the impact of sleep and wake on motor skill learning (acquisition) and subsequent off-line skill improvement (memory consolidation), independent of circadian phase, and compared this to the impact of the endogenous circadian system, independent of whether sleep occurred during the biological night or day. Participants completed two 8-day sleep laboratory visits, adhering on one visit to a circadian aligned ("normal") sleep schedule for the full duration of the protocol, and on the other to a circadian misaligned (12-hour inverted) schedule, with alignment during the first 3 days, a 12-hour 'slam shift' on Day 4, followed by circadian misalignment during the last 4 days of the protocol. Participants were repeatedly trained and tested on different versions of the finger-tapping motor sequence task across each visit. Sleep facilitated offline memory consolidation regardless of whether it occurred during the biological day or night, while circadian phase had no significant impact. These sleep-related benefits remained after accounting for general motor speed, measured in the absence of learning. In addition, motor skill acquisition was facilitated when the training session followed shortly after sleep, without significant impact of circadian phase (biological morning vs. evening). This effect was largely driven by heightened acquisition in participants who slept during the day and were trained shortly thereafter, that is, when acquisition occurred during the biological evening. These benefits were also retained after controlling for general motor speed. Sleep benefits both the acquisition and consolidation of motor skill regardless of whether they occur during the biological day or night. After controlling for general motor speed, a critical adjustment that few studies perform, these sleep benefits remain intact. Our findings have clear implications for night shift workers who obtain their sleep during the day.

Coordination of Slow Waves With Sleep Spindles Predicts Sleep-Dependent Memory Consolidation in Schizophrenia.

Schizophrenia patients have correlated deficits in sleep spindle density and sleep-dependent memory consolidation. In addition to spindle density, memory consolidation is thought to rely on the precise temporal coordination of spindles with slow waves (SWs). We investigated whether this coordination is intact in schizophrenia and its relation to motor procedural memory consolidation. Twenty-one chronic medicated schizophrenia patients and 17 demographically matched healthy controls underwent two nights of polysomnography, with training on the finger tapping motor sequence task (MST) on the second night and testing the following morning. We detected SWs (0.5-4 Hz) and spindles during non-rapid eye movement (NREM) sleep. We measured SW-spindle phase-amplitude coupling and its relation with overnight improvement in MST performance. Patients did not differ from controls in the timing of SW-spindle coupling. In both the groups, spindles peaked during the SW upstate. For patients alone, the later in the SW upstate that spindles peaked and the more reliable this phase relationship, the greater the overnight MST improvement. Regression models that included both spindle density and SW-spindle coordination predicted overnight improvement significantly better than either parameter alone, suggesting that both contribute to memory consolidation. Schizophrenia patients show intact spindle-SW temporal coordination, and these timing relationships, together with spindle density, predict sleep-dependent memory consolidation. These relations were seen only in patients suggesting that their memory is more dependent on optimal spindle-SW timing, possibly due to reduced spindle density. Interventions to improve memory may need to increase spindle density while preserving or enhancing the coordination of NREM oscillations.

High-Intensity Aerobic Exercise Enhances Motor Memory Retrieval.

In previous work, acute high-intensity aerobic exercise benefited continuous motor sequence task learning. As memory processes underlying motor sequence learning vary between tasks involving continuous and discrete movements, the objective of the current study was to determine whether the beneficial effects of acute aerobic exercise generalize to the learning of a discrete motor sequence task. Sixteen young healthy individuals practiced a discrete motor sequence task preceded by either a period of rest or a bout of high-intensity cycling. Participants moved a cursor with a computer mouse to a series of discretely presented targets on a screen. Target presentation followed either a repeated or a random sequence, which allowed the evaluation of implicit sequence-specific motor learning. The change in movement response time over practice (△-ACQ) and from practice to a 24-h "no-exercise" retention test (△-RET) and the rate of improvement over practice (α-ACQ) and during the retention test (α-RET) were calculated. α-RET was greater for the repeated sequence than random sequences after aerobic exercise (P = 0.01), but not rest (P = 0.33). Further, α-RET for the repeated sequence was greater after aerobic exercise than for either sequence (repeated, random) in the rest condition (P ≤ 0.01). There were no differences between sequences and/or conditions for △-ACQ, △-RET, or α-RET (P ≥ 0.57). Our findings show a positive effect of acute high-intensity aerobic exercise on implicit discrete motor sequence learning. Performing exercise before practice increased the rate of improvement at a 24-h delayed retention test, suggesting an effect on the rate of motor memory retrieval. Pairing acute aerobic exercise with motor practice may facilitate learning of discrete movement sequences in sport or rehabilitation settings.

