Movement Planning Research Articles

Posture dependent factors influence movement variability when reaching to nearby virtual objects.

Reaching movements are subject to noise arising during the sensing, planning and execution phases of movement production, which contributes to movement variability. When vision of the moving hand is available, reach endpoint variability appears to be strongly influenced by internal noise associated with the specification and/or online updating of movement plans in visual coordinates. In contrast, without hand vision, endpoint variability appears more dependent upon movement direction, suggesting a greater influence of execution noise. Given that execution noise acts in part at the muscular level, we hypothesized that reaching variability should depend not only on movement direction but initial arm posture as well. Moreover, given that the effects of execution noise are more apparent when hand vision is unavailable, we reasoned that postural effects would be more evident when visual feedback was withheld. To test these hypotheses, participants planned memory-guided reaching movements to three frontal plane targets using one of two initial arm postures ("adducted" or "abducted"), attained by rotating the arm about the shoulder-hand axis. In this way, variability was examined for two sets of movements that were largely identical in endpoint coordinates but different in joint/muscle-based coordinates. We found that patterns of reaching variability differed in several respects when movements were initiated with different arm postures. These postural effects were evident shortly after movement onset, near the midpoints of the movements, and again at the endpoints. At the endpoints, posture dependent effects interacted with effects of visual feedback to determine some aspects of variability. These results suggest that posture dependent execution noise interacts with feedback control mechanisms and biomechanical factors to determine patterns of reach endpoint variability in 3D space.

Aberrant sensorimotor coupling and movement planning in complex regional pain syndrome.

Complex regional pain syndrome (CRPS) is characterized by inflammation and a failure of multimodal signal integration in the central nervous system (CNS). Central nervous system reorganization might account for sensory deficits, pain, and motor symptoms in CRPS, but it is not clear how motor control is affected by CNS mechanisms. The present study characterized the motor performance and related cortical activity of 16 CRPS patients and 16 control participants during the planning of visually guided unimanual grips, in patients with either the unaffected left or the affected right hand, and investigated resting-state sensorimotor coupling in MRI. Patients started isometric movements further in advance of the "go" cue and earlier than control participants. Even when accounting for this different timing, results showed side-independent overactivation in planning-related sensorimotor regions in CRPS during manual grips and increased functional coupling between those regions at rest. Fear of movement or individual pain scores contributed only marginally to the observed effects. The study suggests that changes in planning-related sensorimotor CNS regions may explain difficulties with force exertion and motor control in CRPS.Perspective : Functional changes in motor planning-related brain regions might indicate that feedback-enhanced functional motor training may be effective for CRPS rehabilitation.

Grip force as a functional window to somatosensory cognition.

Analysis of grip force signals tailored to hand and finger movement evolution and changes in grip force control during task execution provide unprecedented functional insight into somatosensory cognition. Somatosensory cognition is the basis of our ability to act upon and to transform the physical world around us, to recognize objects on the basis of touch alone, and to grasp them with the right amount of force for lifting and manipulating them. Recent technology has permitted the wireless monitoring of grip force signals recorded from biosensors in the palm of the human hand to track and trace human grip forces deployed in cognitive tasks executed under conditions of variable sensory (visual, auditory) input. Non-invasive multi-finger grip force sensor technology can be exploited to explore functional interactions between somatosensory brain mechanisms and motor control, in particular during learning a cognitive task where the planning and strategic execution of hand movements is essential. Sensorial and cognitive processes underlying manual skills and/or hand-specific (dominant versus non-dominant hand) behaviors can be studied in a variety of contexts by probing selected measurement loci in the fingers and palm of the human hand. Thousands of sensor data recorded from multiple spatial locations can be approached statistically to breathe functional sense into the forces measured under specific task constraints. Grip force patterns in individual performance profiling may reveal the evolution of grip force control as a direct result of cognitive changes during task learning. Grip forces can be functionally mapped to from-global-to-local coding principles in brain networks governing somatosensory processes for motor control in cognitive tasks leading to a specific task expertise or skill. Under the light of a comprehensive overview of recent discoveries into the functional significance of human grip force variations, perspectives for future studies in cognition, in particular the cognitive control of strategic and task relevant hand movements in complex real-world precision task, are pointed out.

Use of multi-perturbation Shapley analysis in lesion studies of functional networks: The case of upper limb paresis.

