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Sample records for motor task variation

  1. Motor Task Variation Induces Structural Learning

    PubMed Central

    Braun, Daniel A.; Aertsen, Ad; Wolpert, Daniel M.; Mehring, Carsten

    2009-01-01

    Summary When we have learned a motor skill, such as cycling or ice-skating, we can rapidly generalize to novel tasks, such as motorcycling or rollerblading [1–8]. Such facilitation of learning could arise through two distinct mechanisms by which the motor system might adjust its control parameters. First, fast learning could simply be a consequence of the proximity of the original and final settings of the control parameters. Second, by structural learning [9–14], the motor system could constrain the parameter adjustments to conform to the control parameters' covariance structure. Thus, facilitation of learning would rely on the novel task parameters' lying on the structure of a lower-dimensional subspace that can be explored more efficiently. To test between these two hypotheses, we exposed subjects to randomly varying visuomotor tasks of fixed structure. Although such randomly varying tasks are thought to prevent learning, we show that when subsequently presented with novel tasks, subjects exhibit three key features of structural learning: facilitated learning of tasks with the same structure, strong reduction in interference normally observed when switching between tasks that require opposite control strategies, and preferential exploration along the learned structure. These results suggest that skill generalization relies on task variation and structural learning. PMID:19217296

  2. Classification of EEG signals to identify variations in attention during motor task execution.

    PubMed

    Aliakbaryhosseinabadi, Susan; Kamavuako, Ernest Nlandu; Jiang, Ning; Farina, Dario; Mrachacz-Kersting, Natalie

    2017-06-01

    Brain-computer interface (BCI) systems in neuro-rehabilitation use brain signals to control external devices. User status such as attention affects BCI performance; thus detecting the user's attention drift due to internal or external factors is essential for high detection accuracy. An auditory oddball task was applied to divert the users' attention during a simple ankle dorsiflexion movement. Electroencephalogram signals were recorded from eighteen channels. Temporal and time-frequency features were projected to a lower dimension space and used to analyze the effect of two attention levels on motor tasks in each participant. Then, a global feature distribution was constructed with the projected time-frequency features of all participants from all channels and applied for attention classification during motor movement execution. Time-frequency features led to significantly better classification results with respect to the temporal features, particularly for electrodes located over the motor cortex. Motor cortex channels had a higher accuracy in comparison to other channels in the global discrimination of attention level. Previous methods have used the attention to a task to drive external devices, such as the P300 speller. However, here we focus for the first time on the effect of attention drift while performing a motor task. It is possible to explore user's attention variation when performing motor tasks in synchronous BCI systems with time-frequency features. This is the first step towards an adaptive real-time BCI with an integrated function to reveal attention shifts from the motor task. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Brain oscillatory signatures of motor tasks.

    PubMed

    Ramos-Murguialday, Ander; Birbaumer, Niels

    2015-06-01

    Noninvasive brain-computer-interfaces (BCI) coupled with prosthetic devices were recently introduced in the rehabilitation of chronic stroke and other disorders of the motor system. These BCI systems and motor rehabilitation in general involve several motor tasks for training. This study investigates the neurophysiological bases of an EEG-oscillation-driven BCI combined with a neuroprosthetic device to define the specific oscillatory signature of the BCI task. Controlling movements of a hand robotic orthosis with motor imagery of the same movement generates sensorimotor rhythm oscillation changes and involves three elements of tasks also used in stroke motor rehabilitation: passive and active movement, motor imagery, and motor intention. We recorded EEG while nine healthy participants performed five different motor tasks consisting of closing and opening of the hand as follows: 1) motor imagery without any external feedback and without overt hand movement, 2) motor imagery that moves the orthosis proportional to the produced brain oscillation change with online proprioceptive and visual feedback of the hand moving through a neuroprosthetic device (BCI condition), 3) passive and 4) active movement of the hand with feedback (seeing and feeling the hand moving), and 5) rest. During the BCI condition, participants received contingent online feedback of the decrease of power of the sensorimotor rhythm, which induced orthosis movement and therefore proprioceptive and visual information from the moving hand. We analyzed brain activity during the five conditions using time-frequency domain bootstrap-based statistical comparisons and Morlet transforms. Activity during rest was used as a reference. Significant contralateral and ipsilateral event-related desynchronization of sensorimotor rhythm was present during all motor tasks, largest in contralateral-postcentral, medio-central, and ipsilateral-precentral areas identifying the ipsilateral precentral cortex as an integral

  4. Brain oscillatory signatures of motor tasks

    PubMed Central

    Birbaumer, Niels

    2015-01-01

    Noninvasive brain-computer-interfaces (BCI) coupled with prosthetic devices were recently introduced in the rehabilitation of chronic stroke and other disorders of the motor system. These BCI systems and motor rehabilitation in general involve several motor tasks for training. This study investigates the neurophysiological bases of an EEG-oscillation-driven BCI combined with a neuroprosthetic device to define the specific oscillatory signature of the BCI task. Controlling movements of a hand robotic orthosis with motor imagery of the same movement generates sensorimotor rhythm oscillation changes and involves three elements of tasks also used in stroke motor rehabilitation: passive and active movement, motor imagery, and motor intention. We recorded EEG while nine healthy participants performed five different motor tasks consisting of closing and opening of the hand as follows: 1) motor imagery without any external feedback and without overt hand movement, 2) motor imagery that moves the orthosis proportional to the produced brain oscillation change with online proprioceptive and visual feedback of the hand moving through a neuroprosthetic device (BCI condition), 3) passive and 4) active movement of the hand with feedback (seeing and feeling the hand moving), and 5) rest. During the BCI condition, participants received contingent online feedback of the decrease of power of the sensorimotor rhythm, which induced orthosis movement and therefore proprioceptive and visual information from the moving hand. We analyzed brain activity during the five conditions using time-frequency domain bootstrap-based statistical comparisons and Morlet transforms. Activity during rest was used as a reference. Significant contralateral and ipsilateral event-related desynchronization of sensorimotor rhythm was present during all motor tasks, largest in contralateral-postcentral, medio-central, and ipsilateral-precentral areas identifying the ipsilateral precentral cortex as an integral

  5. Differential Contribution of Bilateral Supplementary Motor Area to the Effective Connectivity Networks Induced by Task Conditions Using Dynamic Causal Modeling

    PubMed Central

    Tao, Zhongping; Zhang, Mu

    2014-01-01

    Abstract Functional imaging studies have indicated hemispheric asymmetry of activation in bilateral supplementary motor area (SMA) during unimanual motor tasks. However, the hemispherically special roles of bilateral SMAs on primary motor cortex (M1) in the effective connectivity networks (ECN) during lateralized tasks remain unclear. Aiming to study the differential contribution of bilateral SMAs during the motor execution and motor imagery tasks, and the hemispherically asymmetric patterns of ECN among regions involved, the present study used dynamic causal modeling to analyze the functional magnetic resonance imaging data of the unimanual motor execution/imagery tasks in 12 right-handed subjects. Our results demonstrated that distributions of network parameters underlying motor execution and motor imagery were significantly different. The variation was mainly induced by task condition modulations of intrinsic coupling. Particularly, regardless of the performing hand, the task input modulations of intrinsic coupling from the contralateral SMA to contralateral M1 were positive during motor execution, while varied to be negative during motor imagery. The results suggested that the inhibitive modulation suppressed the overt movement during motor imagery. In addition, the left SMA also helped accomplishing left hand tasks through task input modulation of left SMA→right SMA connection, implying that hemispheric recruitment occurred when performing nondominant hand tasks. The results specified differential and altered contributions of bilateral SMAs to the ECN during unimanual motor execution and motor imagery, and highlighted the contributions induced by the task input of motor execution/imagery. PMID:24606178

  6. Aging and Concurrent Task Performance: Cognitive Demand and Motor Control

    ERIC Educational Resources Information Center

    Albinet, Cedric; Tomporowski, Phillip D.; Beasman, Kathryn

    2006-01-01

    A motor task that requires fine control of upper limb movements and a cognitive task that requires executive processing--first performing them separately and then concurrently--was performed by 18 young and 18 older adults. The motor task required participants to tap alternatively on two targets, the sizes of which varied systematically. The…

  7. Cortical activity predicts good variation in human motor output.

    PubMed

    Babikian, Sarine; Kanso, Eva; Kutch, Jason J

    2017-04-01

    Human movement patterns have been shown to be particularly variable if many combinations of activity in different muscles all achieve the same task goal (i.e., are goal-equivalent). The nervous system appears to automatically vary its output among goal-equivalent combinations of muscle activity to minimize muscle fatigue or distribute tissue loading, but the neural mechanism of this "good" variation is unknown. Here we use a bimanual finger task, electroencephalography (EEG), and machine learning to determine if cortical signals can predict goal-equivalent variation in finger force output. 18 healthy participants applied left and right index finger forces to repeatedly perform a task that involved matching a total (sum of right and left) finger force. As in previous studies, we observed significantly more variability in goal-equivalent muscle activity across task repetitions compared to variability in muscle activity that would not achieve the goal: participants achieved the task in some repetitions with more right finger force and less left finger force (right > left) and in other repetitions with less right finger force and more left finger force (left > right). We found that EEG signals from the 500 milliseconds (ms) prior to each task repetition could make a significant prediction of which repetitions would have right > left and which would have left > right. We also found that cortical maps of sites contributing to the prediction contain both motor and pre-motor representation in the appropriate hemisphere. Thus, goal-equivalent variation in motor output may be implemented at a cortical level.

  8. Dual-task practice enhances motor learning: a preliminary investigation.

    PubMed

    Goh, Hui-Ting; Sullivan, Katherine J; Gordon, James; Wulf, Gabriele; Winstein, Carolee J

    2012-10-01

    Practicing a motor task under dual-task conditions can be beneficial to motor learning when the secondary task is difficult (Roche et al. in Percept Psychophys 69(4):513-522, 2007) or when it engages similar processes as the primary motor task (Hemond et al. in J Neurosci 30(2):650-654, 2010). The purpose of this pilot study was to determine which factor, difficulty level or engaged processes, of a secondary task is more critical in determining dual-task benefit. Participants practiced a discrete arm task in conjunction with an audio-vocal reaction time (RT) task. We presented two different RT tasks that differed in difficulty, simple versus choice (i.e., more difficult), at two different arm task phases that differed in engaged processes, preparation versus execution, resulting in four dual-task conditions. A simple RT task is thought to predominantly engage motor execution processes, therefore would engage similar processes as the arm movement task when it is presented during the execution phase, while a choice RT task is thought to engage planning processes and therefore would engage similar processes too when it is presented during the preparation phase. Enhanced motor learning was found in those who engaged similar process as the primary task during dual-tasking (i.e., choice RT presented during preparation and simple RT presented during execution). Moreover, those who showed enhanced learning also demonstrated high dual-task cost (poor RT task performance) during practice, indicating that both tasks were taxing the same resource pool possibly due to engaging similar cognitive processes. To further test the relation between dual-task cost and enhanced learning, we delayed the presentation timing of the choice RT task during the preparation phase and the simple RT task during the execution phase in two control experiments. Dual-task cost was reduced in these delayed timing conditions, and the enhanced learning effect was attenuated. Together, our preliminary

  9. Random walk of motor planning in task-irrelevant dimensions.

    PubMed

    van Beers, Robert J; Brenner, Eli; Smeets, Jeroen B J

    2013-02-01

    The movements that we make are variable. It is well established that at least a part of this variability is caused by noise in central motor planning. Here, we studied how the random effects of planning noise translate into changes in motor planning. Are the random effects independently added to a constant mean end point, or do they accumulate over movements? To distinguish between these possibilities, we examined repeated, discrete movements in various tasks in which the motor output could be decomposed into a task-relevant and a task-irrelevant component. We found in all tasks that the task-irrelevant component had a positive lag 1 autocorrelation, suggesting that the random effects of planning noise accumulate over movements. In contrast, the task-relevant component always had a lag 1 autocorrelation close to zero, which can be explained by effective trial-by-trial correction of motor planning on the basis of observed motor errors. Accumulation of the effects of planning noise is consistent with current insights into the stochastic nature of synaptic plasticity. It leads to motor exploration, which may subserve motor learning and performance optimization.

  10. Variation in motor output and motor performance in a centrally generated motor pattern.

    PubMed

    Wenning, Angela; Norris, Brian J; Doloc-Mihu, Anca; Calabrese, Ronald L

    2014-07-01

    Central pattern generators (CPGs) produce motor patterns that ultimately drive motor outputs. We studied how functional motor performance is achieved, specifically, whether the variation seen in motor patterns is reflected in motor performance and whether fictive motor patterns differ from those in vivo. We used the leech heartbeat system in which a bilaterally symmetrical CPG coordinates segmental heart motor neurons and two segmented heart tubes into two mutually exclusive coordination modes: rear-to-front peristaltic on one side and nearly synchronous on the other, with regular side-to-side switches. We assessed individual variability of the motor pattern and the beat pattern in vivo. To quantify the beat pattern we imaged intact adults. To quantify the phase relations between motor neurons and heart constrictions we recorded extracellularly from two heart motor neurons and movement from the corresponding heart segments in minimally dissected leeches. Variation in the motor pattern was reflected in motor performance only in the peristaltic mode, where larger intersegmental phase differences in the motor neurons resulted in larger phase differences between heart constrictions. Fictive motor patterns differed from those in vivo only in the synchronous mode, where intersegmental phase differences in vivo had a larger front-to-rear bias and were more constrained. Additionally, load-influenced constriction timing might explain the amplification of the phase differences between heart segments in the peristaltic mode and the higher variability in motor output due to body shape assumed in this soft-bodied animal. The motor pattern determines the beat pattern, peristaltic or synchronous, but heart mechanics influence the phase relations achieved.

  11. Variation in motor output and motor performance in a centrally generated motor pattern

    PubMed Central

    Norris, Brian J.; Doloc-Mihu, Anca; Calabrese, Ronald L.

    2014-01-01

    Central pattern generators (CPGs) produce motor patterns that ultimately drive motor outputs. We studied how functional motor performance is achieved, specifically, whether the variation seen in motor patterns is reflected in motor performance and whether fictive motor patterns differ from those in vivo. We used the leech heartbeat system in which a bilaterally symmetrical CPG coordinates segmental heart motor neurons and two segmented heart tubes into two mutually exclusive coordination modes: rear-to-front peristaltic on one side and nearly synchronous on the other, with regular side-to-side switches. We assessed individual variability of the motor pattern and the beat pattern in vivo. To quantify the beat pattern we imaged intact adults. To quantify the phase relations between motor neurons and heart constrictions we recorded extracellularly from two heart motor neurons and movement from the corresponding heart segments in minimally dissected leeches. Variation in the motor pattern was reflected in motor performance only in the peristaltic mode, where larger intersegmental phase differences in the motor neurons resulted in larger phase differences between heart constrictions. Fictive motor patterns differed from those in vivo only in the synchronous mode, where intersegmental phase differences in vivo had a larger front-to-rear bias and were more constrained. Additionally, load-influenced constriction timing might explain the amplification of the phase differences between heart segments in the peristaltic mode and the higher variability in motor output due to body shape assumed in this soft-bodied animal. The motor pattern determines the beat pattern, peristaltic or synchronous, but heart mechanics influence the phase relations achieved. PMID:24717348

  12. Motor hysteresis in a sequential grasping and pointing task is absent in task-critical joints.

    PubMed

    Schütz, Christoph; Weigelt, Matthias; Schack, Thomas

    2017-03-01

    In a prior study (Schütz et al. in Exp Brain Res 2016. doi: 10.1007/s00221-016-4608-6 ), we demonstrated that the cognitive cost of motor planning did not differ in a vertical pointing and grasping task. It was unclear whether the similar cost implied that both tasks required the same number of independent degrees of freedom (IDOFs) or that the number of IDOFs did not affect motor planning. To differentiate between both cases, a reanalysis of the prior data was conducted. The number of IDOFs in the pointing and grasping tasks was computed by factor analysis. In both tasks, two IDOFs were used, which was the minimum number required for position control. This indicates that hand alignment in the grasping task did not require an additional IDOF. No conclusions regarding the link between the cognitive cost of motor planning and the number of IDOFs could be drawn. A subset of task-critical joint angles was not affected by motor hysteresis. This indicates that a joint's susceptibility to motor hysteresis depends on its relevance to the task goal. In task-critical joints, planning cost minimization by motor plan reuse is suppressed in favor of the task goal.

  13. Motor Cortex Inhibition is Increased During a Secondary Cognitive Task.

    PubMed

    Holste, Katherine G; Yasen, Alia L; Hill, Matthew J; Christie, Anita D

    2016-10-01

    The purpose of this study was to assess the effect of a cognitive task on motor cortex excitability and inhibition. Transcranial magnetic stimulation of the motor cortex was performed on 20 healthy individuals (18-24 years; 9 females) to measure motor evoked potentials (MEPs) and cortical silent periods at baseline, during, and following a secondary cognitive task. The MEP amplitude increased from 0.50 ± 0.09-0.87 ± 0.50 mV during a secondary cognitive task (p = .04), and returned to baseline (0.48 ± 0.31 mV; p = .90) posttask. The CSP duration also increased from 93.48 ± 28.76-113.6 ± 33.68 ms (p = .001) during the cognitive task, and returned to baseline posttask (89.0 ± 6.9 ms; p = .88). In the presence of a cognitive task, motor cortex excitability and inhibition were both increased relative to baseline. The increase in inhibition may help to explain the motor deficits experienced while performing a secondary cognitive task.

  14. Changes in corticospinal motor excitability induced by non-motor linguistic tasks.

    PubMed

    Papathanasiou, I; Filipović, S R; Whurr, R; Rothwell, J C; Jahanshahi, M

    2004-01-01

    The excitability of the corticospinal motor pathways to transcranial magnetic stimulation (TMS) can be differentially modulated by a variety of motor tasks. However, there is emerging evidence that linguistic tasks may alter excitability of the corticospinal motor pathways also. In this study we evaluated the effect of several movement-free, low-level linguistic processes involved in reading and writing on the excitability of the bilateral corticospinal motor pathways in a group of right-handed subjects. The study included two series of tasks, visual searching/matching and imaginal writing/drawing. The tasks were designed to roughly correspond with elemental aspects of the reading and writing, grapheme recognition and grapheme generation, respectively. Each task series included separate blocks with different task targets: letters, digits, semantically easy-to-code (i.e. geometric) shapes, and semantically hard-to-code shapes, as well as control blocks with no task. During task performance, TMS was delivered randomly over the hand area of either the left or right motor cortex and the modulation of the excitability of the corticospinal motor pathways was measured bilaterally through changes of the size of the motor-evoked potential (MEP) induced in the relaxed right and left first dorsal interosseous (FDI) muscles. We found that the size of the MEP in hand muscles increased during visual searching/matching tasks, particularly when targets were letters or geometric shapes, and the increase was significant for the dominant hand (left hemisphere) only. No such consistent effects were seen across subjects during imaginal tasks. This study provides evidence that even the performance of certain low-level linguistic tasks can modulate the excitability of the corticospinal motor pathways, particularly those originating from the left (dominant) hemisphere, despite the absence of overt motor activity. Moreover, in the light of the recently increased awareness of the role of

  15. The effectiveness of robotic training depends on motor task characteristics.

    PubMed

    Marchal-Crespo, Laura; Rappo, Nicole; Riener, Robert

    2017-10-05

    Previous research suggests that the effectiveness of robotic training depends on the motor task to be learned. However, it is still an open question which specific task's characteristics influence the efficacy of error-modulating training strategies. Motor tasks can be classified based on the time characteristics of the task, in particular the task's duration (discrete vs. continuous). Continuous tasks require movements without distinct beginning or end. Discrete tasks require fast movements that include well-defined postures at the beginning and the end. We developed two games, one that requires a continuous movement-a tracking task-and one that requires discrete movements-a fast reaching task. We conducted an experiment with thirty healthy subjects to evaluate the effectiveness of three error-modulating training strategies-no guidance, error amplification (i.e., repulsive forces proportional to errors) and haptic guidance-on self-reported motivation and learning of the continuous and discrete games. Training with error amplification resulted in better motor learning than haptic guidance, besides the fact that error amplification reduced subjects' interest/enjoyment and perceived competence during training. Only subjects trained with error amplification improved their performance after training the discrete game. In fact, subjects trained without guidance improved the performance in the continuous game significantly more than in the discrete game, probably because the continuous task required greater attentional levels. Error-amplifying training strategies have a great potential to provoke better motor learning in continuous and discrete tasks. However, their long-lasting negative effects on motivation might limit their applicability in intense neurorehabilitation programs.

  16. Motor Dual-Task Effect on Gait and Task of Upper Limbs in Older Adults under Specific Task Prioritization: Pilot Study

    PubMed Central

    Oh-Park, Mooyeon; Holtzer, Roee; Mahoney, Jeannette; Wang, Cuiling; Raghavan, Preeti; Verghese, Joe

    2014-01-01

    Background and Aims Performing multiple tasks simultaneously may result in reduced performance of subtasks (dual-task cost) particularly among old individuals. Subtask performance during dual-tasking is also known to be affected by task prioritization. However, it has not been well studied how the performance of subtasks is affected during motor dual-task in old adults compared to young when instructed to prioritize one task over the other. This study aims to investigate the dual-task effect on subtasks during motor dual-tasking under specific instruction of task prioritization in old compared to young adults. Methods Sixteen independent old and 18 young adults performed two single tasks (usual walking, holding a tray as steady as possible while standing) and two dual-tasks (walking while holding a tray focusing attention on keeping tray as steady as possible-WTAT, and walking while holding tray focusing attention on walking -WTAW). Gait parameters [velocity and variability (coefficient of variation; CV) of stride length] and the pitch (forward-backward) and roll (side-to-side) angles of the tray were measured during the four conditions. Results During the WTAT compared to single tasks, both young and old groups showed reduced gait velocity (β = -14.0 for old, -34.3 for young), increased gait variability (β = 0.19 for old, 0.51 for young), and increased tray tilt (β =9.4 for old, 7.9 for young in pitch; β =8.8 for old, 5.9 for young in roll). Higher proportion of older individuals showed higher dual-task effect on tray stability, but lower dual-task effect on gait compared to young individuals. During WTAW, there was no difference in dual-task effect between age groups in tray stability or gait performance. Conclusions Compared to young, older adults tend to compromise the task involving upper limbs during motor dual-tasking even when instructed to prioritize this task over gait. These findings may have ramifications on developing training strategies to learn

  17. Motor skill experience modulates executive control for task switching.

    PubMed

    Yu, Qiuhua; Chan, Chetwyn C H; Chau, Bolton; Fu, Amy S N

    2017-09-15

    This study aimed to investigate the effect of types of motor skills, including open and closed skills on enhancing proactive and reactive controls for task switching. Thirty-six athletes in open (n=18) or closed (n=18) sports and a control group (n=18) completed the task-switching paradigm and the simple reaction task. The task-switching paradigm drew on the proactive and reactive control of executive functions, whereas the simple reaction task assessed the processing speed. Significant Validity×Group effect revealed that the participants with open skills had a lower switch cost of response time compared to the other two groups when the task cue was 100% valid; whereas the participants regardless of motor skills had a lower switch cost of response time compared to the control group when the task cue was 50% valid. Hierarchical stepwise regression analysis further confirmed these findings. For the simple reaction task, there were no differences found among the three groups. These findings suggest that experience in open skills has benefits of promoting both proactive and reactive controls for task switching, which corresponds to the activity context exposed by the participants. In contrast, experience in closed skills appears to only benefit development of reactive control for task switching. The neural mechanisms for the proactive and reactive controls of executive functions between experts with open and closed skills call for future study. Copyright © 2017. Published by Elsevier B.V.

  18. Electroencephalography Pattern Variations During Motor Skill Acquisition.

    PubMed

    Ghasemian, Mohammadreza; Taheri, Hamidreza; Saberi Kakhki, Alireza; Ghoshuni, Majid

    2017-01-01

    The present study examined how motor skill acquisition affects electroencephalography patterns and compared short- and long-term electroencephalography variations. For this purpose, 17 volunteers with no history of disease, aged 18 to 22 years, attended seven training sessions every other day to practice a pursuit tracking motor skill. Electroencephalography brainwaves were recorded and analyzed on the first and last days within pre- and post-training intervals. The results showed a significant decrease in performance error and variability with practice over time. This progress slowed at the end of training, and there was no significant improvement in individual performance at the last session. In accordance with performance variations, some changes occurred in brainwaves. Specifically, θ power at Fz and α power at Cz increased on the last test day, compared with the first, while the coherence of α at Fz-T3 and Fz-Cz decreased. β Coherence between Fz-Cz was significantly reduced from pre- to posttest. Based on these results, power changes seem to be more affected by long-term training, whereas coherence changes are sensitive to both short- and long-term training. Specifically, β coherence at Fz-Cz was more influenced by short-term effects of training, whereas θ power at Fz, α power at Cz, and α coherence at Fz-T3 and Fz-Cz were affected by longer training.

  19. Individual differences in the exploration of a redundant space-time motor task.

    PubMed

    King, Adam C; Ranganathan, Rajiv; Newell, Karl M

    2012-11-07

    Individual differences in learning a motor task are rarely assessed even though they can potentially contribute to our understanding of the problem of motor redundancy-i.e., how individuals can exploit multiple different strategies to realize the task goal. This study examined individual variations in the preferred movement strategy of a redundant motor task. Thirty-two participants performed a star tracing task on a digitizing tablet with the goal of minimizing a performance score that was given as feedback. The performance score was a weighted combination of spatial error and movement time, meaning that multiple strategies could yield the same score. A cluster analysis revealed three distinct groups of individuals based on their initial movement strategy preferences. These groups were not only different on their initial performance, but also exhibited differences in both local (trial-to-trial change) and global (average change) search strategies that were reflected through differential modification of spatial and temporal components. Overall, the results in this space-time task reveal that the intrinsic dynamics of the individual channel the initial exploratory solutions to learning a redundant motor task.

  20. Task-Specific Motor Rehabilitation Therapy After Stroke Improves Performance in a Different Motor Task: Translational Evidence.

    PubMed

    El Amki, M; Baumgartner, P; Bracko, O; Luft, A R; Wegener, S

    2017-01-14

    While the stroke survivor with a motor deficit strives for recovery of all aspects of daily life movements, neurorehabilitation training is often task specific and does not generalize to movements other than the ones trained. In rodent models of post-stroke recovery, this problem is poorly investigated as the training task is often the same as the one that measures motor function. The present study investigated whether motor training by pellet reaching translates into enhancement of different motor functions in rats after stroke. Adult rats were subjected to 60-min middle cerebral artery occlusion (MCAO). Five days after stroke, animals received either training consisting of 7 days of pellet reaching with the affected forelimb (n = 18) or no training (n = 18). Sensorimotor deficits were assessed using the sticky tape test and a composite neuroscore. Infarct volumes were measured by T2-weighted MRI on day 28. Both groups of rats showed similar lesion volume and forelimb impairment after stroke. Trained animals improved in the sticky tape test after day 7 post-stroke reaching peak performance on day 14. More reaching attempts during rehabilitation were associated with a better performance in the sticky tape removal time. Task-oriented motor training generalizes to other motor functions after experimental stroke. Training intensity correlates with recovery.

  1. Effects of Concurrent Motor, Linguistic, or Cognitive Tasks on Speech Motor Performance

    ERIC Educational Resources Information Center

    Dromey, Christopher; Benson, April

    2003-01-01

    This study examined the influence of 3 different types of concurrent tasks on speech motor performance. The goal was to uncover potential differences in speech movements relating to the nature of the secondary task. Twenty young adults repeated sentences either with or without simultaneous distractor activities. These distractions included a motor…

  2. Toy Story: Illustrating Gender Differences in a Motor Skills Task

    ERIC Educational Resources Information Center

    Knight, Jennifer L.; Hebl, Michelle R.; Mendoza, Miriam

    2004-01-01

    To challenge students' stereotypes about gendered performance on motor skills tasks, we developed a classroom active learning demonstration. Four 3-person, same-gender teams received either a Barbie(r) doll or a Transformer(r), and team members dressed the Barbie or manipulated the Transformer from a tank to a robot as quickly as possible, with…

  3. Electromyographic Study of Motor Learning for a Voice Production Task

    ERIC Educational Resources Information Center

    Yiu, Edwin M.-L.; Verdolini, Katherine; Chow, Linda P. Y.

    2005-01-01

    Purpose: This study's broad objective was to examine the effectiveness of surface electromyographic (EMG) biofeedback for motor learning in the voice production domain. The specific objective was to examine whether concurrent or terminal biofeedback would facilitate learning for a relaxed laryngeal musculature task during spoken reading. Method:…

  4. Toy Story: Illustrating Gender Differences in a Motor Skills Task

    ERIC Educational Resources Information Center

    Knight, Jennifer L.; Hebl, Michelle R.; Mendoza, Miriam

    2004-01-01

    To challenge students' stereotypes about gendered performance on motor skills tasks, we developed a classroom active learning demonstration. Four 3-person, same-gender teams received either a Barbie(r) doll or a Transformer(r), and team members dressed the Barbie or manipulated the Transformer from a tank to a robot as quickly as possible, with…

  5. Electromyographic Study of Motor Learning for a Voice Production Task

    ERIC Educational Resources Information Center

    Yiu, Edwin M.-L.; Verdolini, Katherine; Chow, Linda P. Y.

    2005-01-01

    Purpose: This study's broad objective was to examine the effectiveness of surface electromyographic (EMG) biofeedback for motor learning in the voice production domain. The specific objective was to examine whether concurrent or terminal biofeedback would facilitate learning for a relaxed laryngeal musculature task during spoken reading. Method:…

  6. Motor planning flexibly optimizes performance under uncertainty about task goals

    PubMed Central

    Wong, Aaron L.; Haith, Adrian M.

    2017-01-01

    In an environment full of potential goals, how does the brain determine which movement to execute? Existing theories posit that the motor system prepares for all potential goals by generating several motor plans in parallel. One major line of evidence for such theories is that presenting two competing goals often results in a movement intermediate between them. These intermediate movements are thought to reflect an unintentional averaging of the competing plans. However, normative theories suggest instead that intermediate movements might actually be deliberate, generated because they improve task performance over a random guessing strategy. To test this hypothesis, we vary the benefit of making an intermediate movement by changing movement speed. We find that participants generate intermediate movements only at (slower) speeds where they measurably improve performance. Our findings support the normative view that the motor system selects only a single, flexible motor plan, optimized for uncertain goals. PMID:28256513

  7. Visual Motor and Perceptual Task Performance in Astigmatic Students.

    PubMed

    Harvey, Erin M; Twelker, J Daniel; Miller, Joseph M; Leonard-Green, Tina K; Mohan, Kathleen M; Davis, Amy L; Campus, Irene

    2017-01-01

    Purpose. To determine if spectacle corrected and uncorrected astigmats show reduced performance on visual motor and perceptual tasks. Methods. Third through 8th grade students were assigned to the low refractive error control group (astigmatism < 1.00 D, myopia < 0.75 D, hyperopia < 2.50 D, and anisometropia < 1.50 D) or bilateral astigmatism group (right and left eye ≥ 1.00 D) based on cycloplegic refraction. Students completed the Beery-Buktenica Developmental Test of Visual Motor Integration (VMI) and Visual Perception (VMIp). Astigmats were randomly assigned to testing with/without correction and control group was tested uncorrected. Analyses compared VMI and VMIp scores for corrected and uncorrected astigmats to the control group. Results. The sample included 333 students (control group 170, astigmats tested with correction 75, and astigmats tested uncorrected 88). Mean VMI score in corrected astigmats did not differ from the control group (p = 0.829). Uncorrected astigmats had lower VMI scores than the control group (p = 0.038) and corrected astigmats (p = 0.007). Mean VMIp scores for uncorrected (p = 0.209) and corrected astigmats (p = 0.124) did not differ from the control group. Uncorrected astigmats had lower mean scores than the corrected astigmats (p = 0.003). Conclusions. Uncorrected astigmatism influences visual motor and perceptual task performance. Previously spectacle treated astigmats do not show developmental deficits on visual motor or perceptual tasks when tested with correction.

  8. Visual Motor and Perceptual Task Performance in Astigmatic Students

    PubMed Central

    Twelker, J. Daniel; Miller, Joseph M.; Mohan, Kathleen M.; Campus, Irene

    2017-01-01

    Purpose. To determine if spectacle corrected and uncorrected astigmats show reduced performance on visual motor and perceptual tasks. Methods. Third through 8th grade students were assigned to the low refractive error control group (astigmatism < 1.00 D, myopia < 0.75 D, hyperopia < 2.50 D, and anisometropia < 1.50 D) or bilateral astigmatism group (right and left eye ≥ 1.00 D) based on cycloplegic refraction. Students completed the Beery-Buktenica Developmental Test of Visual Motor Integration (VMI) and Visual Perception (VMIp). Astigmats were randomly assigned to testing with/without correction and control group was tested uncorrected. Analyses compared VMI and VMIp scores for corrected and uncorrected astigmats to the control group. Results. The sample included 333 students (control group 170, astigmats tested with correction 75, and astigmats tested uncorrected 88). Mean VMI score in corrected astigmats did not differ from the control group (p = 0.829). Uncorrected astigmats had lower VMI scores than the control group (p = 0.038) and corrected astigmats (p = 0.007). Mean VMIp scores for uncorrected (p = 0.209) and corrected astigmats (p = 0.124) did not differ from the control group. Uncorrected astigmats had lower mean scores than the corrected astigmats (p = 0.003). Conclusions. Uncorrected astigmatism influences visual motor and perceptual task performance. Previously spectacle treated astigmats do not show developmental deficits on visual motor or perceptual tasks when tested with correction. PMID:28293434

  9. Cortical gamma-oscillations modulated by auditory-motor tasks

    PubMed Central

    Nagasawa, Tetsuro; Rothermel, Robert; Juhász, Csaba; Fukuda, Miho; Nishida, Masaaki; Akiyama, Tomoyuki; Sood, Sandeep; Asano, Eishi

    2010-01-01

    SUMMARY Human activities often involve hand-motor responses following external auditory-verbal commands. It has been believed that hand movements are predominantly driven by the contralateral primary sensorimotor cortex, whereas auditory-verbal information is processed in both superior temporal gyri. It remains unknown whether cortical activation in the superior temporal gyrus during an auditory-motor task is affected by laterality of hand-motor responses. Here, event-related gamma-oscillations were intracranially recorded as quantitative measures of cortical activation; we determined how cortical structures were activated by auditory-cued movement using each hand in 15 patients with focal epilepsy. Auditory-verbal stimuli elicited augmentation of gamma-oscillations in a posterior portion of the superior temporal gyrus, whereas hand-motor responses elicited gamma-augmentation in the pre- and post-central gyri. The magnitudes of such gamma-augmentation in the superior temporal, pre-central and post-central gyri were significantly larger when the hand contralateral to the recorded hemisphere was required to be used for motor responses, compared to when the ipsilateral hand was. The superior temporal gyrus in each hemisphere might play a greater pivotal role when the contralateral hand needs to be used for motor responses, compared to when the ipsilateral hand does. PMID:20143383

  10. Forced Aerobic Exercise Preceding Task Practice Improves Motor Recovery Poststroke

    PubMed Central

    Rosenfeldt, Anson B.; Dey, Tanujit; Alberts, Jay L.

