Visuomotor Skill Learning Research Articles

Exploring brain plasticity in developmental dyslexia through implicit sequence learning.

Developmental dyslexia (DD) is defined as difficulties in learning to read even with normal intelligence and adequate educational guidance. Deficits in implicit sequence learning (ISL) abilities have been reported in children with DD. We investigated brain plasticity in a group of 17 children with DD, compared with 18 typically developing (TD) children, after two sessions of training on a serial reaction time (SRT) task with a 24-h interval. Our outcome measures for the task were: a sequence-specific implicit learning measure (ISL), entailing implicit recognition and learning of sequential associations; and a general visuomotor skill learning measure (GSL). Gray matter volume (GMV) increased, and white matter volume (WMV) decreased from day 1 to day 2 in cerebellar areas regardless of group. A moderating effect of group was found on the correlation between WMV underlying the left precentral gyrus at day 2 and the change in ISL performance, suggesting the use of different underlying learning mechanisms in DD and TD children during the ISL task. Moreover, DD had larger WMV in the posterior thalamic radiation compared with TD, supporting previous reports of atypical development of this structure in DD. Further studies with larger sample sizes are warranted to validate these results.

Prefrontal theta—gamma transcranial alternating current stimulation improves non-declarative visuomotor learning in older adults

The rise in the global population of older adults underscores the significance to investigate age-related cognitive disorders and develop early treatment modalities. Previous research suggests that non-invasive transcranial Alternating Current Stimulation (tACS) can moderately improve cognitive decline in older adults. However, non-declarative cognition has received relatively less attention. This study investigates whether repeated (16-day) bilateral theta—gamma cross-frequency tACS targeting the Dorsolateral Prefrontal Cortex (DLPFC) enhances non-declarative memory. Computerized cognitive training was applied alongside stimulation to control for the state-of-the-brain. The Alternating Serial Reaction Time (ASRT) task was employed to assess non-declarative functions such as visuomotor skill and probabilistic sequence learning. Results from 35 participants aged 55–82 indicated that active tACS led to more substantial improvements in visuomotor skills immediately after treatment, which persisted 3 months later, compared to sham tACS. Treatment benefit was more pronounced in older adults of younger age and those with pre-existing cognitive decline. However, neither intervention group exhibited modulation of probabilistic sequence learning. These results suggest that repeated theta—gamma tACS can selectively improve distinct non-declarative cognitive aspects when targeting the DLPFC. Our findings highlight the therapeutic potential of tACS in addressing deficits in learning and retaining general skills, which could have a positive impact on the quality of life for cognitively impaired older individuals by preserving independence in daily activities.

Visuomotor skill learning in young adults with Down syndrome

BackgroundIndividuals with Down syndrome (DS) have impaired general motor skills compared to typically developed (TD) individuals. AimsTo gain knowledge on how young adults with DS learn and retain new motor skills. Methods and ProceduresA DS-group (mean age = 23.9 ± 3 years, N = 11), and an age-matched TD-group (mean age 22.8 ± 1.8, N = 14) were recruited. The participants practiced a visuomotor accuracy tracking task (VATT) in seven blocks (10.6 min). Online and offline effects of practice were assessed based on tests of motor performance at baseline immediate and 7-day retention. Outcomes and ResultsThe TD-group performed better than the DS-group on all blocks (all P < 0.001). Both groups improved VATT-performance online from baseline to immediate retention, (all P < 0.001) with no difference in online effect between groups. A significant between-group difference was observed in the offline effect (∆TD - ∆DS, P = 0.04), as the DS-group’s performance at 7-day retention was equal to their performance at immediate retention (∆DS, P > 0.05), whereas an offline decrease in performance was found in the TD-group (∆TD, P < 0.001). Conclusions and ImplicationsVisuomotor pinch force accuracy is lower for adults with DS compared to TD. However, adults with DS display significant online improvements in performance with motor practice similar to changes observed for TD. Additionally, adults with DS demonstrate offline consolidation following motor learning leading to significant retention effects.

NMDA receptors in visual cortex are necessary for normal visuomotor integration and skill learning.