Motor sequencing in older adulthood: relationships with executive functioning and effects of complexity

Objective: Older adults’ motor sequencing performance is more reliant on executive functioning (EF) and more susceptible to complexity than that of younger adults. This study examined for which aspects of motor sequencing performance these relationships hold. Methods: Fifty-seven younger and 90 non-demented, community-dwelling, older adults completed selected subtests from the Delis–Kaplan Executive Function System as indices of EF and component processes (CP; graphomotor speed; visual scanning; etc.), as well as a computerized motor sequencing task (Push Turn Taptap task; PTT). The PTT requires participants to perform motor sequences that become progressively more complex across the task’s four blocks, and is designed to assess action planning, action learning, and motor control speed and accuracy. Results: Hierarchical regressions using each discrete aspect of performance as the dependent variable revealed that action planning is the only aspect of motor sequencing that is uniquely related to EF (beyond the CP composite) for both age groups. Action learning and motor control accuracy are uniquely associated with EF for older adults only, and only if the sequences are complex. Component processes do not fully account for the unique relationships between motor sequencing and EF in older adults. Conclusions: These results clarify prior findings by showing (a) more aspects of motor sequencing relate to EF for older compared to younger adults and (b) for these unique relationships, EF is only related to action during the generation of sequences that are complex. These findings further our understanding of how aging shapes the links between EF and motor actions, and can be used in evidence-based and theoretically driven intervention programs that promote healthy aging.

Motor sequence learning-induced neural efficiency in functional brain connectivity

Previous studies have shown the functional neural circuitry differences before and after an explicitly learned motor sequence task, but have not assessed these changes during the process of motor skill learning. Functional magnetic resonance imaging activity was measured while participants (n=13) were asked to tap their fingers to visually presented sequences in blocks that were either the same sequence repeated (learning block) or random sequences (control block). Motor learning was associated with a decrease in brain activity during learning compared to control. Lower brain activation was noted in the posterior parietal association area and bilateral thalamus during the later periods of learning (not during the control). Compared to the control condition, we found the task-related motor learning was associated with decreased connectivity between the putamen and left inferior frontal gyrus and left middle cingulate brain regions. Motor learning was associated with changes in network activity, spatial extent, and connectivity.

Corticospinal excitability in the non-dominant hand is affected by BDNF genotype.

The objective of this study was to assess the functional state of corticospinal projections in the non-dominant hand according to brain-derived neurotrophic factor (BDNF) Val66Met polymorphisms. We investigated this in 34 healthy right-handed individuals (12 men, mean age 27.4±3.4years) who underwent two experimental sessions consisting of corticospinal excitability measurements with single-pulse transcranial magnetic stimulation (TMS) and hand motor function assessments with a sequential finger motor task of the non-dominant hand. Experimental sessions were separated by periods of at least 2days to avoid carryover effects. Data were analyzed according to BDNF polymorphism (Val/Val vs. Val/Met vs. Met/Met group). Ten (29.4%), seventeen (50.0%), and seven (20.6%) participants were allocated to the Val/Val, Val/Met, and Met/Met groups, respectively. Motor thresholds to TMS did not differ among groups, but the amplitude of the motor-evoked potentials in the non-dominant hand induced by suprathreshold (120% of MT) TMS was significantly lower in the Met/Met group than in the other two groups (p<0.05). Movement accuracy and reaction time in the sequential finger motor task showed no significant differences among groups. These results indicate that Met/Met BDNF homozygote status affects corticospinal excitability, and should be controlled for in studies of motor system function using brain stimulation. Our findings may have clinical implications regarding further investigation of the impact of BDNF genotype on the human motor system.

Children's initial sleep-associated changes in motor skill are unrelated to long-term skill levels.

