Retention Of Motor Skill Research Articles

Motor Skill Retention Is Modulated by Strategy Choice During Self-Controlled Knowledge of Results Schedules

Investigations into the strategies that are used by participants when they control their knowledge of results (KR) schedule during practice have predominantly relied on multiple-choice questionnaires. More recently, open-ended questions have been used to allow participants to produce their own descriptions rather than selecting a strategy from a predetermined list. This approach has in fact generated new information about the cognitive strategies used by learners to request KR during practice (e.g., Laughlin et al., 2015). Consequently, we examined strategy use in self-controlled KR learning situations using open-ended questions at two different time points during practice. An inductive thematic content analysis revealed five themes that represented participants’ unique strategies for requesting KR. This analysis identified two dominant KR strategies: “establish a baseline understanding” in the first half of practice and “confirm a perceived good trial” in the second half of practice. Both strategies were associated with superior retention compared with a yoked group, a group that was unable to engage in KR request strategies because KR was imposed rather than chosen. Our results indicate that the learning advantages of self-controlled KR schedules over yoked schedules may not only depend on what strategy is used, but also when it is used.

A Single Bout of Moderate Aerobic Exercise Improves Motor Skill Acquisition.

Long-term exercise is associated with improved performance on a variety of cognitive tasks including attention, executive function, and long-term memory. Remarkably, recent studies have shown that even a single bout of aerobic exercise can lead to immediate improvements in declarative learning and memory, but less is known about the effect of exercise on motor learning. Here we sought to determine the effect of a single bout of moderate intensity aerobic exercise on motor skill learning. In experiment 1, we investigated the effect of moderate aerobic exercise on motor acquisition. 24 young, healthy adults performed a motor learning task either immediately after 30 minutes of moderate intensity running, after running followed by a long rest period, or after slow walking. Motor skill was assessed via a speed-accuracy tradeoff function to determine how exercise might differentially affect two distinct components of motor learning performance: movement speed and accuracy. In experiment 2, we investigated both acquisition and retention of motor skill across multiple days of training. 20 additional participants performed either a bout of running or slow walking immediately before motor learning on three consecutive days, and only motor learning (no exercise) on a fourth day. We found that moderate intensity running led to an immediate improvement in motor acquisition for both a single session and on multiple sessions across subsequent days, but had no effect on between-day retention. This effect was driven by improved movement accuracy, as opposed to speed. However, the benefit of exercise was dependent upon motor learning occurring immediately after exercise–resting for a period of one hour after exercise diminished the effect. These results demonstrate that moderate intensity exercise can prime the nervous system for the acquisition of new motor skills, and suggest that similar exercise protocols may be effective in improving the outcomes of movement rehabilitation programs.

Interactions Among Learning Stage, Retention, and Primary Motor Cortex Excitability in Motor Skill Learning.

Previous studies have shown that primary motor cortex (M1) excitability is modulated by motor skill learning and that the M1 plays a crucial role in motor memory. However, the following questions remain: (1) At what stage do changes in M1 excitability occur? (2) Are learning-induced changes in leg M1 excitability associated with motor memory? Here, we did two experiments to answer these questions. In experiment 1, subjects learned a visuomotor tracking task over two consecutive days. Before and after the task in Day 1, we recorded input-output curves of the motor evoked potentials (I-O curve) produced in the tibialis anterior muscle by transcranial magnetic stimulation. We found that the changes in M1 excitability were affected by learning stage. In addition, the changes in M1 excitability in Day 1 were correlated with the retention. In experiment 2, we recorded I-O curves before learning, after the fast-learning stage, and after learning. We found no changes in M1 excitability immediately after the fast-learning stage. Furthermore, a significant relationship between the length of slow-learning stage and the changes in M1 excitability was detected. Previous studies have suggested that optimal motor commands are repeatedly used during the slow-learning stage. Therefore, present results indicate that changes in M1 excitability occur during the slow-learning stage and that such changes are proportional to motor skill retention because use-dependent plasticity occur by repetitive use of same motor commands during the slow-learning stage.