The experience of coupling between motor output and visual feedback is necessary for the development of visuomotor skills and shapes visuomotor integration in visual cortex. Whether these experience-dependent changes of responses in V1 depend on modifications of the local circuit or are the consequence of circuit changes outside of V1 remains unclear. Here, we probed the role of N-methyl-d-aspartate (NMDA) receptor-dependent signaling, which is known to be involved in neuronal plasticity, in mouse primary visual cortex (V1) during visuomotor development. We used a local knockout of NMDA receptors and a photoactivatable inhibition of CaMKII in V1 during the first visual experience to probe for changes in neuronal activity in V1 as well as the influence on performance in a visuomotor task. We found that a knockout of NMDA receptors before, but not after, first visuomotor experience reduced responses to unpredictable stimuli, diminished the suppression of predictable feedback in V1, and impaired visuomotor skill learning later in life. Our results demonstrate that NMDA receptor-dependent signaling in V1 is critical during the first visuomotor experience for shaping visuomotor integration and enabling visuomotor skill learning.

Motor cortex plasticity and visuomotor skill learning in upper and lower limbs of endurance-trained cyclists.

Studies with transcranial magnetic stimulation (TMS) show that both acute and long-term exercise can influence TMS-induced plasticity within primary motor cortex (M1). However, it remains unclear how regular exercise influences skill training-induced M1 plasticity and motor skill acquisition. This study aimed to investigate whether skill training-induced plasticity and motor skill learning is modified in endurance-trained cyclists. In 16 endurance-trained cyclists (24.4 yrs; 4 female) and 17 sedentary individuals (23.9 yrs; 4 female), TMS was applied in 2 separate sessions: one targeting a hand muscle not directly involved in habitual exercise and one targeting a leg muscle that was regularly trained. Single- and paired-pulse TMS was used to assess M1 and intracortical excitability in both groups before and after learning a sequential visuomotor isometric task performed with the upper (pinch task) and lower (ankle dorsiflexion) limb. Endurance-trained cyclists displayed greater movement times (slower movement) compared with the sedentary group for both upper and lower limbs (all P < 0.05), but there was no difference in visuomotor skill acquisition between groups (P > 0.05). Furthermore, endurance-trained cyclists demonstrated a greater increase in M1 excitability and reduced modulation of intracortical facilitation in resting muscles of upper and lower limbs after visuomotor skill learning (all P < 0.005). Under the present experimental conditions, these results indicate that a history of regular cycling exercise heightens skill training-induced M1 plasticity in upper and lower limb muscles, but it does not facilitate visuomotor skill acquisition.

Implicit contextual learning in spinocerebellar ataxia.

Cerebellum is traditionally associated with motor functions, but recently its functions were broadened to include cognitive and affective functions as well. The impairment of these nonmotor functions was subsumed under the term cerebellar cognitive-affective syndrome (CCAS). Spinocerebellar ataxias (SCAs) are a family of hereditary degeneration, which is associated with progressive atrophy of the cerebellum. This study aimed to examine the cerebellar contribution to nonmotor implicit learning, which is the ability to acquire visual contextual information via repeated spatial configurations from the environment without conscious awareness in patients with SCA. Twenty patients with SCA and matched healthy controls performed implicit contextual learning task that is a nonmotor, implicit, visual learning task consisting displays of a target (letter T) and a number of distractors (letter L). We found implicit contextual learning impairment vis-à-vis spared visuomotor skill learning in SCA. Moreover, this impairment did not correlate with any other measure, including demographics, clinical measures, and neuropsychological measures. These findings broaden the role of cerebellum in nonmotor, implicit, spatial learning processes. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Deep intrinsically motivated continuous actor-critic for efficient robotic visuomotor skill learning

Abstract In this paper, we present a new intrinsically motivated actor-critic algorithm for learning continuous motor skills directly from raw visual input. Our neural architecture is composed of a critic and an actor network. Both networks receive the hidden representation of a deep convolutional autoencoder which is trained to reconstruct the visual input, while the centre-most hidden representation is also optimized to estimate the state value. Separately, an ensemble of predictive world models generates, based on its learning progress, an intrinsic reward signal which is combined with the extrinsic reward to guide the exploration of the actor-critic learner. Our approach is more data-efficient and inherently more stable than the existing actor-critic methods for continuous control from pixel data. We evaluate our algorithm for the task of learning robotic reaching and grasping skills on a realistic physics simulator and on a humanoid robot. The results show that the control policies learned with our approach can achieve better performance than the compared state-of-the-art and baseline algorithms in both dense-reward and challenging sparse-reward settings.