Sleep is considered to support the formation of skill memory. In juvenile but not adult song birds learning a tutor's song, a stronger initial deterioration of song performance over night-sleep predicts better song performance in the long run. This and similar observations have stimulated the view of sleep supporting skill formation during development in an unsupervised off-line learning process that, in the absence of external feedback, can initially also enhance inaccuracies in skill performance. Here we explored whether in children learning a motor sequence task, as in song-learning juvenile birds, changes across sleep after initial practice predict performance levels achieved in the long run. The task was a serial reaction time task (SRTT) where subjects had to press buttons which were lighted up in a repeating eight-element sequence as fast as possible. Twenty-five children (8-12years) practised the task in the evening before nocturnal sleep which was recorded polysomnographically. Retrieval was tested on the following morning and again 1week later after daily training on the SRTT. As expected, changes in response speed over the initial night of sleep were negatively correlated with final performance speed after the 1-week training. However, unlike in song birds, this correlation was driven by the baseline speed level achieved before sleep. Baseline-corrected changes in speed or variability over the initial sleep period did not predict final performance on the trained SRTT sequence, or on different sequences introduced to assess generalization of the trained behaviour. The lack of correlation between initial sleep-dependent changes and long-term performance might reflect that the children were too experienced for the simple SRTT, possibly also favouring ceiling effects in performance. A consistent association found between sleep spindle activity and explicit sequence knowledge alternatively suggests that the expected correlation was masked by explicit memory systems interacting with skill memory formation.

Cerebral Activity Associated with Transient Sleep-Facilitated Reduction in Motor Memory Vulnerability to Interference.

Motor memory consolidation is characterized, in part, by a sleep-facilitated decrease in susceptibility to subsequent interfering experiences. Surprisingly, the cerebral substrates supporting this phenomenon have never been examined. We used fMRI to investigate the neural correlates of the influence of sleep on interference to motor memory consolidation. Healthy young adults were trained on a sequential motor task, and subsequently practiced a second competing sequence after an interval including diurnal sleep or wakefulness. Participants were then retested on the initial sequence 8 h and 24 h (including nocturnal sleep) after training. Results demonstrated that a post-training nap significantly protected memory against interference at 8 h and modulated the link between cerebral activity and behavior, such that a smaller post-interference decrease in cortico-striatal activity was associated with better performance. Interestingly, the protective effect of a nap was only transitory, as both groups performed similarly at 24 h. Activity in cortico-striatal areas that was disrupted during the day, presumably due to interference and accentuated in the absence of a nap, was restored overnight. Altogether, our findings offer the first evidence that cortico-striatal areas play a critical role in the transient sleep-facilitated reduction in motor memory vulnerability and in the overnight restoration of previously degraded memories.

The Effect of Age-Related Changes and Explicit and Implicit Awareness on Mixed Motor Sequence Learning and its Consolidation

Introduction: This study aimed to investigate the effects of age-related changes and explicit and implicit knowledge on mixed motor sequence learning and its consolidation. Materials and Methods: In this study, 96 right-handed boys who were healthy considering nervous system with age range of 6-18 years were selected via convenience sampling method. Serial reaction time task (SRTT) was used to evaluate and compare the performance in two components of response time and accuracy. The intervention was consisted of 10 stages (8 blocks for acquisition and 2 blocks for consolidation) in which the performances of groups were compared. The data were analyzed using mixed ANOVA test in 2 (type of learning) × 4 (age groups) × 8 (blocks) and Bonferroni test was used for paired comparisons. Results: In acquisition phase for response time, significant main effects were observed for block (P = 0.031) and age (P = 0.001), not learning conditions (P = 0.431). For response accuracy, significant main effects were observed for block (P = 0.001), age (P = 0.001) and learning conditions (P = 0.003). In addition, the performances of groups across the two first blocks of practice on the second day were better compared with the first day in response time (P = 0.001) and accuracy (P = 0.001), which represented the consolidation of motor learning. Conclusion: The findings showed that among different age groups, there were age-related functional changes in the acquisition and consolidation of response time and accuracy for motor sequence task. Moreover, the various components of the movement (speed and accuracy) can be performed and consolidated in different ways. This matter should be considered in educational and rehabilitation interventions related to children and adolescents.

Experience Playing a Musical Instrument and Overnight Sleep Enhance Performance on a Sequential Typing Task.