    2017-01-01

    OBJECTIVE. To understand how two types of aerobic exercise affect upper-extremity motor recovery post-stroke. Our aims were to (1) evaluate the feasibility of having people who had a stroke complete an aerobic exercise intervention and (2) determine whether forced or voluntary exercise differentially facilitates upper-extremity recovery when paired with task practice. METHOD. Seventeen participants with chronic stroke completed twenty-four 90-min sessions over 8 wk. Aerobic exercise was immediately followed by task practice. Participants were randomized to forced or voluntary aerobic exercise groups or to task practice only. RESULTS. Improvement on the Fugl-Meyer Assessment exceeded the minimal clinically important difference: 12.3, 4.8, and 4.4 for the forced exercise, voluntary exercise, and repetitive task practice–only groups, respectively. Only the forced exercise group exhibited a statistically significant improvement. CONCLUSION. People with chronic stroke can safely complete intensive aerobic exercise. Forced aerobic exercise may be optimal in facilitating motor recovery associated with task practice. PMID:28218596

  11. Forced Aerobic Exercise Preceding Task Practice Improves Motor Recovery Poststroke.

    PubMed

    Linder, Susan M; Rosenfeldt, Anson B; Dey, Tanujit; Alberts, Jay L

    To understand how two types of aerobic exercise affect upper-extremity motor recovery post-stroke. Our aims were to (1) evaluate the feasibility of having people who had a stroke complete an aerobic exercise intervention and (2) determine whether forced or voluntary exercise differentially facilitates upper-extremity recovery when paired with task practice. Seventeen participants with chronic stroke completed twenty-four 90-min sessions over 8 wk. Aerobic exercise was immediately followed by task practice. Participants were randomized to forced or voluntary aerobic exercise groups or to task practice only. Improvement on the Fugl-Meyer Assessment exceeded the minimal clinically important difference: 12.3, 4.8, and 4.4 for the forced exercise, voluntary exercise, and repetitive task practice-only groups, respectively. Only the forced exercise group exhibited a statistically significant improvement. People with chronic stroke can safely complete intensive aerobic exercise. Forced aerobic exercise may be optimal in facilitating motor recovery associated with task practice.

  12. Effect of constant, predictable, and unpredictable motor tasks on motor performance and blood markers of stress.

    PubMed

    Kyguoliene, Laura; Skurvydas, Albertas; Eimantas, Nerijus; Baranauskienė, Neringa; Mickeviciene, Dalia; Urboniene, Daiva; Cernych, Margarita; Brazaitis, Marius

    2017-05-01

    An unfamiliar or novel physical stimulus induces activation of dopaminergic neurons within the brain and greater activity in areas involved in emotion; considering this, we aimed to establish whether unpredictable prolonged (fatiguing) motor task (vs. constant vs. predictable) evokes greater dopaminergic activity, enhances neuromuscular performance, motor accuracy, and perception of effort, and delays overall central fatigue. Fifteen healthy male volunteers (aged 22 ± 4 years) were required to perform 1 of 3 exercise trials (at least 1 week apart) of 100 intermittent isometric contraction (IIC) tasks involving knee extensions at 60° flexion. Trials were structured differently by simulated contraction intensity. A fatigue task involved 5-s contractions and 20-s rest. Variables measured before, during, and after IIC were electrically induced force, maximal voluntary contraction, central activation ratio, intramuscular temperature, and blood levels of dopamine, cortisol, and prolactin, and intraindividual motor variability and accuracy (constant and absolute error). We found that IIC increased central and peripheral fatigue, force sensation, and T mu, and decreased absolute and constant error without visual feedback, but did not affect motor variability. There were no significant differences between the three IIC tasks. However, only unpredictable tasks increased dopaminergic activity, which was insufficient to affect central motivation to perform isometric exercise and alter centrally mediated components of fatigue.

  13. Learning optimal adaptation strategies in unpredictable motor tasks

    PubMed Central

    Braun, D. A.; Aertsen, A.; Wolpert, D. M.; Mehring, C.

    2009-01-01

    Picking up an empty milk carton that we believe to be full is a familiar example of adaptive control, because the adaptation process of estimating the carton's weight must proceed simultaneously to the control process of moving the carton to a desired location. Here we show that the motor system initially generates highly variable behavior in such unpredictable tasks but eventually converges to stereotyped patterns of adaptive responses predicted by a simple optimality principle. These results suggest that adaptation can become specifically tuned to identify task-specific parameters in an optimal manner. PMID:19458218

  14. Task-dependent signal variations in EEG error-related potentials for brain-computer interfaces

    NASA Astrophysics Data System (ADS)

    Iturrate, I.; Montesano, L.; Minguez, J.

    2013-04-01

    Objective. A major difficulty of brain-computer interface (BCI) technology is dealing with the noise of EEG and its signal variations. Previous works studied time-dependent non-stationarities for BCIs in which the user’s mental task was independent of the device operation (e.g., the mental task was motor imagery and the operational task was a speller). However, there are some BCIs, such as those based on error-related potentials, where the mental and operational tasks are dependent (e.g., the mental task is to assess the device action and the operational task is the device action itself). The dependence between the mental task and the device operation could introduce a new source of signal variations when the operational task changes, which has not been studied yet. The aim of this study is to analyse task-dependent signal variations and their effect on EEG error-related potentials.Approach. The work analyses the EEG variations on the three design steps of BCIs: an electrophysiology study to characterize the existence of these variations, a feature distribution analysis and a single-trial classification analysis to measure the impact on the final BCI performance.Results and significance. The results demonstrate that a change in the operational task produces variations in the potentials, even when EEG activity exclusively originated in brain areas related to error processing is considered. Consequently, the extracted features from the signals vary, and a classifier trained with one operational task presents a significant loss of performance for other tasks, requiring calibration or adaptation for each new task. In addition, a new calibration for each of the studied tasks rapidly outperforms adaptive techniques designed in the literature to mitigate the EEG time-dependent non-stationarities.

  15. Task-dependent signal variations in EEG error-related potentials for brain-computer interfaces.

    PubMed

    Iturrate, I; Montesano, L; Minguez, J

    2013-04-01

    A major difficulty of brain-computer interface (BCI) technology is dealing with the noise of EEG and its signal variations. Previous works studied time-dependent non-stationarities for BCIs in which the user's mental task was independent of the device operation (e.g., the mental task was motor imagery and the operational task was a speller). However, there are some BCIs, such as those based on error-related potentials, where the mental and operational tasks are dependent (e.g., the mental task is to assess the device action and the operational task is the device action itself). The dependence between the mental task and the device operation could introduce a new source of signal variations when the operational task changes, which has not been studied yet. The aim of this study is to analyse task-dependent signal variations and their effect on EEG error-related potentials. The work analyses the EEG variations on the three design steps of BCIs: an electrophysiology study to characterize the existence of these variations, a feature distribution analysis and a single-trial classification analysis to measure the impact on the final BCI performance. The results demonstrate that a change in the operational task produces variations in the potentials, even when EEG activity exclusively originated in brain areas related to error processing is considered. Consequently, the extracted features from the signals vary, and a classifier trained with one operational task presents a significant loss of performance for other tasks, requiring calibration or adaptation for each new task. In addition, a new calibration for each of the studied tasks rapidly outperforms adaptive techniques designed in the literature to mitigate the EEG time-dependent non-stationarities.

  16. Task related modulation of the motor system during language processing.

    PubMed

    Sato, Marc; Mengarelli, Marisa; Riggio, Lucia; Gallese, Vittorio; Buccino, Giovanni

    2008-05-01

    Recent neurophysiological and brain imaging studies have shown that the motor system is involved in language processing. However, it is an open question whether this involvement is a necessary requisite to understand language or rather a side effect of distinct cognitive processes underlying it. In order to clarify this issue we carried out three behavioral experiments, using a go-no go paradigm. Italian verbs expressing hand actions, foot actions or an abstract content served as stimuli. Participants used their right hands to respond. In Experiment 1, in which a semantics decision task with an early delivery of the go signal (during processing language material) was used, slower responses were found for hand action-related verbs than for foot action-related verbs. In Experiment 2, using the same task with either an early or a delayed delivery of the go signal (when language material had been already processed), no difference was found between responses to the two verb categories in the delayed delivery condition. In Experiment 3, in which a lexical decision task with an early delivery of the go signal was used, again no difference between the two verb categories was found. The present findings demonstrate that during language processing the modulation of the motor system crucially occurs while performing a semantics decision task, thus supporting the notion that this involvement is a necessary step to understand language rather than a side effect of upstream cognitive processes.

  17. Age-Related Differences in Corticospinal Excitability during Observation and Motor Imagery of Balance Tasks

    PubMed Central

    Mouthon, Audrey A.; Ruffieux, Jan; Keller, Martin; Taube, Wolfgang

    2016-01-01

    Postural control declines across adult lifespan. Non-physical balance training has been suggested as an alternative to improve postural control in frail/immobilized elderly people. Previous studies showed that this kind of training can improve balance control in young and older adults. However, it is unclear whether the brain of young and older adults is activated differently during mental simulations of balance tasks. For this purpose, soleus (SOL) and tibialis motor evoked potentials (MEPs) and SOL H-reflexes were elicited while 15 elderly (mean ± SD = 71 ± 4.6 years) and 15 young participants (mean ± SD = 27 ± 4.6 years) mentally simulated static and dynamic balance tasks using motor imagery (MI), action observation (AO) or the combination of AO and MI (AO + MI). Young subjects displayed significant modulations of MEPs that depended on the kind of mental simulation and the postural task. Elderly adults also revealed differences between tasks, but not between mental simulation conditions. Furthermore, the elderly displayed larger MEP facilitation during mental simulation (AGE-GROUP; F(1,28) = 5.9; p = 0.02) in the SOL muscle compared to the young and a task-dependent modulation of the tibialis background electromyography (bEMG) activity. H-reflex amplitudes and bEMG in the SOL showed neither task- nor age-dependent modulation. As neither mental simulation nor balance tasks modulated H-reflexes and bEMG in the SOL muscle, despite large variations in the MEP-amplitudes, there seems to be an age-related change in the internal cortical representation of balance tasks. Moreover, the modulation of the tibialis bEMG in the elderly suggests that aging partially affects the ability to inhibit motor output. PMID:28066238

  18. Variations in Articulatory Movement with Changes in Speech Task.

    ERIC Educational Resources Information Center

    Tasko, Stephen M.; McClean, Michael D.

    2004-01-01

    Studies of normal and disordered articulatory movement often rely on the use of short, simple speech tasks. However, the severity of speech disorders can be observed to vary markedly with task. Understanding task-related variations in articulatory kinematic behavior may allow for an improved understanding of normal and disordered speech motor…

  19. Variations in Articulatory Movement with Changes in Speech Task.

    ERIC Educational Resources Information Center

    Tasko, Stephen M.; McClean, Michael D.

    2004-01-01

    Studies of normal and disordered articulatory movement often rely on the use of short, simple speech tasks. However, the severity of speech disorders can be observed to vary markedly with task. Understanding task-related variations in articulatory kinematic behavior may allow for an improved understanding of normal and disordered speech motor…

  20. Motor abundance contributes to resolving multiple kinematic task constraints

    PubMed Central

    G, Gera; SMSF, Freitas; ML, Latash; K, Monahan; G, Schöner; JP, Scholz

    2009-01-01

    This study investigated the use of motor abundance during the transport and placing of objects that required either precise or minimal orientation to the target. Analyses across repetitions of the structure of joint configuration variance relative to the position and orientation constraints were performed using the Uncontrolled Manifold (UCM) approach. Results indicated that the orientation constraint did not affect stability of the hand's spatial trajectory. Orientation was weakly stabilized during the late transport phase independent of the orientation constraint, indicating no default synergy stabilizing orientation. Stabilization of orientation for conditions most requiring it for successful insertion of the object was present primarily during the adjustment phase. The results support the hypothesis that a major advantage of a control scheme that utilizes motor abundance is the ability to resolve multiple task constraints simultaneously without undue interference among them. PMID:20237405

  1. EFFECT OF ENERGY DRINKS ON SELECTED FINE MOTOR TASKS.

    PubMed

    Jacobson, B H; Hughes, P P; Conchola, E C; Hester, G M; Woolsey, C L

    2015-08-01

    This study assessed the effect of energy shots on selected fine motor tasks. The participants were college-age male (n=19; M age=20.5 yr., SD=0.7) and female (n=21; M age=21.1 yr., SD=0.7) volunteers who were assessed on hand steadiness, choice reaction time, rotary pursuit, and simple reaction time. The energy shots group scored significantly poorer on the hand steadiness tests and significantly better on choice reaction time and simple reaction time tests. The enhanced reaction time and disruption in hand steadiness afforded by energy shots would not be apparent in many gross motor activities, but it is possible that reaction time improvement could be beneficial in sports that require quick, reflexive movements. However, the potential adverse psychological and physiological effects warrant discretionary use of such products.

  2. Effects of long-term practice and task complexity in musicians and nonmusicians performing simple and complex motor tasks: implications for cortical motor organization.

    PubMed

    Meister, Ingo; Krings, Timo; Foltys, Henrik; Boroojerdi, Babak; Müller, Mareike; Töpper, Rudolf; Thron, Armin

    2005-07-01

    Motor practice induces plastic changes within the cortical motor system. Whereas rapidly evolving changes of cortical motor representations were the subject of a number of recent studies, effects of long-term practice on the motor system are so far poorly understood. In the present study pianists and nonmusicians were investigated using functional magnetic resonance imaging. Both groups performed simple and complex movement sequences on a keyboard with the right hand, the tasks requiring different levels of ordinal complexity. The aim of this study was to characterize motor representations related to sequence complexity and to long-term motor practice. In nonmusicians, complex motor sequences showed higher fMRI activations of the presupplementary motor area (pre-SMA) and the rostral part of the dorsal premotor cortex (PMd) compared to simple motor sequences, whereas musicians showed no differential activations. These results may reflect the higher level of visuomotor integration required in the complex task in nonmusicians, whereas in musicians this rostral premotor network was employed during both tasks. Comparison of subject groups revealed increased activation of a more caudal premotor network in nonmusicians comprising the caudal part of the PMd and the supplementary motor area. This supports recent results suggesting a specialization within PMd. Furthermore, we conclude that plasticity due to long-term practice mainly occurs in caudal motor areas directly related to motor execution. The slowly evolving changes in M1 during motor skill learning may extend to adjacent areas, leading to more effective motor representations in pianists.

  3. Kinetic measurements of hand motor impairments after mild to moderate stroke using grip control tasks.

    PubMed

    Ye, Yu; Ma, Le; Yan, Tiebin; Liu, Huihua; Wei, Xijun; Song, Rong

    2014-05-11

    The aim of this study is to investigate quantitative outcome measurements of hand motor performance for subjects after mild to moderate stroke using grip control tasks and characterize abnormal flexion synergy of upper extremities after stroke. A customized dynamometer with force sensors was used to measure grip force and calculate rotation torque during the sub-maximal grip control tasks. The paretic and nonpartic sides of eleven subjects after stroke and the dominant sides of ten healthy persons were tested. Their maximal voluntary grip force was measured and used to set sub-maximal grip control tasks at three different target force levels. Force control ability was characterized by the maximal grip force, mean force percentage, coefficient of variation (CV), target deviation ratio (TDR), and rotation torque ratio (RTR). The motor impairments of subjects after stroke were also evaluated using the Fugl-Meyer assessment for upper extremity (FMA-UE) and Wolf Motor Function Test (WMFT). Maximal grip force of the paretic side was significantly reduced as compared to the nonparetic side and the healthy group, while the difference of maximal grip force between the nonparetic side and the healthy group was not significant. TDR and RTR increased for all three groups with increasing target force level. There were significant differences of CV, TDR and RTR between the paretic side and the healthy group at all the force levels. CV, TDR and RTR showed significant negative correlations with FMA-UE and WMFT at 50% of maximum grip force. This study designed a customized dynamometer together with an innovative measurement, RTR, to investigate the hand motor performance of subjects after mild to moderate stroke during force control tasks. And stroke-induced abnormal flexion synergy of wrist and finger muscles could be characterized by RTR. This study also identified a set of kinetic parameters which can be applied to quantitatively assess the hand motor function of subjects after

  4. Transfer of training between distinct motor tasks after stroke: Implications for task- specific approaches to upper extremity neurorehabilitation

    PubMed Central

    Schaefer, Sydney Y.; Patterson, Chavelle B.; Lang, Catherine E.

    2013-01-01

    Background Although task-specific training is emerging as a viable approach for recovering motor function after stroke, there is little evidence for whether the effects of such training transfer to other functional motor tasks not directly practiced in therapy. Objective The purpose of the current study was to test whether training on one motor task would transfer to untrained tasks that were either spatiotemporally similar or different in individuals with chronic hemiparesis post-stroke. Methods Eleven participants with chronic mild-to-moderate hemiparesis following stroke completed five days of supervised massed practice of a feeding task with their affected side. Performance on the feeding task, along with two other untrained functional upper extremity motor tasks (sorting, dressing) was assessed before and after training. Results Performance of all three tasks improved significantly after training exclusively on one motor task. The amount of improvement in the untrained tasks was comparable, and was not dependent on the degree of similarity to the trained task. Conclusions Because the number and type of tasks that can be practiced are often limited within standard stroke rehabilitation, results from this study will be useful for designing task-specific training plans to maximize therapy benefits. PMID:23549521

  5. Neurofeedback-based functional near-infrared spectroscopy upregulates motor cortex activity in imagined motor tasks.

    PubMed

    Lapborisuth, Pawan; Zhang, Xian; Noah, Adam; Hirsch, Joy

    2017-04-01

    Neurofeedback is a method for using neural activity displayed on a computer to regulate one's own brain function and has been shown to be a promising technique for training individuals to interact with brain-machine interface applications such as neuroprosthetic limbs. The goal of this study was to develop a user-friendly functional near-infrared spectroscopy (fNIRS)-based neurofeedback system to upregulate neural activity associated with motor imagery, which is frequently used in neuroprosthetic applications. We hypothesized that fNIRS neurofeedback would enhance activity in motor cortex during a motor imagery task. Twenty-two participants performed active and imaginary right-handed squeezing movements using an elastic ball while wearing a 98-channel fNIRS device. Neurofeedback traces representing localized cortical hemodynamic responses were graphically presented to participants in real time. Participants were instructed to observe this graphical representation and use the information to increase signal amplitude. Neural activity was compared during active and imaginary squeezing with and without neurofeedback. Active squeezing resulted in activity localized to the left premotor and supplementary motor cortex, and activity in the motor cortex was found to be modulated by neurofeedback. Activity in the motor cortex was also shown in the imaginary squeezing condition only in the presence of neurofeedback. These findings demonstrate that real-time fNIRS neurofeedback is a viable platform for brain-machine interface applications.

  6. Force-stabilizing synergies in motor tasks involving two actors

    PubMed Central

    Solnik, Stanislaw; Reschechtko, Sasha; Wu, Yen-Hsun; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2015-01-01

    We investigated the ability of two persons to produce force-stabilizing synergies in accurate multi-finger force production tasks under visual feedback on the total force only. The subjects produced a time profile of total force (the sum of two hand forces in one-person tasks and the sum of two subject forces in two-person tasks) consisting of a ramp-up, steady-state, and ramp-down segments; the steady-state segment was interrupted in the middle by a quick force pulse. Analyses of the structure of inter-trial finger force variance, motor equivalence, anticipatory synergy adjustments (ASAs), and the unintentional drift of the sharing pattern were performed. The two-person performance was characterized by a dramatically higher amount of inter-trial variance that did not affect total force, higher finger force deviations that did not affect total force (motor equivalent deviations), shorter ASAs, and larger drift of the sharing pattern. The rate of sharing pattern drift correlated with the initial disparity between the forces produced by the two persons (or two hands). The drift accelerated following the quick force pulse. Our observations show that sensory information on the task-specific performance variable is sufficient for the organization of performance-stabilizing synergies. They suggest, however, that two actors are less likely to follow a single optimization criterion as compared to a single performer. The presence of ASAs in the two-person condition might reflect fidgeting by one or both of the subjects. We discuss the characteristics of the drift in the sharing pattern as reflections of different characteristic times of motion within the sub-spaces that affect and do not affect salient performance variables. PMID:26105756

  7. Force-stabilizing synergies in motor tasks involving two actors.

    PubMed

    Solnik, Stanislaw; Reschechtko, Sasha; Wu, Yen-Hsun; Zatsiorsky, Vladimir M; Latash, Mark L

    2015-10-01

    We investigated the ability of two persons to produce force-stabilizing synergies in accurate multi-finger force production tasks under visual feedback on the total force only. The subjects produced a time profile of total force (the sum of two hand forces in one-person tasks and the sum of two subject forces in two-person tasks) consisting of a ramp-up, steady-state, and ramp-down segments; the steady-state segment was interrupted in the middle by a quick force pulse. Analyses of the structure of inter-trial finger force variance, motor equivalence, anticipatory synergy adjustments (ASAs), and the unintentional drift of the sharing pattern were performed. The two-person performance was characterized by a dramatically higher amount of inter-trial variance that did not affect total force, higher finger force deviations that did not affect total force (motor equivalent deviations), shorter ASAs, and larger drift of the sharing pattern. The rate of sharing pattern drift correlated with the initial disparity between the forces produced by the two persons (or two hands). The drift accelerated following the quick force pulse. Our observations show that sensory information on the task-specific performance variable is sufficient for the organization of performance-stabilizing synergies. They suggest, however, that two actors are less likely to follow a single optimization criterion as compared to a single performer. The presence of ASAs in the two-person condition might reflect fidgeting by one or both of the subjects. We discuss the characteristics of the drift in the sharing pattern as reflections of different characteristic times of motion within the subspaces that affect and do not affect salient performance variables.

  8. The effect of various jaw motor tasks on body sway.

    PubMed

    Hellmann, Daniel; Giannakopoulos, N N; Blaser, R; Eberhard, L; Schindler, H J

    2011-10-01

    Alterations of body sway caused by isometric contractions of the jaw muscles have been reported previously. The objective of this study was to test if motor tasks of the masticatory system with different control demands affect body posture differently during quiet stance. Position and sway displacements of the center of foot pressure (COP) were measured for 20 healthy subjects who either kept the mandible at rest or performed unilateral and bilateral maximum voluntary teeth clenching, feedback-controlled biting tasks at submaximum bite forces, or unilateral chewing. Two weeks later the measurements were repeated. Compared with quiet stance, the COP results revealed significant changes during the feedback-controlled biting tasks. Robust sway reduction and anterior displacement of the COP were observed under these conditions. Body oscillations were not significantly affected by maximum bites or by unilateral chewing. For most of the variables investigated there were no significant differences between unilateral and bilateral biting. Robust sway reduction during feedback-controlled biting tasks in healthy subjects involved a stiffening phenomenon that was attributed to the common physiological repertoire of posture control, and might optimize the stability of posture under these conditions. © 2011 Blackwell Publishing Ltd.

  9. Individual Differences in Learning a Novel Discrete Motor Task

    PubMed Central

    Golenia, Laura; Schoemaker, Marina M.; Mouton, Leonora J.; Bongers, Raoul M.

    2014-01-01

    Many motor learning studies focus on average performance while it is known from everyday life experience that humans differ in their way of learning new motor tasks. This study emphasises the importance of recognizing individual differences in motor learning. We studied individual tool grasping profiles of individuals who learned to pick up objects with a novel tool, a pair of pliers. The pair of pliers was attached to the thumb and the index finger so that the tip of the thumb and the tip of the index finger were displaced to the beaks of the pair of pliers. The grasp component was manipulated by varying the location of the hinge of the pair of pliers, which resulted in different relations between beak opening and closing and finger opening and closing. The Wider Beak group had the hinge at 7 cm, the Same Beak group had the hinge at 10 cm (i.e., in the middle), and the Smaller Beak group had the hinge at 13 cm from the digits. Each group consisted of ten right-handed participants who picked up an object with one of the pairs of pliers 200 times on two subsequent days. Hand opening, plateau phase, hand closing, grasping time and maximum aperture were analyzed. To characterize individual changes over practice time, a log function was fitted on these dependent variables and the ratio of improvement was determined. Results showed that at the beginning stage of tool use learning the characteristic grasping profile consisted of three phases; hand opening, plateau phase and hand closing. Over practicing individual participants differed in the number of phases that changed, the amount of change in a phase and/or the direction of change. Moreover, with different pliers different learning paths were found. The importance of recognizing individual differences in motor learning is discussed. PMID:25386708

  10. Adaptation to visual feedback delay in a redundant motor task.

    PubMed

    Farshchiansadegh, Ali; Ranganathan, Rajiv; Casadio, Maura; Mussa-Ivaldi, Ferdinando A

    2015-01-15

    The goal of this study was to examine the reorganization of hand movements during adaptation to delayed visual feedback in a novel and redundant environment. In most natural behaviors, the brain must learn to invert a many-to-one map from high-dimensional joint movements and muscle forces to a low-dimensional goal. This spatial "inverse map" is learned by associating motor commands to their low-dimensional consequences. How is this map affected by the presence of temporal delays? A delay presents the brain with a new set of kinematic data, and, because of redundancy, the brain may use these data to form a new inverse map. We consider two possible responses to a novel visuomotor delay. In one case, the brain updates the previously learned spatial map, building a new association between motor commands and visual feedback of their effects. In the alternative case, the brain preserves the original map and learns to compensate the delay by a temporal shift of the motor commands. To test these alternative possibilities, we developed a virtual reality game in which subjects controlled the two-dimensional coordinates of a cursor by continuous hand gestures. Two groups of subjects tracked a target along predictable paths by wearing an instrumented data glove that recorded finger motions. The 19-dimensional glove signals controlled a cursor on a 2-dimensional computer display. The experiment was performed on 2 consecutive days. On the 1st day, subjects practiced tracking movements without delay. On the 2nd day, the test group performed the same task with a delay of 300 ms between the glove signals and the cursor display, whereas the control group continued practicing the nondelayed trials. We found evidence that to compensate for the delay, the test group relied on the coordination patterns established during the baseline, e.g., their hand-to-cursor inverse map was robust to the delay perturbation, which was counteracted by an anticipation of the motor command.

  11. Effect of motor practice on dual-task performance in older adults.

    PubMed

    Voelcker-Rehage, Claudia; Alberts, Jay L

    2007-05-01

    The aim of this study was to determine the effects of motor practice on cognitive and motor performance in older adults under single- and dual-task conditions. Fourteen younger (19-28 years) and 12 older adults (67-75 years) performed a precision grip sine wave force-tracking and a working memory task under single- and dual-task conditions. Participants performed a pretest, 100 motor practice trials, and a post-test. In the force-tracking and cognitive task, young outperformed older adults. Motor practice improved force-tracking under single- and dual-task conditions for both groups. However, practice did not prevent a decline in motor performance for older adults when they moved from single- to dual-task conditions. After practice, older adults improved cognitive performance in dual-task conditions. Advances in age appear to be associated with a decrease in the ability to manage and coordinate multiple tasks, which remains after extended practice.

  12. Comparison of Motor Inhibition in Variants of the Instructed-Delay Choice Reaction Time Task

    PubMed Central

    Quoilin, Caroline; Lambert, Julien; Jacob, Benvenuto; Klein, Pierre-Alexandre; Duque, Julie

    2016-01-01

    Using instructed-delay choice reaction time (RT) paradigms, many previous studies have shown that the motor system is transiently inhibited during response preparation: motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) over the primary motor cortex are typically suppressed during the delay period. This effect has been observed in both selected and non-selected effectors, although MEP changes in selected effectors have been more inconsistent across task versions. Here, we compared changes in MEP amplitudes in three different variants of an instructed-delay choice RT task. All variants required participants to choose between left and right index finger movements but the responses were either provided “in the air” (Variant 1), on a regular keyboard (Variant 2), or on a response device designed to control from premature responses (Variant 3). The task variants also differed according to the visual layout (more concrete in Variant 3) and depending on whether participants received a feedback of their performance (absent in Variant 1). Behavior was globally comparable between the three variants of the task although the propensity to respond prematurely was highest in Variant 2 and lowest in Variant 3. MEPs elicited in a non-selected hand were similarly suppressed in the three variants of the task. However, significant differences emerged when considering MEPs elicited in the selected hand: these MEPs were suppressed in Variants 1 and 3 whereas they were often facilitated in Variant 2, especially in the right dominant hand. In conclusion, MEPs elicited in selected muscles seem to be more sensitive to small variations to the task design than those recorded in non-selected effectors, probably because they reflect a complex combination of inhibitory and facilitatory influences on the motor output system. Finally, the use of a standard keyboard seems to be particularly inappropriate because it encourages participants to respond promptly

  13. Effects of cognitive and motor tasks on the walking speed of individuals with chronic stroke

    PubMed Central

    Goh, Lee-Yin.; Tan, Isaac O.; Yang, Li C.; Ng, Shamay S.M.

    2017-01-01

    Abstract Walking speed is a measure of gait performance after a stroke and a predictor of community ambulatory competence. Although gait decrements during a cognitive or motor task after stroke are well-documented, the differential effects of motor and cognitive tasks on the comfortable and maximum walking speeds of individuals with chronic stroke have not been investigated. This study aimed to compare the effects of cognitive and motor tasks on the comfortable and maximum walking speeds of individuals with chronic stroke. This is a cross-sectional study. Thirty community-dwelling chronic stroke individuals were included. Time taken to complete the 10-meter Walk Test under various conditions, including walking alone, walking while completing a cognitive task, and walking while completing a motor task, was recorded, with each condition performed at comfortable as well as maximum walking speeds. Accuracy in performing the cognitive tasks was also assessed. The cognitive and motor tasks caused decrements in both comfortable and maximum walking speeds (P ≤ 0.001). The cognitive task had a greater influence than the motor task on maximum walking speed (P < 0.01). Individuals with chronic stroke tend to prioritize task accuracy and completion over maintaining walking speed. This phenomenon was more evident during the cognitive task than the motor task and was especially evident at maximum walking speed. PMID:28248885

  14. Vestibular benefits to task savings in motor adaptation.

    PubMed

    Sarwary, A M E; Selen, L P J; Medendorp, W P

    2013-09-01

    In everyday life, we seamlessly adapt our movements and consolidate them to multiple behavioral contexts. This natural flexibility seems to be contingent on the presence of movement-related sensorimotor cues and cannot be reproduced when static visual or haptic cues are given to signify different behavioral contexts. So far, only sensorimotor cues that dissociate the sensorimotor plans prior to force field exposure have been successful in learning two opposing perturbations. Here we show that vestibular cues, which are only available during the perturbation, improve the formation and recall of multiple control strategies. We exposed subjects to inertial forces by accelerating them laterally on a vestibular platform. The coupling between reaching movement (forward-backward) and acceleration direction (leftward-rightward) switched every 160 trials, resulting in two opposite force environments. When exposed for a second time to the same environment, with the opposite environment in between, subjects showed retention resulting in an ∼3 times faster adaptation rate compared with the first exposure. Our results suggest that vestibular cues provide contextual information throughout the reach, which is used to facilitate independent learning and recall of multiple motor memories. Vestibular cues provide feedback about the underlying cause of reach errors, thereby disambiguating the various task environments and reducing interference of motor memories.

  15. Action observation versus motor imagery in learning a complex motor task: a short review of literature and a kinematics study.

    PubMed

    Gatti, R; Tettamanti, A; Gough, P M; Riboldi, E; Marinoni, L; Buccino, G

    2013-04-12

    Both motor imagery and action observation have been shown to play a role in learning or re-learning complex motor tasks. According to a well accepted view they share a common neurophysiological basis in the mirror neuron system. Neurons within this system discharge when individuals perform a specific action and when they look at another individual performing the same or a motorically related action. In the present paper, after a short review of literature on the role of action observation and motor imagery in motor learning, we report the results of a kinematics study where we directly compared motor imagery and action observation in learning a novel complex motor task. This involved movement of the right hand and foot in the same angular direction (in-phase movement), while at the same time moving the left hand and foot in an opposite angular direction (anti-phase movement), all at a frequency of 1Hz. Motor learning was assessed through kinematics recording of wrists and ankles. The results showed that action observation is better than motor imagery as a strategy for learning a novel complex motor task, at least in the fast early phase of motor learning. We forward that these results may have important implications in educational activities, sport training and neurorehabilitation.

  16. Observation learning of a motor task: who and when?

    PubMed

    Andrieux, Mathieu; Proteau, Luc

    2013-08-01

    Observation contributes to motor learning. It was recently demonstrated that the observation of both a novice and an expert model (mixed observation) resulted in better learning of a complex spatiotemporal task than the observation of either a novice or an expert model. In experiment 1, we aimed to determine whether mixed observation better promotes learning due to the information that can be gained from two models who exhibit different skill levels or simply because multiple models, regardless of their level of expertise, better promote learning than would a single model. The results revealed that the observation of both an expert and a novice model resulted in better short-term retention than the observation of either two novice or two expert models. In experiment 2, we wanted to determine whether these benefits would last longer if physical practice trials were interspersed with observation. Mixed and (to some extent) expert observations resulted in better long-term retention than observation of a novice model. We suggest that alternating mixed/expert observation with physical practice trials makes one's error more salient than when all observation trials are completed before one first starts performing the experimental task, which increases activation of the action observation network.

  17. Learning redundant motor tasks with and without overlapping dimensions: facilitation and interference effects.

    PubMed

    Ranganathan, Rajiv; Wieser, Jon; Mosier, Kristine M; Mussa-Ivaldi, Ferdinando A; Scheidt, Robert A

    2014-06-11

    Prior learning of a motor skill creates motor memories that can facilitate or interfere with learning of new, but related, motor skills. One hypothesis of motor learning posits that for a sensorimotor task with redundant degrees of freedom, the nervous system learns the geometric structure of the task and improves performance by selectively operating within that task space. We tested this hypothesis by examining if transfer of learning between two tasks depends on shared dimensionality between their respective task spaces. Human participants wore a data glove and learned to manipulate a computer cursor by moving their fingers. Separate groups of participants learned two tasks: a prior task that was unique to each group and a criterion task that was common to all groups. We manipulated the mapping between finger motions and cursor positions in the prior task to define task spaces that either shared or did not share the task space dimensions (x-y axes) of the criterion task. We found that if the prior task shared task dimensions with the criterion task, there was an initial facilitation in criterion task performance. However, if the prior task did not share task dimensions with the criterion task, there was prolonged interference in learning the criterion task due to participants finding inefficient task solutions. These results show that the nervous system learns the task space through practice, and that the degree of shared task space dimensionality influences the extent to which prior experience transfers to subsequent learning of related motor skills. Copyright © 2014 the authors 0270-6474/14/348289-11$15.00/0.