The Role of Task Difficulty in Learning a Visuomotor Skill.

Task difficulty affects the amount of interpretable information from a task, which is thought to interfere with motor learning. However, it is unclear whether task difficulty in itself is a stimulus for motor learning because the experimental evidence is mixed in support of the optimal challenge point framework that predicts one specific level of task difficulty to produce the greatest magnitude of motor learning. We determined the effects of functional task difficulty on motor skill acquisition, retention, and transfer. Healthy young participants (N = 36) learned a mirror star-tracing task at a low, medium, or hard difficulty level defined by the bandwidth of the star. We measured skill acquisition, retention, and transfer to untrained difficulty levels, as well as the perceived mental workload during the task. Task difficulty affected motor performance, but did not affect motor learning and transfer. For the groups that practiced the task at the medium and hard but not at the low difficulty level, initial skill level correlated with the magnitude of learning. The optimal challenge point framework does not capture the complex relationship between task difficulty and motor learning. Previously reported effects of task difficulty on the magnitude of motor learning are probably mediated by perceived mental workload. Task difficulty did not affect the magnitude of visuomotor skill learning but it affected how learning occurred. The data have implications on how athletes learn new motor skills and patients relearn injury-impaired motor skills during rehabilitation.

Resting-state connectivity after visuo-motor skill learning is inversely associated with offline consolidation in Parkinson's disease and healthy controls

Procedural memory refers to skills acquired through practice and depends on cortico-striatal and cortico-cerebellar circuits. These circuits are typically affected in Parkinson's disease (PD), leading to impaired skill learning, including defective offline consolidation, early in the course of the disease. Evidence points to a role of slow oscillations (<4 Hz) during sleep for offline consolidation. However recent studies showed consolidation over the course of the day, suggesting that consolidation may arise during wakefulness, too. Here we investigate whether functional connectivity (FC) at rest after visuo-motor skill learning is associated with the extent of offline improvements in healthy controls and PD patients. Nineteen participants (9 PD, 10 healthy controls) performed a mirror-drawing task. High-density 156-channel resting state EEG was recorded before and immediately after training. Performance on the task was measured again 24 h later to test for offline consolidation. Delta-band (1–3.5 Hz) FC centered on the left parietal cortex after training predicted offline consolidation. Weak FC was observed in most healthy controls and associated with marked overnight improvement, while strong FC was observed in most PD patients and associated with weak offline consolidation or loss of the skill. These findings indicate that offline consolidation starts immediately after visuo-motor skill learning in brain regions and frequencies typically involved in sleep-related consolidation.

Resting-state connectivity predicts visuo-motor skill learning

Spontaneous brain activity at rest is highly organized even when the brain is not explicitly engaged in a task. Functional connectivity (FC) in the alpha frequency band (α, 8–12 Hz) during rest is associated with improved performance on various cognitive and motor tasks. In this study we explored how FC is associated with visuo-motor skill learning and offline consolidation. We tested two hypotheses by which resting-state FC might achieve its impact on behavior: preparing the brain for an upcoming task or consolidating training gains. Twenty-four healthy participants were assigned to one of two groups: The experimental group (n = 12) performed a computerized mirror-drawing task. The control group (n = 12) performed a similar task but with concordant cursor direction. High-density 156-channel resting-state EEG was recorded before and after learning. Subjects were tested for offline consolidation 24h later. The Experimental group improved during training and showed offline consolidation. Increased α-FC between the left superior parietal cortex and the rest of the brain before training and decreased α-FC in the same region after training predicted learning. Resting-state FC following training did not predict offline consolidation and none of these effects were present in controls. These findings indicate that resting-state alpha-band FC is primarily implicated in providing optimal neural resources for upcoming tasks.