P195. Impaired motor learning in older adults-concepts of underlying mechanisms and strategies for supporting impaired functions

Introduction The aging population is facing important challenges associated to impairments in cognitive abilities including sensorimotor functions. In our daily life the acquisition and long-term retention of motor skills play a crucial role for the appropriate implementation of motor acts, such as practicing sport or the use of modern communication tools. Notably, motor cortical plasticity is altered in older adults (OA) due to changes in neurotransmission and synaptic functioning. Changes in GABAergic activity and its modulatory capacity has been described, as well as diminished LTP-like mechanisms contributing to associative plasticity and motor memory formation. Strong interest lies in the understanding of age-associated mechanisms underlying impairment of motor performance and motor learning in old and in possible ways of ameliorating age-related deficits in these domains. Methods Experiment 1: We investigated the process of learning of sequential finger tapping in a group of 15 healthy OA (73.9 ± 5.9 years ± standard deviation [SD]) and compared to 15 healthy young subjects (24.4 ± 3.5 SD). The learning process was accompanied by double-pulse transcranial magnetic stimulation (dp-TMS) in order to investigate intracortical effects during the learning process reflecting activity of GABAergic neurotransmission. The task was performed during 5 consecutive training days, with 3 follow-up time points on day 10, 20 and 60. Experiment 2 : In a subsequent experiment, we investigated the effects of transcranial direct current stimulation (tDCS) in a group of 28 healthy OA aged 72.0 ± 5.4 SD. tDCS provides the possibility to modulate cortical excitability and neuroplasticity. We tested the hypothesis that tDCS in combination with training will enhance the effect of skill acquisition in OA. In our double-blind, placebo controlled study tDCS was applied to the motor cortex, contralateral to the training performing hand. Either anodal or placebo/sham stimulation was applied for 20 min while subjects underwent the same training as mentioned above. Results Experiment 1: Analyses revealed impaired skill acquisition in the OA group in relation to the young group during training period (pMOVE). The group of young healthy subjects showed learning related changes of SICI MOVE towards an enhanced event-related disinhibition. This was not the case for OA. Experiment 2: The group receiving real stimulation showed a different learning curve in the 5 days of training with significantly enhanced skill acquisition compared to the sham group ( p = 0.044), a behavioral effect still apparent 60 days after interventions. Conclusions Motor skill acquisition was impaired in healthy older subjects, this effect was mainly driven by a reduction in offline effects. Furthermore, tDCS can ameliorate age-related deficits in the acquisition of a novel motor skill, offering a promising interventional strategy to address age-related cognitive deficits.

Effects of Visual Feedback Distortion on Gait Adaptation: Comparison of Implicit Visual Distortion Versus Conscious Modulation on Retention of Motor Learning.

Visual feedback can be used during gait rehabilitation to improve the efficacy of training. We presented a paradigm called visual feedback distortion; the visual representation of step length was manipulated during treadmill walking. Our prior work demonstrated that an implicit distortion of visual feedback of step length entails an unintentional adaptive process in the subjects' spatial gait pattern. Here, we investigated whether the implicit visual feedback distortion, versus conscious correction, promotes efficient locomotor adaptation that relates to greater retention of a task. Thirteen healthy subjects were studied under two conditions: (1) we implicitly distorted the visual representation of their gait symmetry over 14 min, and (2) with help of visual feedback, subjects were told to walk on the treadmill with the intent of attaining the gait asymmetry observed during the first implicit trial. After adaptation, the visual feedback was removed while subjects continued walking normally. Over this 6-min period, retention of preserved asymmetric pattern was assessed. We found that there was a greater retention rate during the implicit distortion trial than that of the visually guided conscious modulation trial. This study highlights the important role of implicit learning in the context of gait rehabilitation by demonstrating that training with implicit visual feedback distortion may produce longer lasting effects. This suggests that using visual feedback distortion could improve the effectiveness of treadmill rehabilitation processes by influencing the retention of motor skills.