Understanding the impact of variation in lesion topography on the expression of functional impairments following stroke is important, as it may pave the way to modeling structure-function relations in statistical terms while pointing to constraints for adaptive remapping and functional recovery. Multi-perturbation Shapley-value analysis (MSA) is a relatively novel game-theoretical approach for multivariate lesion-symptom mapping. In this methodological paper, we provide a comprehensive explanation of MSA. We use synthetic data to assess the method's accuracy and perform parameter optimization. We then demonstrate its application using a cohort of 107 first-event subacute stroke patients, assessed for upper limb (UL) motor impairment (Fugl-Meyer Assessment scale). Under the conditions tested, MSA could correctly detect simulated ground-truth lesion-symptom relationships with a sensitivity of 75% and specificity of ~90%. For real behavioral data, MSA disclosed a strong hemispheric effect in the relative contribution of specific regions-of-interest (ROIs): poststroke UL motor function was mostly contributed by damage to ROIs associated with movement planning (supplementary motor cortex and superior frontal gyrus) following left-hemispheric damage (LHD) and by ROIs associated with movement execution (primary motor and somatosensory cortices and the ventral brainstem) following right-hemispheric damage (RHD). Residual UL motor ability following LHD was found to depend on a wider array of brain structures compared to the residual motor ability of RHD patients. The results demonstrate that MSA can provide a unique insight into the relative importance of different hubs in neural networks, which is difficult to obtain using standard univariate methods.

Spontaneous sensorimotor beta power and cortical thickness uniquely predict motor function in healthy aging

BackgroundSpontaneous beta activity in the primary motor cortices has been shown to increase in amplitude with advancing age, and that such increases are tightly coupled to stronger motor-related beta oscillations during movement planning. However, the relationship between these age-related changes in spontaneous beta in the motor cortices, local cortical thickness, and overall motor function remains unclear. MethodsWe collected resting-state magnetoencephalography (MEG), high-resolution structural MRI, and motor function scores using a neuropsychological battery from 126 healthy adults (56 female; age range = 22–72 years). MEG data were source-imaged and a whole-brain vertex-wise regression model was used to assess age-related differences in spontaneous beta power across the cortex. Cortical thickness was computed from the structural MRI data and local beta power and cortical thickness values were extracted from the sensorimotor cortices. To determine the unique contribution of age, spontaneous beta power, and cortical thickness to the prediction of motor function, a hierarchical regression approach was used. ResultsThere was an increase in spontaneous beta power with age across the cortex, with the strongest increase being centered on the sensorimotor cortices. Sensorimotor cortical thickness was not related to spontaneous beta power, above and beyond age. Interestingly, both cortical thickness and spontaneous beta power in sensorimotor regions each uniquely contributed to the prediction of motor function when controlling for age. DiscussionThis multimodal study showed that cortical thickness and spontaneous beta activity in the sensorimotor cortices have dissociable contributions to motor function across the adult lifespan. These findings highlight the complexity of interactions between structure and function and the importance of understanding these interactions in order to advance our understanding of healthy aging and disease.

Use of remote data collection methodology to test for an illusory effect on visually guided cursor movements.

Investigating the influence of perception on the control of visually guided action typically involves controlled experimentation within the laboratory setting. When appropriate, however, behavioral research of this nature may benefit from the use of methods that allow for remote data collection outside of the lab. This study tested the feasibility of using remote data collection methods to explore the influence of perceived target size on visually guided cursor movements using the Ebbinghaus illusion. Participants completed the experiment remotely, using the trackpad of their personal laptop computers. The task required participants to click on a single circular target presented at either the left or right side of their screen as quickly and accurately as possible (Experiment 1), or to emphasize speed (Experiment 2) or accuracy (Experiment 3). On each trial the target was either surrounded by small or large context circles, or no context circles. Participants’ judgments of the targets’ perceived size were influenced by the illusion, however, the illusion failed to produce differences in click-point accuracy or movement time. Interestingly, the illusion appeared to affect participants’ movement of the cursor toward the target; more directional changes were made when clicking the Perceived Large version of the illusion compared to the Perceived Small version. These results suggest the planning of the cursor movement may have been influenced by the illusion, while later stages of the movement were not, and cursor movements directed toward targets perceived as smaller required less correction compared to targets perceived as larger.