Consolidation of a Learned Skill Correlates with Dopamine SPECT Uptake in Early Parkinson's Disease.

Background and PurposeBasal ganglia play a pivotal role in procedural memory. However, the correlation between skill learning and striatal 123I-ioflupane uptake in Parkinson's disease (PD) has not been reported previously. Our objective was to determine whether visuomotor skill learning is associated with striatal 123I-ioflupane uptake in early PD.MethodsWe designed a case–control study to assess learning and consolidation of a visuomotor learning task (mirrored drawing of star-shaped figures) performed on two consecutive days by early-PD patients (disease duration <2 years) and age-matched healthy subjects. Outcomes were the error rate and time per trial, as well as performance indices to assess the relative improvement on the first day (learning) and the retention on the second day (consolidation). For PD patients, we evaluated the correlation of skill learning with semiquantitative 123I-ioflupane uptake.ResultsWe included 9 PD patients and 10 control subjects with the same baseline characteristics (age, male/female ratio, educational level, Mini Mental State Examination score, and Hospital Anxiety and Depression Scale score, all p>0.18) other than the score on part III of the Movement Disorders Society Unified Parkinson's Disease Rating Scale, which was higher in the PD patients (mean±SD: 15.0±10.4 vs. 1.3±1.1, p<0.001). The learning indices were the same in the two groups (p>0.5), whereas PD patients showed a lower consolidation index for the time per trial (p=0.009). Moreover, this performance was correlated with uptake in the right caudate nucleus (Spearman's rho=0.82, p=0.007) and the right striatum (Spearman's rho=0.67, p=0.049), including when multiple linear regression adjusting for the levodopa equivalent daily dose was performed (p=0.005 for the caudate nucleus and p=0.024 for the striatum).ConclusionsThis study provides evidence of a correlation between procedural memory impairment and striatal dopaminergic dysfunction in early PD.

Neural substrates underlying motor skill learning in chronic hemiparetic stroke patients.

Motor skill learning is critical in post-stroke motor recovery, but little is known about its underlying neural substrates. Recently, using a new visuomotor skill learning paradigm involving a speed/accuracy trade-off in healthy individuals we identified three subpopulations based on their behavioral trajectories: fitters (in whom improvement in speed or accuracy coincided with deterioration in the other parameter), shifters (in whom speed and/or accuracy improved without degradation of the other parameter), and non-learners. We aimed to identify the neural substrates underlying the first stages of motor skill learning in chronic hemiparetic stroke patients and to determine whether specific neural substrates were recruited in shifters versus fitters. During functional magnetic resonance imaging (fMRI), 23 patients learned the visuomotor skill with their paretic upper limb. In the whole-group analysis, correlation between activation and motor skill learning was restricted to the dorsal prefrontal cortex of the damaged hemisphere (DLPFCdamh: r = −0.82) and the dorsal premotor cortex (PMddamh: r = 0.70); the correlations was much lesser (−0.16 < r > 0.25) in the other regions of interest. In a subgroup analysis, significant activation was restricted to bilateral posterior parietal cortices of the fitters and did not correlate with motor skill learning. Conversely, in shifters significant activation occurred in the primary sensorimotor cortexdamh and supplementary motor areadamh and in bilateral PMd where activation changes correlated significantly with motor skill learning (r = 0.91). Finally, resting-state activity acquired before learning showed a higher functional connectivity in the salience network of shifters compared with fitters (qFDR < 0.05). These data suggest a neuroplastic compensatory reorganization of brain activity underlying the first stages of motor skill learning with the paretic upper limb in chronic hemiparetic stroke patients, with a key role of bilateral PMd.