Functional connectivity underlying postural motor adaptation in people with multiple sclerosis.

A well-characterized neural network is associated with motor learning, involving several brain regions known to have functional and structural deficits in persons with multiple sclerosis (PwMS). However, it is not known how MS affects postural motor learning or the neural networks involved. The aim of this study was to gain a better understanding of the neural networks underlying adaptation of postural responses within PwMS. Participants stood on a hydraulically driven, servo-controlled platform that translated horizontally forward and backward in a continuous sinusoidal pattern across multiple trials over two consecutive days. Our results show similar postural adaptation between PwMS and age-matched control participants despite overall deficits in postural motor control in PwMS. Moreover, PwMS demonstrated better retention the following day. PwMS had significantly reduced functional connectivity within both the cortico-cerebellar and cortico-striatal motor loops; neural networks that subserve implicit motor learning. In PwMS, greater connectivity strength within the cortico-cerebellar circuit was strongly related to better baseline postural control, but not to postural adaptation as it was in control participants. Further, anti-correlated cortico-striatal connectivity within the right hemisphere was related to improved postural adaptation in both groups. Taken together with previous studies showing a reduced reliance on cerebellar- and proprioceptive-related feedback control in PwMS, we suggest that PwMS may rely on cortico-striatal circuitry to a greater extent than cortico-cerebellar circuitry for the acquisition and retention of motor skills.

Interaction of memory systems during acquisition of tool knowledge and skills in Parkinson's disease

Previous research suggests that different aspects of tool knowledge are mediated by different memory systems. It is believed that tool attributes (e.g., function, color) are represented as declarative memory while skill learning is supported by procedural memory. It has been proposed that other aspects (e.g., skilled tool use) may rely on an interaction of both declarative and procedural memory. However, the specific form of procedural memory underlying skilled tool use and the nature of interaction between declarative and procedural memory systems remain unclear. In the current study, individuals with Parkinson's disease (PD) and healthy controls were trained over 2 sessions, 3 weeks apart, to use a set of novel complex tools. They were also tested on their ability to recall tool attributes as well as their ability to demonstrate grasp and use of the tools to command. Results showed that, compared to controls, participants with PD showed intact motor skill acquisition and tool use to command within sessions, but failed to retain performance across sessions. In contrast, people with PD showed equivalent recall of tool attributes and tool grasping relative to controls, both within and across sessions. Current findings demonstrate that the frontal-striatal network, compromised in PD, mediates long-term retention of motor skills. Intact initial skill learning raises the possibility of compensation from declarative memory for frontal-striatal dysfunction. Lastly, skilled tool use appears to rely on both memory systems which may reflect a cooperative interaction between the two systems. Current findings regarding memory representations of tool knowledge and skill learning may have important implications for delivery of rehabilitation programs for individuals with PD.

BDNF Val66Met polymorphism is associated with abnormal interhemispheric transfer of a newly acquired motor skill

Recent data suggest that the Val66Met polymorphism of the brain-derived neurotrophic factor (BDNF) gene can alter cortical plasticity within the motor cortex of carriers, which exhibits abnormally low rates of cortical reorganization after repetitive motor tasks. To verify whether long-term retention of a motor skill is also modulated by the presence of the polymorphism, 20 participants (10 Val66Val, 10 Val66Met) were tested twice at a 1-wk interval. During each visit, excitability of the motor cortex was measured by transcranial magnetic stimulations (TMS) before and after performance of a procedural motor learning task (serial reaction time task) designed to study sequence-specific learning of the right hand and sequence-specific transfer from the right to the left hand. Behavioral results showed a motor learning effect that persisted for at least a week and task-related increases in corticospinal excitability identical for both sessions and without distinction for genetic group. Sequence-specific transfer of the motor skill from the right hand to the left hand was greater in session 2 than in session 1 only in the Val66Met genetic group. Further analysis revealed that the sequence-specific transfer occurred equally at both sessions in the Val66Val genotype group. In the Val66Met genotype group, sequence-specific transfer did not occur at session 1 but did at session 2. These data suggest a limited impact of Val66Met polymorphism on the learning and retention of a complex motor skill and its associated changes in corticospinal excitability over time, and a possible modulation of the interhemispheric transfer of procedural learning.