Development of a novel method for estimating and planning automatic skimmer operation in response to offshore oil spills.

Offshore oil production and transportation of oil by pipelines and tankers are associated with the risks of an oil spill, and accidents of various scales, from emissions of several liters to several thousand tons, occur regularly in different parts of the world. Currently, there are no automatic or automated systems for responding to such incidents, although special equipment exists that is able to collect oil from the surface of water. The oil collected by skimmers can be used for its intended purpose. The purpose of this research is to develop a novel method for estimating the number of skimmers required for automated oil recovery in the event of oil contamination in the open sea, taking into account errors in measured weather conditions and initial spill information. In this work, a program is developed to simulate the position and state of an oil slick on the water surface, based on realistic weather conditions, and the movement of a group of skimmers while performing the oil removal task. The results of the study demonstrate the robustness of the system with respect to errors in the initial data, weather condition, position and parameters of the oil spill. Two main emergencies are considered: an instantaneous release of oil from a tanker and continuous leakage from a damaged pipeline. The developed system detects and collects oil on the map in a limited time, even with a significant shift in the initial coordinates, and limits the spread of the oil slick where there is continuous leakage. In addition, the designed method has a short-term overestimation of the skimmer group size in case of time delay in the response to the spill. The developed method can be applied in real cases of oil spills to create and update the plan of movement and collection of oil for a group of skimmers.

Pelatihan Dan Pemanfaatan E-Commerce Sebagai Media Pemasaran Produk Umkm Di Desa Donowati

Mechanical advancements lead society towards effectiveness in exchanging exchange exercises. In its elemental, innovation assumes a part and turns into an option for society to go through with exchanges. This innovation is adjusted rapidly believing capacity to be a mechanism for exchanges should be possible anyplace and whenever. In accordance with mechanical turns of events, online business has turned into an additional coordinated method for exchanges among purchasers and venders. The common sense and variety of installment systems are the qualities of online business so that an ever increasing number of individuals are utilizing the stage. Be that as it may, there are additionally numerous MSME entertainers who don't grasp the ongoing improvement of exchange innovation, particularly the MSME entertainers in Donowati town. Most MSME entertainers in Donowati town don't figure out the activity of online business. The presence of this local area administration movement plans to clarify how the method involved with presenting the local area for internet business and its varieties. The technique completed during administration exercises utilizes distinct subjective exploration strategies through socialization and appraisal of the improvement of the utilization of web based business to SME entertainers in Donowati town.

Local field potentials reflect cortical population dynamics in a region-specific and frequency-dependent manner.

The spiking activity of populations of cortical neurons is well described by the dynamics of a small number of population-wide covariance patterns, whose activation we refer to as 'latent dynamics'. These latent dynamics are largely driven by the same correlated synaptic currents across the circuit that determine the generation of local field potentials (LFPs). Yet, the relationship between latent dynamics and LFPs remains largely unexplored. Here, we characterised this relationship for three different regions of primate sensorimotor cortex during reaching. The correlation between latent dynamics and LFPs was frequency-dependent and varied across regions. However, for any given region, this relationship remained stable throughout the behaviour: in each of primary motor and premotor cortices, the LFP-latent dynamics correlation profile was remarkably similar between movement planning and execution. These robust associations between LFPs and neural population latent dynamics help bridge the wealth of studies reporting neural correlates of behaviour using either type of recordings.

Don't watch your step: gaze behavior adapts with practice of a target stepping task.

Vision plays a vital role in locomotor learning, providing feedback information to correct movement errors, and feedforward information to inform learned movement plans. Gaze behavior, or the distribution of fixation locations, can quantify how visual information is used during the motor learning process. How gaze behavior adapts during motor learning and in response to changing motor performance is poorly understood. This study examines if and how an individual's gaze behavior adapts during a sequence learning, target stepping task. We monitored the gaze behavior of 12 healthy young adults while they walked on a treadmill and attempted to precisely step on moving targets that were separated by variable distances (80%, 100%, and 120% of preferred step length). Participants completed a total of 11 trial blocks of 102 steps each. We hypothesized that both mean fixation distance would increase (participants would look farther ahead), and step error would decrease with experience. Following practice, participants significantly increased their fixation distance (P < 0.001) by 0.27 ± 0.18 steps and decreased their step error (P < 0.001) by 4.0 ± 1.7 cm, supporting our hypothesis. Our results suggest that early in the learning process, participants gaze behavior emphasized gathering visual information necessary for feedback motor control. As motor performance improved with experience, participants shifted their gaze fixation farther ahead placing greater emphasis on the visual information used for feedforward motor control. These findings provide important information about how gaze behavior changes in parallel with improvements in walking performance.NEW & NOTEWORTHY People consistently vary how they use visual information to inform walking. However, what drives this variation and how sampled visual information changes with locomotor learning is not well understood. Here, we find that gaze fixation locations moved farther ahead while step error decreases as participants practice a target stepping task. The results suggest that participants increasingly used a feedforward locomotor control strategy with practice.