  18. Compromised Motor Dexterity Confounds Processing Speed Task Outcomes in Stroke Patients.

    PubMed

    Low, Essie; Crewther, Sheila Gillard; Ong, Ben; Perre, Diana; Wijeratne, Tissa

    2017-01-01

    Most conventional measures of information processing speed require motor responses to facilitate performance. However, although not often addressed clinically, motor impairment, whether due to age or acquired brain injury, would be expected to confound the outcome measure of such tasks. The current study recruited 29 patients (20 stroke and 9 transient ischemic attack) with documented reduction in dexterity of the dominant hand, and 29 controls, to investigate the extent to which 3 commonly used processing speed measures with varying motor demands (a Visuo-Motor Reaction Time task, and the Wechsler Adult Intelligence Scale-IV Symbol Search and Coding subtests) may be measuring motor-related speed more so than cognitive speed. Analyses include correlations between indices of cognitive and motor speed obtained from two other tasks (Inspection Time and Pegboard task, respectively) with the three speed measures, followed by hierarchical regressions to determine the relative contribution of cognitive and motor speed indices toward task performance. Results revealed that speed outcomes on tasks with relatively high motor demands, such as Coding, were largely reflecting motor speed in individuals with reduced dominant hand dexterity. Thus, findings indicate the importance of employing measures with minimal motor requirements, especially when the assessment of speed is aimed at understanding cognitive rather than physical function.

  19. Complementary activation of the ipsilateral primary motor cortex during a sustained handgrip task.

    PubMed

    Shibuya, Kenichi; Kuboyama, Naomi; Yamada, Seigo

    2016-01-01

    Near-infrared spectroscopy (NIRS) can be used to examine bilateral motor cortex activation during a sustained motor task in brain areas where increased oxygenation reflects cortical activation. This study examines the time course of activation of the bilateral motor cortex during a moderate-intensity handgrip task. Ten healthy right-handed male subjects participated in this study. Functional NIRS probes were placed over the cortex to measure motor cortical activations while the subjects performed a 180-s handgrip task incrementally [30-60% of the maximal voluntary contraction (MVC) at 0.17% increase/s] Contralateral primary motor cortex (ContraM1) oxygenation values significantly increased from baseline between 40 and 120 s after the start of the motor task (p < 0.05). Moreover, the ipsilateral primary motor cortex (IpsiM1) oxygenation values significantly increased from baseline between 140 and 180 s after the start of the motor task (p < 0.05). IpsiM1 oxygenation gradually increased from 140 to 180 s, whereas ContraM1 oxygenation gradually decreased from 120 to 180 s after the start of the motor task. These results suggest that the complementary functions of IpsiM1 become activated in response to the working of the ContraM1 during a continuous handgrip task.

  20. Self-Control of Task Difficulty during Training Enhances Motor Learning of a Complex Coincidence-Anticipation Task

    ERIC Educational Resources Information Center

    Andrieux, Mathieu; Danna, Jeremy; Thon, Bernard

    2012-01-01

    The aim of the present work was to analyze the influence of self-controlled task difficulty on motor learning. Participants had to intercept three targets falling at different velocities by displacing a stylus above a digitizer. Task difficulty corresponded to racquet width. Half the participants (self-control condition) could choose the racquet…

  1. Self-Control of Task Difficulty during Training Enhances Motor Learning of a Complex Coincidence-Anticipation Task

    ERIC Educational Resources Information Center

    Andrieux, Mathieu; Danna, Jeremy; Thon, Bernard

    2012-01-01

    The aim of the present work was to analyze the influence of self-controlled task difficulty on motor learning. Participants had to intercept three targets falling at different velocities by displacing a stylus above a digitizer. Task difficulty corresponded to racquet width. Half the participants (self-control condition) could choose the racquet…

  2. Effect of evaluative others upon learning and performance of a complex motor task.

    PubMed

    Haas, J; Roberts, G C

    1975-06-01

    Two experiments were conducted to assess the effect of evaluation potential upon learning and performing a complex motor task. In Experiment 1, 45 subjects learned the motor task (mirror tracing) to criterion and were then introduced to one of three treatments. Subjects performed the task either (a) alone, (b) in the presence of a blindfolded audience, or (c) in the presence of an evaluative audience. In Experiment 2, 45 subjects were introduced to the same three treatments but the subjects did not learn the task beforehand. The subjects learning the motor task were significantly inhibited by the evaluative audience, while the subjects who had already learned the task were significantly facilitated in their motor responses. The blindfolded audience also had an effect upon learning and performance. The results of both experiments were discussed in relation to their support of Cottrell's evaluation potential hypothesis.

  3. Task-dependent modulation of excitatory and inhibitory functions within the human primary motor cortex.

    PubMed

    Tinazzi, Michele; Farina, Simona; Tamburin, Stefano; Facchini, Stefano; Fiaschi, Antonio; Restivo, Domenico; Berardelli, Alfredo

    2003-05-01

    We evaluated motor evoked potentials (MEPs) and duration of the cortical silent period (CSP) from the right first dorsal interosseous (FDI) muscle to transcranial magnetic stimulation (TMS) of the left motor cortex in ten healthy subjects performing different manual tasks. They abducted the index finger alone, pressed a strain gauge with the thumb and index finger in a pincer grip, and squeezed a 4-cm brass cylinder with all digits in a power grip. The level of FDI EMG activity across tasks was kept constant by providing subjects with acoustic-visual feedback of their muscle activity. The TMS elicited larger amplitude FDI MEPs during pincer and power grip than during the index finger abduction task, and larger amplitude MEPs during pincer gripping than during power gripping. The CSP was shorter during pincer and power grip than during the index finger abduction task and shorter during power gripping than during pincer gripping. These results suggest excitatory and inhibitory task-dependent changes in the motor cortex. Complex manual tasks (pincer and power gripping) elicit greater motor cortical excitation than a simple task (index finger abduction) presumably because they activate multiple synergistic muscles thus facilitating corticomotoneurons. The finger abduction task probably yielded greater motor cortical inhibition than the pincer and power tasks because muscles uninvolved in the task activated the cortical inhibitory circuit. Increased cortical excitatory and inhibitory functions during precision tasks (pincer gripping) probably explain why MEPs have larger amplitudes and CSPs have longer durations during pincer gripping than during power gripping.

  4. Neural Correlates of Task Cost for Stance Control with an Additional Motor Task: Phase-Locked Electroencephalogram Responses

    PubMed Central

    Hwang, Ing-Shiou; Huang, Cheng-Ya

    2016-01-01

    With appropriate reallocation of central resources, the ability to maintain an erect posture is not necessarily degraded by a concurrent motor task. This study investigated the neural control of a particular postural-suprapostural procedure involving brain mechanisms to solve crosstalk between posture and motor subtasks. Participants completed a single posture task and a dual-task while concurrently conducting force-matching and maintaining a tilted stabilometer stance at a target angle. Stabilometer movements and event-related potentials (ERPs) were recorded. The added force-matching task increased the irregularity of postural response rather than the size of postural response prior to force-matching. In addition, the added force-matching task during stabilometer stance led to marked topographic ERP modulation, with greater P2 positivity in the frontal and sensorimotor-parietal areas of the N1-P2 transitional phase and in the sensorimotor-parietal area of the late P2 phase. The time-frequency distribution of the ERP primary principal component revealed that the dual-task condition manifested more pronounced delta (1–4 Hz) and beta (13–35 Hz) synchronizations but suppressed theta activity (4–8 Hz) before force-matching. The dual-task condition also manifested coherent fronto-parietal delta activity in the P2 period. In addition to a decrease in postural regularity, this study reveals spatio-temporal and temporal-spectral reorganizations of ERPs in the fronto-sensorimotor-parietal network due to the added suprapostural motor task. For a particular set of postural-suprapostural task, the behavior and neural data suggest a facilitatory role of autonomous postural response and central resource expansion with increasing interregional interactions for task-shift and planning the motor-suprapostural task. PMID:27010634

  5. Quantification of Perfusion Changes during a Motor Task Using Arterial Spin Labeling.

    PubMed

    Vilela, P; Pimentel, M; Sousa, I; Figueiredo, P

    2011-03-29

    Arterial spin labeling (ASL) is a non-invasive MRI technique that allows the quantitative measurement of perfusion, (regional cerebral blood flow (rCBF)). The ASL techniques use the labeling of the blood, by inverting or saturating the spins of water molecules of the blood supplying the imaged region. When reaching the capillary bed, these will be exchanged with tissue water giving rise to a perfusion-weighted signal. The subtraction of control (without label) from labeled images yields a signal difference that directly reflects the local perfusion. Being a non-invasive method, it can be repeated as many times as needed allowing the brain perfusion variation quantification associated with endogenous and exogenous stimuli. In this study, the authors have evaluated the CBF variation induced by the neural activity during a common motor task. The study was conducted on a Siemens Verio 3T system using a 12-channel head coil and a pulsed ASL Q2TIPS-PICORE sequence with a GE-EPI readout. The sequences were driven in 3D PACE mode for prospective motion correction. Fifteen healthy volunteers were studied using a simple motor task consisting in sequential thumb-digit opposition. Two different functional ASL protocols were used: #1 one perfusion scan was obtained during rest and another one during an equal period of motor task (total scan time ~8 min) (TI1 = 700 ms, TI1s = 1600 ms, TI2 =1800 ms; 91 Interleaved tag and control volumes were acquired; TR/TE = 2500/25 ms and flip angle = 90°; nine contiguous axial slices of 8 mm thickness acquired in-line with the AC-PC axis, positioned from the vertex of the brain to the top of cerebellum; FOV = 256 × 256 mm(2); matrix 64 × 64; gap between the labeling slab and the proximal 18.8 mm) and #2 a block design alternating five 25s periods of motor task with five 25s periods of rest (total scan time ~4 min) (TI1 = 700 ms, TI1s = 1600 ms, TI2 = 1800 ms; 101 interleaved tag and control volumes were acquired; TR/TE = 2500/11 ms and

  6. Response inhibition in motor and oculomotor conflict tasks: different mechanisms, different dynamics?

    PubMed

    Wijnen, Jasper G; Ridderinkhof, K Richard

    2007-04-01

    Previous research has shown that the appearance of task-irrelevant abrupt onsets influences saccadic eye movements during visual search and may slow down manual reactions to target stimuli. Analysis of reaction time distributions in the present study offers evidence suggesting that top-down inhibition processes actively suppress oculomotor or motor responses elicited by a salient distractor, in order to resolve the conflict that arises when reflex-like and deliberate responses are in opposition. Twenty-six participants carried out a variation of the oculomotor capture task. They were instructed to respond with either a saccade toward or with a button press at the side of the hemifield in which a target color singleton appeared. A distractor stimulus could appear either in the same or in the opposite hemifield. Delta plots revealed competition between reflex-like and deliberate response activation, and highlighted selective inhibition of automatic responses: While participants generally responded more slowly in incongruent compared to congruent situations, this effect diminished and even reversed in the slowest speed quantiles. These effects were present in both the oculomotor and motor response-mode conditions.

  7. The Effects of Divided Attention on Speech Motor, Verbal Fluency, and Manual Task Performance

    ERIC Educational Resources Information Center

    Dromey, Christopher; Shim, Erin

    2008-01-01

    Purpose: The goal of this study was to evaluate aspects of the "functional distance hypothesis," which predicts that tasks regulated by brain networks in closer anatomic proximity will interfere more with each other than tasks controlled by spatially distant regions. Speech, verbal fluency, and manual motor tasks were examined to ascertain whether…

  8. Non-motor tasks improve adaptive brain-computer interface performance in users with severe motor impairment

    PubMed Central

    Faller, Josef; Scherer, Reinhold; Friedrich, Elisabeth V. C.; Costa, Ursula; Opisso, Eloy; Medina, Josep; Müller-Putz, Gernot R.

    2014-01-01

    Individuals with severe motor impairment can use event-related desynchronization (ERD) based BCIs as assistive technology. Auto-calibrating and adaptive ERD-based BCIs that users control with motor imagery tasks (“SMR-AdBCI”) have proven effective for healthy users. We aim to find an improved configuration of such an adaptive ERD-based BCI for individuals with severe motor impairment as a result of spinal cord injury (SCI) or stroke. We hypothesized that an adaptive ERD-based BCI, that automatically selects a user specific class-combination from motor-related and non motor-related mental tasks during initial auto-calibration (“Auto-AdBCI”) could allow for higher control performance than a conventional SMR-AdBCI. To answer this question we performed offline analyses on two sessions (21 data sets total) of cue-guided, five-class electroencephalography (EEG) data recorded from individuals with SCI or stroke. On data from the twelve individuals in Session 1, we first identified three bipolar derivations for the SMR-AdBCI. In a similar way, we determined three bipolar derivations and four mental tasks for the Auto-AdBCI. We then simulated both, the SMR-AdBCI and the Auto-AdBCI configuration on the unseen data from the nine participants in Session 2 and compared the results. On the unseen data of Session 2 from individuals with SCI or stroke, we found that automatically selecting a user specific class-combination from motor-related and non motor-related mental tasks during initial auto-calibration (Auto-AdBCI) significantly (p < 0.01) improved classification performance compared to an adaptive ERD-based BCI that only used motor imagery tasks (SMR-AdBCI; average accuracy of 75.7 vs. 66.3%). PMID:25368546

  9. Dual-task motor performance with a tongue-operated assistive technology compared with hand operations

    PubMed Central

    2012-01-01

    Background To provide an alternative motor modality for control, navigation, and communication in individuals suffering from impairment or disability in hand functions, a Tongue Drive System (TDS) has been developed that allows for real time tracking of tongue motion in an unobtrusive, wireless, and wearable device that utilizes the magnetic field generated by a miniature disk shaped magnetic tracer attached to the tip of the tongue. The purpose of the study was to compare the influence of a concurrent motor or cognitive task on various aspects of simple movement control between hand and tongue using the TDS technology. Methods Thirteen young able-bodied adults performed rapid and slow goal-directed movements of hand and tongue (with TDS) with and without a concurrent motor (hand or tongue) or cognitive (arithmetic and memory) task. Changes in reaction time, completion time, speed, correctness, accuracy, variability of displacement, and variability of time due to the addition of a concurrent task were compared between hand and tongue. Results The influence of an additional concurrent task on motor performance was similar between the hand and tongue for slow movement in controlling their displacement. In rapid movement with a concurrent motor task, most aspects of motor performance were degraded in hand, while tongue speed during rapid continuous task was maintained. With a concurrent cognitive task, most aspects of motor performance were degraded in tongue, while hand accuracy during the rapid discrete task and hand speed during the rapid continuous task were maintained. Conclusion Rapid goal-directed hand and tongue movements were more consistently susceptible to interference from concurrent motor and cognitive tasks, respectively, compared with the other movement. PMID:22244362

  10. Cerebral-cortical networking and activation increase as a function of cognitive-motor task difficulty.

    PubMed

    Rietschel, Jeremy C; Miller, Matthew W; Gentili, Rodolphe J; Goodman, Ronald N; McDonald, Craig G; Hatfield, Bradley D

    2012-05-01

    Excessive increases in task difficulty typically result in marked attenuation of cognitive-motor performance. The psychomotor efficiency hypothesis suggests that poor performance is mediated by non-essential neural activity and cerebral cortical networking (inefficient cortical dynamics). This phenomenon may underlie the inverse relationship between excessive task difficulty and performance. However, investigation of the psychomotor efficiency hypothesis as it relates to task difficulty has not been conducted. The present study used electroencephalography (EEG) to examine cerebral cortical dynamics while participants were challenged with both Easy and Hard conditions during a cognitive-motor task (Tetris(®)). In accord with the psychomotor efficiency hypothesis, it was predicted that with increases in task difficulty, participants would demonstrate greater 'neural effort,' as indexed by EEG spectral power and cortical networking (i.e., EEG coherence) between the premotor (motor planning) region and sensory, executive, and motor regions. Increases in neural activation and cortical networking were observed during the Hard condition relative to the Easy condition, thus supporting the psychomotor efficiency hypothesis. To further determine the unique contributions of cognitive versus sensory-motor demands, a control experiment was conducted in which cognitive demand was increased while sensory-motor demand was held constant. This experiment revealed that regionally specific neural activation was influenced by changes in cognitive demand, whereas cortical networking to the motor planning region was sensitive only to changes in sensory-motor demand. Crucially, the present study is the first, to our knowledge, to characterize the separate impact of cognitive versus sensory-motor demands on cerebral cortical dynamics. The findings further inform the dynamics of the cortical processes that underlie the quality of cognitive-motor performance particularly with regard to task

  11. Bilateral tDCS on Primary Motor Cortex: Effects on Fast Arm Reaching Tasks

    PubMed Central

    Arias, Pablo; Corral-Bergantiños, Yoanna; Robles-García, Verónica; Madrid, Antonio; Oliviero, Antonio; Cudeiro, Javier

    2016-01-01

    Background The effects produced by transcranial direct current stimulation (tDCS) applied to the motor system have been widely studied in the past, chiefly focused on primary motor cortex (M1) excitability. However, the effects on functional tasks are less well documented. Objective This study aims to evaluate the effect of tDCS-M1 on goal-oriented actions (i.e., arm-reaching movements; ARM), in a reaction-time protocol. Methods 13 healthy subjects executed dominant ARM as fast as possible to one of two targets in front of them while surface EMG was recorded. Participants performed three different sessions. In each session they first executed ARM (Pre), then received tDCS, and finally executed Post, similar to Pre. Subjects received three different types of tDCS, one per session: In one session the anode was on right-M1 (AR), and the cathode on the left-M1 (CL), thus termed AR-CL; AL-CR reversed the montage; and Sham session was applied likewise. Real stimulation was 1mA-10min while subjects at rest. Three different variables and their coefficients of variation (CV) were analyzed: Premotor times (PMT), reaction-times (RT) and movement-times (MT). Results triceps-PMT were significantly increased at Post-Sham, suggesting fatigue. Results obtained with real tDCS were not different depending on the montage used, in both cases PMT were significantly reduced in all recorded muscles. RT and MT did not change for real or sham stimulation. RT-CV and PMT-CV were reduced after all stimulation protocols. Conclusion tDCS reduces premotor time and fatigability during the execution of fast motor tasks. Possible underlying mechanisms are discussed. PMID:27490752

  12. Aging affects motor skill learning when the task requires inhibitory control.

    PubMed

    Brosseau, Julie; Potvin, Marie-Julie; Rouleau, Isabelle

    2007-01-01

    Few studies have examined the influence of aging on motor skill learning (MSL) tasks involving different skills and conditions. Two tasks, each including two different conditions (repeated and nonrepeated), were used: (a) the Mirror Tracing task, requiring the inhibition of an overlearned response and the learning of a new visuomotor association, and (b) the Pursuit Tracking task, mainly requiring the processing of visuospatial stimuli. We hypothesized that older participants would benefit as much as younger participants from the stimuli repetition and that they would exhibit a slower learning rate exclusively on the Mirror Tracing task. As expected, older and younger participants' MSL were not differentially affected by task conditions. They also showed a similar learning rate on the Pursuit Tracking task and a subgroup of older participants exhibited MSL difficulties on the Mirror Tracing task. Problems in the inhibitory control of competing motor memories could explain these age-related MSL difficulties.

  13. Interference of concomitant tasks on simple reaction time: attentional and motor factors.

    PubMed

    Rizzolatti, G; Bertoloni, G; De Bastiani, P L

    1982-01-01

    Simple reaction times to lateralized unstructured visual stimuli were measured in normal subjects while they were carrying out concomitant left hemisphere tasks. Three tasks were used. In the first task the subjects had to pay attention to strings of digits, acoustically presented, and detect letters randomly interspersed among the digits; in the second task the subjects had to memorize strings of acoustically presented digits; in the third task they had to repeat each digit of a string as soon as they heard it. In spite of the greater difficulty of the first two tasks with respect to the third one, only this last task, the only one requiring a verbo-motor response, produced a significant disadvantage for the left hemisphere responses to light. It is argued that in RT experiments a specific left hemisphere interference takes place when the secondary task requires the organization of a motor response

  14. Self-modulation of primary motor cortex activity with motor and motor imagery tasks using real-time fMRI-based neurofeedback

    PubMed Central

    Berman, Brian D.; Horovitz, Silvina G.; Venkataraman, Gaurav; Hallett, Mark

    2011-01-01

    Advances in fMRI data acquisition and processing have made it possible to analyze brain activity as rapidly as the images are acquired allowing this information to be fed back to subjects in the scanner. The ability of subjects to learn to volitionally control localized brain activity within motor cortex using such real-time fMRI-based neurofeedback (NF) is actively being investigated as it may have clinical implications for motor rehabilitation after central nervous system injury and brain-computer interfaces. We investigated the ability of fifteen healthy volunteers to use NF to modulate brain activity within the primary motor cortex (M1) during a finger tapping and tapping imagery task. The M1 hand area ROI (ROIm) was functionally localized during finger tapping and a visual representation of BOLD signal changes within the ROIm fed back to the subject in the scanner. Surface EMG was used to assess motor output during tapping and ensure no motor activity was present during motor imagery task. Subjects quickly learned to modulate brain activity within their ROIm during the finger-tapping task, which could be dissociated from the magnitude of the tapping, but did not show a significant increase within the ROIm during the hand motor imagery task at the group level despite strongly activating a network consistent with the performance of motor imagery. The inability of subjects to modulate M1 proper with motor imagery may reflect an inherent difficulty in activating synapses in this area, with or without NF, since such activation may lead to M1 neuronal output and obligatory muscle activity. Future real-time fMRI-based NF investigations involving motor cortex may benefit from focusing attention on cortical regions other than M1 for feedback training or alternative feedback strategies such as measures of functional connectivity within the motor system. PMID:21803163

  15. Sleep-dependent motor memory consolidation in older adults depends on task demands.

    PubMed

    Gudberg, Christel; Wulff, Katharina; Johansen-Berg, Heidi

    2015-03-01

    It is often suggested that sleep-dependent consolidation of motor learning is impaired in older adults. The current study challenges this view and suggests that the degree of motor consolidation seen with sleep in older age groups depends on the kinematic demands of the task. We show that, when tested with a classic sequence learning task, requiring individuated finger movements, older adults did not show sleep-dependent consolidation. By contrast, when tested with an adapted sequence learning task, in which movements were performed with the whole hand, sleep-dependent motor improvement was observed in older adults. We suggest that age-related decline in fine motor dexterity may in part be responsible for the previously described deficit in sleep-dependent motor consolidation with aging.

  16. Sleep-dependent motor memory consolidation in older adults depends on task demands

    PubMed Central

    Gudberg, Christel; Wulff, Katharina; Johansen-Berg, Heidi

    2015-01-01

    It is often suggested that sleep-dependent consolidation of motor learning is impaired in older adults. The current study challenges this view and suggests that the degree of motor consolidation seen with sleep in older age groups depends on the kinematic demands of the task. We show that, when tested with a classic sequence learning task, requiring individuated finger movements, older adults did not show sleep-dependent consolidation. By contrast, when tested with an adapted sequence learning task, in which movements were performed with the whole hand, sleep-dependent motor improvement was observed in older adults. We suggest that age-related decline in fine motor dexterity may in part be responsible for the previously described deficit in sleep-dependent motor consolidation with aging. PMID:25618616

  17. Oral Motor Abilities Are Task Dependent: A Factor Analytic Approach to Performance Rate.

    PubMed

    Staiger, Anja; Schölderle, Theresa; Brendel, Bettina; Bötzel, Kai; Ziegler, Wolfram

    2017-01-01

    Measures of performance rates in speech-like or volitional nonspeech oral motor tasks are frequently used to draw inferences about articulation rate abnormalities in patients with neurologic movement disorders. The study objective was to investigate the structural relationship between rate measures of speech and of oral motor behaviors different from speech. A total of 130 patients with neurologic movement disorders and 130 healthy subjects participated in the study. Rate data was collected for oral reading (speech), rapid syllable repetition (speech-like), and rapid single articulator movements (nonspeech). The authors used factor analysis to determine whether the different rate variables reflect the same or distinct constructs. The behavioral data were most appropriately captured by a measurement model in which the different task types loaded onto separate latent variables. The data on oral motor performance rates show that speech tasks and oral motor tasks such as rapid syllable repetition or repetitive single articulator movements measure separate traits.

  18. The influence of motor expertise on the brain activity of motor task performance: A meta-analysis of functional magnetic resonance imaging studies.

    PubMed

    Yang, Jie

    2015-06-01

    Previous research has investigated the influence of long-term motor training on the brain activity of motor processes, but the findings are inconsistent. To clarify how acquiring motor expertise induces cortical reorganization during motor task performance, the current study conducted a quantitative meta-analysis on 26 functional magnetic resonance imaging (fMRI) studies that investigate motor task performance in people with long-term motor training experience (e.g., athletes, musicians, and dancers) and control participants. Meta-analysis of the brain activation in motor experts and novices showed similar effects in the bilateral frontal and parietal regions. The meta-analysis on the contrast between motor experts and novices indicated that experts showed stronger effects in the left inferior parietal lobule (BA 40) than did novices in motor execution and prediction tasks. In motor observation tasks, experts showed stronger effects in the left inferior frontal gyrus (BA 9) and left precentral gyrus (BA 6) than novices. On the contrary, novices had stronger effects in the right motor areas and basal ganglia as compared with motor experts. These results indicate that motor experts have effect increases in brain areas involved in action planning and action comprehension, and suggest that intensive motor training might elaborate the motor representation related to the task performance.

  19. A Developmental Study of the Influence of Task Characteristics on Motor Overflow

    ERIC Educational Resources Information Center

    Addamo, Patricia K.; Farrow, Maree; Hoy, Kate E.; Bradshaw, John L.; Georgiou-Karistianis, Nellie

    2009-01-01

    Motor overflow refers to involuntary movement or muscle activity that may coincide with voluntary movement. This study examined factors influencing motor overflow in 17 children (8-11 years), and 17 adults (18-35 years). Participants performed a finger pressing task by exerting either 33% or 66% of their maximal force output using their dominant…

  20. The Source of Execution-Related Dual-Task Interference: Motor Bottleneck or Response Monitoring?

    ERIC Educational Resources Information Center

    Bratzke, Daniel; Rolke, Bettina; Ulrich, Rolf

    2009-01-01

    The present study assessed the underlying mechanism of execution-related dual-task interference in the psychological refractory period (PRP) paradigm. The motor bottleneck hypothesis attributes this interference to a processing limitation at the motor level. By contrast, the response monitoring hypothesis attributes it to a bottleneck process that…

  1. Effects of Dispositional Mindfulness on the Self-Controlled Learning of a Novel Motor Task

    ERIC Educational Resources Information Center

    Kee, Ying Hwa; Liu, Yeou-Teh

    2011-01-01

    Current literature suggests that mindful learning is beneficial to learning but its links with motor learning is seldom examined. In the present study, we examine the effects of learners' mindfulness disposition on the self-controlled learning of a novel motor task. Thirty-two participants undertook five practice sessions, in addition to a pre-,…

  2. The Source of Execution-Related Dual-Task Interference: Motor Bottleneck or Response Monitoring?

    ERIC Educational Resources Information Center

    Bratzke, Daniel; Rolke, Bettina; Ulrich, Rolf

    2009-01-01

    The present study assessed the underlying mechanism of execution-related dual-task interference in the psychological refractory period (PRP) paradigm. The motor bottleneck hypothesis attributes this interference to a processing limitation at the motor level. By contrast, the response monitoring hypothesis attributes it to a bottleneck process that…

  3. Effects of Dispositional Mindfulness on the Self-Controlled Learning of a Novel Motor Task

    ERIC Educational Resources Information Center

    Kee, Ying Hwa; Liu, Yeou-Teh

    2011-01-01

    Current literature suggests that mindful learning is beneficial to learning but its links with motor learning is seldom examined. In the present study, we examine the effects of learners' mindfulness disposition on the self-controlled learning of a novel motor task. Thirty-two participants undertook five practice sessions, in addition to a pre-,…

  4. Trial-to-Trial Reoptimization of Motor Behavior Due to Changes in Task Demands Is Limited

    PubMed Central

    de Xivry, Jean-Jacques Orban

    2013-01-01

    Each task requires a specific motor behavior that is tuned to task demands. For instance, writing requires a lot of accuracy while clapping does not. It is known that the brain adjusts the motor behavior to different task demands as predicted by optimal control theory. In this study, the mechanism of this reoptimization process is investigated by varying the accuracy demands of a reaching task. In this task, the width of the reaching target (0.5 or 8 cm) was varied either on a trial-to-trial basis (random schedule) or in blocks (blocked schedule). On some trials, the hand of the subjects was clamped to a rectilinear trajectory that ended 2 cm on the left or right of the target center. The rejection of this perturbation largely varied with target width in the blocked schedule but not in the random schedule. That is, subjects exhibited different motor behavior in the different schedules despite identical accuracy demands. Therefore, while reoptimization has been considered immediate and automatic, the differences in motor behavior observed across schedules suggest that the reoptimization of the motor behavior is neither happening on a trial-by-trial basis nor obligatory. The absence of trial-to-trial mechanisms, the inability of the brain to adapt to two conflicting task demands and the existence of a switching cost are discussed as possible sources of the non-optimality of motor behavior during the random schedule. PMID:23776593

  5. Not all choices are created equal: Task-relevant choices enhance motor learning compared to task-irrelevant choices.

    PubMed

    Carter, Michael J; Ste-Marie, Diane M

    2017-02-21

    Lewthwaite et al. (2015) reported that the learning benefits of exercising choice (i.e., their self-controlled condition) are not restricted to task-relevant features (e.g., feedback). They found that choosing one's golf ball color (Exp. 1) or choosing which of two tasks to perform at a later time plus which of two artworks to hang (Exp. 2) resulted in better retention than did being denied these same choices (i.e., yoked condition). The researchers concluded that the learning benefits derived from choice, whether irrelevant or relevant to the to-be-learned task, are predominantly motivational because choice is intrinsically rewarding and satisfies basic psychological needs. However, the absence of a group that made task-relevant choices and the lack of psychological measures significantly weakened their conclusions. Here, we investigated how task-relevant and task-irrelevant choices affect motor-skill learning. Participants practiced a spatiotemporal motor task in either a task-relevant group (choice over feedback schedule), a task-irrelevant group (choice over the color of an arm-wrap plus game selection), or a no-choice group. The results showed significantly greater learning in the task-relevant group than in both the task-irrelevant and no-choice groups, who did not differ significantly. Critically, these learning differences were not attributed to differences in perceptions of competence or autonomy, but instead to superior error-estimation abilities. These results challenge the perspective that motivational influences are the root cause of self-controlled learning advantages. Instead, the findings add to the growing evidence highlighting that the informational value gained from task-relevant choices makes a greater relative contribution to these advantages than motivational influences do.

  6. Mitochondrial DNA variations in Madras motor neuron disease

    PubMed Central

    Govindaraj, Periyasamy; Nalini, Atchayaram; Krishna, Nithin; Sharath, Anugula; Khan, Nahid Akhtar; Tamang, Rakesh; Devi, M. Gourie; Brown, Robert H.; Thangaraj, Kumarasamy

    2013-01-01

    Although the Madras Motor Neuron Disease (MMND) was found three decades ago, its genetic basis has not been elucidated, so far. The symptom at onset was impaired hearing, upper limb weakness and atrophy. Since some clinical features of MMND overlap with mitochondrial disorders, we analyzed the complete mitochondrial genome of 45 MMND patients and found 396 variations, including 13 disease-associated, 2 mt-tRNA and 33 non-synonymous (16 MT-ND, 10 MT-CO, 3 MT-CYB and 4 MT-ATPase). A rare variant (m.8302A>G) in mt-tRNALeu was found in three patients. We predict that these variation(s) may influence the disease pathogenesis along with some unknown factor(s). PMID:23419391

  7. Reducing task difficulty during practice improves motor learning in older adults.

    PubMed

    Onushko, Tanya; Kim, Changki; Christou, Evangelos A

    2014-09-01

    Theoretically, greater motor output variability can inhibit motor learning by inhibiting task acquisition during practice. Although the age-associated differences in motor output variability exacerbate with more difficult tasks, it remains unknown whether task difficulty during task acquisition influences motor learning in older adults. The purpose of this study was to determine whether the difficulty of the practice task affects motor learning in older adults. Twenty four older (72.7±7.4years; 11 women) and 7 young (23.1±4years; 1 man) adults participated in this study. Participants were divided into four groups: 8 older adults who practiced an easy task (O-Easy), 8 older adults who practiced a harder task (O-Hard), 8 older adults who did not practice (O-None), and 7 young adults who did not practice (Y-None). The level of difficulty depended on the relative timing (i.e. phase) of abduction force generation between the index and little fingers to track a moving target on the monitor. The O-Easy group practiced the task with 0°, whereas the O-Hard group practiced the task with 90° relative phase. Practice occurred within a single session for 80 trials. Motor learning was quantified as the ability to transfer the practiced tasks to 45°, 135° and 180° relative phases 24 and 168h after acquisition. Only the O-Easy group was able to significantly transfer the practiced task, as it was indicated by significantly lower force variability and error during all transfer tasks compared with the O-None group (P<0.05). The O-Hard group was not significantly different from the O-None group (P>0.2). In addition, during the transfer tasks the O-Easy group exhibited performance similar to that of the young adults who did not practice. These findings suggest that practice with easier tasks may be advantageous to practice with more difficult tasks to improve motor learning in older adults. Copyright © 2014. Published by Elsevier Inc.

  8. Facilitation effect of observed motor deviants in a cooperative motor task: Evidence for direct perception of social intention in action.