The effects of inaccessible visual feedback used concurrently or terminally.

[Purpose] Concurrent feedback is more detrimental for long-term retention of motor skills because learners depend on accessible visual information provided in parallel with movements. However, visual information is not always accessible. Furthermore, the effects of concurrent feedback vary with aspects of the task being performed. We investigated the effects of inaccessible visual feedback used concurrently or terminally, focusing on aspects of movement. [Subjects and Methods] Fourteen subjects were quasi-randomly assigned to either a concurrent feedback group or a terminal feedback group. They practiced a task that involved right shoulder flexion with a specific acceleration. Learning achievements were assessed by measurement of errors in movement duration, peak timing, and strength. [Results] Regarding errors in movement duration, the concurrent feedback group was superior to the terminal feedback group during the midterm and final sessions. Regarding errors in peak timing, learning occurred in the concurrent feedback group, but not in the terminal feedback group because the improvement in performance during practice was inadequate. Regarding errors in peak strength, learning occurred in both groups. [Conclusion] Concurrent visual feedback that is used inaccessibly has learning effects that either equal or surpass those of terminal feedback that is used with inaccessible visual information for all parameters.

Synapses need coordination to learn motor skills

Experience-dependent remodeling of synaptic structure and function underlies information storage in the mammalian central nervous system. Although accumulating evidence suggests synergistic roles of long-term depression (LTD) and long-term potentiation (LTP) in cerebellar motor learning, their structural correlates and operational mechanisms have not been clearly addressed. A recent three-dimensional electron microscopic study provides insight for a potential complementary interplay between LTP and LTD in local dendritic segments of Purkinje cells of motor skill-trained animals. Complex motor skill training induced strengthening of a subset of parallel fiber synapses onto Purkinje cells by forming multiple-synapse boutons (MSBs) contacting spine pairs arising from the same dendrite, whereas MSB-neighboring synapses were weakened by reducing the size of the postsynaptic density. Here, we discuss these orchestrated structural modifications of neighboring synapses that may sharpen synaptic weight contrast in local dendritic segments, leading to enhanced signal-to-noise ratio for optimal motor skill retention.

Noninvasive brain stimulation can elucidate and interact with the mechanisms underlying motor learning and retention: implications for rehabilitation

Seminal work in animals indicates that learning a motor task results in long-term potentiation (LTP) in primary motor cortex (M1) and a subsequent occlusion of LTP induction (Rioult-Pedotti et al. J Neurophysiol 98: 3688-3695, 2007). Using various forms of noninvasive brain stimulation in conjunction with a motor learning paradigm, Cantarero et al. (J Neurosci 33: 12862-12869, 2013) recently provided novel evidence to support the hypothesis that retention of motor skill is contingent upon this postlearning occlusion.

Persistent coordination patterns in a complex task after 10 years delay: Subtitle: How validate the old saying “Once you have learned how to ride a bicycle, you never forget!”