The smooth, coordinated fine motor movements required to play a musical instrument are not only highly valued in our society; they also predict academic success in areas that generalize beyond the motor domain, including reading and math readiness, and verbal abilities. Interestingly, motor skills that overlap with those required to play a musical instrument (e.g., sequential finger tapping) markedly improve (get faster) over a night of sleep, but not after a day spent awake. Here we studied whether individuals who play musical instruments that require fine finger motor skill are better able to learn and consolidate a simple motor skill task compared to those who do not play an instrument, and whether sleep-specific motor skill benefits interact with those imparted by musical experience. We used the motor sequence task (MST), which taps into a core skill learned and used by musicians, namely, the repetition of learned sequences of key presses. Not surprisingly, we found that musicians were faster than non-musicians throughout the learning session, typing more correct sequences per 30-sec trial. In the 12hrs that followed learning we found that sleep and musical experience both led to greater improvement in performance. Surprisingly, musicians retested after a day of wake performed slightly better than non-musicians who had slept between training and retest, suggesting that musicians have the capacity to consolidate a motor skill across waking hours, while non-musicians appear to lack this capacity. These findings suggest that the musically trained brain is optimized for motor skill consolidation across both wake and sleep, and that sleep may simply promote a more effective use of this machinery. In sum, there may be something special about musicians, perhaps a neurophysiological advantage, that leads to both the expected—greater motor speed at learning—and the surprising—greater motor skill improvement over time.

Motor Skills Enhance Procedural Memory Formation and Protect against Age-Related Decline.

The ability to consolidate procedural memories declines with increasing age. Prior knowledge enhances learning and memory consolidation of novel but related information in various domains. Here, we present evidence that prior motor experience–in our case piano skills–increases procedural learning and has a protective effect against age-related decline for the consolidation of novel but related manual movements. In our main experiment, we tested 128 participants with a sequential finger-tapping motor task during two sessions 24 hours apart. We observed enhanced online learning speed and offline memory consolidation for piano players. Enhanced memory consolidation was driven by a strong effect in older participants, whereas younger participants did not benefit significantly from prior piano experience. In a follow up independent control experiment, this compensatory effect of piano experience was not visible after a brief offline period of 30 minutes, hence requiring an extended consolidation window potentially involving sleep. Through a further control experiment, we rejected the possibility that the decreased effect in younger participants was caused by training saturation. We discuss our results in the context of the neurobiological schema approach and suggest that prior experience has the potential to rescue memory consolidation from age-related cognitive decline.

Reported Expressive Suppression in Daily Life Is Associated with Slower Action Planning.

Objectives Growing evidence demonstrates that (a) executive functioning (EF) becomes deleteriously affected by engagement in the emotion regulation strategy known as expressive suppression and (b) EF shows considerable functional and neuroanatomical overlap with motor output. The current study aimed to bridge these two literatures by examining the relationships between naturally occurring expressive suppression and several different aspects of motor output, including action planning, action learning, and motor-control speed and accuracy. In addition, we investigated whether any identified relationships could be explained by EF. Methods Fifty-one healthy young adults completed selected subtests from the Delis-Kaplan Executive Function System as indices of EF, a self-report measure of expressive suppression, and a computerized motor sequencing task (Push Turn Taptap task; PTT) designed to assess action planning, action learning, and motor control speed and accuracy. Results Hierarchical regressions using each aspect of PTT performance as the dependent variable revealed that higher than usual self-reported expressive suppression on the day of testing (relative to the 2 weeks preceding testing) was associated with longer action-planning latencies. This relationship was fully explained by EF. No other PTT variables related to expressive suppression on the day of testing. Conclusions These results suggest that increased expressive suppression in daily life is associated with slower action planning, an aspect of motor output that is reliant on EF, highlighting the importance of factors that lead to intra-individual fluctuations in EF and motor performance. (JINS, 2016, 22, 671-681).

Stage 2 Sleep EEG Sigma Activity and Motor Learning in Childhood ADHD: A Pilot Study

Attention deficit hyperactivity disorder (ADHD) is associated with deficits in motor learning and sleep. In healthy adults, overnight improvements in motor skills are associated with sleep spindle activity in the sleep electroencephalogram (EEG). This association is poorly characterized in children, particularly in pediatric ADHD. Polysomnographic sleep was monitored in 7 children with ADHD and 14 typically developing controls. All children were trained on a validated motor sequence task (MST) in the evening with retesting the following morning. Analyses focused on MST precision (speed–accuracy trade-off). NREM Stage 2 sleep EEG power spectral analyses focused on spindle-frequency EEG activity in the sigma (12–15 Hz) band. The ADHD group demonstrated a selective decrease in power within the sigma band. Evening MST precision was lower in ADHD, yet no difference in performance was observed following sleep. Moreover, ADHD status moderated the association between slow sleep spindle activity (12–13.5 Hz) and overnight improvement; spindle-frequency EEG activity was positively associated with performance improvements in children with ADHD but not in controls. These data highlight the importance of sleep in supporting next-day behavior in ADHD while indicating that differences in sleep neurophysiology may contribute to deficits in this population.