    PubMed

    Quesque, François; Delevoye-Turrell, Yvonne; Coello, Yann

    2016-01-01

    Spatiotemporal parameters of voluntary motor action may help optimize human social interactions. Yet it is unknown whether individuals performing a cooperative task spontaneously perceive subtly informative social cues emerging through voluntary actions. In the present study, an auditory cue was provided through headphones to an actor and a partner who faced each other. Depending on the pitch of the auditory cue, either the actor or the partner were required to grasp and move a wooden dowel under time constraints from a central to a lateral position. Before this main action, the actor performed a preparatory action under no time constraint, consisting in placing the wooden dowel on the central location when receiving either a neutral ("prêt"-ready) or an informative auditory cue relative to who will be asked to perform the main action (the actor: "moi"-me, or the partner: "lui"-him). Although the task focused on the main action, analysis of motor performances revealed that actors performed the preparatory action with longer reaction times and higher trajectories when informed that the partner would be performing the main action. In this same condition, partners executed the main actions with shorter reaction times and lower velocities, despite having received no previous informative cues. These results demonstrate that the mere observation of socially driven motor actions spontaneously influences the low-level kinematics of voluntary motor actions performed by the observer during a cooperative motor task. These findings indicate that social intention can be anticipated from the mere observation of action patterns.

  9. Task-dependent engagements of the primary visual cortex during kinesthetic and visual motor imagery.

    PubMed

    Mizuguchi, Nobuaki; Nakamura, Maiko; Kanosue, Kazuyuki

    2017-01-01

    Motor imagery can be divided into kinesthetic and visual aspects. In the present study, we investigated excitability in the corticospinal tract and primary visual cortex (V1) during kinesthetic and visual motor imagery. To accomplish this, we measured motor evoked potentials (MEPs) and probability of phosphene occurrence during the two types of motor imageries of finger tapping. The MEPs and phosphenes were induced by transcranial magnetic stimulation to the primary motor cortex and V1, respectively. The amplitudes of MEPs and probability of phosphene occurrence during motor imagery were normalized based on the values obtained at rest. Corticospinal excitability increased during both kinesthetic and visual motor imagery, while excitability in V1 was increased only during visual motor imagery. These results imply that modulation of cortical excitability during kinesthetic and visual motor imagery is task dependent. The present finding aids in the understanding of the neural mechanisms underlying motor imagery and provides useful information for the use of motor imagery in rehabilitation or motor imagery training.

  10. Region and task-specific activation of Arc in primary motor cortex of rats following motor skill learning.

    PubMed

    Hosp, J A; Mann, S; Wegenast-Braun, B M; Calhoun, M E; Luft, A R

    2013-10-10

    Motor learning requires protein synthesis within the primary motor cortex (M1). Here, we show that the immediate early gene Arc/Arg3.1 is specifically induced in M1 by learning a motor skill. Arc mRNA was quantified using a fluorescent in situ hybridization assay in adult Long-Evans rats learning a skilled reaching task (SRT), in rats performing reaching-like forelimb movement without learning (ACT) and in rats that were trained in the operant but not the motor elements of the task (controls). Apart from M1, Arc expression was assessed within the rostral motor area (RMA), primary somatosensory cortex (S1), striatum (ST) and cerebellum. In SRT animals, Arc mRNA levels in M1 contralateral to the trained limb were 31% higher than ipsilateral (p<0.001), 31% higher than in the contralateral M1 of ACT animals (p<0.001) and 48% higher than in controls (p<0.001). Arc mRNA expression in SRT was positively correlated with learning success between two sessions (r=0.52; p=0.026). For RMA, S1, ST or cerebellum no significant differences in Arc mRNA expression were found between hemispheres or across behaviors. As Arc expression has been related to different forms of cellular plasticity, these findings suggest a link between M1 Arc expression and motor skill learning in rats. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  11. PHENOTYPIC VARIATION OF COLONIC MOTOR FUNCTIONS IN CHRONIC CONSTIPATION

    PubMed Central

    Ravi, Karthik; Bharucha, Adil E.; Camilleri, Michael; Rhoten, Deborah; Bakken, Timothy; Zinsmeister, Alan R.

    2009-01-01

    Background & Aims Colonic motor disturbances in chronic constipation (CC) are heterogeneous and incompletely understood; the relationship between colonic transit and motor activity is unclear. We sought to characterize the phenotypic variability in chronic constipation. Methods Fasting and postprandial colonic tone and phasic activity and pressure–volume relationships were assessed by a barostat manometric assembly in 35 healthy women and 111 women with CC who had normal colon transit (NTC, n=25), slow transit (STC, n=19), and defecatory disorders with normal (DD-normal, n=34) or slow transit (DD-slow, n=33). Logistic regression models assessed whether motor parameters could discriminate among these groups. Among CC, phenotypes were characterized by principal components analysis of these measurements. Results Compared to 10th percentile values in healthy subjects, fasting and/or postprandial colonic tone and/or compliance were reduced in 40% with NTC, 47% with STC, 53% with DD-normal, and 42% with DD-slow transit. Compared to healthy subjects, compliance was reduced (p ≤ 0.05) in isolated STC and DD but not in NTC. Four principal components accounted for 85% of the total variation among patients; factors 1 and 2 were predominantly weighted by fasting and postprandial colonic phasic activity and tone respectively; factor 3 by postprandial high-amplitude propagated contractions, and factor 4 by postprandial tonic response. Conclusions Fasting and/or postprandial colonic tone are reduced, reflecting motor dysfunctions, even in NTC. Colonic motor assessments allow chronic constipation to be characterized into phenotypes. Further studies are needed to evaluate the relationship between these phenotypes, enteric neuropathology and response to treatment in CC. PMID:19660461

  12. Effects of Peer Mediated Instruction with Task Cards on Motor Skill Acquisition in Tennis

    ERIC Educational Resources Information Center

    Iserbyt, Peter; Madou, Bob; Vergauwen, Lieven; Behets, Daniel

    2011-01-01

    This study compared the motor skill effects of a peer teaching format by means of task cards with a teacher-centered format. Tennis performance of eighth grade students (n = 55) was measured before and after a four week intervention period in a regular physical education program. Results show that peer mediated learning with task cards…

  13. High variability impairs motor learning regardless of whether it affects task performance.

    PubMed

    Cardis, Marco; Casadio, Maura; Ranganathan, Rajiv

    2017-09-27

    Motor variability plays an important role in motor learning, although the exact mechanisms of how variability affects learning is not well understood. Recent evidence suggests that motor variability may have different effects on learning in redundant tasks, depending on whether it is present in the task space (where it affects task performance), or in the null space (where it has no effect on task performance). Here we examined the effect of directly introducing null and task space variability using a manipulandum during the learning of a motor task. Participants learned a bimanual shuffleboard task for 2 days, where their goal was to slide a virtual puck as close as possible towards a target. Critically, the distance traveled by the puck was determined by the sum of the left and right hand velocities, which meant that there was redundancy in the task. Participants were divided into five groups - based on both the dimension in which the variability was introduced and the amount of variability that was introduced during training. Results showed that although all groups were able to reduce error with practice, learning was affected more by the amount of variability introduced rather than the dimension in which variability was introduced. Specifically, groups with higher movement variability during practice showed larger errors at the end of practice compared to groups that had low variability during learning. These results suggest that although introducing variability can increase exploration of new solutions, this may adversely affect the ability to retain the learned solution. Copyright © 2017, Journal of Neurophysiology.

  14. Perceived Difficulty of a Motor-Skill Task as a Function of Training.

    ERIC Educational Resources Information Center

    Bratfisch, Oswald; And Others

    A simple device called a "wire labyrinth" was used in an experiment involving learning of a two-hand motor task. The Ss were asked, after completing each of 7 successive trails, to give their estimates of perceived (subjective) difficulty of the task. For this purpose, the psychophysical method of magnitude estimation was used. Time was…

  15. Neural Correlates of Dual-Task Walking: Effects of Cognitive versus Motor Interference in Young Adults.

    PubMed

    Beurskens, Rainer; Steinberg, Fabian; Antoniewicz, Franziska; Wolff, Wanja; Granacher, Urs

    2016-01-01

    Walking while concurrently performing cognitive and/or motor interference tasks is the norm rather than the exception during everyday life and there is evidence from behavioral studies that it negatively affects human locomotion. However, there is hardly any information available regarding the underlying neural correlates of single- and dual-task walking. We had 12 young adults (23.8 ± 2.8 years) walk while concurrently performing a cognitive interference (CI) or a motor interference (MI) task. Simultaneously, neural activation in frontal, central, and parietal brain areas was registered using a mobile EEG system. Results showed that the MI task but not the CI task affected walking performance in terms of significantly decreased gait velocity and stride length and significantly increased stride time and tempo-spatial variability. Average activity in alpha and beta frequencies was significantly modulated during both CI and MI walking conditions in frontal and central brain regions, indicating an increased cognitive load during dual-task walking. Our results suggest that impaired motor performance during dual-task walking is mirrored in neural activation patterns of the brain. This finding is in line with established cognitive theories arguing that dual-task situations overstrain cognitive capabilities resulting in motor performance decrements.

  16. Effects of Peer Mediated Instruction with Task Cards on Motor Skill Acquisition in Tennis

    ERIC Educational Resources Information Center

    Iserbyt, Peter; Madou, Bob; Vergauwen, Lieven; Behets, Daniel

    2011-01-01

    This study compared the motor skill effects of a peer teaching format by means of task cards with a teacher-centered format. Tennis performance of eighth grade students (n = 55) was measured before and after a four week intervention period in a regular physical education program. Results show that peer mediated learning with task cards…

  17. Task-specific compensation and recovery following focal motor cortex lesion in stressed rats.

    PubMed

    Kirkland, Scott W; Smith, Lori K; Metz, Gerlinde A

    2012-03-01

    One reason for the difficulty to develop effective therapies for stroke is that intrinsic factors, such as stress, may critically influence pathological mechanisms and recovery. In cognitive tasks, stress can both exaggerate and alleviate functional loss after focal ischemia in rodents. Using a comprehensive motor assessment in rats, this study examined if chronic stress and corticosterone treatment affect skill recovery and compensation in a task-specific manner. Groups of rats received daily restraint stress or oral corticosterone supplementation for two weeks prior to a focal motor cortex lesion. After lesion, stress and corticosterone treatments continued for three weeks. Motor performance was assessed in two skilled reaching tasks, skilled walking, forelimb inhibition, forelimb asymmetry and open field behavior. The results revealed that persistent stress and elevated corticosterone levels mainly limit motor recovery. Treated animals dropped larger amounts of food in successful reaches and showed exaggerated loss of forelimb inhibition early after lesion. Stress also caused a moderate, but non-significant increase in infarct size. By contrast, stress and corticosterone treatments promoted reaching success and other quantitative measures in the tray reaching task. Comparative analysis revealed that improvements are due to task-specific development of compensatory strategies. These findings suggest that stress and stress hormones may partially facilitate task-specific and adaptive compensatory movement strategies. The observations support the notion that hypothalamic-pituitary-adrenal axis activation may be a key determinant of recovery and motor system plasticity after ischemic stroke.

  18. Musician's dystonia is highly task specific: no strong evidence for everyday fine motor deficits in patients.

    PubMed

    Hofmann, Aurélie; Grossbach, Michael; Baur, Volker; Hermsdörfer, Joachim; Altenmüller, Eckart

    2015-03-01

    1) To examine the fine motor skills used everyday by patients suffering from musician's dystonia (MD) in the upper limb in order to verify whether MD is task-specific; and 2) to compare the affected and non-affected hands of MD musicians vs healthy musicians in performance of these tasks in order to clarify whether dystonic symptoms can be found in the non-affected side of MD patients. MD is typically considered to be focal and task specific, but patients often report impairment in everyday life activities. Furthermore, in the course of MD, about 15% of patients complain of dystonic symptoms in other parts of the body. Twenty-seven musicians affected by MD and 27 healthy musicians were studied using 1) the Motor Performance Test Series, 2) a kinematic analysis of handwriting, and 3) an assessment of the grip force regulation while lifting and moving a manipulandum. Patients performed most fine motor tasks without any evidence of a deficit. Exclusively in the handwriting tasks (2), they exhibited fewer frequencies of the written trace and a prolonged overall writing time. MD is highly task specific and does not strongly affect other motor skills. The subtle deficits in handwriting may be explained as a consequence of a general psychological disposition rather than as compensatory mechanisms to avoid the appearance of dystonic symptoms. Furthermore, we did not find signs of multifocal motor deficits in the unaffected hands of MD patients.

  19. Task Related Modulation of the Motor System during Language Processing

    ERIC Educational Resources Information Center

    Sato, Marc; Mengarelli, Marisa; Riggio, Lucia; Gallese, Vittorio; Buccino, Giovanni

    2008-01-01

    Recent neurophysiological and brain imaging studies have shown that the motor system is involved in language processing. However, it is an open question whether this involvement is a necessary requisite to understand language or rather a side effect of distinct cognitive processes underlying it. In order to clarify this issue we carried out three…

  20. Transcranial direct current stimulation (tDCS) to the supplementary motor area (SMA) influences performance on motor tasks.

    PubMed

    Hupfeld, K E; Ketcham, C J; Schneider, H D

    2017-03-01

    The supplementary motor area (SMA) is believed to be highly involved in the planning and execution of both simple and complex motor tasks. This study aimed to examine the role of the SMA in planning the movements required to complete reaction time, balance, and pegboard tasks using anodal transcranial direct current stimulation (tDCS), which passes a weak electrical current between two electrodes, in order to modulate neuronal activity. Twenty healthy adults were counterbalanced to receive either tDCS (experimental condition) or no tDCS (control condition) for 3 days. During administration of tDCS, participants performed a balance task significantly faster than controls. After tDCS, subjects significantly improved their simple and choice reaction time. These results demonstrate that the SMA is highly involved in planning and executing fine and gross motor skill tasks and that tDCS is an effective modality for increasing SMA-related performance on these tasks. The findings may be generalizable and therefore indicate implications for future interventions using tDCS as a therapeutic tool.

  1. Training Attentional Control Improves Cognitive and Motor Task Performance.

    PubMed

    Ducrocq, Emmanuel; Wilson, Mark; Vine, Sam; Derakshan, Nazanin

    2016-10-01

    Attentional control is a necessary function for the regulation of goal-directed behavior. In three experiments we investigated whether training inhibitory control using a visual search task could improve task-specific measures of attentional control and performance. In Experiment 1 results revealed that training elicited a near-transfer effect, improving performance on a cognitive (antisaccade) task assessing inhibitory control. In Experiment 2 an initial far-transfer effect of training was observed on an index of attentional control validated for tennis. The principal aim of Experiment 3 was to expand on these findings by assessing objective gaze measures of inhibitory control during the performance of a tennis task. Training improved inhibitory control and performance when pressure was elevated, confirming the mechanisms by which cognitive anxiety impacts performance. These results suggest that attentional control training can improve inhibition and reduce taskspecific distractibility with promise of transfer to more efficient sporting performance in competitive contexts.

  2. Facilitation of learning induced by both random and gradual visuomotor task variation.

    PubMed

    Turnham, Edward J A; Braun, Daniel A; Wolpert, Daniel M

    2012-02-01

    Motor task variation has been shown to be a key ingredient in skill transfer, retention, and structural learning. However, many studies only compare training of randomly varying tasks to either blocked or null training, and it is not clear how experiencing different nonrandom temporal orderings of tasks might affect the learning process. Here we study learning in human subjects who experience the same set of visuomotor rotations, evenly spaced between -60° and +60°, either in a random order or in an order in which the rotation angle changed gradually. We compared subsequent learning of three test blocks of +30°→-30°→+30° rotations. The groups that underwent either random or gradual training showed significant (P < 0.01) facilitation of learning in the test blocks compared with a control group who had not experienced any visuomotor rotations before. We also found that movement initiation times in the random group during the test blocks were significantly (P < 0.05) lower than for the gradual or the control group. When we fit a state-space model with fast and slow learning processes to our data, we found that the differences in performance in the test block were consistent with the gradual or random task variation changing the learning and retention rates of only the fast learning process. Such adaptation of learning rates may be a key feature of ongoing meta-learning processes. Our results therefore suggest that both gradual and random task variation can induce meta-learning and that random learning has an advantage in terms of shorter initiation times, suggesting less reliance on cognitive processes.

  3. Facilitation of learning induced by both random and gradual visuomotor task variation

    PubMed Central

    Braun, Daniel A.; Wolpert, Daniel M.

    2012-01-01

    Motor task variation has been shown to be a key ingredient in skill transfer, retention, and structural learning. However, many studies only compare training of randomly varying tasks to either blocked or null training, and it is not clear how experiencing different nonrandom temporal orderings of tasks might affect the learning process. Here we study learning in human subjects who experience the same set of visuomotor rotations, evenly spaced between −60° and +60°, either in a random order or in an order in which the rotation angle changed gradually. We compared subsequent learning of three test blocks of +30°→−30°→+30° rotations. The groups that underwent either random or gradual training showed significant (P < 0.01) facilitation of learning in the test blocks compared with a control group who had not experienced any visuomotor rotations before. We also found that movement initiation times in the random group during the test blocks were significantly (P < 0.05) lower than for the gradual or the control group. When we fit a state-space model with fast and slow learning processes to our data, we found that the differences in performance in the test block were consistent with the gradual or random task variation changing the learning and retention rates of only the fast learning process. Such adaptation of learning rates may be a key feature of ongoing meta-learning processes. Our results therefore suggest that both gradual and random task variation can induce meta-learning and that random learning has an advantage in terms of shorter initiation times, suggesting less reliance on cognitive processes. PMID:22131385

  4. Task Complexity Modulates Sleep-Related Offline Learning in Sequential Motor Skills

    PubMed Central

    Blischke, Klaus; Malangré, Andreas

    2017-01-01

    Recently, a number of authors have advocated the introduction of gross motor tasks into research on sleep-related motor offline learning. Such tasks are often designed to be more complex than traditional key-pressing tasks. However, until now, little effort has been undertaken to scrutinize the role of task complexity in any systematic way. Therefore, the effect of task complexity on the consolidation of gross motor sequence memory was examined by our group in a series of three experiments. Criterion tasks always required participants to produce unrestrained arm movement sequences by successively fitting a small peg into target holes on a pegboard. The sequences always followed a certain spatial pattern in the horizontal plane. The targets were visualized prior to each transport movement on a computer screen. The tasks differed with respect to sequence length and structural complexity. In each experiment, half of the participants initially learned the task in the morning and were retested 12 h later following a wake retention interval. The other half of the subjects underwent practice in the evening and was retested 12 h later following a night of sleep. The dependent variables were the error rate and total sequence execution time (inverse to the sequence execution speed). Performance generally improved during acquisition. The error rate was always low and remained stable during retention. The sequence execution time significantly decreased again following sleep but not after waking when the sequence length was long and structural complexity was high. However, sleep-related offline improvements were absent when the sequence length was short or when subjects performed a highly regular movement pattern. It is assumed that the occurrence of sleep-related offline performance improvements in sequential motor tasks is associated with a sufficient amount of motor task complexity. PMID:28790905

  5. Task Complexity Modulates Sleep-Related Offline Learning in Sequential Motor Skills.

    PubMed

    Blischke, Klaus; Malangré, Andreas

    2017-01-01

    Recently, a number of authors have advocated the introduction of gross motor tasks into research on sleep-related motor offline learning. Such tasks are often designed to be more complex than traditional key-pressing tasks. However, until now, little effort has been undertaken to scrutinize the role of task complexity in any systematic way. Therefore, the effect of task complexity on the consolidation of gross motor sequence memory was examined by our group in a series of three experiments. Criterion tasks always required participants to produce unrestrained arm movement sequences by successively fitting a small peg into target holes on a pegboard. The sequences always followed a certain spatial pattern in the horizontal plane. The targets were visualized prior to each transport movement on a computer screen. The tasks differed with respect to sequence length and structural complexity. In each experiment, half of the participants initially learned the task in the morning and were retested 12 h later following a wake retention interval. The other half of the subjects underwent practice in the evening and was retested 12 h later following a night of sleep. The dependent variables were the error rate and total sequence execution time (inverse to the sequence execution speed). Performance generally improved during acquisition. The error rate was always low and remained stable during retention. The sequence execution time significantly decreased again following sleep but not after waking when the sequence length was long and structural complexity was high. However, sleep-related offline improvements were absent when the sequence length was short or when subjects performed a highly regular movement pattern. It is assumed that the occurrence of sleep-related offline performance improvements in sequential motor tasks is associated with a sufficient amount of motor task complexity.

  6. Adults with dyslexia: theta power changes during performance of a sequential motor task.

    PubMed

    Coombes, Stephen A; Janelle, Christopher M; Duley, Aaron R; Conway, Timothy

    2005-04-01

    Performance deficits during cerebellar intensive motor tasks maybe reflected by discrepant theta activity in the cerebral cortex. The present experiment examined the relationship between performance on a novel motor task and theta activity in adults with developmental dyslexia (DD) and an age- and IQ-matched control group (CG). Time-locked tonic and phasic lower and upper theta measures were derived and separate event-related theta band power (ERBP) scores were calculated for each of three experimental trials. The DD made significantly more errors than CG during Trials 1 and 2 of the motor task. Tonic theta did not differ between groups; however, the DD group displayed a significant decrease in ERBP across all trials and sites, specifically in central and parietal regions during Trial 3. No significant behavioral or physiological evidence supported the notion of conscious compensation (CC). Rather, deficient task performance in the DD group was associated with a general inability to recruit sufficient working memory processes.

  7. The effect of transcranial direct current stimulation on the motor suppression in stop-signal task.

    PubMed

    Kwon, Jung Won; Nam, Seok Hyun; Lee, Na Kyung; Son, Sung Min; Choi, Yong Won; Kim, Chung Sun

    2013-01-01

    This study examined whether transcranial direct current stimulation (tDCS) of the primary motor cortex alters the response time in motor suppression using the stop-signal task (SST). Forty healthy subjects were enrolled in this study. The subjects were assigned randomly to either the tDCS condition or sham control condition. All subjects performed a stop-signal task in three consecutive phases: without, during or after the delivery of anodal tDCS on the primary motor cortex (the pre-tDCS motor phase, on-tDCS motor phase, and after-tDCS motor phase). The response times of the stopping process were significantly lower in each SST motor phase during or after tDCS (p < 0.05) and shorter immediately during delivery of the tDCS, whereas there was no change after the delivery of tDCS compared to sham condition. In contrast, the response times of the going process were similar under the two conditions (p > 0.05). No subjects complained of any adverse symptoms or signs. Anodal tDCS enhances voluntary going and stopping of movement in executive control. tDCS appears to be an effective modality to modulate motor suppression and its related dynamic behavioral changes in motor sequential learning.

  8. Effect of observation combined with motor imagery of a skilled hand-motor task on motor cortical excitability: difference between novice and expert.

    PubMed

    Tsukazaki, Izumi; Uehara, Kazumasa; Morishita, Takuya; Ninomiya, Masato; Funase, Kozo

    2012-06-19

    We examined the effects of observation combined with motor imagery (MI) of a skilled hand-motor task on motor cortex excitability, which was assessed by transcranial magnetic stimulation (TMS). Novices and experts at 3-ball cascade juggling (3BCJ) participated in this study. In one trial, the subjects observed a video clip of 3BCJ while imagining performing it. In addition, the subjects also imagined performing 3BCJ without video clip observation. Motor evoked potentials (MEPs) were recorded from the hand muscles that were activated by the task during each trial. In the novices, the MEP amplitude was significantly increased by video clip observation combined with MI. In contrast, MI without video clip observation significantly increased the MEP amplitude of the experts. These results suggest that action observation of 3BCJ increases the ability of novices to make their MI performing the task. Meanwhile, experts use their own motor program to recall their MI of the task. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  9. Human Footprint Variation while Performing Load Bearing Tasks

    PubMed Central

    Wall-Scheffler, Cara M.; Wagnild, Janelle; Wagler, Emily

    2015-01-01

    Human footprint fossils have provided essential evidence about the evolution of human bipedalism as well as the social dynamics of the footprint makers, including estimates of speed, sex and group composition. Generally such estimates are made by comparing footprint evidence with modern controls; however, previous studies have not accounted for the variation in footprint dimensions coming from load bearing activities. It is likely that a portion of the hominins who created these fossil footprints were carrying a significant load, such as offspring or foraging loads, which caused variation in the footprint which could extend to variation in any estimations concerning the footprint’s maker. To identify significant variation in footprints due to load-bearing tasks, we had participants (N = 30, 15 males and 15 females) walk at a series of speeds carrying a 20kg pack on their back, side and front. Paint was applied to the bare feet of each participant to create footprints that were compared in terms of foot length, foot width and foot area. Female foot length and width increased during multiple loaded conditions. An appreciation of footprint variability associated with carrying loads adds an additional layer to our understanding of the behavior and morphology of extinct hominin populations. PMID:25738496

  10. Corticospinal excitability during observation and imagery of simple and complex hand tasks: implications for motor rehabilitation.

    PubMed

    Roosink, Meyke; Zijdewind, Inge

    2010-11-12

    Movement observation and imagery are increasingly propagandized for motor rehabilitation. Both observation and imagery are thought to improve motor function through repeated activation of mental motor representations. However, it is unknown what stimulation parameters or imagery conditions are optimal for rehabilitation purposes. A better understanding of the mechanisms underlying movement observation and imagery is essential for the optimization of functional outcome using these training conditions. This study systematically assessed the corticospinal excitability during rest, observation, imagery and execution of a simple and a complex finger-tapping sequence in healthy controls using transcranial magnetic stimulation (TMS). Observation was conducted passively (without prior instructions) as well as actively (in order to imitate). Imagery was performed visually and kinesthetically. A larger increase in corticospinal excitability was found during active observation in comparison with passive observation and visual or kinesthetic imagery. No significant difference between kinesthetic and visual imagery was found. Overall, the complex task led to a higher corticospinal excitability in comparison with the simple task. In conclusion, the corticospinal excitability was modulated during both movement observation and imagery. Specifically, active observation of a complex motor task resulted in increased corticospinal excitability. Active observation may be more effective than imagery for motor rehabilitation purposes. In addition, the activation of mental motor representations may be optimized by varying task-complexity. (c) 2010 Elsevier B.V. All rights reserved.

  11. Changes in electroencephalographic activity during observation, preparation, and execution of a motor learning task.

    PubMed

    Nakano, Hideki; Osumi, Michihiro; Ueta, Kozo; Kodama, Takayuki; Morioka, Shu

    2013-12-01

    This study aimed to compare electroencephalographic (EEG) activity between high- and low-motor learning groups (n = 10 each) during observation of, preparation for, and execution of a motor learning task. The subjects performed a ball rotation task in which two balls were rotated clockwise with the right hand. Each trial started with a rest period (5 s), subjects then observed the task action on a computer screen (30 s), this was followed by another rest (5 s), preparation for performing the action (5 s), and finally action execution (30 s); five trials were performed. The number of rotations during execution and EEG activities during observation, preparation, and execution were recorded. The EEG data of the high-motor learning group were compared with those of the low-motor learning group and were analyzed using exact low-resolution electromagnetic tomography (eLORETA). The left sensorimotor and parietal areas of the high-motor learning group showed a greater decrease in the alpha-2 (10.5-12.0 Hz) and beta-2 (18.5-21.0 Hz) rhythms than those of the low-motor learning group during all three phases of the trials. The study results suggest that the decreases in the alpha-2 and beta-2 rhythms in these areas during observation, preparation, and execution are associated with motor skill improvement.

  12. Sleep enhances learning of a functional motor task in young adults.

    PubMed

    Al-Sharman, Alham; Siengsukon, Catherine F

    2013-12-01

    Sleep has been demonstrated to enhance simple motor skill learning "offline" in young adults. "Offline learning" refers to either the stabilization or the enhancement of a memory through the passage of time without additional practice. It remains unclear whether a functional motor task will benefit from sleep to produce offline motor skill enhancement. Physical therapists often teach clients functional motor skills; therefore, it is important to understand how sleep affects learning of these skills. The purpose of this study was to determine whether sleep enhances the learning of a functional motor task. A prospective, cross-sectional, repeated-measures design was used. Young participants who were healthy (N=24) were randomly assigned to either a sleep group or a no-sleep group. The sleep group practiced a novel walking task in the evening and underwent retention testing the following morning, and the no-sleep group practiced the task in the morning and underwent retention testing in the evening. Outcome measures included time around the walking path and spatiotemporal gait parameters. Only participants who slept after practicing the novel walking task demonstrated a significant offline improvement in performance. Compared with the no-sleep group, participants in the sleep group demonstrated a significant decrease in the time around the walking path, an increase in tandem velocity, an increase in tandem step length, and a decline in tandem step time. Time-of-day effect and inability to ensure a certain amount of sleep quantity and quality of participants were limitations of the study. This study is the first to provide evidence that sleep facilitates learning clinically relevant functional motor tasks. Sleep is an important factor that physical therapists should consider when teaching clients motor skills.

  13. Solid-propellant rocket motor ballistic performance variation analyses

    NASA Technical Reports Server (NTRS)

    Sforzini, R. H.; Foster, W. A., Jr.

    1975-01-01

    Results are presented of research aimed at improving the assessment of off-nominal internal ballistic performance including tailoff and thrust imbalance of two large solid-rocket motors (SRMs) firing in parallel. Previous analyses using the Monte Carlo technique were refined to permit evaluation of the effects of radial and circumferential propellant temperature gradients. Sample evaluations of the effect of the temperature gradients are presented. A separate theoretical investigation of the effect of strain rate on the burning rate of propellant indicates that the thermoelastic coupling may cause substantial variations in burning rate during highly transient operating conditions. The Monte Carlo approach was also modified to permit the effects on performance of variation in the characteristics between lots of propellants and other materials to be evaluated. This permits the variabilities for the total SRM population to be determined. A sample case shows, however, that the effect of these between-lot variations on thrust imbalances within pairs of SRMs is minor in compariosn to the effect of the within-lot variations. The revised Monte Carlo and design analysis computer programs along with instructions including format requirements for preparation of input data and illustrative examples are presented.

  14. Functional Near Infrared Spectroscopy of the Sensory and Motor Brain Regions with Simultaneous Kinematic and EMG Monitoring During Motor Tasks

    PubMed Central

    Sukal-Moulton, Theresa; de Campos, Ana Carolina; Stanley, Christopher J.; Damiano, Diane L.

    2014-01-01

    There are several advantages that functional near-infrared spectroscopy (fNIRS) presents in the study of the neural control of human movement. It is relatively flexible with respect to participant positioning and allows for some head movements during tasks. Additionally, it is inexpensive, light weight, and portable, with very few contraindications to its use. This presents a unique opportunity to study functional brain activity during motor tasks in individuals who are typically developing, as well as those with movement disorders, such as cerebral palsy. An additional consideration when studying movement disorders, however, is the quality of actual movements performed and the potential for additional, unintended movements. Therefore, concurrent monitoring of both blood flow changes in the brain and actual movements of the body during testing is required for appropriate interpretation of fNIRS results. Here, we show a protocol for the combination of fNIRS with muscle and kinematic monitoring during motor tasks. We explore gait, a unilateral multi-joint movement (cycling), and two unilateral single-joint movements (isolated ankle dorsiflexion, and isolated hand squeezing). The techniques presented can be useful in studying both typical and atypical motor control, and can be modified to investigate a broad range of tasks and scientific questions. PMID:25548919

  15. Temporary Nerve Block at Selected Digits Revealed Hand Motor Deficits in Grasping Tasks

    PubMed Central

    Carteron, Aude; McPartlan, Kerry; Gioeli, Christina; Reid, Emily; Turturro, Matt; Hahn, Barry; Benson, Cynthia; Zhang, Wei

    2016-01-01

    Peripheral sensory feedback plays a crucial role in ensuring correct motor execution throughout hand grasp control. Previous studies utilized local anesthesia to deprive somatosensory feedback in the digits or hand, observations included sensorimotor deficits at both corticospinal and peripheral levels. However, the questions of how the disturbed and intact sensory input integrate and interact with each other to assist the motor program execution, and whether the motor coordination based on motor output variability between affected and non-affected elements (e.g., digits) becomes interfered by the local sensory deficiency, have not been answered. The current study aims to investigate the effect of peripheral deafferentation through digital nerve blocks at selective digits on motor performance and motor coordination in grasp control. Our results suggested that the absence of somatosensory information induced motor deficits in hand grasp control, as evidenced by reduced maximal force production ability in both local and non-local digits, impairment of force and moment control during object lift and hold, and attenuated motor synergies in stabilizing task performance variables, namely the tangential force and moment of force. These findings implied that individual sensory input is shared across all the digits and the disturbed signal from local sensory channel(s) has a more comprehensive impact on the process of the motor output execution in the sensorimotor integration process. Additionally, a feedback control mechanism with a sensation-based component resides in the formation process for the motor covariation structure. PMID:27932964

  16. Time to task failure and motor cortical activity depend on the type of feedback in visuomotor tasks.

    PubMed

    Lauber, Benedikt; Leukel, Christian; Gollhofer, Albert; Taube, Wolfgang

    2012-01-01

    The present study aimed to elucidate whether the type of feedback influences the performance and the motor cortical activity when executing identical visuomotor tasks. For this purpose, time to task failure was measured during position- and force-controlled muscular contractions. Subjects received either visual feedback about the force produced by pressing a force transducer or about the actual position between thumb and index finger. Participants were instructed to either match the force level of 30% MVC or the finger position corresponding to the thumb and index finger angle at this contraction intensity. Subjects demonstrated a shorter time to task failure when they were provided with feedback about their joint position (11.5 ± 6.2 min) instead of force feedback (19.2 ± 12.8 min; P = 0.01). To test differences in motor cortical activity between position- and force-controlled contractions, subthreshold transcranial magnetic stimulation (subTMS) was applied while executing submaximal (20% MVC) contractions. SubTMS resulted in a suppression of the first dorsal interosseus muscle (FDI) EMG in both tasks. However, the mean suppression for the position-controlled task was significantly greater (18.6 ± 9.4% vs. 13.3 ± 7.5%; P = 0.025) and lasted longer (13.9 ± 7.5 ms vs. 9.3 ± 4.3 ms; P = 0.024) compared to the force-controlled task. The FDI background EMG obtained without stimulation was comparable in all conditions. The present results demonstrate that the presentation of different feedback modalities influences the time to task failure as well as the cortical activity. As only the feedback was altered but not the mechanics of the task, the present results add to the body of evidence that suggests that the central nervous system processes force and position information in different ways.