Motor learning studies have for a long time focused on performance variables (in terms of speed or accuracy) in assessing learning, transfer and retention of motor skills. We argue, however, that learning essentially resides in changes in coordination variables (in terms of qualitative organization of behavior) and that relevant tests for assessing the effectiveness of learning and retention should consider these variables. The aim of this experiment was to test the retention of a complex motor skill, after a long-term delay. Ten years ago, five participants were involved in an experiment during which they practiced for 39 sessions of ten 1-min trials on a ski-simulator. All participants volunteered for a retention test, ten years after, for one session of ten 1-min trials. Analyses focused on the oscillations of the platform of the simulator. Performance was assessed in terms of amplitude and frequency. Coordination was accounted for by an analysis of dynamical properties of the motion of the platform, and especially the nature of the damping function that was exploited for sustaining the limit cycle dynamics. Results showed a significant decrement in performance variables. In contrast, all participants adopted from the first trial onwards the coordination mode they learned 10years ago. These results confirm the strong persistence of coordination modes, once acquired and stabilized in the behavioral repertoire. They also support the importance of coordination variables for a valid assessment of learning and retention.

Promoting neuroplasticity for motor rehabilitation after stroke: considering the effects of aerobic exercise and genetic variation on brain-derived neurotrophic factor.

Recovery of motor function after stroke involves relearning motor skills and is mediated by neuroplasticity. Recent research has focused on developing rehabilitation strategies that facilitate such neuroplasticity to maximize functional outcome poststroke. Although many molecular signaling pathways are involved, brain-derived neurotrophic factor (BDNF) has emerged as a key facilitator of neuroplasticity involved in motor learning and rehabilitation after stroke. Thus, rehabilitation strategies that optimize BDNF effects on neuroplasticity may be especially effective for improving motor function poststroke. Two potential poststroke rehabilitation strategies that consider the importance of BDNF are the use of aerobic exercise to enhance brain function and the incorporation of genetic information to individualize therapy. Converging evidence demonstrates that aerobic exercise increases BDNF production and consequently enhances learning and memory processes. Nevertheless, a common genetic variant reduces activity-dependent secretion of the BDNF protein. Thus, BDNF gene variation may affect response to motor rehabilitation training and potentially modulate the effects of aerobic exercise on neuroplasticity. This perspective article discusses evidence that aerobic exercise promotes neuroplasticity by increasing BDNF production and considers how aerobic exercise may facilitate the acquisition and retention of motor skills for poststroke rehabilitation. Next, the impact of the BDNF gene val66met polymorphism on motor learning and response to rehabilitation is explored. It is concluded that the effects of aerobic exercise on BDNF and motor learning may be better exploited if aerobic exercise is paired more closely in time with motor training. Additionally, information about BDNF genotype could provide insight into the type and magnitude of effects that aerobic exercise may have across individuals and potentially help guide an individualized prescription of aerobic exercise to enhance motor rehabilitation poststroke.

Basketball training increases striatum volume

The striatum is associated with the learning and retention of motor skills. Several studies have shown that motor learning induces neuronal changes in the striatum. We investigated whether macroscopic change in striatum volume occurs in a segment of the human population who learned basketball-related motor skills and practiced them throughout their entire athletic life. Three-dimensional magnetic resonance imaging volumetry was performed in basketball players and healthy controls, and striatum volumes were compared based on basketball proficiency, region and side. We identified morphological enlargement in the striatum of basketball players in comparison with controls. Our results suggest that continued practice and repetitive performance of basketball-related motor skills may induce plastic structural changes in the human striatum.

The Resting Human Brain and Motor Learning

SummaryFunctionally related brain networks are engaged even in the absence of an overt behavior. The role of this resting state activity, evident as low-frequency fluctuations of BOLD (see [1] for review, [2–4]) or electrical [5, 6] signals, is unclear. Two major proposals are that resting state activity supports introspective thought or supports responses to future events [7]. An alternative perspective is that the resting brain actively and selectively processes previous experiences [8]. Here we show that motor learning can modulate subsequent activity within resting networks. BOLD signal was recorded during rest periods before and after an 11 min visuomotor training session. Motor learning but not motor performance modulated a fronto-parietal resting state network (RSN). Along with the fronto-parietal network, a cerebellar network not previously reported as an RSN was also specifically altered by learning. Both of these networks are engaged during learning of similar visuomotor tasks [9–22]. Thus, we provide the first description of the modulation of specific RSNs by prior learning—but not by prior performance—revealing a novel connection between the neuroplastic mechanisms of learning and resting state activity. Our approach may provide a powerful tool for exploration of the systems involved in memory consolidation.