Effects of Movement-Based Interventions on Imitation and Praxis Skills in Children With Autism Spectrum Disorder: A Comparison of Face-to-Face Versus Telehealth Modes of Delivery

Background Children with autism spectrum disorder (ASD) exhibit poor imitation, movement planning, and praxis skills that in turn compound their core social communication and behavioral difficulties. Objective Our randomized controlled trial compares the effects of 2 whole-body movement interventions (creative movement [“Play”] and general exercise [“Move”]) to those of a seated play standard-of-care intervention (“Create”) on imitation and praxis skills in children with ASD. As part of this clinical trial, we also compare face-to-face (F2F) versus telehealth (TH) modes of intervention delivery in each of the three groups. Methods A total of 44 children with ASD aged between 5 and 14 years participated in this 10-week study. Children were matched at baseline and assigned to the Play, Move, or Create groups (n=14-15/group). Approximately half of the children in each group were seen F2F, while the other half were seen via TH. Training was provided 2 times/week (60-90 minutes/session) for 8 weeks. We administered the Bilateral Motor Coordination (BMC) and Postural Praxis (PP) subtests of the Sensory Integration and Praxis Test (SIPT) at pretest and posttest and assessed spatial and temporal errors in movement execution during both tests. We calculated the percent total imitation error score for both subtests. Results For the SIPT-PP, we found a reduction in percent total errors from pretest to posttest in the Play (pretest: mean 15.8%, SE 1.1%; posttest: mean 12.9%, SE 1.1%; P≤.05), Move (pretest: mean 17.1%, SE 1.4%; posttest: mean 14.8%, SE 1.2%; P≤.05), and Create groups (pretest: mean 16.5%, SE 1.5%; posttest: mean 12.7%, SE 1.7%; P≤.05). There were no statistically significant differences in the percent reduction in total errors among children seen F2F versus via TH in the Play (F2F: mean 3.4%, SE 1.5%; TH: mean 2.4%, SE 2.1%; P=.72), Move (F2F: mean 2.6%, SE 1.6%; TH: mean 2.1%, SE 1.5%; P=.84), and Create groups (F2F: mean 6.1%, SE 1.2%; TH: mean 3.4%, SE 1.8%; P=.22). For the SIPT-BMC, children significantly reduced their percent total error scores from pretest to posttest in the Play group (pretest: mean 8.6%, SE 2.4%; posttest: mean 3.9%, SE 0.7%; P≤.05) but not in the Move and Create groups. Specifically, children in the Play group improved on spatial errors (pretest: mean 9.1%, SE 1.9%; posttest: mean 5.4%, SE 1.2%; P≤.05) and also showed a nonsignificant trend for improvement in temporal errors (pretest: mean 9.2%, SE 3.3%; posttest: mean 3.1%, SE 0.6%; P=.06). Similar to the SIPT-PP, we found no significant differences in the percent reduction in total errors among children seen F2F versus via TH (F2F: mean 2.0%, SE 1.5%; TH: mean 7.3%, SE 3.8%; P=.23). Conclusions Our pilot data suggest that imitation-based gross and fine motor training activities led to improved postural imitation skills in children with ASD across all 3 groups. However, only the Play group that received rhythmic movement practice improved on the BMC subtest of the SIPT. Our findings suggest that improvements in imitation and praxis skills are highly training-specific in children with ASD. The lack of significant differences between the F2F and TH modes across all groups suggests that TH could be a successful method of intervention delivery for promoting imitation and praxis skills in children with ASD. Conflicts of Interest None declared.

Reward-dependent Graded Suppression of Sensorimotor Beta-band Local Field Potentials During an Arm Reaching Task in NHP.