  17. Effects of Variations in Task Design on Mathematics Teachers' Learning Experiences: A Case of a Sorting Task

    ERIC Educational Resources Information Center

    Koichu, Boris; Zaslavsky, Orit; Dolev, Lea

    2016-01-01

    The goal of the study presented in this article was to examine how variations in task design may affect mathematics teachers' learning experiences. The study focuses on sorting tasks, i.e., learning tasks that require grouping a given set of mathematical items, in as many ways as possible, according to different criteria suggested by the learners.…

  18. Effects of Variations in Task Design on Mathematics Teachers' Learning Experiences: A Case of a Sorting Task

    ERIC Educational Resources Information Center

    Koichu, Boris; Zaslavsky, Orit; Dolev, Lea

    2016-01-01

    The goal of the study presented in this article was to examine how variations in task design may affect mathematics teachers' learning experiences. The study focuses on sorting tasks, i.e., learning tasks that require grouping a given set of mathematical items, in as many ways as possible, according to different criteria suggested by the learners.…

  19. Self-control of task difficulty during training enhances motor learning of a complex coincidence-anticipation task.

    PubMed

    Andrieux, Mathieu; Danna, Jérémy; Thon, Bernard

    2012-03-01

    The aim of the present work was to analyze the influence of self-controlled task difficulty on motor learning. Participants had to intercept three targets falling at different velocities by displacing a stylus above a digitizer Task difficulty corresponded to racquet width. Half the participants (self-control condition) could choose the racquet width at the beginning of each trial. Each was paired with a participant from the yoked group. The self-control condition resulted in better performances and accuracy during immediate and delayed retention tests. These results confirm the advantage of a self-control condition on motor learning. They are discussed with reference to the challenge point hypothesis (Guadagnoli & Lee, 2004).

  20. Effects of cognitive task on gait initiation in Parkinson disease: evidence of motor prioritization?

    PubMed

    Nocera, Joe R; Roemmich, Ryan; Elrod, Jonathan; Altmann, Lori J P; Hass, Chris J

    2013-01-01

    While much is known about the effects of dual tasking on cyclical and continuous motor performance (e.g., locomotion), there is a paucity of information on the effect of dual tasking on the initiation of movement. Therefore, the purpose of this study was to investigate the effect of a concurrent cognitive task on gait initiation in three groups: patients with Parkinson disease, healthy older adults, and healthy young adults. We examined the anticipatory postural adjustment displacements and velocities during single-task gait initiation as well as two dual-task conditions: (1) 0-back + gait initiation and (2) 2-back + gait initiation. The Parkinson disease group exhibited less anticipatory postural adjustment displacement and velocity than their aged-matched healthy peers and young adults during the single- and dual-task gait initiation settings (p < 0.05). Of interest was the finding of no additional effect on anticipatory postural adjustment displacement or velocity of gait initiation during the dual-task conditions in any group, including the Parkinson disease group. More traditionally studied gait/balance dual-task paradigms have demonstrated both motor and cognitive decline. Therefore, our results may suggest a prioritization of more "intentional" movement task (e.g., gait initiation) while dual tasking in Parkinson disease.

  1. Novel Nut and Bolt Task Quantifies Motor Deficits in Premanifest and Manifest Huntington’s Disease

    PubMed Central

    Collins, Lucy M.; Begeti, Faye; Panin, Francesca; Lazar, Alpar S.; Cruickshank, Travis; Ziman, Mel; Mason, Sarah L.; Barker, Roger A.

    2015-01-01

    Background: We investigated the use of a simple novel nut and bolt task in premanifest and manifest Huntington’s disease (HD) patients to detect and quantify motor impairments at all stages of the disease. Methods: Premanifest HD (n=24), manifest HD (n=27) and control (n=32) participants were asked to screw a nut onto a bolt in one direction, using three different sized bolts with their left and right hand in turn. Results: We identified some impairments at all stages of HD and in the premanifest individuals, deficits in the non-dominant hand correlated with disease burden scores. Conclusion: This simple, cheap motor task was able to detect motor impairments in both premanifest and manifest HD and as such might be a useful quantifiable measure of motor function for use in clinical studies. PMID:26421223

  2. Chaos and Fractal Analysis of Electroencephalogram Signals during Different Imaginary Motor Movement Tasks

    NASA Astrophysics Data System (ADS)

    Soe, Ni Ni; Nakagawa, Masahiro

    2008-04-01

    This paper presents the novel approach to evaluate the effects of different motor activation tasks of the human electroencephalogram (EEG). The applications of chaos and fractal properties that are the most important tools in nonlinear analysis are been presented for four tasks of EEG during the real and imaginary motor movement. Three subjects, aged 23-30 years, participated in the experiment. Correlation dimension (D2), Lyapunov spectrum (λi), and Lyapunov dimension (DL) are been estimated to characterize the movement related EEG signals. Experimental results show that these nonlinear measures are good discriminators of EEG signals. There are significant differences in all conditions of subjective task. The fractal dimension appeared to be higher in movement conditions compared to the baseline condition. It is concluded that chaos and fractal analysis could be powerful methods in investigating brain activities during motor movements.

  3. Improvements in motor tasks through the use of smartphone technology for individuals with Duchenne muscular dystrophy.

    PubMed

    Capelini, Camila Miliani; da Silva, Talita Dias; Tonks, James; Watson, Suzanna; Alvarez, Mayra Priscila Boscolo; de Menezes, Lilian Del Ciello; Favero, Francis Meire; Caromano, Fátima Aparecida; Massetti, Thais; de Mello Monteiro, Carlos Bandeira

    2017-01-01

    In individuals severely affected with Duchenne muscular dystrophy (DMD), virtual reality has recently been used as a tool to enhance community interaction. Smartphones offer the exciting potential to improve communication, access, and participation, and present the unique opportunity to directly deliver functionality to people with disabilities. To verify whether individuals with DMD improve their motor performance when undertaking a visual motor task using a smartphone game. Fifty individuals with DMD and 50 healthy, typically developing (TD) controls, aged 10-34 years participated in the study. The functional characterization of the sample was determined through Vignos, Egen Klassifikation, and the Motor Function Measure scales. To complete the task, individuals moved a virtual ball around a virtual maze and the time in seconds was measured after every attempt in order to analyze improvement of performance after the practice trials. Motor performance (time to finish each maze) was measured in phases of acquisition, short-term retention, and transfer. Use of the smartphone maze game promoted improvement in performance during acquisition in both groups, which remained in the retention phase. At the transfer phases, with alternative maze tasks, the performance in DMD group was similar to the performance of TD group, with the exception of the transfer to the contralateral hand (nondominant). However, the group with DMD demonstrated longer movement time at all stages of learning, compared with the TD group. The practice of a visual motor task delivered via smartphone game promoted an improvement in performance with similar patterns of learning in both groups. Performance can be influenced by task difficulty, and for people with DMD, motor deficits are responsible for the lower speed of execution. This study indicates that individuals with DMD showed improved performance in a short-term motor learning protocol using a smartphone. We advocate that this technology could

  4. Perceptual-Motor and Cognitive Performance Task-Battery for Pilot Selection

    DTIC Science & Technology

    1981-01-01

    computerized testing station. The current effort was intended to update previously developed batteries which concentrated primarily upon motor skill ...importance of the perceptual-motor skills to pilot performance has long been considered crucial, as is evident both in the extent to which pilot training...control ability." While the authors suggest that the task parameters vary too widely for the correlations to emerge, nonetheless no evidence for a qeneral

  5. Inferior frontal gyrus links visual and motor cortices during a visuomotor precision grip force task.

    PubMed

    Papadelis, Christos; Arfeller, Carola; Erla, Silvia; Nollo, Giandomenico; Cattaneo, Luigi; Braun, Christoph

    2016-11-01

    Coordination between vision and action relies on a fronto-parietal network that receives visual and proprioceptive sensory input in order to compute motor control signals. Here, we investigated with magnetoencephalography (MEG) which cortical areas are functionally coupled on the basis of synchronization during visuomotor integration. MEG signals were recorded from twelve healthy adults while performing a unimanual visuomotor (VM) task and control conditions. The VM task required the integration of pinch motor commands with visual sensory feedback. By using a beamformer, we localized the neural activity in the frequency range of 1-30Hz during the VM compared to rest. Virtual sensors were estimated at the active locations. A multivariate autoregressive model was used to estimate the power and coherence of estimated activity at the virtual sensors. Event-related desynchronisation (ERD) during VM was observed in early visual areas, the rostral part of the left inferior frontal gyrus (IFG), the right IFG, the superior parietal lobules, and the left hand motor cortex (M1). Functional coupling in the alpha frequency band bridged the regional activities observed in motor and visual cortices (the start and the end points in the visuomotor loop) through the left or right IFG. Coherence between the left IFG and left M1 correlated inversely with the task performance. Our results indicate that an occipital-prefrontal-motor functional network facilitates the modulation of instructed motor responses to visual cues. This network may supplement the mechanism for guiding actions that is fully incorporated into the dorsal visual stream.

  6. The influence of task paradigm on motor imagery ability in children with Developmental Coordination Disorder.

    PubMed

    Ferguson, G D; Wilson, P H; Smits-Engelsman, B C M

    2015-12-01

    Children with Developmental Coordination Disorder (DCD) have difficulty imagining movements such that they conform to the customary temporal constraints of real performance. We examined whether this ability is influenced by the choice of task used to elicit motor imagery (MI). Performance of typically developing (TD) (n=30) and children with DCD (n=30) was compared on two tasks: the Visually Guided Pointing Task (VGPT) and the Computerized Virtual Radial Fitts Task (C-VRFT). Since the VGPT places higher demands on executive functions like working memory but requires less spatial planning, we reasoned that the C-VRFT would provide a purer measure of motor imagery (or simulation). Based on our earlier work, we predicted that imagery deficits in DCD would more likely manifest on the C-VRFT. Results showed high correlations between tasks in terms of executed and imagined movement time suggest that both tasks measure MI ability. However, group differences were more pronounced in the imagined condition of the radial Fitts' task. Taken together, the more spatially complex C-VRFT appears to be a more sensitive measure of motor imagery, better discriminating between DCD and TD. Implications for theory and practice are discussed. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Evoked Potentials in Motor Cortical Local Field Potentials Reflect Task Timing and Behavioral Performance

    PubMed Central

    Confais, Joachim; Ponce-Alvarez, Adrián; Diesmann, Markus; Riehle, Alexa

    2010-01-01

    Evoked potentials (EPs) are observed in motor cortical local field potentials (LFPs) during movement execution (movement-related potentials [MRPs]) and in response to relevant visual cues (visual evoked potentials [VEPs]). Motor cortical EPs may be directionally selective, but little is known concerning their relation to other aspects of motor behavior, such as task timing and performance. We recorded LFPs in motor cortex of two monkeys during performance of a precued arm-reaching task. A time cue at the start of each trial signaled delay duration and thereby the pace of the task and the available time for movement preparation. VEPs and MRPs were strongly modulated by the delay duration, VEPs being systematically larger in short-delay trials and MRPs larger in long-delay trials. Despite these systematic modulations related to the task timing, directional selectivity was similar in short and long trials. The behavioral reaction time was positively correlated with MRP size and negatively correlated with VEP size, within sessions. In addition, the behavioral performance improved across sessions, in parallel with a slow decrease in the size of VEPs and MRPs. Our results clearly show the strong influence of the behavioral context and performance on motor cortical population activity during movement preparation and execution. PMID:20884766

  8. Disrupting the ipsilateral motor cortex interferes with training of a complex motor task in older adults.

    PubMed

    Zimerman, Máximo; Heise, Kirstin-F; Gerloff, Christian; Cohen, Leonardo G; Hummel, Friedhelm C

    2014-04-01

    Performance of unimanual movements is associated with bihemispheric activity in the motor cortex in old adults. However, the causal functional role of the ipsilateral MC (iMC) for motor control is still not completely known. Here, the behavioral consequences of interference of the iMC during training of a complex motor skill were tested. Healthy old (58-85 years) and young volunteers (22-35 years) were tested in a double-blind, cross-over, sham-controlled design. Participants attended 2 different study arms with either cathodal transcranial direct current stimulation (ctDCS) or sham concurrent with training. Motor performance was evaluated before, during, 90 min, and 24 h after training. During training, a reduced slope of performance with ctDCS relative to sham was observed in old compared with young (F = 5.8, P = 0.02), with a decrease of correctly rehearsed sequences, an effect that was evident even after 2 consecutive retraining periods without intervention. Furthermore, the older the subject, the more prominent was the disruptive effect of ctDCS (R(2) = 0.50, P = 0.01). These data provide direct evidence for a causal functional link between the iMC and motor skill acquisition in old subjects pointing toward the concept that the recruitment of iMC in old is an adaptive process in response to age-related declines in motor functions.

  9. Neuromuscular adaptations during the acquisition of muscle strength, power and motor tasks.

    PubMed

    Moritani, T

    1993-01-01

    Neuromuscular performance is determined not only by the size of the involved muscles, but also by the ability of the nervous system to appropriately activate the muscles. Adaptive changes in the nervous system in response to training are referred to as neural adaptation. This article briefly reviews current evidence regarding the neural adaptations during the acquisition of muscle strength power and motor tasks and will be organized under four main topics, namely: (i) muscle strength gain: neural factors versus hypertrophy, (ii) neural adaptations during power training, (iii) neuromuscular adaptations during the acquisition of a motor task, and (iv) neuromuscular adaptations during a ballistic movement.

  10. Task-specific changes in motor evoked potentials of lower limb muscles after different training interventions.

    PubMed

    Beck, S; Taube, W; Gruber, M; Amtage, F; Gollhofer, A; Schubert, M

    2007-11-07

    This study aimed to identify sites and mechanisms of long-term plasticity following lower limb muscle training. Two groups performing either a postural stability maintenance training (SMT) or a ballistic ankle strength training (BST) were compared to a non-training group. The hypothesis was that practicing of a self-initiated voluntary movement would facilitate cortico-spinal projections, while practicing fast automatic adjustments during stabilization of stance would reduce excitatory influence from the primary motor cortex. Training effects were expected to be confined to the practiced task. To test for training specificity, motor evoked potentials (MEP) induced by transcranial magnetic stimulation (TMS) were recorded at rest and during motor tasks that were similar to each training. Intracortical, cortico-spinal, as well as spinal parameters were assessed at rest and during these tasks. The results show high task and training specificity. Training effects were only observable during performance of the trained task. While MEP size was decreased in the SMT group for the trained tasks, MEP recruitment was increased in the BST group in the trained task only. The control group did not show any changes. Background electromyogram levels, M. soleus H-reflex amplitudes and intracortical parameters were unaltered. In summary, it is suggested that the changes of MEP parameters in both training groups, but not in the control group, reflect cortical motor plasticity. While cortico-spinal activation was enhanced in the BST group, SMT may be associated with improved motor control through increased inhibitory trans-cortical effects. Since spinal excitability remained unaltered, changes most likely occur on the supraspinal level.

  11. Neural model for learning-to-learn of novel task sets in the motor domain.

    PubMed

    Pitti, Alexandre; Braud, Raphaël; Mahé, Sylvain; Quoy, Mathias; Gaussier, Philippe

    2013-01-01

    During development, infants learn to differentiate their motor behaviors relative to various contexts by exploring and identifying the correct structures of causes and effects that they can perform; these structures of actions are called task sets or internal models. The ability to detect the structure of new actions, to learn them and to select on the fly the proper one given the current task set is one great leap in infants cognition. This behavior is an important component of the child's ability of learning-to-learn, a mechanism akin to the one of intrinsic motivation that is argued to drive cognitive development. Accordingly, we propose to model a dual system based on (1) the learning of new task sets and on (2) their evaluation relative to their uncertainty and prediction error. The architecture is designed as a two-level-based neural system for context-dependent behavior (the first system) and task exploration and exploitation (the second system). In our model, the task sets are learned separately by reinforcement learning in the first network after their evaluation and selection in the second one. We perform two different experimental setups to show the sensorimotor mapping and switching between tasks, a first one in a neural simulation for modeling cognitive tasks and a second one with an arm-robot for motor task learning and switching. We show that the interplay of several intrinsic mechanisms drive the rapid formation of the neural populations with respect to novel task sets.

  12. Patterned-String Tasks: Relation between Fine Motor Skills and Visual-Spatial Abilities in Parrots

    PubMed Central

    Krasheninnikova, Anastasia

    2013-01-01

    String-pulling and patterned-string tasks are often used to analyse perceptual and cognitive abilities in animals. In addition, the paradigm can be used to test the interrelation between visual-spatial and motor performance. Two Australian parrot species, the galah (Eolophus roseicapilla) and the cockatiel (Nymphicus hollandicus), forage on the ground, but only the galah uses its feet to manipulate food. I used a set of string pulling and patterned-string tasks to test whether usage of the feet during foraging is a prerequisite for solving the vertical string pulling problem. Indeed, the two species used techniques that clearly differed in the extent of beak-foot coordination but did not differ in terms of their success in solving the string pulling task. However, when the visual-spatial skills of the subjects were tested, the galahs outperformed the cockatiels. This supports the hypothesis that the fine motor skills needed for advanced beak-foot coordination may be interrelated with certain visual-spatial abilities needed for solving patterned-string tasks. This pattern was also found within each of the two species on the individual level: higher motor abilities positively correlated with performance in patterned-string tasks. This is the first evidence of an interrelation between visual-spatial and motor abilities in non-mammalian animals. PMID:24376885

  13. Patterned-string tasks: relation between fine motor skills and visual-spatial abilities in parrots.

    PubMed

    Krasheninnikova, Anastasia

    2013-01-01

    String-pulling and patterned-string tasks are often used to analyse perceptual and cognitive abilities in animals. In addition, the paradigm can be used to test the interrelation between visual-spatial and motor performance. Two Australian parrot species, the galah (Eolophus roseicapilla) and the cockatiel (Nymphicus hollandicus), forage on the ground, but only the galah uses its feet to manipulate food. I used a set of string pulling and patterned-string tasks to test whether usage of the feet during foraging is a prerequisite for solving the vertical string pulling problem. Indeed, the two species used techniques that clearly differed in the extent of beak-foot coordination but did not differ in terms of their success in solving the string pulling task. However, when the visual-spatial skills of the subjects were tested, the galahs outperformed the cockatiels. This supports the hypothesis that the fine motor skills needed for advanced beak-foot coordination may be interrelated with certain visual-spatial abilities needed for solving patterned-string tasks. This pattern was also found within each of the two species on the individual level: higher motor abilities positively correlated with performance in patterned-string tasks. This is the first evidence of an interrelation between visual-spatial and motor abilities in non-mammalian animals.

  14. Sensorimotor Adaptability Training Improves Motor and Dual-Task Performance

    NASA Technical Reports Server (NTRS)

    Bloomberg, J.J.; Peters, B.T.; Mulavara, A.P.; Brady, R.; Batson, C.; Cohen, H.S.

    2009-01-01

    The overall objective of our project is to develop a sensorimotor adaptability (SA) training program designed to facilitate recovery of functional capabilities when astronauts transition to different gravitational environments. The goal of our current study was to determine if SA training using variation in visual flow and support surface motion produces improved performance in a novel sensory environment and demonstrate the retention characteristics of SA training.

  15. Motor Control in Keyboard Tasks and Research on Morse Code Copy

    DTIC Science & Technology

    1992-07-01

    active long- term memory nodes, assumed to be relatively independent of the short - term memory capacity related to controlled processing. Logan (1988...subsequent to visual perception and prior to storage of information in a short - term buffer, this step is questionable. Rumelhart and Norman (1981... effects of variables related to component processes of the Morse code copy task. Experiment 2 studied the motor response component of the copy task

  16. Knowledge discovery in databases of biomechanical variables: application to the sit to stand motor task

    PubMed Central

    Vannozzi, Giuseppe; Della Croce, Ugo; Starita, Antonina; Benvenuti, Francesco; Cappozzo, Aurelio

    2004-01-01

    Background The interpretation of data obtained in a movement analysis laboratory is a crucial issue in clinical contexts. Collection of such data in large databases might encourage the use of modern techniques of data mining to discover additional knowledge with automated methods. In order to maximise the size of the database, simple and low-cost experimental set-ups are preferable. The aim of this study was to extract knowledge inherent in the sit-to-stand task as performed by healthy adults, by searching relationships among measured and estimated biomechanical quantities. An automated method was applied to a large amount of data stored in a database. The sit-to-stand motor task was already shown to be adequate for determining the level of individual motor ability. Methods The technique of search for association rules was chosen to discover patterns as part of a Knowledge Discovery in Databases (KDD) process applied to a sit-to-stand motor task observed with a simple experimental set-up and analysed by means of a minimum measured input model. Selected parameters and variables of a database containing data from 110 healthy adults, of both genders and of a large range of age, performing the task were considered in the analysis. Results A set of rules and definitions were found characterising the patterns shared by the investigated subjects. Time events of the task turned out to be highly interdependent at least in their average values, showing a high level of repeatability of the timing of the performance of the task. Conclusions The distinctive patterns of the sit-to-stand task found in this study, associated to those that could be found in similar studies focusing on subjects with pathologies, could be used as a reference for the functional evaluation of specific subjects performing the sit-to-stand motor task. PMID:15679936

  17. Acquisition of internal models of motor tasks in children with autism.

    PubMed

    Gidley Larson, Jennifer C; Bastian, Amy J; Donchin, Opher; Shadmehr, Reza; Mostofsky, Stewart H

    2008-11-01

    Children with autism exhibit a host of motor disorders including poor coordination, poor tool use and delayed learning of complex motor skills like riding a tricycle. Theory suggests that one of the crucial steps in motor learning is the ability to form internal models: to predict the sensory consequences of motor commands and learn from errors to improve performance on the next attempt. The cerebellum appears to be an important site for acquisition of internal models, and indeed the development of the cerebellum is abnormal in autism. Here, we examined autistic children on a range of tasks that required a change in the motor output in response to a change in the environment. We first considered a prism adaptation task in which the visual map of the environment was shifted. The children were asked to throw balls to visual targets with and without the prism goggles. We next considered a reaching task that required moving the handle of a novel tool (a robotic arm). The tool either imposed forces on the hand or displaced the cursor associated with the handle position. In all tasks, the children with autism adapted their motor output by forming a predictive internal model, as exhibited through after-effects. Surprisingly, the rates of acquisition and washout were indistinguishable from normally developing children. Therefore, the mechanisms of acquisition and adaptation of internal models in self-generated movements appeared normal in autism. Sparing of adaptation suggests that alternative mechanisms contribute to impaired motor skill development in autism. Furthermore, the findings may have therapeutic implications, highlighting a reliable mechanism by which children with autism can most effectively alter their behaviour.

  18. Acquisition of internal models of motor tasks in children with autism

    PubMed Central

    Gidley Larson, Jennifer C.; Bastian, Amy J.; Donchin, Opher; Shadmehr, Reza

    2008-01-01

    Children with autism exhibit a host of motor disorders including poor coordination, poor tool use and delayed learning of complex motor skills like riding a tricycle. Theory suggests that one of the crucial steps in motor learning is the ability to form internal models: to predict the sensory consequences of motor commands and learn from errors to improve performance on the next attempt. The cerebellum appears to be an important site for acquisition of internal models, and indeed the development of the cerebellum is abnormal in autism. Here, we examined autistic children on a range of tasks that required a change in the motor output in response to a change in the environment. We first considered a prism adaptation task in which the visual map of the environment was shifted. The children were asked to throw balls to visual targets with and without the prism goggles. We next considered a reaching task that required moving the handle of a novel tool (a robotic arm). The tool either imposed forces on the hand or displaced the cursor associated with the handle position. In all tasks, the children with autism adapted their motor output by forming a predictive internal model, as exhibited through after-effects. Surprisingly, the rates of acquisition and washout were indistinguishable from normally developing children. Therefore, the mechanisms of acquisition and adaptation of internal models in self-generated movements appeared normal in autism. Sparing of adaptation suggests that alternative mechanisms contribute to impaired motor skill development in autism. Furthermore, the findings may have therapeutic implications, highlighting a reliable mechanism by which children with autism can most effectively alter their behaviour. PMID:18819989

  19. Pre-Trial EEG-Based Single-Trial Motor Performance Prediction to Enhance Neuroergonomics for a Hand Force Task

    PubMed Central

    Meinel, Andreas; Castaño-Candamil, Sebastián; Reis, Janine; Tangermann, Michael

    2016-01-01

    We propose a framework for building electrophysiological predictors of single-trial motor performance variations, exemplified for SVIPT, a sequential isometric force control task suitable for hand motor rehabilitation after stroke. Electroencephalogram (EEG) data of 20 subjects with mean age of 53 years was recorded prior to and during 400 trials of SVIPT. They were executed within a single session with the non-dominant left hand, while receiving continuous visual feedback of the produced force trajectories. The behavioral data showed strong trial-by-trial performance variations for five clinically relevant metrics, which accounted for reaction time as well as for the smoothness and precision of the produced force trajectory. 18 out of 20 tested subjects remained after preprocessing and entered offline analysis. Source Power Comodulation (SPoC) was applied on EEG data of a short time interval prior to the start of each SVIPT trial. For 11 subjects, SPoC revealed robust oscillatory EEG subspace components, whose bandpower activity are predictive for the performance of the upcoming trial. Since SPoC may overfit to non-informative subspaces, we propose to apply three selection criteria accounting for the meaningfulness of the features. Across all subjects, the obtained components were spread along the frequency spectrum and showed a variety of spatial activity patterns. Those containing the highest level of predictive information resided in and close to the alpha band. Their spatial patterns resemble topologies reported for visual attention processes as well as those of imagined or executed hand motor tasks. In summary, we identified subject-specific single predictors that explain up to 36% of the performance fluctuations and may serve for enhancing neuroergonomics of motor rehabilitation scenarios. PMID:27199701

  20. Pre-Trial EEG-Based Single-Trial Motor Performance Prediction to Enhance Neuroergonomics for a Hand Force Task.

    PubMed

    Meinel, Andreas; Castaño-Candamil, Sebastián; Reis, Janine; Tangermann, Michael

    2016-01-01

    We propose a framework for building electrophysiological predictors of single-trial motor performance variations, exemplified for SVIPT, a sequential isometric force control task suitable for hand motor rehabilitation after stroke. Electroencephalogram (EEG) data of 20 subjects with mean age of 53 years was recorded prior to and during 400 trials of SVIPT. They were executed within a single session with the non-dominant left hand, while receiving continuous visual feedback of the produced force trajectories. The behavioral data showed strong trial-by-trial performance variations for five clinically relevant metrics, which accounted for reaction time as well as for the smoothness and precision of the produced force trajectory. 18 out of 20 tested subjects remained after preprocessing and entered offline analysis. Source Power Comodulation (SPoC) was applied on EEG data of a short time interval prior to the start of each SVIPT trial. For 11 subjects, SPoC revealed robust oscillatory EEG subspace components, whose bandpower activity are predictive for the performance of the upcoming trial. Since SPoC may overfit to non-informative subspaces, we propose to apply three selection criteria accounting for the meaningfulness of the features. Across all subjects, the obtained components were spread along the frequency spectrum and showed a variety of spatial activity patterns. Those containing the highest level of predictive information resided in and close to the alpha band. Their spatial patterns resemble topologies reported for visual attention processes as well as those of imagined or executed hand motor tasks. In summary, we identified subject-specific single predictors that explain up to 36% of the performance fluctuations and may serve for enhancing neuroergonomics of motor rehabilitation scenarios.

  1. Does physical activity benefit motor performance and learning of upper extremity tasks in older adults? - A systematic review.

    PubMed

    Hübner, Lena; Voelcker-Rehage, Claudia

    2017-01-01

    Upper extremity motor performance declines with increasing age. However, older adults need to maintain, learn new and relearn known motor tasks. Research with young adults indicated that regular and acute physical activity might facilitate motor performance and motor learning processes. Therefore, this review aimed to examine the association between chronic physical activity and acute bouts of exercise on motor performance and motor learning in upper extremity motor tasks in older adults. Literature was searched via Cochrane library, PubMED, PsycINFO and Scopus and 27 studies met all inclusion criteria. All studies dealt with the influence of chronic physical activity on motor performance or motor learning, no appropriate study examining the influence of an acute bout of exercise in older adults was found. Results concerning the association of chronic physical activity and motor performance are mixed and seem to be influenced by the study design, kind of exercise, motor task, and exercise intensity. Regarding motor learning, a high physical activity or cardiovascular fitness level seems to boost the initial phase of motor learning; results differ with respect to motor retention. Overall, (motor-coordinative) intervention studies seem to be more promising than cross-sectional studies.

  2. Dynamic Monitoring Reveals Motor Task Characteristics in Prehistoric Technical Gestures

    PubMed Central

    Pfleging, Johannes; Stücheli, Marius; Iovita, Radu; Buchli, Jonas

    2015-01-01

    Reconstructing ancient technical gestures associated with simple tool actions is crucial for understanding the co-evolution of the human forelimb and its associated control-related cognitive functions on the one hand, and of the human technological arsenal on the other hand. Although the topic of gesture is an old one in Paleolithic archaeology and in anthropology in general, very few studies have taken advantage of the new technologies from the science of kinematics in order to improve replicative experimental protocols. Recent work in paleoanthropology has shown the potential of monitored replicative experiments to reconstruct tool-use-related motions through the study of fossil bones, but so far comparatively little has been done to examine the dynamics of the tool itself. In this paper, we demonstrate that we can statistically differentiate gestures used in a simple scraping task through dynamic monitoring. Dynamics combines kinematics (position, orientation, and speed) with contact mechanical parameters (force and torque). Taken together, these parameters are important because they play a role in the formation of a visible archaeological signature, use-wear. We present our new affordable, yet precise methodology for measuring the dynamics of a simple hide-scraping task, carried out using a pull-to (PT) and a push-away (PA) gesture. A strain gage force sensor combined with a visual tag tracking system records force, torque, as well as position and orientation of hafted flint stone tools. The set-up allows switching between two tool configurations, one with distal and the other one with perpendicular hafting of the scrapers, to allow for ethnographically plausible reconstructions. The data show statistically significant differences between the two gestures: scraping away from the body (PA) generates higher shearing forces, but requires greater hand torque. Moreover, most benchmarks associated with the PA gesture are more highly variable than in the PT gesture

  3. Dynamic Monitoring Reveals Motor Task Characteristics in Prehistoric Technical Gestures.

    PubMed

    Pfleging, Johannes; Stücheli, Marius; Iovita, Radu; Buchli, Jonas

    2015-01-01

    Reconstructing ancient technical gestures associated with simple tool actions is crucial for understanding the co-evolution of the human forelimb and its associated control-related cognitive functions on the one hand, and of the human technological arsenal on the other hand. Although the topic of gesture is an old one in Paleolithic archaeology and in anthropology in general, very few studies have taken advantage of the new technologies from the science of kinematics in order to improve replicative experimental protocols. Recent work in paleoanthropology has shown the potential of monitored replicative experiments to reconstruct tool-use-related motions through the study of fossil bones, but so far comparatively little has been done to examine the dynamics of the tool itself. In this paper, we demonstrate that we can statistically differentiate gestures used in a simple scraping task through dynamic monitoring. Dynamics combines kinematics (position, orientation, and speed) with contact mechanical parameters (force and torque). Taken together, these parameters are important because they play a role in the formation of a visible archaeological signature, use-wear. We present our new affordable, yet precise methodology for measuring the dynamics of a simple hide-scraping task, carried out using a pull-to (PT) and a push-away (PA) gesture. A strain gage force sensor combined with a visual tag tracking system records force, torque, as well as position and orientation of hafted flint stone tools. The set-up allows switching between two tool configurations, one with distal and the other one with perpendicular hafting of the scrapers, to allow for ethnographically plausible reconstructions. The data show statistically significant differences between the two gestures: scraping away from the body (PA) generates higher shearing forces, but requires greater hand torque. Moreover, most benchmarks associated with the PA gesture are more highly variable than in the PT gesture

  4. Gradual training reduces practice difficulty while preserving motor learning of a novel locomotor task.

    PubMed

    Sawers, Andrew; Hahn, Michael E

    2013-08-01

    Motor learning strategies that increase practice difficulty and the size of movement errors are thought to facilitate motor learning. In contrast to this, gradual training minimizes movement errors and reduces practice difficulty by incrementally introducing task requirements, yet remains as effective as sudden training and its large movement errors for learning novel reaching tasks. While attractive as a locomotor rehabilitation strategy, it remains unknown whether the efficacy of gradual training extends to learning locomotor tasks and their unique requirements. The influence of gradual vs. sudden training on learning a locomotor task, asymmetric split belt treadmill walking, was examined by assessing whole body sagittal plane kinematics during 24 hour retention and transfer performance following either gradual or sudden training. Despite less difficult and less specific practice for the gradual cohort on day 1, gradual training resulted in equivalent motor learning of the novel locomotor task as sudden training when assessed by retention and transfer a day later. This suggests that large movement errors and increased practice difficulty may not be necessary for learning novel locomotor tasks. Further, gradual training may present a viable locomotor rehabilitation strategy avoiding large movement errors that could limit or impair improvements in locomotor performance. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Dynamics of Sensorimotor Oscillations in a Motor Task

    NASA Astrophysics Data System (ADS)

    Pfurtscheller, Gert; Neuper, Christa

    Many BCI systems rely on imagined movement. The brain activity associated with real or imagined movement produces reliable changes in the EEG. Therefore, many people can use BCI systems by imagining movements to convey information. The EEG has many regular rhythms. The most famous are the occipital alpha rhythm and the central mu and beta rhythms. People can desynchronize the alpha rhythm (that is, produce weaker alpha activity) by being alert, and can increase alpha activity by closing their eyes and relaxing. Sensory processing or motor behavior leads to EEG desynchronization or blocking of central beta and mu rhythms, as originally reported by Berger [1], Jasper and Andrew [2] and Jasper and Penfield [3]. This desynchronization reflects a decrease of oscillatory activity related to an internally or externally-paced event and is known as Event-Related Desynchronization (ERD, [4]). The opposite, namely the increase of rhythmic activity, was termed Event-Related Synchronization (ERS, [5]). ERD and ERS are characterized by fairly localized topography and frequency specificity [6]. Both phenomena can be studied through topographiuthc maps, time courses, and time-frequency representations (ERD maps, [7]).

  6. The effect of task difficulty on motor performance and frontal-striatal connectivity in cocaine users.

    PubMed

    Lench, Daniel H; DeVries, William; Hanlon, Colleen A

    2017-04-01

    There is growing recognition that chronic cocaine users have alterations in sensorimotor control that are positively related to low frontal-striatal connectivity within the motor system. These frontal-striatal motor circuits however, are modulated by circuits governing attention, which are also disrupted in cocaine users. This study's aim was to determine if sensorimotor control deficits are positively related to the difficulty of a motor task or exist independent of the increasing cognitive demand. Functional MRI data was collected from 40 individuals (20 non-treatment seeking chronic cocaine users, 20 age and gender matched non-drug using controls) as they mimicked an unpredictable finger-tapping sequence at various speeds. Dependent measures included task accuracy, percent BOLD signal change in sensorimotor regions of interest (ROIs), and functional connectivity (temporal correlations) between ROIs. In both groups, as speed increased, the BOLD signal change increased in the primary motor cortex, supplementary motor area (SMA), cerebellum, and anterior cingulate cortex. Compared to controls, cocaine user SMA-Caudate and ACC-Putamen connectivity was lower at all speeds in the contralateral hemisphere. Furthermore, as speed increased there was a decrease in connectivity between additional ROI pairs among users. These data support previous observations of sensorimotor performance deficits and dorsal frontal-striatal connectivity impairments among cocaine users. While previous studies demonstrate these deficits when performing a finger-tapping task at a single speed, we show that these same impairments exist at multiple levels of task difficulty. These data suggest that previously observed frontal-striatal connectivity in cocaine users during sensorimotor task performance are stable and not directly related to cognitive demands of the task. Copyright © 2017. Published by Elsevier B.V.