Complimentary lower-level and higher-order systems underpin imitation learning

We examined whether the temporal representation developed during motor training with reduced-frequency knowledge of results (KR; feedback available on every other trial) was transferred to an imitation learning task. To this end, four groups first practised a three-segment motor sequence task with different KR protocols. Two experimental groups received reduced-frequency KR, one group received high-frequency KR (feedback available on every trial), and one received no-KR. Compared to the no-KR group, the groups that received KR learned the temporal goal of the movement sequence, as evidenced by increased accuracy and consistency across training. Next, all groups learned a single-segment movement that had the same temporal goal as the motor sequence task but required the imitation of biological and nonbiological motion kinematics. Kinematic data showed that whilst all groups imitated biological motion kinematics, the two experimental reduced-frequency KR groups were on average ∼800ms more accurate at imitating movement time than the high-frequency KR and no-KR groups. The interplay between learning biological motion kinematics and the transfer of temporal representation indicates imitation involves distinct, but complementary lower-level sensorimotor and higher-level cognitive processing systems.

Thinking About a Task Is Associated with Increased Connectivity in Regions Activated by Task Performance.

We investigated whether functional neuroimaging of quiet "rest" can reveal the neural correlates of conscious thought. Using resting-state functional MRI, we measured functional connectivity during a resting scan that immediately followed performance of a finger tapping motor sequence task. Self-reports of the amount of time spent thinking about the task during the resting scan correlated with connectivity between regions of the motor network activated during task performance. Thus, thinking about a task is associated with coordinated activity in brain regions responsible for that task's performance. More generally, this study demonstrates the feasibility of using the combination of functional connectivity MRI and self-reports to examine the neural correlates of thought.

Does Transcranial Alternating Current Stimulation Induce Cerebellum Plasticity? Feasibility, Safety and Efficacy of a Novel Electrophysiological Approach.

Cerebellum-brain functional connectivity can be shaped through different non-invasive neurostimulation approaches. In this study, we propose a novel approach to perturb the cerebellum-brain functional connectivity by means of transcranial alternating current stimulation (tACS). Twenty-five healthy individuals underwent a cerebellar tACS protocol employing different frequencies (10, 50, and 300 Hz) and a sham-tACS over the right cerebellar hemisphere. We measured their after-effects on the motor evoked potential (MEP) amplitude, the cerebellum-brain inhibition (CBI), the long-latency intracortical inhibition (LICI), from the primary motor cortex of both the hemispheres. In addition, we assessed the functional adaptation to a right hand sequential tapping motor task. None of the participants had any side-effect. Following 50 Hz-tACS, we observed a clear contralateral CBI weakening, paralleled by a MEP increase with a better adaptation to frequency variations during the sequential tapping. The 300 Hz-tACS induced a contralateral CBI strengthening, without significant MEP and kinematic after-effects. The 10 Hz-tACS conditioning was instead ineffective. We may argue that tACS protocols could have interfered with the activity of CBI-sustaining Purkinje cell, affecting motor adaptation. Our safe approach seems promising in studying the cerebellum-brain functional connectivity, with possible implications in neurorehabilitative settings.

Magnifying visual target information and the role of eye movements in motor sequence learning

An experiment investigated the influence of eye movements on learning a simple motor sequence task when the visual display was magnified. The task was to reproduce a 1300ms spatial–temporal pattern of elbow flexions and extensions. The spatial–temporal pattern was displayed in front of the participants. Participants were randomly assigned to four groups differing on eye movements (free to use their eyes/instructed to fixate) and the visual display (small/magnified). All participants had to perform a pre-test, an acquisition phase, a delayed retention test, and a transfer test. The results indicated that participants in each practice condition increased their performance during acquisition. The participants who were permitted to use their eyes in the magnified visual display outperformed those who were instructed to fixate on the magnified visual display. When a small visual display was used, the instruction to fixate induced no performance decrements compared to participants who were permitted to use their eyes during acquisition. The findings demonstrated that a spatial–temporal pattern can be learned without eye movements, but being permitting to use eye movements facilitates the response production when the visual angle is increased.