A better understanding of reward signaling in the sensorimotor cortices can aid in developing Reinforcement Learning-based Brain-Computer Interfaces (RLBCI) for restoration of movement functions with fewer implants. Brain-computer interfaces (BCIs) using local field potentials (LFPs) have recently achieved performance comparable to spike-BCIs [1]. With superior stability over time, LFPs may be the preferred signal for BCIs. We show that sensorimotor LFPs can provide reward level information (R1 - R3) like spikes[2]. We used a cued reward-level reaching task in which reward information was temporally dissociated from movement information. This allowed the study of reward- and movement-related modulations in LFPs. We recorded simultaneously from contralateral primary -somatosensory (S1), -motor (M1), and the dorsal premotor (PMd) cortices in a female Macaca Mulatta. We found that all three cortices' average beta band (14-30 Hz) amplitude showed robust modulation with reward levels during the cue presentation period. Such modulation was consistently observed after controlling for cue color, differences in behavioral variables, and electromyogram (EMG) activity. Statistical amplitude analysis showed that reward level could be extracted from the simple LFP feature of beta band amplitude, even before a reaching target appeared, and no specific reach plan could be developed. Clinical Relevance - The availability of reward-related signals in the sensorimotor cortical (S1, M1,and PMd) LFPs' prior to movement planning opens new avenues to build RLBCIs with fewer implants recording fewer sites among different cortices Reward and motivational representations derived from LFPs compared to spikes allow the development of long-term clinical applications given LFP's stability and ease of recording over long periods.

Emerging signs of autism spectrum disorder in infancy: Putative neural substrate.

Autism spectrum disorder (ASD) is characterized by altered development of the social brain with prominent atypical features in the fronto-temporo-parietal cortex and cerebellum. Early signs of ASD emerge between 6 and 12 months: reduced social communication, slightly less advanced motor development, and repetitive behaviour. The fronto-temporo-parietal cortex and cerebellum play a prominent role in the development of social communication, whereas fronto-parietal-cerebellar networks are involved in the planning of movements, that is, movement selection. Atypical sensory responsivity, a core feature of ASD, may result in impaired development of social communication and motor skills and/or selection of atypical repetitive behaviour. In the first postnatal year, the brain areas involved are characterized by gradual dissolution of temporary structures: the fronto-temporo-parietal cortical subplate and cerebellar external granular layer. It is hypothesized that altered dissolution of the transient structures opens the window for the expression of early signs of ASD arising in the impaired developing permanent networks. WHAT THIS PAPER ADDS: The early social and motor signs of autism spectrum disorder emerge between the ages of 6 and 12 months. Altered dissolution of transient brain structures in the fronto-temporo-parietal cortex and cerebellum may underlie the emergence of these early signs.

Planning and Executing Aiming Movements in Middle Childhood.

Harmonious voluntary movements require efficiency in their planning and execution. Throughout middle childhood structural changes in the central nervous and musculoskeletal systems influence these processes and resultant motor behavior. In this study, we evaluated the characteristics of the motor planning and executing of aiming movements directed at targets located in different positions in space in children aged 7, 9, and 11years. We divided 43 right-handed children, into three age groups and instructed them to perform aiming movements directed at targets using a stylus on a digital tablet. The children performed the movement with their dominant upper limbs from a starting point towards targets positioned ipsilaterally or contralaterally to this dominant limb. We analyzed temporal and spatial variables of motor performance. Younger (7-year-old) children made more errors in the initial movement direction and more frequently corrected their movements during task execution when compared to 9- and 11-year-old children who did not differ from each other. All age groups were similar in movement accuracy and precision. Movements toward contralateral targets were slower and more accurate than movements toward ipsilateral targets for all groups. These results show that performing aiming movements develop with the onset of middle childhood.

Assessing proprioceptive acuity in people with multiple sclerosis.