  7. Brain activity during observation and motor imagery of different balance tasks: an fMRI study.

    PubMed

    Taube, Wolfgang; Mouthon, Michael; Leukel, Christian; Hoogewoud, Henri-Marcel; Annoni, Jean-Marie; Keller, Martin

    2015-03-01

    After immobilization, patients show impaired postural control and increased risk of falling. Therefore, loss of balance control should already be counteracted during immobilization. Previously, studies have demonstrated that both motor imagery (MI) and action observation (AO) can improve motor performance. The current study elaborated how the brain is activated during imagination and observation of different postural tasks to provide recommendations about the conception of non-physical balance training. For this purpose, participants were tested in a within-subject design in an fMRI-scanner in three different conditions: (a) AO + MI, (b) AO, and (c) MI. In (a) participants were instructed to imagine themselves as the person pictured in the video whereas in (b) they were instructed simply to watch the video. In (c) subjects closed their eyes and kinesthetically imagined the task displayed in the video. Two tasks were evaluated in each condition: (i) static standing balance and (ii) dynamic standing balance (medio-lateral perturbation). In all conditions the start of a new trial was indicated every 2 sec by a sound. During AO + MI of the dynamic task, participants activated motor centers including the putamen, cerebellum, supplementary motor area, premotor cortices (PMv/d) and primary motor cortex (M1). MI showed a similar pattern but no activity in M1 and PMv/d. In the SMA and cerebellum, activity was generally higher in the dynamic than in the static condition. AO did not significantly activate any of these brain areas. Our results showed that (I) mainly AO + MI, but also MI, activate brain regions important for balance control; (II) participants display higher levels of brain activation in the more demanding balance task; (III) there is a significant difference between AO + MI and AO. Consequently, best training effects should be expected when participants apply MI during AO (AO + MI) of challenging postural tasks. Copyright © 2014 The Authors. Published by

  8. Task Dependent Motor Strategy of Human Triceps Surae Muscle

    PubMed Central

    Onishi, Hideaki; Ihashi, Kouji; Ichie, Masayoshi; Handa, Yasunobu

    2004-01-01

    Even though many investigators have analyzed the functional difference of the three heads of triceps surae in human, none of them succeeded to clarify the distinctive functional difference of those three muscles. The aim of this study was to investigate whether the integrated EMGs (IEMGs) of the triceps surae muscle, gastrocnemius and soleus, were task dependent. IEMGs of the medial head of the gastrocnemius (GM), lateral head of the gastrocnemius (GL), and soleus (SO) were investigated at three different knee joint angles, at four different duration of ramp contraction, with the generation of a single ongoing force, from 0 to the maximum voluntary contraction (MVC). Three-way ANOVAs for repeated measures were used to estimate differences in IEMG values in each of the GM, GL, and SO, taken at four different durations of ramp contraction (5, 10, 15 and 20 s), at three different knee joint angles (0 deg, 30 deg and 90 deg), across ankle plantar flexion levels of force (10, 20, 30, 40, 50, 60 and 70% MVC). According to three-way ANOVAs for repeated measures, IEMG of the GM muscle showed a first-order interaction between force and knee joint angle. In addition, IEMG of the GL muscle showed first-order interactions between the level of force and knee joint angle, and between the level of force and duration of ramp contraction. Furthermore, IEMG of the SO showed a main effect only on level of force. These results suggest that the each head of the triceps surae may work task dependently. PMID:25792933

  9. Children with cerebral palsy have altered oscillatory activity in the motor and visual cortices during a knee motor task.

    PubMed

    Kurz, Max J; Proskovec, Amy L; Gehringer, James E; Heinrichs-Graham, Elizabeth; Wilson, Tony W

    2017-01-01

    The neuroimaging literature on cerebral palsy (CP) has predominantly focused on identifying structural aberrations within the white matter (e.g., fiber track integrity), with very few studies examining neural activity within the key networks that serve the production of motor actions. The current investigation used high-density magnetoencephalography to begin to fill this knowledge gap by quantifying the temporal dynamics of the alpha and beta cortical oscillations in children with CP (age = 15.5 ± 3 years; GMFCS levels II-III) and typically developing (TD) children (age = 14.1 ± 3 years) during a goal-directed isometric target-matching task using the knee joint. Advanced beamforming methods were used to image the cortical oscillations during the movement planning and execution stages. Compared with the TD children, our results showed that the children with CP had stronger alpha and beta event-related desynchronization (ERD) within the primary motor cortices, premotor area, inferior parietal lobule, and inferior frontal gyrus during the motor planning stage. Differences in beta ERD amplitude extended through the motor execution stage within the supplementary motor area and premotor cortices, and a stronger alpha ERD was detected in the anterior cingulate. Interestingly, our results also indicated that alpha and beta oscillations were weaker in the children with CP within the occipital cortices and visual MT area during movement execution. These altered alpha and beta oscillations were accompanied by slower reaction times and substantial target matching errors in the children with CP. We also identified that the strength of the alpha and beta ERDs during the motor planning and execution stages were correlated with the motor performance. Lastly, our regression analyses suggested that the beta ERD within visual areas during motor execution primarily predicted the amount of motor errors. Overall, these data suggest that uncharacteristic alpha and beta

  10. Time course of corticospinal excitability changes following a novel motor training task.

    PubMed

    Holland, Luc; Murphy, Bernadette; Passmore, Steven; Yielder, Paul

    2015-03-30

    Motor learning is known to take place over several days, and there are a number of studies investigating the time course of improvements in motor performance, yet only a limited number that have investigated the time course of neurophysiological changes that accompany motor learning. The aim of this study was to investigate the time course of changes to corticospinal excitability, following novel motor training in the dominant hand, during two sessions of motor training and testing. This study used the slope of transcranial magnetic stimulation (TMS) input-output (I/O) curves elicited at stimulator intensities between 90 and 150% of resting motor threshold for the first dorsal interosseous (FDI) muscle in order to measure corticospinal excitability. The I/O curves for 12 right-handed males (M age: 21.9+-0.5 years, [Laterality Index]=83.42 SD=4.9) were elicited before and after the performance of novel motor tracing task performed with the right hand on two different testing days. Participants had significant improvements in motor performance during both the initial (mean error improvement=31%, SD=7%, F(1, 11)=22.439 with p=0.001) and follow up session (mean error improvement=19%, SD=6%, F(1, 11)=17.85 with p=0.001). The slope of the TMS I/O curve decreased significantly over the four training blocks, F(1,11)=8.149, p=0.016, however pre-planned contrasts within the repeated measures ANOVA indicated that the decrease was only significant relative to baseline following the first day of training F(1,11)=10.476, p=0.008. This study found that corticospinal excitability measured using I/O curves decreases in response to performance of a novel motor training task, and the majority of this excitability change occurs on the first training day. Crown Copyright © 2015. Published by Elsevier Ireland Ltd. All rights reserved.

  11. Cognitive and motor aspects of a coincidence-timing task in Cerebral Palsy children.

    PubMed

    Olivier, I; Baker, C; Cordier, J; Thomann, G; Nougier, V

    2015-08-18

    Cerebral Palsy (CP) is a clinical syndrome involving postural and motor deficits. CP children are less accurate than healthy ones when trying to reach a target. Thus, it is difficult for CP children to perform anticipation-coincidence tasks requiring temporal and/or spatial accuracy to reach the target at the good place in the right time. The purpose of the present experiment was to further investigate CP children's ability to perform anticipation-coincidence tasks, by dissociating the cognitive from the motor aspects of the task. 11 CP children aged 6-14 years, 51 healthy children aged 6-13 years, and 13 healthy adults performed, as accurately as possible, a coincidence-timing in response to a specific sound of a musical sequence. Two experimental conditions were manipulated: In the verbal condition, temporal estimation occurred through a simple verbal response whereas in the motor condition, temporal estimation was performed by reaching a target at a self-paced velocity. In the verbal condition, CP children made similar temporal errors than their healthy counterpart. However, even though all participants underestimated stimulus occurrence, CP children also exhibited greater and more variable temporal errors when they provided a motor response for estimating stimulus occurrence. These data suggested that CP children were able to anticipate stimulus occurrence and to partially take into account their sensory-motor deficits to reach the target at this time occurrence.

  12. Objective assessment of mandibular motor control using a 'reach-and-hold' task.

    PubMed

    Roatta, Silvestro; Rolando, M; Notaro, V; Testa, M; Bassi, F; Passatore, M

    2011-10-01

    Mandibular motor function is well known to be impaired in the presence of temporomandibular disorders. However, while a vast literature is available concerning accuracy of motor control in limbs, quantitative and objective assessment of mandibular motor control has been seldom performed, also because of the lack of adequate investigative tools. Aim of this work is to present a technique for reliable evaluation of the motor performance of the mandible based on a kinesiography-monitored reach-and-hold task. Nineteen healthy subjects were engaged in a task in which they had to drive a cursor on a screen by corresponding movements of the mandible in the frontal plane and reach 30 random targets sequentially displayed on the screen. The whole task was repeated three times per session in two different days. The individual performance was assessed by different indices evaluating precision and steadiness of target matching. The performance progressively improved in the three trials of the first session, further improved and stabilised in the second session, with an average positioning error of 0·59 ± 038 mm and was slightly correlated with the horizontal dimension of the mandible border movement (r = 0·55). Intraclass correlation coefficient ranged between 0·76 and 0·94 for the different indices indicating good repeatability. The kinesiographic technique allowed for objective and reliable assessment of the voluntary control of the mandible position. Its potential applications include support to the characterisation of temporomandibular disorders and to motor training and progress monitoring in rehabilitation treatments.

  13. Is There an Interaction between Task Complexity and Practice Variability in Speech-Motor learning?

    PubMed

    Kaipa, Ramesh

    2016-09-01

    Prior studies have investigated the influence of principles of motor learning (PMLs) on speech-motor learning. However, the interactive effect of different PMLs on speech-motor learning remains unknown. This study is aimed at investigating the interaction of 2 PMLs, that is, practice variability and task complexity and their influence on speech-motor learning. Forty healthy individuals (aged 18-30 years) were randomly and equally allocated to 2 groups where they had to either practice a simple (simple group) or a complex phrase (complex group). Two levels of practice variability (constant and variable) were considered in training participants in simple and complex groups. Participants practiced 50 practice trials of either complex or simple phrase during the first 2 days. At the end of training on each day, participants produced 10 trials of the phrase they practiced without feedback. On the third day, participants returned for a delayed retention test. The participant utterances on all the 3 days were recorded for later analysis. Data analysis revealed that there was no major effect of practice condition, and there was no interaction of task complexity and practice condition. However, there was an interaction between data collection points and complexity. The findings suggest that irrespective of the complexity of the to-be-learned speech task, there is no preponderance of variable over constant practice, which contradicts the findings of the non-speech-motor learning literature.

  14. Is There an Interaction between Task Complexity and Practice Variability in Speech-Motor learning?

    PubMed Central

    Kaipa, Ramesh

    2016-01-01

    Background Prior studies have investigated the influence of principles of motor learning (PMLs) on speech-motor learning. However, the interactive effect of different PMLs on speech-motor learning remains unknown. Purpose This study is aimed at investigating the interaction of 2 PMLs, that is, practice variability and task complexity and their influence on speech-motor learning. Method Forty healthy individuals (aged 18-30 years) were randomly and equally allocated to 2 groups where they had to either practice a simple (simple group) or a complex phrase (complex group). Two levels of practice variability (constant and variable) were considered in training participants in simple and complex groups. Participants practiced 50 practice trials of either complex or simple phrase during the first 2 days. At the end of training on each day, participants produced 10 trials of the phrase they practiced without feedback. On the third day, participants returned for a delayed retention test. The participant utterances on all the 3 days were recorded for later analysis. Results Data analysis revealed that there was no major effect of practice condition, and there was no interaction of task complexity and practice condition. However, there was an interaction between data collection points and complexity. Conclusion The findings suggest that irrespective of the complexity of the to-be-learned speech task, there is no preponderance of variable over constant practice, which contradicts the findings of the non-speech-motor learning literature. PMID:27721581

  15. Studying Mathematics Teacher Education: Analysing the Process of Task Variation on Learning

    ERIC Educational Resources Information Center

    Bragg, Leicha A.

    2015-01-01

    Self-study of variations to task design offers a way of analysing how learning takes place. Over several years, variations were made to improve an assessment task completed by final-year teacher candidates in a primary mathematics teacher education subject. This article describes how alterations to a task informed on-going developments in…

  16. Studying Mathematics Teacher Education: Analysing the Process of Task Variation on Learning

    ERIC Educational Resources Information Center

    Bragg, Leicha A.

    2015-01-01

    Self-study of variations to task design offers a way of analysing how learning takes place. Over several years, variations were made to improve an assessment task completed by final-year teacher candidates in a primary mathematics teacher education subject. This article describes how alterations to a task informed on-going developments in…

  17. Dramatic Effects of Speech Task on Motor and Linguistic Planning in Severely Dysfluent Parkinsonian Speech

    ERIC Educational Resources Information Center

    Van Lancker Sidtis, Diana; Cameron, Krista; Sidtis, John J.

    2012-01-01

    In motor speech disorders, dysarthric features impacting intelligibility, articulation, fluency and voice emerge more saliently in conversation than in repetition, reading or singing. A role of the basal ganglia in these task discrepancies has been identified. Further, more recent studies of naturalistic speech in basal ganglia dysfunction have…

  18. Dramatic Effects of Speech Task on Motor and Linguistic Planning in Severely Dysfluent Parkinsonian Speech

    ERIC Educational Resources Information Center

    Van Lancker Sidtis, Diana; Cameron, Krista; Sidtis, John J.

    2012-01-01

    In motor speech disorders, dysarthric features impacting intelligibility, articulation, fluency and voice emerge more saliently in conversation than in repetition, reading or singing. A role of the basal ganglia in these task discrepancies has been identified. Further, more recent studies of naturalistic speech in basal ganglia dysfunction have…

  19. The relationship of morphology and motor abilities to specific table tennis tasks in youngsters.

    PubMed

    Nikolić, Ivana; Nikolić, Ivana; Furjan-Mandić, Gordana; Kondric, Miran

    2014-03-01

    The aim of this research was to establish the relationship of certain basic motor abilities and morphological characteristics and efficacy in specific table tennis tasks. The research sample consisted of cadet category table tennis players (N = 101; aged 10.52 +/- 0.78 years, training experience 2.8 +/- 0.93 years). The participants were measured as they performed 24 motor tasks, along with 15 anthropometric measures and 3 specific table tennis tests. Indicators of the relationship between morphological characteristics and motor abilities, coupled with the results of the specific table tennis tests indicate that: a) subcutaneous fatty tissue on the lower extremities significantly limits the test results where movements involving fast changes in direction are required; b) subcutaneous abdominal adipose tissues have a positive influence on tasks demanding controlled and precise alternate bouncing of the ball; c) in general, a positive influence can be seen in the results of specific tests concerning the following motor abilities: arm coordination, agility, explosive arm power, movement frequency speed and repetitive leg power. The test used for a coordination assessment of the whole body revealed a negative influence on the success of performing specific tasks.

  20. Selective Influence of Circadian Modulation and Task Characteristics on Motor Imagery Time

    ERIC Educational Resources Information Center

    Debarnot, Ursula; Sahraoui, Djafar; Champely, Stephane; Collet, Christian; Guillot, Aymeric

    2012-01-01

    In this study, we examined the effect of circadian modulation on motor imagery (MI) time while also considering the effects of task complexity and duration. The ability to imagine in real time was influenced by circadian modulation in a simple walking condition, with longer MI times in the morning and evening sessions. By contrast, there was no…

  1. Park Play: a picture description task for assessing childhood motor speech disorders.

    PubMed

    Patel, Rupal; Connaghan, Kathryn

    2014-08-01

    The purpose of this study was to develop a picture description task for eliciting connected speech from children with motor speech disorders. The Park Play scene is a child-friendly picture description task aimed at augmenting current assessment protocols for childhood motor speech disorders. The design process included a literature review to: (1) establish optimal design features for child assessment, (2) identify a set of evidence-based speech targets specifically tailored to tax the motor speech system, and (3) enhance current assessment tools. To establish proof of concept, five children (ages 4;3-11;1) with dysarthria or childhood apraxia of speech were audio-recorded while describing the Park Play scene. Feedback from the feasibility test informed iterative design modifications. Descriptive, segmental, and prosodic analyses revealed the task was effective in eliciting desired targets in a connected speech sample, thereby yielding additional information beyond the syllables, words, and sentences generally elicited through imitation during the traditional motor speech examination. Further discussion includes approaches to adapt the task for a variety of clinical needs.

  2. Effects of Success/Failure and Extrinsic Rewards on Intrinsic Motivation Using a Competitive Motor Task.

    ERIC Educational Resources Information Center

    McCaughan, Lindsay R.; McKinlay, Sue

    1981-01-01

    Female high school students participated in a motor task to assess the effects of success/failure feedback and extrinsic rewards on intrinsic motivation. It was found that a significant change in intrinsic motivation was due to the effects of success/failure feedback, but not to the effect of a tangible reward. (Authors/FG)

  3. Spontaneous Gestures during Mental Rotation Tasks: Insights into the Microdevelopment of the Motor Strategy

    ERIC Educational Resources Information Center

    Chu, Mingyuan; Kita, Sotaro

    2008-01-01

    This study investigated the motor strategy involved in mental rotation tasks by examining 2 types of spontaneous gestures (hand-object interaction gestures, representing the agentive hand action on an object, vs. object-movement gestures, representing the movement of an object by itself) and different types of verbal descriptions of rotation.…

  4. Search for Autonomy in Motor Task Learning in Physical Education University Students

    ERIC Educational Resources Information Center

    Moreno Murcia, Juan Antonio; Lacarcel, Jose Antonio Vera; Del Villar Alvarez, Fernando

    2010-01-01

    The study focused on discovering the influence that an autonomous motor task learning programme had on the improvement of perceived competence, intrinsic regulation, incremental belief and motivational orientations. The study was performed with two groups of participants (n = 22 and n = 20) aged between 19 and 35 years. The instruments used were…

  5. Impaired Inhibition of Prepotent Motor Tendencies in Friedreich Ataxia Demonstrated by the Simon Interference Task

    ERIC Educational Resources Information Center

    Corben, L. A.; Akhlaghi, H.; Georgiou-Karistianis, N.; Bradshaw, J. L.; Egan, G. F.; Storey, E.; Churchyard, A. J.; Delatycki, M. B.

    2011-01-01

    Friedreich ataxia (FRDA) is the most common of the genetically inherited ataxias. We recently demonstrated that people with FRDA have impairment in motor planning--most likely because of pathology affecting the cerebral cortex and/or cerebello-cortical projections. We used the Simon interference task to examine how effective 13 individuals with…

  6. Short Term Auditory Pacing Changes Dual Motor Task Coordination in Children with and without Dyslexia

    ERIC Educational Resources Information Center

    Getchell, Nancy; Mackenzie, Samuel J.; Marmon, Adam R.

    2010-01-01

    This study examined the effect of short-term auditory pacing practice on dual motor task performance in children with and without dyslexia. Groups included dyslexic with Movement Assessment Battery for Children (MABC) scores greater than 15th percentile (D_HIGH, n = 18; mean age 9.89 [plus or minus] 2.0 years), dyslexic with MABC [less than or…

  7. Selective Influence of Circadian Modulation and Task Characteristics on Motor Imagery Time

    ERIC Educational Resources Information Center

    Debarnot, Ursula; Sahraoui, Djafar; Champely, Stephane; Collet, Christian; Guillot, Aymeric

    2012-01-01

    In this study, we examined the effect of circadian modulation on motor imagery (MI) time while also considering the effects of task complexity and duration. The ability to imagine in real time was influenced by circadian modulation in a simple walking condition, with longer MI times in the morning and evening sessions. By contrast, there was no…

  8. Effects of Success/Failure and Extrinsic Rewards on Intrinsic Motivation Using a Competitive Motor Task.

    ERIC Educational Resources Information Center

    McCaughan, Lindsay R.; McKinlay, Sue

    1981-01-01

    Female high school students participated in a motor task to assess the effects of success/failure feedback and extrinsic rewards on intrinsic motivation. It was found that a significant change in intrinsic motivation was due to the effects of success/failure feedback, but not to the effect of a tangible reward. (Authors/FG)

  9. Impaired Inhibition of Prepotent Motor Tendencies in Friedreich Ataxia Demonstrated by the Simon Interference Task

    ERIC Educational Resources Information Center

    Corben, L. A.; Akhlaghi, H.; Georgiou-Karistianis, N.; Bradshaw, J. L.; Egan, G. F.; Storey, E.; Churchyard, A. J.; Delatycki, M. B.

    2011-01-01

    Friedreich ataxia (FRDA) is the most common of the genetically inherited ataxias. We recently demonstrated that people with FRDA have impairment in motor planning--most likely because of pathology affecting the cerebral cortex and/or cerebello-cortical projections. We used the Simon interference task to examine how effective 13 individuals with…

  10. Short Term Auditory Pacing Changes Dual Motor Task Coordination in Children with and without Dyslexia

    ERIC Educational Resources Information Center

    Getchell, Nancy; Mackenzie, Samuel J.; Marmon, Adam R.

    2010-01-01

    This study examined the effect of short-term auditory pacing practice on dual motor task performance in children with and without dyslexia. Groups included dyslexic with Movement Assessment Battery for Children (MABC) scores greater than 15th percentile (D_HIGH, n = 18; mean age 9.89 [plus or minus] 2.0 years), dyslexic with MABC [less than or…

  11. Responding to a Challenging Perceptual-Motor Task as a Function of Level of Experiential Avoidance

    ERIC Educational Resources Information Center

    Zettle, Robert D.; Petersen, Connie L.; Hocker, Tanya R.; Provines, Jessica L.

    2007-01-01

    Participants displaying high versus low levels of experiential avoidance as assessed by the Acceptance and Action Questionnaire (Hayes, Strosahl, et al., 2004) were compared in their reactions to and performance on a challenging perceptual-motor task. Participants were offered incentives for sorting colored straws into different colored containers…

  12. Responding to a Challenging Perceptual-Motor Task as a Function of Level of Experiential Avoidance

    ERIC Educational Resources Information Center

    Zettle, Robert D.; Petersen, Connie L.; Hocker, Tanya R.; Provines, Jessica L.

    2007-01-01

    Participants displaying high versus low levels of experiential avoidance as assessed by the Acceptance and Action Questionnaire (Hayes, Strosahl, et al., 2004) were compared in their reactions to and performance on a challenging perceptual-motor task. Participants were offered incentives for sorting colored straws into different colored containers…

  13. Search for Autonomy in Motor Task Learning in Physical Education University Students

    ERIC Educational Resources Information Center

    Moreno Murcia, Juan Antonio; Lacarcel, Jose Antonio Vera; Del Villar Alvarez, Fernando

    2010-01-01

    The study focused on discovering the influence that an autonomous motor task learning programme had on the improvement of perceived competence, intrinsic regulation, incremental belief and motivational orientations. The study was performed with two groups of participants (n = 22 and n = 20) aged between 19 and 35 years. The instruments used were…

  14. Somatosensory evoked potentials show plastic changes following a novel motor training task with the thumb.

    PubMed

    Andrew, D; Haavik, H; Dancey, E; Yielder, P; Murphy, B

    2015-03-01

    Accumulating evidence indicates that plastic changes can be maladaptive in nature, resulting in movement and neurological disorders. The aim of this study was to further the understanding of these neurophysiological changes in sensorimotor integration (SMI) using somatosensory evoked potentials (SEPs) and concurrent performance changes following a repetitive typing task. SEPs were recorded following median nerve stimulation at the wrist and performed pre and post intervention. 24 participants were randomly assigned to either an intervention group which performed a 20min repetitive typing task or a control group which participated in a 20min period of mental recitation. The P22-N24 amplitude increased by 59.6%, compared to only 0.96% increase following the control. The P22-N30 SEP peak amplitude increased on average 13.4% following the motor training, compared to only 0.92% following the control. Significant improvement in reaction time when comparing performance of the motor task for the intervention group was observed. The N24 increase supports the involvement of cerebellar connections and the N30 increase provides further support for changes in SMI following motor learning. Combining motor training tasks with electrophysiological techniques gives insight into the mechanisms of disordered SMI and whether the changes are adaptive or maladaptive. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  15. Hemodynamic changes in cortical sensorimotor systems following hand and orofacial motor tasks and pulsed pneumotactile stimulation.

    PubMed

    Rosner, Austin O; Barlow, Steven M

    We performed a functional near-infrared spectroscopy (fNIRS) study of the evoked hemodynamic responses seen in hand and face sensorimotor cortical representations during (1) active motor tasks and (2) pulsed pneumotactile stimulation. Contralateral fNIRS measurements were performed on 22 healthy adult participants using a block paradigm that consisted of repetitive right hand and right oral angle somatosensory stimulation using a pulsed pneumotactile array stimulator, and repetitive right-hand grip compression and bilabial compressions on strain gages. Results revealed significant oxyhemoglobin (HbO) modulation across stimulus conditions in corresponding somatotopic cortical regions. Of the 22 participants, 86% exhibited a decreased HbO response during at least one of the stimulus conditions, which may be indicative of cortical steal, or hypo-oxygenation occurring in channels adjacent to the primary areas of activation. Across all conditions, 56% of participants' HbO responses were positive and 44% were negative. Hemodynamic responses most likely differed across hand and face motor and somatosensory cortical regions due to differences in regional arterial/venous anatomy, cortical vascular beds, extent and orientation of somatotopy, task dynamics, and mechanoreceptor typing in hand and face. The combination of optical imaging and task conditions allowed for non-invasive examination of hemodynamic changes in somatosensory and motor cortices using natural, pneumatic stimulation of glabrous hand and hairy skin of the lower face and functionally relevant and measurable motor tasks involving the same structures.

  16. Motor Learning of a Bimanual Task in Children with Unilateral Cerebral Palsy

    ERIC Educational Resources Information Center

    Hung, Ya-Ching; Gordon, Andrew M.

    2013-01-01

    Children with unilateral cerebral palsy (CP) have been shown to improve their motor performance with sufficient practice. However, little is known about how they learn goal-oriented tasks. In the current study, 21 children with unilateral CP (age 4-10 years old) and 21 age-matched typically developed children (TDC) practiced a simple bimanual…

  17. Effects of Two Practice Style Formats on Fifth Grade Students' Motor Skill Performance and Task Engagement

    ERIC Educational Resources Information Center

    Chatoupis, Constantine C.; Vagenas, George

    2017-01-01

    We investigated the effectiveness of two teaching formats that fall under the canopy of Mosston and Ashworth's (2008) practice style, on fifth grade students' motor skill performance and task engagement. Both formats are also known as station teaching or learning centers. In the teacher-rotated format (TR), the teacher decides the amount of time…

  18. Motor Learning of a Bimanual Task in Children with Unilateral Cerebral Palsy

    ERIC Educational Resources Information Center

    Hung, Ya-Ching; Gordon, Andrew M.

    2013-01-01

    Children with unilateral cerebral palsy (CP) have been shown to improve their motor performance with sufficient practice. However, little is known about how they learn goal-oriented tasks. In the current study, 21 children with unilateral CP (age 4-10 years old) and 21 age-matched typically developed children (TDC) practiced a simple bimanual…

  19. Using the Hand Laterality Judgement Task to Assess Motor Imagery: A Study of Practice Effects in Repeated Measurements

    ERIC Educational Resources Information Center

    Boonstra, Anne M.; de Vries, Sjoerd J.; Veenstra, Evelien; Tepper, Marga; Feenstra, Wya; Otten, Egbert

    2012-01-01

    The aim of this study was to determine whether there is a practice effect on the Hand Laterality Judgement Task (HLJT). The HLJT task is a mental rotation task that can be used to assess motor imagery ability in stroke patients. Thirty-three healthy individuals performed the HLJT and two control tasks twice at a 3-week interval. Differences in the…

  20. Using the Hand Laterality Judgement Task to Assess Motor Imagery: A Study of Practice Effects in Repeated Measurements

    ERIC Educational Resources Information Center

    Boonstra, Anne M.; de Vries, Sjoerd J.; Veenstra, Evelien; Tepper, Marga; Feenstra, Wya; Otten, Egbert

    2012-01-01

    The aim of this study was to determine whether there is a practice effect on the Hand Laterality Judgement Task (HLJT). The HLJT task is a mental rotation task that can be used to assess motor imagery ability in stroke patients. Thirty-three healthy individuals performed the HLJT and two control tasks twice at a 3-week interval. Differences in the…

  1. Selective influence of circadian modulation and task characteristics on motor imagery time.

    PubMed

    Debarnot, Ursula; Sahraoui, Djafar; Champely, Stéphane; Collet, Christian; Guillot, Aymeric

    2012-09-01

    In this study, we examined the effect of circadian modulation on motor imagery (MI) time while also considering the effects of task complexity and duration. The ability to imagine in real time was influenced by circadian modulation in a simple walking condition, with longer MI times in the morning and evening sessions. By contrast, there was no effect of circadian rhythm in the complex, short or long walking conditions. We concluded that motor imagery time is modulated during the course of the day, but the effect of task difficulty is stronger than circadian modulation in altering the temporal congruence between physical practice and MI performance. Practical applications in motor learning and rehabilitation are discussed.

  2. The effects of a concurrent motor task on walking in Alzheimer's disease.

    PubMed

    Wittwer, Joanne E; Webster, Kate E; Hill, Keith

    2014-01-01

    The important relationship between cognition and gait in people with dementia has been explored with dual-task studies using added cognitive tasks. Effects of less commonly studied but also attention-dividing motor dual-tasks are important to assess in this group as they are common in everyday function and may affect gait differently from cognitive dual-tasks. They may also be easier to comprehend allowing their application with more severe cognitive impairment. The aim of this study was to evaluate the effects and feasibility of a motor dual-task (MDT) on gait measures in people with Alzheimer's disease (AD). Thirty people (15 men, mean age ± SD, 80.2 ± 5.8 years) with a diagnosis of probable AD (MMSE range 8-28) walked on an electronic walkway (i) at self-selected comfortable pace and (ii) at self-selected comfortable pace while carrying a tray and glasses. The MDT produced significant decreases in velocity (Baseline=111.5 ± 26.5 cm/s, MDT=96.8 ± 25.7 cm/s, p<0.001) and stride length (Baseline=121.4 ± 21.6 cm, MDT=108.1 ± 21.0 cm, p<0.001) with medium effect sizes, and increased stride time (Baseline=1.11 ± 0.11s, MDT=1.14 ± 0.12s, p=0.001) with small effect size. Measures of spatial (Baseline=3.2 ± 1.0%, MDT=3.9 ± 1.5%, p=0.006) and temporal (Baseline=2.4 ± 0.8%, MDT=2.8 ± 0.8%, p=0.008) variability increased with the motor dual-task, with medium effect sizes. A trend for motor dual-task changes in gait measures to increase with greater disease severity did not reach significance. The tray-carrying task was feasible, even for participants with severe cognitive decline. Further comparison of different types of motor and cognitive dual-tasks may contribute to development of a framework for clinical intervention to improve reduced dual-task walking capacity in people with AD.

  3. The impact of a concurrent motor task on auditory and visual temporal discrimination tasks.

    PubMed

    Mioni, Giovanna; Grassi, Massimo; Tarantino, Vincenza; Stablum, Franca; Grondin, Simon; Bisiacchi, Patrizia S

    2016-04-01

    Previous studies have shown the presence of an interference effect on temporal perception when participants are required to simultaneously execute a nontemporal task. Such interference likely has an attentional source. In the present work, a temporal discrimination task was performed alone or together with a self-paced finger-tapping task used as concurrent, nontemporal task. Temporal durations were presented in either the visual or the auditory modality, and two standard durations (500 and 1,500 ms) were used. For each experimental condition, the participant's threshold was estimated and analyzed. The mean Weber fraction was higher in the visual than in the auditory modality, but only for the subsecond duration, and it was higher with the 500-ms than with the 1,500-ms standard duration. Interestingly, the Weber fraction was significantly higher in the dual-task condition, but only in the visual modality. The results suggest that the processing of time in the auditory modality is likely automatic, but not in the visual modality.

  4. Automatic motor task selection via a bandit algorithm for a brain-controlled button.

    PubMed

    Fruitet, Joan; Carpentier, Alexandra; Munos, Rémi; Clerc, Maureen

    2013-02-01

    Brain-computer interfaces (BCIs) based on sensorimotor rhythms use a variety of motor tasks, such as imagining moving the right or left hand, the feet or the tongue. Finding the tasks that yield best performance, specifically to each user, is a time-consuming preliminary phase to a BCI experiment. This study presents a new adaptive procedure to automatically select (online) the most promising motor task for an asynchronous brain-controlled button. We develop for this purpose an adaptive algorithm UCB-classif based on the stochastic bandit theory and design an EEG experiment to test our method. We compare (offline) the adaptive algorithm to a naïve selection strategy which uses uniformly distributed samples from each task. We also run the adaptive algorithm online to fully validate the approach. By not wasting time on inefficient tasks, and focusing on the most promising ones, this algorithm results in a faster task selection and a more efficient use of the BCI training session. More precisely, the offline analysis reveals that the use of this algorithm can reduce the time needed to select the most appropriate task by almost half without loss in precision, or alternatively, allow us to investigate twice the number of tasks within a similar time span. Online tests confirm that the method leads to an optimal task selection. This study is the first one to optimize the task selection phase by an adaptive procedure. By increasing the number of tasks that can be tested in a given time span, the proposed method could contribute to reducing 'BCI illiteracy'.