Sleep benefits consolidation of visuo-motor adaptation learning in older adults.

Sleep is beneficial for performance across a range of memory tasks in young adults, but whether memories are similarly consolidated in older adults is less clear. Performance benefits have been observed following sleep in older adults for declarative learning tasks, but this benefit may be reduced for non-declarative, motor skill learning tasks. To date, studies of sleep-dependent consolidation of motor learning in older adults are limited to motor sequence tasks. To examine whether reduced sleep-dependent consolidation in older adults is generalizable to other forms of motor skill learning, we examined performance changes over intervals of sleep and wake in young (n = 62) and older adults (n = 61) using a mirror-tracing task, which assesses visuo-motor adaptation learning. Participants learned the task either in the morning or in evening, and performance was assessed following a 12-h interval containing overnight sleep or daytime wake. Contrary to our prediction, both young adults and older adults exhibited sleep-dependent gains in visuo-motor adaptation. There was a correlation between performance improvement over sleep and percent of the night in non-REM stage 2 sleep. These results indicate that motor skill consolidation remains intact with increasing age although this relationship may be limited to specific forms of motor skill learning.

Genetics, sleep and memory: a recall-by-genotype study of ZNF804A variants and sleep neurophysiology.

BackgroundSchizophrenia is a complex, polygenic disorder for which over 100 genetic variants have been identified that correlate with diagnosis. However, the biological mechanisms underpinning the different symptom clusters remain undefined. The rs1344706 single nucleotide polymorphism within ZNF804A was among the first genetic variants found to be associated with schizophrenia. Previously, neuroimaging and cognitive studies have revealed several associations between rs1344706 and brain structure and function. The aim of this study is to use a recall-by-genotype (RBG) design to investigate the biological basis for the association of ZNF804A variants with schizophrenia. A RBG study, implemented in a population cohort, will be used to evaluate the impact of genetic variation at rs1344706 on sleep neurophysiology and procedural memory consolidation in healthy participants.Methods/DesignParticipants will be recruited from the Avon Longitudinal Study of Parents and Children (ALSPAC) on the basis of genotype at rs1344706 (n = 24). Each participant will be asked to take part in two nights of in-depth sleep monitoring (polysomnography) allowing collection of neurophysiological sleep data in a manner not amenable to large-scale study. Sleep questionnaires will be used to assess general sleep quality and subjective sleep experience after each in-house recording. A motor sequencing task (MST) will be performed before and after the second night of polysomnography. In order to gather additional data about habitual sleep behaviour participants will be asked to wear a wrist worn activity monitor (actiwatch) and complete a sleep diary for two weeks.DiscussionThis study will explore the biological function of ZNF804A genotype (rs1344706) in healthy volunteers by examining detailed features of sleep architecture and physiology in relation to motor learning. Using a RBG approach will enable us to collect precise and detailed phenotypic data whilst achieving an informative biological gradient. It would not be feasible to collect such data in the large sample sizes that would be required under a random sampling scheme. By dissecting the role of individual variants associated with schizophrenia in this way, we can begin to unravel the complex genetic mechanisms of psychiatric disorders and pave the way for future development of novel therapeutic approaches.Electronic supplementary materialThe online version of this article (doi:10.1186/s12881-015-0244-4) contains supplementary material, which is available to authorized users.

The Suppression of Beta Oscillations in the Primate Supplementary Motor Complex Reflects a Volatile State During the Updating of Action Sequences

The medial motor areas play crucial but flexible roles in the temporal organizations of multiple movements. The beta oscillation of local field potentials is the predominant oscillatory activity in the motor areas, but the manner in which increases and decreases in beta power contribute to updating of multiple action plans is not yet fully understood. In the present study, beta and high-gamma activities in the supplementary motor area (SMA) and pre-SMA of monkeys were analyzed during performance of a bimanual motor sequence task that required updating and maintenance of the memory of action sequences. Beta power was attenuated during early delay periods of updating trials but was increased during maintenance trials, while there was a reciprocal increase in high-gamma power during updating trials. Moreover, transient attenuation of beta power during maintenance trials resulted in the erroneous selection of an action sequence. Therefore, it was concluded that the suppression of beta power during the early delay period reflects volatility of neural representation of the action sequence. This neural representation would be properly updated to the appropriate instructed action sequence via increases in high-gamma power in updating trials whereas it would be erroneously updated without the appropriate updating signal in maintenance trials.