BackgroundProprioceptive acuity and impairments in proprioceptively guided reaches have not been comprehensively examined in people with multiple sclerosis (MS).ObjectiveTo examine proprioceptive acuity in people with MS who self-report and who do not self-report upper limb (UL) impairment, and to determine how people with MS reach proprioceptive targets.MethodsTwenty-four participants with MS were recruited into two groups based on self-reported UL impairment: MS-R (i.e. report UL impairment; n = 12) vs. MS-NR (i.e. do not report UL impairment; n = 12). Proprioception was assessed using ipsilateral and contralateral robotic proprioceptive matching tasks.ResultsParticipants in the MS-R group demonstrated worse proprioceptive acuity compared to the MS-NR group on the ipsilateral and contralateral robotic matching tasks. Analyses of reaches to proprioceptive targets further revealed that participants in the MS-R group exhibited deficits in movement planning, as demonstrated by greater errors at peak velocity in the contralateral matching task in comparison to the MS-NR group.ConclusionOur findings suggest that people with MS who self-report UL impairment demonstrate worse proprioceptive acuity, as well as poorer movement planning in comparison to people with MS who do not report UL impairment.

Brain Neuroplasticity Effects on the Occurrence of Anterior Cruciate Ligament Injury and the Effect of this Injury on Brain Function and Structure: A Systematic Review

Objective: The present study aimed to investigate the effect of brain neuroplasticity on the incidence of anterior cruciate ligament (ACL) injury and on brain function and structure before and after ligament reconstruction and after a period of rehabilitation exercises. Materials &amp; Methods: In this review study, a search was conducted in PubMed, Scopus, Web of Science, Google Scholar, ScienceDirect, MedLine, Pedro, CINAHL, SPORTDiscus, and Cochrane Databases as well as national databases on related studies published from 1970 to 2021 using keywords in Persian and English related to the research topic. Results: The initial search yielded 65 articles. Based on the inclusion and exclusion criteria, 24 articles were selected for review of which 5 articles prospectively examined the effect of brain neuroplasticity on the incidence of ACL injury. Their results showed that the brains of people with ACL injury was different from the uninjured people, especially in the motor-sensory part of the cerebral cortex and cerebellum, which caused errors during movement planning of these persons. Ten articles examined the effect of ACL injury before reconstruction on brain function and structure and reported that changes occur in the level of motor-sensory cortex of the brain at least two weeks after the injury; after one year, these structural and functional changes were widely increased in injured people compared to healthy people. These studies also showed that the ligament dysfunction and the damage to mechanical receptors cause the reorganization of the central nervous system. In injured people, the control activity of motor-visual areas and their need for visual feedback have increased. Seven articles examined these changes after ligament reconstruction and showed that the brain neuroplasticity or functional and structural changes resulting from the injury not only did not return to normal conditions, but also increased after a while despite the reconstruction. Two articles examined these changes after a period of rehabilitation exercises and showed that functional and Conclusion: The changes in the brain after ACL injury not only persist after ligament reconstruction, but also increase after reconstruction. The common rehabilitation exercises whose main focus is not on eliminating these functional and structural changes in the brain cannot overdrive this negative neuroplasticity after injury which is one of the important causes of secondary injury and subsequent complications. In developing exercises to prevent ACL injury and for rehabilitation, it is better to use the new principles of motor learning and exercises related to visual feedback along with conventional exercises to overdrive negative neuroplasticity created in the brain and create positive neuroplasticity to support ACL.

Statistical determinants of visuomotor adaptation along different dimensions during naturalistic 3D reaches

Neurorehabilitation in patients suffering from motor deficits relies on relearning or re-adapting motor skills. Yet our understanding of motor learning is based mostly on results from one or two-dimensional experimental paradigms with highly confined movements. Since everyday movements are conducted in three-dimensional space, it is important to further our understanding about the effect that gravitational forces or perceptual anisotropy might or might not have on motor learning along all different dimensions relative to the body. Here we test how well existing concepts of motor learning generalize to movements in 3D. We ask how a subject’s variability in movement planning and sensory perception influences motor adaptation along three different body axes. To extract variability and relate it to adaptation rate, we employed a novel hierarchical two-state space model using Bayesian modeling via Hamiltonian Monte Carlo procedures. Our results show that differences in adaptation rate occur between the coronal, sagittal and horizontal planes and can be explained by the Kalman gain, i.e., a statistically optimal solution integrating planning and sensory information weighted by the inverse of their variability. This indicates that optimal integration theory for error correction holds for 3D movements and explains adaptation rate variation between movements in different planes.