  5. Automatic motor task selection via a bandit algorithm for a brain-controlled button

    NASA Astrophysics Data System (ADS)

    Fruitet, Joan; Carpentier, Alexandra; Munos, Rémi; Clerc, Maureen

    2013-02-01

    Objective. Brain-computer interfaces (BCIs) based on sensorimotor rhythms use a variety of motor tasks, such as imagining moving the right or left hand, the feet or the tongue. Finding the tasks that yield best performance, specifically to each user, is a time-consuming preliminary phase to a BCI experiment. This study presents a new adaptive procedure to automatically select (online) the most promising motor task for an asynchronous brain-controlled button. Approach. We develop for this purpose an adaptive algorithm UCB-classif based on the stochastic bandit theory and design an EEG experiment to test our method. We compare (offline) the adaptive algorithm to a naïve selection strategy which uses uniformly distributed samples from each task. We also run the adaptive algorithm online to fully validate the approach. Main results. By not wasting time on inefficient tasks, and focusing on the most promising ones, this algorithm results in a faster task selection and a more efficient use of the BCI training session. More precisely, the offline analysis reveals that the use of this algorithm can reduce the time needed to select the most appropriate task by almost half without loss in precision, or alternatively, allow us to investigate twice the number of tasks within a similar time span. Online tests confirm that the method leads to an optimal task selection. Significance. This study is the first one to optimize the task selection phase by an adaptive procedure. By increasing the number of tasks that can be tested in a given time span, the proposed method could contribute to reducing ‘BCI illiteracy’.

  6. Transcranial direct current stimulation over multiple days enhances motor performance of a grip task.

    PubMed

    Fan, Julie; Voisin, Julien; Milot, Marie-Hélène; Higgins, Johanne; Boudrias, Marie-Hélène

    2017-09-01

    Recovery of handgrip is critical after stroke since it is positively related to upper limb function. To boost motor recovery, transcranial direct current stimulation (tDCS) is a promising, non-invasive brain stimulation technique for the rehabilitation of persons with stroke. When applied over the primary motor cortex (M1), tDCS has been shown to modulate neural processes involved in motor learning. However, no studies have looked at the impact of tDCS on the learning of a grip task in both stroke and healthy individuals. To assess the use of tDCS over multiple days to promote motor learning of a grip task using a learning paradigm involving a speed-accuracy tradeoff in healthy individuals. In a double-blinded experiment, 30 right-handed subjects (mean age: 22.1±3.3 years) participated in the study and were randomly assigned to an anodal (n=15) or sham (n=15) stimulation group. First, subjects performed the grip task with their dominant hand while following the pace of a metronome. Afterwards, subjects trained on the task, at their own pace, over 5 consecutive days while receiving sham or anodal tDCS over M1. After training, subjects performed de novo the metronome-assisted task. The change in performance between the pre and post metronome-assisted task was used to assess the impact of the grip task and tDCS on learning. Anodal tDCS over M1 had a significant effect on the speed-accuracy tradeoff function. The anodal tDCS group showed significantly greater improvement in performance (39.28±15.92%) than the sham tDCS group (24.06±16.35%) on the metronome-assisted task, t(28)=2.583, P=0.015 (effect size d=0.94). Anodal tDCS is effective in promoting grip motor learning in healthy individuals. Further studies are warranted to test its potential use for the rehabilitation of fine motor skills in stroke patients. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  7. Real-time changes in corticospinal excitability related to motor imagery of a force control task.

    PubMed

    Tatemoto, Tsuyoshi; Tsuchiya, Junko; Numata, Atsuki; Osawa, Ryuji; Yamaguchi, Tomofumi; Tanabe, Shigeo; Kondo, Kunitsugu; Otaka, Yohei; Sugawara, Kenichi

    2017-09-29

    To investigate real-time excitability changes in corticospinal pathways related to motor imagery in a changing force control task, using transcranial magnetic stimulation (TMS). Ten healthy volunteers learnt to control the contractile force of isometric right wrist dorsiflexion in order to track an on-screen sine wave form. Participants performed the trained task 40 times with actual muscle contraction in order to construct the motor image. They were then instructed to execute the task without actual muscle contraction, but by imagining contraction of the right wrist in dorsiflexion. Motor evoked potentials (MEPs), induced by TMS in the right extensor carpi radialis muscle (ECR) and flexor carpi radialis muscle (FCR), were measured during motor imagery. MEPs were induced at five time points: prior to imagery, during the gradual generation of the imaged wrist dorsiflexion (Increasing phase), the peak value of the sine wave, during the gradual reduction (Decreasing phase), and after completion of the task. The MEP ratio, as the ratio of imaged MEPs to resting-state, was compared between pre- and post-training at each time point. In the ECR muscle, the MEP ratio significantly increased during the Increasing phase and at the peak force of dorsiflexion imagery after training. Moreover, the MEP ratio was significantly greater in the Increasing phase than in the Decreasing phase. In the FCR, there were no significant consistent changes. Corticospinal excitability during motor imagery in an isometric contraction task was modulated in relation to the phase of force control after image construction. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Task-specific impairment of motor cortical excitation and inhibition in patients with writer's cramp.

    PubMed

    Tinazzi, Michele; Farina, Simona; Edwards, Mark; Moretto, Giuseppe; Restivo, Domenico; Fiaschi, Antonio; Berardelli, Alfredo

    2005-04-11

    Abnormalities in motor cortical excitation and inhibition have been reported in patients with writer's cramp, at rest and during muscle activation. We were interested in whether such abnormalities might be task-specific and depended on the type of movement task used to activate the dystonic hand. We therefore assessed motor-evoked potentials (facilitation/rest MEP amplitude ratio) and duration of the cortical silent period (CSP) from the right first dorsal interosseus (FDI) muscle to transcranial magnetic stimulation (TMS) in 10 patients with writer's cramp and in 10 healthy volunteers performing pincer and power gripping tasks. The mean facilitation/rest MEP amplitude ratio measured during the pincer grip task was significantly larger in dystonic subjects than in controls, but in the power grip condition was similar in the two groups. The CSP measured in the power grip condition was of similar length in normal controls and dystonic subjects, but in the pincer grip condition was significantly shorter in patients than in controls. These results indicate a task-specific impairment of motor cortical excitation and inhibition in writer's cramp.

  9. Implementation of specific motor expertise during a mental rotation task of hands.

    PubMed

    Habacha, Hamdi; Molinaro, Corinne; Tabben, Montassar; Lejeune-Poutrain, Laure

    2014-11-01

    Mental rotation of the hands classically induces kinesthetic effects according to the direction of the rotation, with faster response times to the hands' medial rotations compared with lateral rotations, and is thus commonly used to induce engagement in motor imagery (MI). In the present study, we compared the performances of table tennis players (experts on hand movements), who commonly execute and observe fast hand movements, to those of soccer players (non-experts on hand movements) on a mental rotation task of hands. Our results showed a significant effect of the direction of rotation (DOR) confirming the engagement of the participants in MI. In addition, only hand movement experts were faster when the task figures corresponded to their dominant hand compared with the non-dominant hand, revealing a selective effect of motor expertise. Interestingly, the effect of the DOR collapsed in hand movement experts only when the task figures corresponded to their dominant hand, but it is noteworthy that lateral and medial rotations of the right-hand stimuli were not faster than medial rotations of the left-hand stimuli. These results are discussed in relation to possible strategies during the task. Overall, the present study highlights the embodied nature of the mental rotation task of hands by revealing selective effects of motor expertise.

  10. The Effect of Self-Regulated and Experimenter-Imposed Practice Schedules on Motor Learning for Tasks of Varying Difficulty

    ERIC Educational Resources Information Center

    Keetch, Katherine M.; Lee, Timothy D.

    2007-01-01

    Research suggests that allowing individuals to control their own practice schedule has a positive effect on motor learning. In this experiment we examined the effect of task difficulty and self-regulated practice strategies on motor learning. The task was to move a mouse-operated cursor through pattern arrays that differed in two levels of…

  11. Effect of visual feedback on brain activation during motor tasks: An fMRI study

    PubMed Central

    Noble, Jeremy W.; Eng, Janice J.; Boyd, Lara A.

    2015-01-01

    This study examined the effect of visual feedback and force level on the neural mechanisms responsible for the performance of a motor task. We used a voxel-wise fMRI approach to determine the effect of visual feedback (with and without) during a grip force task at 35% and 70% of maximum voluntary contraction. Two areas (contralateral rostral premotor cortex and putamen) displayed an interaction between force and feedback conditions. When the main effect of feedback condition was analyzed, higher activation when visual feedback was available was found in 22 of the 24 active brain areas, while the two other regions (contralateral lingual gyrus and ipsilateral precuneus) showed greater levels of activity when no visual feedback was available. The results suggest that there is a potentially confounding influence of visual feedback on brain activation during a motor task, and for some regions, this is dependent on the level of force applied. PMID:23761430

  12. Neural correlates of dual-task practice benefit on motor learning: a repetitive transcranial magnetic stimulation study.

    PubMed

    Goh, Hui-Ting; Lee, Ya-Yun; Fisher, Beth E

    2013-06-01

    Dual-task practice has been previously shown to enhance motor learning when both primary and secondary tasks engage similar cognitive processes. In the present study, participants practiced a finger sequence task with the non-dominant hand under a single-task condition (i.e. without a probe task) or a dual-task condition in which a probe choice reaction time (CRT) task was presented during the preparation phase (before movement onset) of the finger task. It was hypothesised that by engaging similar 'planning' processes, the dual-task condition may facilitate the activation of shared 'planning' circuitry that includes dorsal premotor cortex (dPM), an important neural substrate for CRT task performance and movement preparation. Repetitive transcranial magnetic stimulation (rTMS; 1 Hz) was applied to the contralateral dPM immediately following practice. Motor learning was assessed by a retention test conducted ~ 24 h after practice. Consistent with our previous results, the dual-task condition enhanced learning compared with the single-task condition. rTMS applied to dPM attenuated the dual-task practice benefit on motor learning. In contrast, rTMS to M1 did not attenuate the dual-task practice benefit, suggesting the rTMS effect was specific to dPM. Our findings suggest a unique role of dPM in mediating the dual-task practice effect on motor learning. © 2013 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  13. The ecological approach to cognitive–motor dual-tasking: findings on the effects of expertise and age

    PubMed Central

    Schaefer, Sabine

    2014-01-01

    The underlying assumption of studies on cognitive–motor dual-tasking is that resources are limited, and when they have to be shared between a cognitive and a motor task, performances will suffer. Resource competition should therefore be particularly pronounced in children, older adults, or people who are just acquiring a new motor skill. The current review summarizes expertise and age comparative studies that have combined a cognitive and a motor task. Expertise studies have often assessed sports performances (e.g., golf putting, soccer dribbling, rugby drills) and have shown that experts are more successful than novices to keep up their performances in dual-task situations. The review also presents age-comparative studies that have used walking (on narrow tracks or on a treadmill) as the motor task. Older adults often show higher costs than young adults, and they tend to prioritize the motor domain. These findings are discussed in relation to the ecological approach to dual-task research originally introduced by Li et al. (2005). The approach proposes to study ecologically valid dual-task situations, and always to investigate dual-task costs for both domains (cognitive and motor performance) in order to assess potential tradeoffs. In addition, task difficulties should be individually adjusted, and differential-emphasis instructions should be included in the study design. PMID:25352820

  14. Parkinson's Disease and Cognitive-Motor Dual-Task: Is Motor Prioritization Possible in the Early Stages of the Disease?

    PubMed

    Fernandes, Ângela; Sousa, Andreia S P; Rocha, Nuno; Tavares, João Manuel R S

    2016-01-01

    The authors aimed to compare the postural phase of gait initiation under single-task (gait initiation) and dual-task (gait initiation plus Stroop test) conditions in healthy subjects and in subjects with Parkinson's disease (PD) in the early stages (Hoehn and Yahr scale < 3). The postural phase of gait initiation was assessed through the centre of pressure in single and dual task in 10 healthy subjects and 9 with PD. The analysis indicated that in the early stages of PD, an additional cognitive task did not affect the displacement of the gait initiation. No significant effects occurred between the groups and within-subjects (p > .05). Also, no interaction was found between the groups and the conditions (single- and dual-task). Differences were found in the duration of the mediolateral postural phase (p = .003), which was higher in PD subjects than in healthy subjects. The findings suggest that subjects in the early stages of PD prioritize gait initiation, as their motor performance was similar to that of healthy subjects.

  15. Differences in Visuo-Motor Control in Skilled vs. Novice Martial Arts Athletes during Sustained and Transient Attention Tasks: A Motor-Related Cortical Potential Study

    PubMed Central

    Sanchez-Lopez, Javier; Fernandez, Thalia; Silva-Pereyra, Juan; Martinez Mesa, Juan A.; Di Russo, Francesco

    2014-01-01

    Cognitive and motor processes are essential for optimal athletic performance. Individuals trained in different skills and sports may have specialized cognitive abilities and motor strategies related to the characteristics of the activity and the effects of training and expertise. Most studies have investigated differences in motor-related cortical potential (MRCP) during self-paced tasks in athletes but not in stimulus-related tasks. The aim of the present study was to identify the differences in performance and MRCP between skilled and novice martial arts athletes during two different types of tasks: a sustained attention task and a transient attention task. Behavioral and electrophysiological data from twenty-two martial arts athletes were obtained while they performed a continuous performance task (CPT) to measure sustained attention and a cued continuous performance task (c-CPT) to measure transient attention. MRCP components were analyzed and compared between groups. Electrophysiological data in the CPT task indicated larger prefrontal positive activity and greater posterior negativity distribution prior to a motor response in the skilled athletes, while novices showed a significantly larger response-related P3 after a motor response in centro-parietal areas. A different effect occurred in the c-CPT task in which the novice athletes showed strong prefrontal positive activity before a motor response and a large response-related P3, while in skilled athletes, the prefrontal activity was absent. We propose that during the CPT, skilled athletes were able to allocate two different but related processes simultaneously according to CPT demand, which requires controlled attention and controlled motor responses. On the other hand, in the c-CPT, skilled athletes showed better cue facilitation, which permitted a major economy of resources and “automatic” or less controlled responses to relevant stimuli. In conclusion, the present data suggest that motor expertise

  16. Differences in visuo-motor control in skilled vs. novice martial arts athletes during sustained and transient attention tasks: a motor-related cortical potential study.

    PubMed

    Sanchez-Lopez, Javier; Fernandez, Thalia; Silva-Pereyra, Juan; Martinez Mesa, Juan A; Di Russo, Francesco

    2014-01-01

    Cognitive and motor processes are essential for optimal athletic performance. Individuals trained in different skills and sports may have specialized cognitive abilities and motor strategies related to the characteristics of the activity and the effects of training and expertise. Most studies have investigated differences in motor-related cortical potential (MRCP) during self-paced tasks in athletes but not in stimulus-related tasks. The aim of the present study was to identify the differences in performance and MRCP between skilled and novice martial arts athletes during two different types of tasks: a sustained attention task and a transient attention task. Behavioral and electrophysiological data from twenty-two martial arts athletes were obtained while they performed a continuous performance task (CPT) to measure sustained attention and a cued continuous performance task (c-CPT) to measure transient attention. MRCP components were analyzed and compared between groups. Electrophysiological data in the CPT task indicated larger prefrontal positive activity and greater posterior negativity distribution prior to a motor response in the skilled athletes, while novices showed a significantly larger response-related P3 after a motor response in centro-parietal areas. A different effect occurred in the c-CPT task in which the novice athletes showed strong prefrontal positive activity before a motor response and a large response-related P3, while in skilled athletes, the prefrontal activity was absent. We propose that during the CPT, skilled athletes were able to allocate two different but related processes simultaneously according to CPT demand, which requires controlled attention and controlled motor responses. On the other hand, in the c-CPT, skilled athletes showed better cue facilitation, which permitted a major economy of resources and "automatic" or less controlled responses to relevant stimuli. In conclusion, the present data suggest that motor expertise

  17. Cognitive-motor dual-task interference: A systematic review of neural correlates.

    PubMed

    Leone, Carmela; Feys, Peter; Moumdjian, Lousin; D'Amico, Emanuele; Zappia, Mario; Patti, Francesco

    2017-04-01

    Cognitive-motor interference refers to dual-tasking (DT) interference (DTi) occurring when the simultaneous performance of a cognitive and a motor task leads to a percentage change in one or both tasks. Several theories exist to explain DTi in humans: the capacity-sharing, the bottleneck and the cross-talk theories. Numerous studies investigating whether a specific brain locus is associated with cognitive-motor DTi have been conducted, but not systematically reviewed. We aimed to review the evidences on brain activity associated with the cognitive-motor DT, in order to better understand the neurological basis of the CMi. Results were reported according to the technique used to assess brain activity. Twenty-three articles met the inclusion criteria. Out of them, nine studies used functional magnetic resonance imaging to show an additive, under-additive, over- additive, or a mixed activation pattern of the brain. Seven studies used near-infrared spectroscopy, and seven neurophysiological instruments. Yet a specific DT locus in the brain cannot be concluded from the overall current literature. Future studies are warranted to overcome the shortcomings identified. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Adaptation paths to novel motor tasks are shaped by prior structure learning.

    PubMed

    Kobak, Dmitry; Mehring, Carsten

    2012-07-18

    After extensive practice with motor tasks sharing structural similarities (e.g., different dancing movements, or different sword techniques), new tasks of the same type can be learned faster. According to the recent "structure learning" hypothesis (Braun et al., 2009a), such rapid generalization of related motor skills relies on learning the dynamic and kinematic relationships shared by this set of skills. As a consequence, motor adaptation becomes constrained, effectively leading to a dimensionality reduction of the learning problem; at the same time, adaptation to tasks lying outside the structure becomes biased toward the structure. We tested these predictions by investigating how previously learned structures influence subsequent motor adaptation. Human subjects were making reaching movements in 3D virtual reality, experiencing perturbations either in the vertical or in the horizontal plane. Perturbations were either visuomotor rotations of varying angle or velocity-dependent forces of varying strength. We found that, after extensive training with both kinematic or dynamic perturbations, adaptation to unpracticed, diagonal, perturbations happened along the previously learned structure (vertical or horizontal), and resulting adaptation trajectories were curved. This effect is robust, can be observed on the single-subject level, and occurs during adaptation both within and across trials. Additionally, we demonstrate that structure learning changes involuntary visuomotor reflexes and therefore is not exclusively a high-level cognitive phenomenon.

  19. Does photoparoxysmal response in children represent provoked seizure? Evidence from simultaneous motor task during EEG.

    PubMed

    Fallah, Aria; RamachandranNair, Rajesh

    2009-02-01

    Acute cognitive changes during epileptiform discharges have been studied using computer assisted cognitive tasks. We aimed to demonstrate acute behavioral change (using a simple motor response task MRT) during photoparoxysmal response (PPR) in children below 18 years. Children performed a simple repetitive motor task during intermittent photic stimulation (IPS). All episodes of PPR not associated with obvious clinical change (as observed by the technologist or reported by the patient) were analyzed for this study. The average time interval between two successive motor responses across a PPR (test time) was compared to the average time interval between two successive motor responses during IPS not associated with PPR (control time) using Wilcoxon signed ranks test. 21 children who had PPR successfully completed the MRT. The difference between the mean durations was 0.894 s (p=0.002). More than 50% increase compared to the control time was considered a delay in MRT during PPR. 10 children showed slowing of MRT during PPR. By definition, acute behavioral change during generalized epileptiform discharges represent provoked seizures. Detecting subclinical seizures can have important safety implications in children (skiing, skating and driving) with PPR on EEG, but no clinical seizures. We recommend MRT during IPS.

  20. Measuring the cost of cognitive-motor dual tasking during walking in multiple sclerosis.

    PubMed

    Leone, Carmela; Patti, Francesco; Feys, Peter

    2015-02-01

    Purposeful, safe locomotion requires higher-level cortical processes, to meet the real-life demands of walking while performing concurrent cognitive tasks (e.g. recalling a shopping list or attending to a conversation). The assessment of walking and a secondary cognitive task under these 'dual tasking' conditions may represent a more valid outcome measure in multiple sclerosis (MS), by examining the occurrence and magnitude of the cognitive-motor interference of walking. This topical review provides a state-of-the-art overview of research into dual-tasking during walking in persons with MS, based on 14 recent papers. Studies consistently demonstrate a slowing of ambulation under dual tasking, regardless of the cognitive task demand, the stage of the disease and the disability level. The reciprocal effect of walking on the cognitive tasks was rarely assessed. We present our main findings, highlight the different factors contributing to dual-task deficits, identify methodological shortcomings and offer recommendations for constructing dual-tasking paradigms useful in clinical practice and research.

  1. How people with multiple sclerosis cope with a sustained finger motor task: A behavioural and fMRI study.

    PubMed

    Bonzano, Laura; Pardini, Matteo; Roccatagliata, Luca; Mancardi, Giovanni L; Bove, Marco

    2017-05-15

    Motor and non-motor basal ganglia (BG) circuits can help healthy subjects cope with task-induced central fatigue and re-establish motor performance after deterioration. This work aimed to assess whether patients with multiple sclerosis (MS) were able to recover motor performance after deterioration due to a demanding task and whether BG activity played a role in performance recovery in this population. Fourteen patients with MS performed a finger-tapping sequence with their right hand during three fMRI sessions: at baseline, after a demanding finger motor task (5-min sequence repetition) and after a short rest period. We observed deterioration of spatial and temporal accuracy with task repetition, as expected; after rest, temporal but not spatial accuracy recovered. Further, higher subjective fatigue was associated with increased motor performance deterioration and reduced temporal accuracy recovery. The amplitude of the BOLD signal change in the left caudate, putamen, globus pallidus, thalamus and amygdala was high at baseline and significantly reduced after the demanding task. Following rest, activity achieved values similar to the baseline in all these regions except for the amygdala. These findings suggest that patients were in a fatigue-like state since task beginning, as they showed enhanced BOLD signal change in the subcortical structures known to be recruited in healthy subjects only when coping with fatigue to recover motor performance. Abnormalities in motor and non-motor BG functions can contribute to fatigue in MS.

  2. COMMUNICATION: On variability and use of rat primary motor cortex responses in behavioral task discrimination

    NASA Astrophysics Data System (ADS)

    Jensen, Winnie; Rousche, Patrick J.

    2006-03-01

    The success of a cortical motor neuroprosthetic system will rely on the system's ability to effectively execute complex motor tasks in a changing environment. Invasive, intra-cortical electrodes have been successfully used to predict joint movement and grip force of a robotic arm/hand with a non-human primate (Chapin J K, Moxon K A, Markowitz R S and Nicolelis M A L 1999 Real-time control of a robotic arm using simultaneously recorded neurons in the motor cortex Nat. Neurosci. 2 664-70). It is well known that cortical encoding occurs with a high degree of cortical plasticity and depends on both the functional and behavioral context. Questions on the expected robustness of future motor prosthesis systems therefore still remain. The objective of the present work was to study the effect of minor changes in functional movement strategies on the M1 encoding. We compared the M1 encoding in freely moving, non-constrained animals that performed two similar behavioral tasks with the same end-goal, and investigated if these behavioral tasks could be discriminated based on the M1 recordings. The rats depressed a response paddle either with a set of restrictive bars ('WB') or without the bars ('WOB') placed in front of the paddle. The WB task required changes in the motor strategy to complete the paddle press and resulted in highly stereotyped movements, whereas in the WOB task the movement strategy was not restricted. Neural population activity was recorded from 16-channel micro-wire arrays and data up to 200 ms before a paddle hit were analyzed off-line. The analysis showed a significant neural firing difference between the two similar WB and WOB tasks, and using principal component analysis it was possible to distinguish between the two tasks with a best classification at 76.6%. While the results are dependent upon a small, randomly sampled neural population, they indicate that information about similar behavioral tasks may be extracted from M1 based on relatively few

  3. Effects of practice schedule and task specificity on the adaptive process of motor learning.

    PubMed

    Barros, João Augusto de Camargo; Tani, Go; Corrêa, Umberto Cesar

    2017-10-01

    This study investigated the effects of practice schedule and task specificity based on the perspective of adaptive process of motor learning. For this purpose, tasks with temporal and force control learning requirements were manipulated in experiments 1 and 2, respectively. Specifically, the task consisted of touching with the dominant hand the three sequential targets with specific movement time or force for each touch. Participants were children (N=120), both boys and girls, with an average age of 11.2years (SD=1.0). The design in both experiments involved four practice groups (constant, random, constant-random, and random-constant) and two phases (stabilisation and adaptation). The dependent variables included measures related to the task goal (accuracy and variability of error of the overall movement and force patterns) and movement pattern (macro- and microstructures). Results revealed a similar error of the overall patterns for all groups in both experiments and that they adapted themselves differently in terms of the macro- and microstructures of movement patterns. The study concludes that the effects of practice schedules on the adaptive process of motor learning were both general and specific to the task. That is, they were general to the task goal performance and specific regarding the movement pattern. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Motor-Cognitive Dual-Task Training in Neurologic Disorders: A Systematic Review

    PubMed Central

    Fritz, NE; Cheek, FM; Nichols-Larsen, DS

    2015-01-01

    Background and Purpose Deficits in motor-cognitive dual-tasks (e.g., walking while talking) are common in individuals with neurological conditions. This review was conducted to determine the effectiveness of motor-cognitive dual-task training (DTT) compared to usual care on mobility and cognition in individuals with neurologic disorders. Methods Databases searched were Biosis, CINAHL, ERIC, PsychInfo, EBSCO Psychological & Behavioral, PubMed, Scopus, and Web of Knowledge. Eligibility criteria were studies of adults with neurologic disorders that included DTT and outcomes of gait or balance were included. Fourteen studies met inclusion criteria. Participants were individuals with brain injury, Parkinson’s disease (PD) and Alzheimer’s disease (AD). Intervention protocols included cued walking, cognitive tasks paired with gait, balance, and strength training and virtual reality or gaming. Quality of the included trials was evaluated with a standardized rating scale of clinical relevance. Results Results show that DTT improves single-task gait velocity and stride length in PD and AD, dual-task gait velocity and stride length in PD, AD and brain injury, and may improve balance and cognition in PD and AD. The inclusion criteria limited the diagnostic groups included. Discussion and Conclusions The range of training protocols and outcome assessments in available studies limited comparison of the results across studies. Improvement of dual-task ability in individuals with neurologic disorders holds potential for improving gait, balance and cognition. Motor-cognitive dual-task deficits in individuals with neurologic disorders may be amenable to training. Video Abstract available for additional insights from the authors (See Supplemental Digital Content). PMID:26079569

  5. A latent discriminative model-based approach for classification of imaginary motor tasks from EEG data.

    PubMed

    Saa, Jaime F Delgado; Çetin, Müjdat

    2012-04-01

    We consider the problem of classification of imaginary motor tasks from electroencephalography (EEG) data for brain-computer interfaces (BCIs) and propose a new approach based on hidden conditional random fields (HCRFs). HCRFs are discriminative graphical models that are attractive for this problem because they (1) exploit the temporal structure of EEG; (2) include latent variables that can be used to model different brain states in the signal; and (3) involve learned statistical models matched to the classification task, avoiding some of the limitations of generative models. Our approach involves spatial filtering of the EEG signals and estimation of power spectra based on autoregressive modeling of temporal segments of the EEG signals. Given this time-frequency representation, we select certain frequency bands that are known to be associated with execution of motor tasks. These selected features constitute the data that are fed to the HCRF, parameters of which are learned from training data. Inference algorithms on the HCRFs are used for the classification of motor tasks. We experimentally compare this approach to the best performing methods in BCI competition IV as well as a number of more recent methods and observe that our proposed method yields better classification accuracy.

  6. Oscillatory cortical activity during a motor task in a deafferented patient.

    PubMed

    Patino, Luis; Chakarov, Vihren; Schulte-Mönting, Jürgen; Hepp-Reymond, Marie-Claude; Kristeva, Rumyana

    2006-07-03

    Little is known about the influence of the afferent peripheral feedback on the sensorimotor cortex activation. To answer this open question we investigated the alpha and beta band task-related spectral power decreases (TRPow) in the deafferented patient G.L. and compared the results to those of six healthy subjects. The patient has been deafferented up to the nose for 24 years but her motor fibers are unaffected and she can perform complex motor tasks under visual control. We recorded EEG (58 scalp positions) as well as the exerted force during a visuomotor task. The subjects had to maintain in precision grip an isometric force at 15% of the maximal voluntary contraction. In the patient we found a significantly higher alpha band spectral power during rest and larger alpha TRPow decreases during the motor task when compared to the healthy subjects' data. In contrast, we did not observe any significant differences between patient and controls for the beta band TRPow. The results indicate an altered functional alpha band network state in the patient, probably due to the chronic deafferentation leading to a deep 'idling' state of the contralateral sensorimotor area.

  7. A latent discriminative model-based approach for classification of imaginary motor tasks from EEG data

    NASA Astrophysics Data System (ADS)

    Delgado Saa, Jaime F.; Çetin, Müjdat

    2012-04-01

    We consider the problem of classification of imaginary motor tasks from electroencephalography (EEG) data for brain-computer interfaces (BCIs) and propose a new approach based on hidden conditional random fields (HCRFs). HCRFs are discriminative graphical models that are attractive for this problem because they (1) exploit the temporal structure of EEG; (2) include latent variables that can be used to model different brain states in the signal; and (3) involve learned statistical models matched to the classification task, avoiding some of the limitations of generative models. Our approach involves spatial filtering of the EEG signals and estimation of power spectra based on autoregressive modeling of temporal segments of the EEG signals. Given this time-frequency representation, we select certain frequency bands that are known to be associated with execution of motor tasks. These selected features constitute the data that are fed to the HCRF, parameters of which are learned from training data. Inference algorithms on the HCRFs are used for the classification of motor tasks. We experimentally compare this approach to the best performing methods in BCI competition IV as well as a number of more recent methods and observe that our proposed method yields better classification accuracy.

  8. Abnormal motor cortex excitability during linguistic tasks in adductor-type spasmodic dysphonia.

    PubMed

    Suppa, A; Marsili, L; Giovannelli, F; Di Stasio, F; Rocchi, L; Upadhyay, N; Ruoppolo, G; Cincotta, M; Berardelli, A

    2015-08-01

    In healthy subjects (HS), transcranial magnetic stimulation (TMS) applied during 'linguistic' tasks discloses excitability changes in the dominant hemisphere primary motor cortex (M1). We investigated 'linguistic' task-related cortical excitability modulation in patients with adductor-type spasmodic dysphonia (ASD), a speech-related focal dystonia. We studied 10 ASD patients and 10 HS. Speech examination included voice cepstral analysis. We investigated the dominant/non-dominant M1 excitability at baseline, during 'linguistic' (reading aloud/silent reading/producing simple phonation) and 'non-linguistic' tasks (looking at non-letter strings/producing oral movements). Motor evoked potentials (MEPs) were recorded from the contralateral hand muscles. We measured the cortical silent period (CSP) length and tested MEPs in HS and patients performing the 'linguistic' tasks with different voice intensities. We also examined MEPs in HS and ASD during hand-related 'action-verb' observation. Patients were studied under and not-under botulinum neurotoxin-type A (BoNT-A). In HS, TMS over the dominant M1 elicited larger MEPs during 'reading aloud' than during the other 'linguistic'/'non-linguistic' tasks. Conversely, in ASD, TMS over the dominant M1 elicited increased-amplitude MEPs during 'reading aloud' and 'syllabic phonation' tasks. CSP length was shorter in ASD than in HS and remained unchanged in both groups performing 'linguistic'/'non-linguistic' tasks. In HS and ASD, 'linguistic' task-related excitability changes were present regardless of the different voice intensities. During hand-related 'action-verb' observation, MEPs decreased in HS, whereas in ASD they increased. In ASD, BoNT-A improved speech, as demonstrated by cepstral analysis and restored the TMS abnormalities. ASD reflects dominant hemisphere excitability changes related to 'linguistic' tasks; BoNT-A returns these excitability changes to normal.

  9. Preschoolers' motor and verbal self-control strategies during a resistance-to-temptation task.

    PubMed

    Manfra, Louis; Davis, Kelly D; Ducenne, Lesley; Winsler, Adam

    2014-01-01

    Although prior research has shown that young children exhibit enhanced self-control when they use verbal strategies provided through adult instructions, little work has examined the role of children's spontaneous verbalizations or motor behavior as strategies for enhancing self-control. The present study examined the usefulness of spontaneous verbal and motor strategies for 39 3- and 4-year-old children's ability to exercise self-control during a resistance-to-temptation task. After a 2-min play period, participants were asked by an experimenter not to touch an attractive train set while he was out of the room. Children were videotaped during the 3-min waiting period and videos were coded for frequency and duration of touches, motor movements, and verbalizations. Results indicated that self-control was improved by using both motor and verbal strategies. Children who were unable to resist touching the forbidden toy used limited motor or verbal strategies. These findings add to the growing literature demonstrating the positive role of verbalizations on cognitive control and draw attention to motor behaviors as additional strategies used by young children to exercise self-control.

  10. Motor Imagery Cognitive Network after Left Ischemic Stroke: Study of the Patients during Mental Rotation Task

    PubMed Central

    Yan, Jing; Sun, Junfeng; Guo, Xiaoli; Jin, Zheng; Li, Yao; Li, Zhijun; Tong, Shanbao

    2013-01-01

    Although motor imagery could improve motor rehabilitation, the detailed neural mechanisms of motor imagery cognitive process of stroke patients, particularly from functional network perspective, remain unclear. This study investigated functional brain network properties in each cognitive sub-stage of motor imagery of stroke patients with ischemic lesion in left hemisphere to reveal the impact of stroke on the cognition of motor imagery. Both stroke patients and control subjects participated in mental rotation task, which includes three cognitive sub-stages: visual stimulus perception, mental rotation and response cognitive process. Event-related electroencephalograph was recorded and interdependence between two different cortical areas was assessed by phase synchronization. Both global and nodal properties of functional networks in three sub-stages were statistically analyzed. Phase synchronization of stroke patients significantly reduced in mental rotation sub-stage. Longer characteristic path length and smaller global clustering coefficient of functional network were observed in patients in mental rotation sub-stage which implied the impaired segregation and integration. Larger nodal clustering coefficient and betweenness in contralesional occipitoparietal and frontal area respectively were observed in patients in all sub-stages. In addition, patients also showed smaller betweenness in ipsilesional central-parietal area in response sub-stage. The compensatory effects on local connectedness and centrality indicated the neuroplasticity in contralesional hemisphere. The functional brain networks of stroke patients demonstrated significant alterations and compensatory effects during motor imagery. PMID:24167569

  11. Motor imagery cognitive network after left ischemic stroke: study of the patients during mental rotation task.

    PubMed

    Yan, Jing; Sun, Junfeng; Guo, Xiaoli; Jin, Zheng; Li, Yao; Li, Zhijun; Tong, Shanbao

    2013-01-01

    Although motor imagery could improve motor rehabilitation, the detailed neural mechanisms of motor imagery cognitive process of stroke patients, particularly from functional network perspective, remain unclear. This study investigated functional brain network properties in each cognitive sub-stage of motor imagery of stroke patients with ischemic lesion in left hemisphere to reveal the impact of stroke on the cognition of motor imagery. Both stroke patients and control subjects participated in mental rotation task, which includes three cognitive sub-stages: visual stimulus perception, mental rotation and response cognitive process. Event-related electroencephalograph was recorded and interdependence between two different cortical areas was assessed by phase synchronization. Both global and nodal properties of functional networks in three sub-stages were statistically analyzed. Phase synchronization of stroke patients significantly reduced in mental rotation sub-stage. Longer characteristic path length and smaller global clustering coefficient of functional network were observed in patients in mental rotation sub-stage which implied the impaired segregation and integration. Larger nodal clustering coefficient and betweenness in contralesional occipitoparietal and frontal area respectively were observed in patients in all sub-stages. In addition, patients also showed smaller betweenness in ipsilesional central-parietal area in response sub-stage. The compensatory effects on local connectedness and centrality indicated the neuroplasticity in contralesional hemisphere. The functional brain networks of stroke patients demonstrated significant alterations and compensatory effects during motor imagery.