Timing-dependent priming effects of tDCS on ankle motor skill learning

Transcranial direct current stimulation (tDCS) has gained increasing interest in neurorehabilitation with its ability to modulate cortical excitability, and thereby influence neural plasticity and functional recovery. While the beneficial effects of tDCS on motor learning and function have been recognized, there is no clear consensus regarding the timing of the tDCS priming protocol in relation to the intervention especially with respect to lower limb motor learning. Depending on the time of priming in relation to the training task, the neural mechanisms of priming (gating vs. homeostatic plasticity) are different and thereby subsequently affect motor learning. Hence, the aim of this study was to examine the interaction of tDCS with subsequent vs. concurrent motor learning using an ankle visuomotor skill learning paradigm. Twelve healthy participants were tested under three stimulation conditions: (1) anodal tDCS prior to the motor task (tDCS-before), (2) anodal tDCS during the motor task (tDCS-during) and (3) sham tDCS during the motor task (tDCS-sham). Results revealed that tDCS application during practice of a skilled motor task increased motor performance compared to tDCS applied prior to motor practice. Both tDCS groups demonstrated enhanced motor learning when tested 24hours after practice. We conclude that the priming effects of tDCS are timing dependent, and maybe a critical regulatory feature in determining outcomes of priming with tDCS.

Using actigraphy and transcranial magnetic stimulation to assess the relationship between sleep and visuomotor skill learning

Sleep following training can enhance motor skill memory consolidation while chronic sleep disruption can have the converse effect. The aim of this investigation was to explore the relationship between sleep measured by wrist actigraphy, motor skill consolidation and primary motor cortex excitability in young, healthy individuals. Training was a visuospatial finger-tracking task. Dependent measures included tracking skill performance, cortical excitability, measures of sleep, and level of arousal. Assessments occurred pre-training, post-training and at 12 h and 24 h retention. An activity monitor was worn on the wrist during the nights preceding and following training. Results indicate that sleep during the night following training was predictive of 1) offline skill consolidation following training (R² = 0.34) and 2) cortical excitability at 24 h follow-up (R² = 0.35) with less time spent awake associated with better skill performance and lower cortical excitability at 24 h follow-up. No difference in measures of sleep was observed between nights of sleep (p > 0.05). Sleep the night before training did not influence skill performance, skill acquisition during training, nor measures of cortical excitability at pre-training assessment. These findings suggest a relationship between motor skill development, cortical excitability and sleep following training. These results invite further investigation into the utility of actigraphy as a low-cost, easy-to-administer alternative to polysomnography for short and long-term evaluation of the relationship between sleep, cortical excitability and motor skill learning in healthy and patient populations.

Goal-directed visuomotor skill learning: Off-line enhancement and the importance of the primary motor cortex

The time course and neural substrates of motor skill learning are not well-understood in healthy or neurologic patient populations. Certain motor skills undergo off-line skill enhancement following training and the primary motor cortex (M1) may be involved. It is unknown if goal-directed visuomotor skill undergoes off-line enhancement or if M1 is associated with that enhancement. 32 right-handed, healthy subjects were randomly assigned to two groups: real repetitive transcranial magnetic stimulation (rTMS) or sham rTMS applied to the contralateral M1 immediately following one 20-minute finger tracking training session. Tracking performance and cortical excitability were assessed before and after training, following rTMS and 24 hours post-training. Results demonstrate that skill performance continues to develop for at least 30 minutes after training completion, is maintained for 24 hours post-training, and is not affected by inhibitory rTMS applied to M1. Level of skill improvement was associated with the degree of intracortical inhibition increase. These results suggest dispersed information processing for goal-directed visuomotor skill learning following training and a relationship between cortical excitability and skill development in healthy individuals. These findings invite further investigation of the neural mechanisms underlying motor skill learning and may have rehabilitation implications for patients with neurologic injury.

Poster 433: A Difference in Visuomotor Skill Learning Among Healthy People, Patients With the Left Brain Damage and Patients With Right Brain Damage

Poster 433: A Difference in Visuomotor Skill Learning Among Healthy People, Patients With the Left Brain Damage and Patients With Right Brain Damage

Motor skill training and strength training are associated with different plastic changes in the central nervous system