Experience-Dependent Plasticity of Cerebellar Vermis in Basketball Players

The cerebellum is involved in the learning and retention of motor skills. Using animal and human models, a number of studies have shown that long-term motor skill training induces structural and functional plasticity in the cerebellum. The aim of this study was to investigate whether macroscopic alteration in the volume of cerebellum occurs in basketball players who had learned complex motor skills and practiced them intensively for a long time. Three-dimensional magnetic resonance imaging volumetry was performed in basketball players (n = 19) and healthy controls (n = 20), and the volumes of cerebellum and vermian lobules were compared between two groups. Although there was no macroscopic plasticity detected in the cerebellum as a whole, detailed parcellation of cerebellum revealed morphological enlargement in the vermian lobules VI-VII (declive, folium, and tuber) of basketball players (P < 0.0166), which might then be interpreted as evidence for plasticity. This finding suggests that the extensive practice and performance of sports-related motor skills activate structural plasticity of vermian lobules in human cerebellum and suggests that vermian VI-VII plays an important role in motor learning.

Revisiting the Value of Somatic Education in Dance Training Through an Inquiry into Practice Schedules

The practice conditions within dance training have remained essentially unchanged for decades. Those conditions appear to be based largely on a “culture of rigor,” a philosophy of which implies that continuous practice is the most beneficial way to improve (motor) skills. Current evidence in motor learning supports the concept of “distributed practice,” in which the resting phase within a practice session is comparable to, or longer than, the activity phase. Researchers in motor learning have shown distributed practice to be more beneficial to acquisition and retention of motor skills, and to decreased rates of injury, than continuous (“massed”) practice. At the center of somatic education is a pedagogical emphasis on balancing rest with activity. The authors reopen the question of the value of somatic education within dance training, drawing upon experiential evidence from their qualitative research and other recent research in neuroscience and motor learning.

A comparison of modelling and imagery in the acquisition and retention of motor skills

Although many researchers have examined the effects of imagery and/or modelling interventions, it is unclear which of the two interventions is more effective. In two experiments, novice learners assessed over multiple trials of a free weight squat lifting or a stabilometer balancing task were given modelling, imagery, a combination of modelling and imagery, or control interventions. Group differences indicated, in general, that groups receiving modelling (modelling, combination) evidenced a more appropriate form than groups that did not receive modelling (imagery, control). When apparent, these differences were already in place after the first of several interventions. Practical implications are that even a single bout of modelling can have immediate beneficial effects on movement form (Experiments 1 and 2) and outcome (Experiment 1).

Dance Learning and the Mirror: Comparison Study of Dance Phrase Learning with and without Mirrors

In the dance studio, the mirror can play a large role in the dancer's learning process. Research on learning and memory shows that reducing the amount of feedback during training enhances long-term motor skill retention and that more externally focused attention may aid performance. Research testing the effectiveness of training with a mirror as a source of external feedback is scarce. This study involved 22 college dance students between the ages of 17 to 22 who had studied dance for an average of 13 years. The purpose of the research was to examine how learning and performing dance combinations in mirrored and non-mirrored situations affected student's ability to remember and replicate movement sequences one week later. The testing occurred over two weeks during which time subjects learned and performed the given movement phrases and completed a questionnaire. Collected data included electronic scoring of footwork accuracy and video analysis and scoring by five dance teachers. Results showed that initial learning in a mirrored setting produced better performances in the retest one week later.

Drugs and human memory (part 1): Clinical, theoretical, and methodologic issues.

Drugs and human memory (part 1): Clinical, theoretical, and methodologic issues.