Prolonged eye-hand decoupling deficits in young adults with a history of concussion from adolescence

ABSTRACT Previous studies reported that adolescents with a sport-related concussion history showed prolonged visuomotor deficits during an eye-hand decoupling task until around 1.5–2 years post-event. The present study expands this work, examining whether such deficits do or do not emerge when testing individuals in young adulthood, i.e. later post-event. Twenty-one non-athlete college students with sport-related concussion history from adolescence (CH; M = 21 yrs.; M = 46 months post-concussion, range 10–90 months) and twenty controls with no history of concussion (NoH; M = 21 yrs.) performed two touchscreen-based visuomotor tasks. It included a coupled task where eyes and hand moved in similar directions, and decoupled-task with eyes and hand going to different directions. Movement planning (e.g. reaction time, initial direction error) and execution (e.g. movement time, path length) related variables were analyzed in both groups and conditions. Movement execution measures were similar for both groups and conditions (all p > 0.05). However, movement planning was impaired in the CH participants in the eye-hand decoupling condition (p < 0.05). CH’s initial direction error was larger (i.e. worse spatial movement planning) than in the NoH group. Although movement execution deficits shown in earlier work in youth were not present in young adults, the present results suggest that a sport-related concussion sustained in adolescence can lead to prolonged deficits with spatial movement planning processes while performing eye-hand decoupling tasks about four years post-injury. Further research should investigate whether these deficits continue into adulthood and expand control on time since concussion and number of concussion metrics. Highlights Young adult college students with a history of a sport-related concussion from adolescence, tested about four years post-incident, showed spatial movement preparation deficits during an eye-hand decoupling visuomotor task. Eye-hand reversal decoupling errors also correlated with time since concussion in those with concussion history. These prolonged eye-hand decoupling deficits may emerge with ongoing time post-event, as comparable deficits were absent in previous work where youth were tested sooner post-injury. Our current findings point towards long-lasting performance impairments in young adult non-athletes after a sport-related concussion from adolescence.

Motivated for movement: Beta activation over the motor cortex resulting from intrinsic and extrinsic motivators.

Past work on motivation has primarily studied dichotomous distinctions of motivation (e.g., extrinsic or intrinsic). However, focusing on the overall motivational intensity may be better at accentuating the unique differences within and between varying motivators as it pertains to the impetus to act. Specifically, motivational intensity influences neural patterns of beta band frequency (13-30 Hz) as measured by electroencephalography (EEG) that enable motor-action preparation, a neural correlate of motivated movement. The primary aim of across three experiments was to investigate neural motor-action preparation to modified flanker tasks within achievement (Experiment 1), autonomous (Experiment 2), and extrinsic vs. intrinsic (Experiment 3) motivational contexts. Experiment 1 revealed greater motor-action preparation for challenging trial cues and did not differ in behavioral attentional and performance measures across both trial types. Experiment 2 revealed no significant difference in motor-action preparation, did not differ in behavioral attentional narrowing and had worse behavioral performance in high autonomy relative to low autonomy trials. Experiment 3 revealed greater motor-action preparation for challenging trial cues, did not differ in behavioral attentional narrowing and had a faster performance for reward trials relative to high autonomy trials. These findings suggest motivators of the same category (i.e., intrinsic) may differ in motivational strength, as suggested by a neurophysiological measure of immediate motivated movement planning.

From thinking fast to moving fast: motor control of fast limb movements in healthy individuals.

The ability to produce high movement speeds is a crucial factor in human motor performance, from the skilled athlete to someone avoiding a fall. Despite this relevance, there remains a lack of both an integrative brain-to-behavior analysis of these movements and applied studies linking the known dependence on open-loop, central control mechanisms of these movements to their real-world implications, whether in the sports, performance arts, or occupational setting. In this review, we cover factors associated with the planning and performance of fast limb movements, from the generation of the motor command in the brain to the observed motor output. At each level (supraspinal, peripheral, and motor output), the influencing factors are presented and the changes brought by training and fatigue are discussed. The existing evidence of more applied studies relevant to practical aspects of human performance is also discussed. Inconsistencies in the existing literature both in the definitions and findings are highlighted, along with suggestions for further studies on the topic of fast limb movement control. The current heterogeneity in what is considered a fast movement and in experimental protocols makes it difficult to compare findings in the existing literature. We identified the role of the cerebellum in movement prediction and of surround inhibition in motor slowing, as well as the effects of fatigue and training on central motor control, as possible avenues for further research, especially in performance-driven populations.