Changes in corticospinal excitability induced by 4 wk of heavy strength training or visuomotor skill learning were investigated in 24 healthy human subjects. Measurements of the input-output relation for biceps brachii motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation were obtained at rest and during voluntary contraction in the course of the training. The training paradigms induced specific changes in the motor performance capacity of the subjects. The strength training group increased maximal dynamic and isometric muscle strength by 31% (P < 0.001) and 12.5% (P = 0.045), respectively. The skill learning group improved skill performance significantly (P < 0.001). With one training bout, the only significant change in transcranial magnetic stimulation parameters was an increase in skill learning group maximal MEP level (MEP(max)) at rest (P = 0.02) for subjects performing skill training. With repeated skill training three times per week for 4 wk, MEP(max) increased and the minimal stimulation intensity required to elicit MEPs decreased significantly at rest and during contraction (P < 0.05). In contrast, MEP(max) and the slope of the input-output relation both decreased significantly at rest but not during contraction in the strength-trained subjects (P < or = 0.01). No significant changes were observed in a control group. A significant correlation between changes in neurophysiological parameters and motor performance was observed for skill learning but not strength training. The data show that increased corticospinal excitability may develop over several weeks of skill training and indicate that these changes may be of importance for task acquisition. Because strength training was not accompanied by similar changes, the data suggest that different adaptive changes are involved in neural adaptation to strength training.

Prefrontal lesions impair the implicit and explicit learning of sequences on visuomotor tasks

(1) To verify whether the prefrontal cortex (PFC) is specifically involved in visuomotor sequence learning as opposed to other forms of motor learning and (2) to establish the role of executive functions in visuomotor sequence learning. Visuomotor skill learning depends on the integrity of the premotor and parietal cortex; the prefrontal cortex, however, is essential when the learning of a sequence is required. We studied 25 patients with PFC lesions and 86 controls matched for age and educational level. Participants performed: (1) a Pursuit Tracking Task (PTT), composed of a random tracking task (perceptual learning) and a pattern tracking task (explicit motor sequence learning with learning indicated by the decrease in mean root square error across trial blocks), (2) a 12-item sequence version of a serial reaction time task (SRTT) with specific implicit motor sequence learning indicated by the rebound increase in response time when comparing the last sequence block with the next random block, and (3) a neuropsychological battery that assessed executive functions. PFC patients were impaired in sequence learning on the pattern tracking task of the PTT and on the SRTT as compared to controls, but performed normally on the PTT random tracking task. Learning on the PTT did not correlate with learning on the SRTT. PTT performance correlated with planning functions while SRTT performance correlated with working memory capacity. The PFC is specifically involved in explicit and implicit motor sequence learning. Different PFC regions may be selectively involved in such learning depending on the cognitive demands of the sequential task.

Skill Learning

This chapter reviews recent experiments that have examined the functional neuroanatomy of motor and visuomotor skill learning using brain imaging techniques such as single photon emission computed tomography, positron emission tomography, and functional magnetic resonance imaging. Special attention has been given to the cerebral blood flow changes in the cerebellum that are associated with the acquisition of these skills, although localizations of other activated regions (cortical and subcortical) are also included. The cognitive processes involved in different skill acquisition paradigms are discussed with particular reference to the learning stages at which subjects were scanned. This approach examines the conditions that are likely to produce cerebellar activation and helps us understand the role of the cerebellum in acquiring skilled behaviors.

Functional anatomy of visuomotor skill learning in human subjects examined with positron emission tomography.

The present study was designed to examine patterns of regional cerebral blood flow (CBF) associated with the learning of a repeated visuomotor sequence both in the early and late phases of the acquisition process. In addition, changes in blood flow related to the implicit versus explicit aspects of learning such a skill were investigated. Fourteen normal control subjects were scanned while performing the task (i) in both early and advanced learning stages of the visuomotor sequence; (ii) after having acquired explicit knowledge of the sequences; and (iii) in two control conditions (perceptual and random sequence). Subtraction of the random condition from the highly learned condition revealed specific areas of activity in the right ventral striatum and dentate nucleus of the cerebellum. Blood flow changes in the right hemisphere were also seen in the medial posterior parietal and prestriate regions, as well as in the anterior cingulate cortex. Finally, once the subjects had acquired explicit knowledge of the embedded sequence that was presented in the highly learned condition, increased CBF activity was observed only in the mid-ventrolateral frontal area in the right hemisphere. These findings confirm that both the striatum and the cerebellum are involved in the implicit acquisition of a visuomotor skill, especially in the advanced stages of the learning process, and furthermore that the ventrolateral prefrontal cortex contributes preferentially to the declarative aspect of this task.