  12. Event-related brain potentials during the visuomotor mental rotation task: The contingent negative variation scales to angle of rotation.

    PubMed

    Heath, M; Hassall, C D; MacLean, S; Krigolson, O E

    2015-12-17

    Perceptual judgments about the angular disparity of a character from its standard upright (i.e., mental rotation task) result in a concurrent increase in reaction time (RT) and modulation of the amplitude of the P300 event-related brain potential (ERP). It has therefore been proposed that the P300 represents the neural processes associated with a visual rotation. In turn, the visuomotor mental rotation (VMR) task requires reaching to a location that deviates from a target by a predetermined angle. Although the VMR task exhibits a linear increase in RT with increasing oblique angles of rotation, work has not examined whether the task is supported via a visual rotation analogous to its mental rotation task counterpart. This represents a notable issue because seminal work involving non-human primates has ascribed VMR performance to the motor-related rotation of directionally tuned neurons in the primary motor cortex. Here we examined the concurrent behavioral and ERP characteristics of a standard reaching task and VMR tasks of 35°, 70°, and 105° of rotation. Results showed that the P300 amplitude was larger for the standard compared to each VMR task--an effect independent of the angle of rotation. In turn, the amplitude of the contingent negative variation (CNV)--an ERP related to cognitive and visuomotor integration for movement preparation--was systematically modulated with angle of rotation. Thus, we propose that the CNV represents an ERP correlate related to the cognitive and/or visuomotor transformation demands of increasing the angular separation between a stimulus and a movement goal. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Self-Control of Task Difficulty During Early Practice Promotes Motor Skill Learning.

    PubMed

    Andrieux, Mathieu; Boutin, Arnaud; Thon, Bernard

    2016-01-01

    This study was designed to determine whether the effect of self-control of task difficulty on motor learning is a function of the period of self-control administration. In a complex anticipation-coincidence task that required participants to intercept 3 targets with a virtual racquet, the task difficulty was either self-controlled or imposed to the participants in the two phases of the acquisition session. First, the results confirmed the beneficial effects of self-control over fully prescribed conditions. Second, the authors also demonstrated that a partial self-control of task difficulty better promotes learning than does a complete self-controlled procedure. Overall, the results revealed that these benefits are increased when this choice is allowed during early practice. The findings are discussed in terms of theoretical and applied perspectives.

  14. Influence of task constraints and device properties on motor patterns in a realistic control situation.

    PubMed

    Loeches De La Fuente, Hugo; Fernandez, Laure; Sarrazin, Jean-Christophe; Berton, Eric; Rao, Guillaume

    2014-01-01

    The influences of task difficulty (index difficulty: 2-4), input device of different length, range of motion and mode of resistance (joystick or rotorcraft stick), and directions of movement (leftward rightward) on motor patterns in a realistic control situation were examined with a multilevel analysis (joint kinematics and muscular variables, and global task performance). Eight subjects controlled the displacements of a virtual object during a slalom task characterized by a realistic inertial model. Pilots adapted the endpoint kinematic organization to increasing accuracy constraints to preserve task success whatever the device and the direction. However, the rotorcraft stick manipulation remains highly complex in comparison to the joystick due to poorer proprioceptive information, higher inertial constraints, and an asymmetrical muscle control.

  15. The spinning task: a new protocol to easily assess motor coordination and resistance in zebrafish.

    PubMed

    Blazina, Ana R; Vianna, Mônica R; Lara, Diogo R

    2013-12-01

    The increasing use of adult zebrafish in behavioral studies has created the need for new and improved protocols. Our investigation sought to evaluate the swimming behavior of zebrafish against a water current using the newly developed Spinning Task. Zebrafish were individually placed in a beaker containing a spinning magnetic stirrer and their latency to be swept into the whirlpool was recorded. We characterized that larger fish (>4 cm) and lower rpm decreased the swimming time in the Spinning Task. There was also a dose-related reduction in swimming after acute treatment with haloperidol, valproic acid, clonazepam, and ethanol, which alter coordination. Importantly, at doses that reduced swimming time in the Spinning Task, these drugs influenced absolute turn angle (ethanol increased and the other drugs decreased), but had no effect of distance travelled in a regular water tank. These results suggest that the Spinning Task is a useful protocol to add information to the assessment of zebrafish motor behavior.

  16. Effects of dual task difficulty in motor and cognitive performance: Differences between adults and adolescents.

    PubMed

    Bustillo-Casero, Pilar; Villarrasa-Sapiña, Israel; García-Massó, Xavier

    2017-10-01

    In the present study our aim was to compare dual-task performance in thirteen adolescents and fifteen young adults while concurrently performing a cognitive and a motor task. The postural control variables were obtained under three different conditions: i) bipedal stance, ii) tandem stance and iii) unipedal stance. The cognitive task consisted of a backward digit span test in which the participants were asked to memorize a sequence of numbers and then repeat the number in reverse order at three different difficulty levels (i.e. with 3, 4 and 5 digits). The difficulty of the cognitive task was seen to have different effects on adolescents and young adults. Adolescents seem to prioritize postural control during high difficulty postural conditions while a cross-domain competition model appeared in easy postural conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Discriminating hand gesture motor imagery tasks using cortical current density estimation.

    PubMed

    Edelman, Bradley; Baxter, Bryan; He, Bin

    2014-01-01

    Current EEG based brain computer interface (BCI) systems have achieved successful control in up to 3 dimensions; however the current paradigm may be unnatural for many rehabilitative and recreational applications. Therefore there is a great need to find motor imagination (MI) tasks that are realistic for output device control. In this paper we present our results on classifying hand gesture MI tasks, including right hand flexion, extension, supination and pronation using a novel EEG inverse imaging approach. By using both temporal and spatial specificity in the source domain we were able to separate MI tasks with up to 95% accuracy for binary classification of any two tasks compared to a maximum of only 79% in the sensor domain.

  18. Intended actions and unexpected outcomes: automatic and controlled processing in a rapid motor task

    PubMed Central

    Cheyne, Douglas O.; Ferrari, Paul; Cheyne, James A.

    2012-01-01

    Human action involves a combination of controlled and automatic behavior. These processes may interact in tasks requiring rapid response selection or inhibition, where temporal constraints preclude timely intervention by conscious, controlled processes over automatized prepotent responses. Such contexts tend to produce frequent errors, but also rapidly executed correct responses, both of which may sometimes be perceived as surprising, unintended, or “automatic”. In order to identify neural processes underlying these two aspects of cognitive control, we measured neuromagnetic brain activity in 12 right-handed subjects during manual responses to rapidly presented digits, with an infrequent target digit that required switching response hand (bimanual task) or response finger (unimanual task). Automaticity of responding was evidenced by response speeding (shorter response times) prior to both failed and fast correct switches. Consistent with this automaticity interpretation of fast correct switches, we observed bilateral motor preparation, as indexed by suppression of beta band (15–30 Hz) oscillations in motor cortex, prior to processing of the switch cue in the bimanual task. In contrast, right frontal theta activity (4–8 Hz) accompanying correct switch responses began after cue onset, suggesting that it reflected controlled inhibition of the default response. Further, this activity was reduced on fast correct switch trials suggesting a more automatic mode of inhibitory control. We also observed post-movement (event-related negativity) ERN-like responses and theta band increases in medial and anterior frontal regions that were significantly larger on error trials, and may reflect a combination of error and delayed inhibitory signals. We conclude that both automatic and controlled processes are engaged in parallel during rapid motor tasks, and that the relative strength and timing of these processes may underlie both optimal task performance and subjective

  19. Motor imagery modulation of body sway is task-dependent and relies on imagery ability

    PubMed Central

    Lemos, Thiago; Souza, Nélio S.; Horsczaruk, Carlos H. R.; Nogueira-Campos, Anaelli A.; de Oliveira, Laura A. S.; Vargas, Claudia D.; Rodrigues, Erika C.

    2014-01-01

    In this study we investigate to what extent the effects of motor imagery on postural sway are constrained by movement features and the subject's imagery ability. Twenty-three subjects were asked to imagine three movements using the kinesthetic modality: rising on tiptoes, whole-body forward reaching, and whole-body lateral reaching. After each task, subjects reported the level of imagery vividness and were subsequently grouped into a HIGH group (scores ≥3, “moderately intense” imagery) or a LOW group (scores ≤2, “mildly intense” imagery). An eyes closed trial was used as a control task. Center of gravity (COG) coordinates were collected, along with surface EMG of the deltoid (medial and anterior portion) and lateral gastrocnemius muscles. COG variability was quantified as the amount of fluctuations in position and velocity in the forward-backward and lateral directions. Changes in COG variability during motor imagery were observed only for the HIGH group. COG variability in the forward-backward direction was increased during the rising on tiptoes imagery, compared with the control task (p = 0.01) and the lateral reaching imagery (p = 0.02). Conversely, COG variability in the lateral direction was higher in rising on tiptoes and lateral reaching imagery than during the control task (p < 0.01); in addition, COG variability was higher during the lateral reaching imagery than in the forward reaching imagery (p = 0.02). EMG analysis revealed no effects of group (p > 0.08) or task (p > 0.46) for any of the tested muscles. In summary, motor imagery influences body sway dynamics in a task-dependent manner, and relies on the subject' imagery ability. PMID:24847241

  20. Motor imagery modulation of body sway is task-dependent and relies on imagery ability.

    PubMed

    Lemos, Thiago; Souza, Nélio S; Horsczaruk, Carlos H R; Nogueira-Campos, Anaelli A; de Oliveira, Laura A S; Vargas, Claudia D; Rodrigues, Erika C

    2014-01-01

    In this study we investigate to what extent the effects of motor imagery on postural sway are constrained by movement features and the subject's imagery ability. Twenty-three subjects were asked to imagine three movements using the kinesthetic modality: rising on tiptoes, whole-body forward reaching, and whole-body lateral reaching. After each task, subjects reported the level of imagery vividness and were subsequently grouped into a HIGH group (scores ≥3, "moderately intense" imagery) or a LOW group (scores ≤2, "mildly intense" imagery). An eyes closed trial was used as a control task. Center of gravity (COG) coordinates were collected, along with surface EMG of the deltoid (medial and anterior portion) and lateral gastrocnemius muscles. COG variability was quantified as the amount of fluctuations in position and velocity in the forward-backward and lateral directions. Changes in COG variability during motor imagery were observed only for the HIGH group. COG variability in the forward-backward direction was increased during the rising on tiptoes imagery, compared with the control task (p = 0.01) and the lateral reaching imagery (p = 0.02). Conversely, COG variability in the lateral direction was higher in rising on tiptoes and lateral reaching imagery than during the control task (p < 0.01); in addition, COG variability was higher during the lateral reaching imagery than in the forward reaching imagery (p = 0.02). EMG analysis revealed no effects of group (p > 0.08) or task (p > 0.46) for any of the tested muscles. In summary, motor imagery influences body sway dynamics in a task-dependent manner, and relies on the subject' imagery ability.

  1. Discrimination of motor imagery tasks via information flow pattern of brain connectivity.

    PubMed

    Liang, Shuang; Choi, Kup-Sze; Qin, Jing; Wang, Qiong; Pang, Wai-Man; Heng, Pheng-Ann

    2016-04-29

    The effective connectivity refers explicitly to the influence that one neural system exerts over another in frequency domain. To investigate the propagation of neuronal activity in certain frequency can help us reveal the mechanisms of information processing by brain. This study investigates the detection of effective connectivity and analyzes the complex brain network connection mode associated with motor imagery (MI) tasks. The effective connectivity among the primary motor area is firstly explored using partial directed coherence (PDC) combined with multivariate empirical mode decomposition (MEMD) based on electroencephalography (EEG) data. Then a new approach is proposed to analyze the connection mode of the complex brain network via the information flow pattern. Our results demonstrate that significant effective connectivity exists in the bilateral hemisphere during the tasks, regardless of the left-/right-hand MI tasks. Furthermore, the out-in rate results of the information flow reveal the existence of the contralateral lateralization. The classification performance of left-/right-hand MI tasks can be improved by careful selection of intrinsic mode functions (IMFs). The proposed method can provide efficient features for the detection of MI tasks and has great potential to be applied in brain computer interface (BCI).

  2. Age-related trends in Stroop and conflicting motor response task findings.

    PubMed

    Nichelli, Francesca; Scala, Gabriella; Vago, Chiara; Riva, Daria; Bulgheroni, Sara

    2005-10-01

    Inhibition problems are reportedly at the heart of several childhood pathologies and learning disorders, but few instruments are available for their in-depth investigation. The main aim of the present study was to investigate the development of a capacity to inhibit automatic responses in young and middle childhood. For this purpose, 100 children between 6 and 11 years old were administered two tests that measure executive inhibition: an animal Stroop task (in a paper-and-pencil version of the computerized original proposed by Wright and colleagues in 2003) and a conflicting motor response task. Our results indicate that performance clearly improves in both tests during the course of a child's development and the data obtained with the paper-and-pencil animal Stroop task overlap with those obtained with the computerized version. When the task calls for a stronger inhibitory control (the incongruent situation in the Stroop task and in the opposite condition in the conflicting motor response test) the trend of the response times is less homogeneous, peaking in the youngest and oldest age brackets considered. The positivity and significance of the correlation coefficients between the two tests also suggest that the two measures are tapping cognitive abilities that are developing in a parallel fashion.

  3. Hand preference consistency and eye-hand coordination in young children during a motor task.

    PubMed

    Mori, Shiro; Iteya, Misaki; Gabbard, Carl

    2006-02-01

    Indications of earlier research are that individuals exhibiting a consistent hand preference are better coordinated on selected motor tasks than peers with inconsistent hand preference. The present study examined eye-hand coordination via inter- and intramodal matching behavior by handedness groups for 55 5- and 6-yr.-olds using the Pinboard Test. Analysis indicated the Consistent group scored better, leading to the speculation that children with consistent laterality may possess an advantage in interhemispheric communication, especially when the task requires coordination of both limbs.

  4. Cognitive-Motor Interference on Upper Extremity Motor Performance in a Robot-Assisted Planar Reaching Task Among Patients With Stroke.

    PubMed

    Shin, Joon-Ho; Park, Gyulee; Cho, Duk Youn

    2017-04-01

    To explore motor performance on 2 different cognitive tasks during robotic rehabilitation in which motor performance was longitudinally assessed. Prospective study. Rehabilitation hospital. Patients (N=22) with chronic stroke and upper extremity impairment. A total of 640 repetitions of robot-assisted planar reaching, 5 times a week for 4 weeks. Longitudinal robotic evaluations regarding motor performance included smoothness, mean velocity, path error, and reach error by the type of cognitive task. Dual-task effects (DTEs) of motor performance were computed to analyze the effect of the cognitive task on dual-task interference. Cognitive task type influenced smoothness (P=.006), the DTEs of smoothness (P=.002), and the DTEs of reach error (P=.052). Robotic rehabilitation improved smoothness (P=.007) and reach error (P=.078), while stroke severity affected smoothness (P=.01), reach error (P<.001), and path error (P=.01). Robotic rehabilitation or severity did not affect the DTEs of motor performance. The results provide evidence for the effect of cognitive-motor interference on upper extremity performance among participants with stroke using a robotic-guided rehabilitation system. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  5. Measurement of functional task difficulty during motor learning: What level of difficulty corresponds to the optimal challenge point?

    PubMed

    Akizuki, Kazunori; Ohashi, Yukari

    2015-10-01

    The relationship between task difficulty and learning benefit was examined, as was the measurability of task difficulty. Participants were required to learn a postural control task on an unstable surface at one of four different task difficulty levels. Results from the retention test showed an inverted-U relationship between task difficulty during acquisition and motor learning. The second-highest level of task difficulty was the most effective for motor learning, while learning was delayed at the most and least difficult levels. Additionally, the results indicate that salivary α-amylase and the performance dimension of the National Aeronautics and Space Administration-Task Load Index (NASA-TLX) are useful indices of task difficulty. Our findings suggested that instructors may be able to adjust task difficulty based on salivary α-amylase and the performance dimension of the NASA-TLX to enhance learning. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Reading Rate, Readability, and Variations in Task-Induced Processing

    ERIC Educational Resources Information Center

    Coke, Esther U.

    1976-01-01

    This study explored the hypothesis that task variables account for previous findings that reading rate is unaffected by readability. The findings suggest that when appropriate reading tasks are chosen, reading rate can be used to infer underlying processes in reading. (Author/DEP)

  7. Reading Rate, Readability, and Variations in Task-Induced Processing

    ERIC Educational Resources Information Center

    Coke, Esther U.

    1976-01-01

    This study explored the hypothesis that task variables account for previous findings that reading rate is unaffected by readability. The findings suggest that when appropriate reading tasks are chosen, reading rate can be used to infer underlying processes in reading. (Author/DEP)

  8. Motor expertise and performance in spatial tasks: A meta-analysis.

    PubMed

    Voyer, Daniel; Jansen, Petra

    2017-08-01

    The present study aimed to provide a summary of findings relevant to the influence of motor expertise on performance in spatial tasks and to examine potential moderators of this effect. Studies of relevance were those in which individuals involved in activities presumed to require motor expertise were compared to non-experts in such activities. A final set of 62 effect sizes from 33 samples was included in a multilevel meta-analysis. The results showed an overall advantage in favor of motor experts in spatial tasks (d=0.38). However, the magnitude of that effect was moderated by expert type (athlete, open skills/ball sports, runner/cyclist, gymnast/dancers, musicians), stimulus type (2D, blocks, bodies, others), test category (mental rotation, spatial perception, spatial visualization), specific test (Mental Rotations Test, generic mental rotation, disembedding, rod-and-frame test, other), and publication status. These findings are discussed in the context of embodied cognition and the potential role of activities requiring motor expertise in promoting good spatial performance. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Motor units are recruited in a task-dependent fashion during locomotion.

    PubMed

    Wakeling, James M

    2004-10-01

    Muscle fibres have a range of contractile properties from fast to slow. Traditional understanding of muscle fibre recruitment suggests that the slower fibres within a mixed muscle are used for all contractions including those at rapid speeds. However, mechanical arguments predict that some locomotor tasks are best performed by solely the faster fibres. Motor recruitment patterns can be indicated by the spectral properties of the myoelectric signals. High- and low-frequency myoelectric spectra that have similar spectral power indicate the activity of faster and slower motor units, respectively. In this study, the myoelectric signals in humans were measured from nine muscles of the leg during walking and running at 1.5, 3 and 4.5 m s(-1). The myoelectric spectra for 20 points in each stride were calculated using wavelet techniques, and the spectral properties quantified using principal component analysis. Bursts of muscle activity were characterized by hysteresis in the myoelectric frequencies, with different frequencies occurring at different times, indicating time-varying shifts in the motor recruitment patterns. This hysteresis occurred at all locomotor speeds tested. It is likely that the different types of motor unit are recruited in a task-dependent fashion during locomotion.

  10. Scale-Dependent Signal Identification in Low-Dimensional Subspace: Motor Imagery Task Classification

    PubMed Central

    Gan, Haitao; Potter, Tom

    2016-01-01

    Motor imagery electroencephalography (EEG) has been successfully used in locomotor rehabilitation programs. While the noise-assisted multivariate empirical mode decomposition (NA-MEMD) algorithm has been utilized to extract task-specific frequency bands from all channels in the same scale as the intrinsic mode functions (IMFs), identifying and extracting the specific IMFs that contain significant information remain difficult. In this paper, a novel method has been developed to identify the information-bearing components in a low-dimensional subspace without prior knowledge. Our method trains a Gaussian mixture model (GMM) of the composite data, which is comprised of the IMFs from both the original signal and noise, by employing kernel spectral regression to reduce the dimension of the composite data. The informative IMFs are then discriminated using a GMM clustering algorithm, the common spatial pattern (CSP) approach is exploited to extract the task-related features from the reconstructed signals, and a support vector machine (SVM) is applied to the extracted features to recognize the classes of EEG signals during different motor imagery tasks. The effectiveness of the proposed method has been verified by both computer simulations and motor imagery EEG datasets. PMID:27891256

  11. How do children complete a seated combined cognitive and motor multi-tasking paradigm?

    PubMed

    Hinton, Dorelle C; Vallis, Lori Ann

    2015-06-01

    Healthy children (n=12, age 7years) and young adults (n=11, age 21years) were asked to perform a bimanual balance and reaching protocol in a seated posture. Subjects balanced a ball on a Frisbee on the non-dominant palm of the hand while reaching with the dominant hand to pick up a toy off the ground. During half of the trials, an auditory Stroop task was administered simultaneous to onset of the participants' reach. All children (CH) and adults (AD) successfully completed both motor and cognitive tasks when combined: the ball and Frisbee were not dropped and cognitive accuracy rate for both groups was 77%. Angular range of motion (ROM) measures indicated that the trunk, upper arm (UA) and forearm (FA) segments were moving as articulated individual segments in both adults and children (ROM for trunk≠UA≠FA; p<.001). However, differences between CH and AD upper body segmental control were evident: greater variability existed between trials and between subjects for segmental ROM in CH compared to AD (p<.001), suggesting that adult-like control is still developing in this age group. Results indicate children aged 7years can successfully perform a simultaneous upper body motor and cognitive task in a seated posture, however motor performance control is not yet at the same level as adults.

  12. Relationship between reaction time, fine motor control, and visual-spatial perception on vigilance and visual-motor tasks in 22q11.2 Deletion Syndrome.

    PubMed

    Howley, Sarah A; Prasad, Sarah E; Pender, Niall P; Murphy, Kieran C

    2012-01-01

    22q11.2 Deletion Syndrome (22q11DS) is a common microdeletion disorder associated with mild to moderate intellectual disability and specific neurocognitive deficits, particularly in visual-motor and attentional abilities. Currently there is evidence that the visual-motor profile of 22q11DS is not entirely mediated by intellectual disability and that these individuals have specific deficits in visual-motor integration. However, the extent to which attentional deficits, such as vigilance, influence impairments on visual motor tasks in 22q11DS is unclear. This study examines visual-motor abilities and reaction time using a range of standardised tests in 35 children with 22q11DS, 26 age-matched typically developing (TD) sibling controls and 17 low-IQ community controls. Statistically significant deficits were observed in the 22q11DS group compared to both low-IQ and TD control groups on a timed fine motor control and accuracy task. The 22q11DS group performed significantly better than the low-IQ control group on an untimed drawing task and were equivalent to the TD control group on point accuracy and simple reaction time tests. Results suggest that visual motor deficits in 22q11DS are primarily attributable to deficits in psychomotor speed which becomes apparent when tasks are timed versus untimed. Moreover, the integration of visual and motor information may be intact and, indeed, represent a relative strength in 22q11DS when there are no time constraints imposed. While this may have significant implications for cognitive remediation strategies for children with 22q11DS, the relationship between reaction time, visual reasoning, cognitive complexity, fine motor speed and accuracy, and graphomotor ability on visual-motor tasks is still unclear.

  13. Functional architecture of the cortico-basal ganglia circuitry during motor task execution: correlations of strength of functional connectivity with neuropsychological task performance among female subjects.

    PubMed

    Marchand, William R; Lee, James N; Suchy, Yana; Garn, Cheryl; Chelune, Gordon; Johnson, Susanna; Wood, Nicole

    2013-05-01

    The primary aim of this study was to enhance our understanding of the functional architecture of the cortico-basal ganglia circuitry during motor task execution. Twenty right-handed female subjects without any history of neuropsychiatric illness underwent fMRI at 3 T. The activation paradigm was a complex motor task completed with the nondominant hand. Analyses of functional connectivity strength were conducted for pairs of structures in input, intrinsic, and output segments of the circuitry. Next, connectivity strengths were correlated with results of neurocognitive testing conducted outside of the scanner, which provided information about both motor and cognitive processes. For input pathways, results indicate that SMA-striatum interactions are particularly relevant for motor behavior and disruptions may impact both motor and cognitive functions. For intrinsic pathways, results indicate that thalamus (VA nucleus) to striatum feedback pathway appears to have an important role during task execution and carries information relevant for motor planning. Together, these findings add to accumulating evidence that the GPe may play a role in higher order basal ganglia processing. A potentially controversial finding was that strong functional connectivity appears to occur across intrinsic inhibitory pathways. Finally, output (thalamus to cortex) feedback was only correlated with motor planning. This result suggests circuit processes may be more relevant for future behaviors than the execution of the current task. Copyright © 2012 Wiley Periodicals, Inc.

  14. Processing of visual information compromises the ability of older adults to control novel fine motor tasks.

    PubMed

    Baweja, Harsimran S; Kwon, MinHyuk; Onushko, Tanya; Wright, David L; Corcos, Daniel M; Christou, Evangelos A

    2015-12-01

    We performed two experiments to determine whether amplified motor output variability and compromised processing of visual information in older adults impair short-term adaptations when learning novel fine motor tasks. In Experiment 1, 12 young and 12 older adults underwent training to learn how to accurately trace a sinusoidal position target with abduction-adduction of their index finger. They performed 48 trials, which included 8 blocks of 6 trials (the last trial of each block was performed without visual feedback). Afterward, subjects received an interference task (watched a movie) for 60 min. We tested retention by asking subjects to perform the sinusoidal task (5 trials) with and without visual feedback. In Experiment 2, 12 young and 10 older adults traced the same sinusoidal position target with their index finger and ankle at three distinct visual angles (0.25°, 1° and 5.4°). In Experiment 1, the movement error and variability were greater for older adults during the visual feedback trials when compared with young adults. In contrast, during the no-vision trials, age-associated differences in movement error and variability were ameliorated. Short-term adaptations in learning the sinusoidal task were similar for young and older adults. In Experiment 2, lower amount of visual feedback minimized the age-associated differences in movement variability for both the index finger and ankle movements. We demonstrate that although short-term adaptations are similar for young and older adults, older adults do not process visual information as well as young adults and that compromises their ability to control novel fine motor tasks during acquisition, which could influence long-term retention and transfer.

  15. Attention during functional tasks is associated with motor performance in children with developmental coordination disorder

    PubMed Central

    Fong, Shirley S.M.; Chung, Joanne W.Y.; Cheng, Yoyo T.Y.; Yam, Timothy T.T.; Chiu, Hsiu-Ching; Fong, Daniel Y.T.; Cheung, C.Y.; Yuen, Lily; Yu, Esther Y.T.; Hung, Yeung Sam; Macfarlane, Duncan J.; Ng, Shamay S.M.

    2016-01-01

    Abstract This cross-sectional and exploratory study aimed to compare motor performance and electroencephalographic (EEG) attention levels in children with developmental coordination disorder (DCD) and those with typical development, and determine the relationship between motor performance and the real-time EEG attention level in children with DCD. Eighty-six children with DCD [DCD: n = 57; DCD and attention deficit hyperactivity disorder (ADHD): n = 29] and 99 children with typical development were recruited. Their motor performance was assessed with the Movement Assessment Battery for Children (MABC) and attention during the tasks of the MABC was evaluated by EEG. All children with DCD had higher MABC impairment scores and lower EEG attention scores than their peers (P < 0.05). After accounting for age, sex, body mass index, and physical activity level, the attention index remained significantly associated with the MABC total impairment score and explained 14.1% of the variance in children who had DCD but not ADHD (P = 0.009) and 17.5% of the variance in children with both DCD and ADHD (P = 0.007). Children with DCD had poorer motor performance and were less attentive to movements than their peers. Their poor motor performance may be explained by inattention. PMID:27631272

  16. Task-Dependent Intermuscular Motor Unit Synchronization between Medial and Lateral Vastii Muscles during Dynamic and Isometric Squats

    PubMed Central

    Mohr, Maurice; Nann, Marius; von Tscharner, Vinzenz; Eskofier, Bjoern; Nigg, Benno Maurus

    2015-01-01

    Purpose Motor unit activity is coordinated between many synergistic muscle pairs but the functional role of this coordination for the motor output is unclear. The purpose of this study was to investigate the short-term modality of coordinated motor unit activity–the synchronized discharge of individual motor units across muscles within time intervals of 5ms–for the Vastus Medialis (VM) and Lateralis (VL). Furthermore, we studied the task-dependency of intermuscular motor unit synchronization between VM and VL during static and dynamic squatting tasks to provide insight into its functional role. Methods Sixteen healthy male and female participants completed four tasks: Bipedal squats, single-leg squats, an isometric squat, and single-leg balance. Monopolar surface electromyography (EMG) was used to record motor unit activity of VM and VL. For each task, intermuscular motor unit synchronization was determined using a coherence analysis between the raw EMG signals of VM and VL and compared to a reference coherence calculated from two desynchronized EMG signals. The time shift between VM and VL EMG signals was estimated according to the slope of the coherence phase angle spectrum. Results For all tasks, except for singe-leg balance, coherence between 15–80Hz significantly exceeded the reference. The corresponding time shift between VM and VL was estimated as 4ms. Coherence between 30–60Hz was highest for the bipedal squat, followed by the single-leg squat and the isometric squat. Conclusion There is substantial short-term motor unit synchronization between VM and VL. Intermuscular motor unit synchronization is enhanced for contractions during dynamic activities, possibly to facilitate a more accurate control of the joint torque, and reduced during single-leg tasks that require balance control and thus, a more independent muscle function. It is proposed that the central nervous system scales the degree of intermuscular motor unit synchronization according to the

  17. Task-dependent activity of motor unit populations in feline ankle extensor muscles

    PubMed Central

    Hodson-Tole, Emma F.; Pantall, Annette; Maas, Huub; Farrell, Brad; Gregor, Robert J.; Prilutsky, Boris I.

    2012-01-01

    SUMMARY Understanding the functional significance of the morphological diversity of mammalian skeletal muscles is limited by technical difficulties of estimating the contribution of motor units with different properties to unconstrained motor behaviours. Recently developed wavelet and principal components analysis of intramuscular myoelectric signals has linked signals with lower and higher frequency contents to the use of slower and faster motor unit populations. In this study we estimated the relative contributions of lower and higher frequency signals of cat ankle extensors (soleus, medial and lateral gastrocnemii, plantaris) during level, downslope and upslope walking and the paw-shake response. This was done using the first two myoelectric signal principal components (PCI, PCII), explaining over 90% of the signal, and an angle θ, a function of PCI/PCII, indicating the relative contribution of slower and faster motor unit populations. Mean myoelectric frequencies in all walking conditions were lowest for slow soleus (234 Hz) and highest for fast gastrocnemii (307 and 330 Hz) muscles. Motor unit populations within and across the studied muscles that demonstrated lower myoelectric frequency (suggesting slower populations) were recruited during tasks and movement phases with lower mechanical demands on the ankle extensors – during downslope and level walking and in early walking stance and paw-shake phases. With increasing mechanical demands (upslope walking, mid-phase of paw-shake cycles), motor unit populations generating higher frequency signals (suggesting faster populations) contributed progressively more. We conclude that the myoelectric frequency contents within and between feline ankle extensors vary across studied motor behaviours, with patterns that are generally consistent with muscle fibre-type composition. PMID:22811250

  18. Sleep-Related Offline Improvements in Gross Motor Task Performance Occur Under Free Recall Requirements

    PubMed Central

    Malangré, Andreas; Blischke, Klaus

    2016-01-01

    Nocturnal sleep effects on memory consolidation following gross motor sequence learning were examined using a complex arm movement task. This task required participants to produce non-regular spatial patterns in the horizontal plane by successively fitting a small peg into different target-holes on an electronic pegboard. The respective reaching movements typically differed in amplitude and direction. Targets were visualized prior to each transport movement on a computer screen. With this task we tested 18 subjects (22.6 ± 1.9 years; 8 female) using a between-subjects design. Participants initially learned a 10-element arm movement sequence either in the morning or in the evening. Performance was retested under free recall requirements 15 min post training, as well as 12 and 24 h later. Thus, each group was provided with one sleep-filled and one wake retention interval. Dependent variables were error rate (number of Erroneous Sequences, ES) and average sequence execution time (correct sequences only). Performance improved during acquisition. Error rate remained stable across retention. Sequence execution time (inverse to execution speed) significantly decreased again during the sleep-filled retention intervals, but remained stable during the respective wake intervals. These results corroborate recent findings on sleep-related enhancement consolidation in ecological valid, complex gross motor tasks. At the same time, they suggest this effect to be truly memory-based and independent from repeated access to extrinsic sequence information during retests. PMID:27065834

  19. Motor Imagery in Asperger Syndrome: Testing Action Simulation by the Hand Laterality Task

    PubMed Central

    Conson, Massimiliano; Mazzarella, Elisabetta; Frolli, Alessandro; Esposito, Dalila; Marino, Nicoletta; Trojano, Luigi; Massagli, Angelo; Gison, Giovanna; Aprea, Nellantonio; Grossi, Dario

    2013-01-01

    Asperger syndrome (AS) is a neurodevelopmental condition within the Autism Spectrum Disorders (ASD) characterized by specific difficulties in social interaction, communication and behavioural control. In recent years, it has been suggested that ASD is related to a dysfunction of action simulation processes, but studies employing imitation or action observation tasks provided mixed results. Here, we addressed action simulation processes in adolescents with AS by means of a motor imagery task, the classical hand laterality task (to decide whether a rotated hand image is left or right); mental rotation of letters was also evaluated. As a specific marker of action simulation in hand rotation, we assessed the so-called biomechanical effect, that is the advantage for judging hand pictures showing physically comfortable versus physically awkward positions. We found the biomechanical effect in typically-developing participants but not in participants with AS. Overall performance on both hand laterality and letter rotation tasks, instead, did not differ in the two groups. These findings demonstrated a specific alteration of motor imagery skills in AS. We suggest that impaired mental simulation and imitation of goal-less movements in ASD could be related to shared cognitive mechanisms. PMID:23894683

  20. Perceptual effect on motor learning in the serial reaction-time task.

    PubMed

    Kemény, Ferenc; Lukács, Agnes

    2011-01-01

    Although the Serial Reaction-Time Task has been an effective tool in studying procedural learning, there is still a debate as to whether learning in the task is effector-based, stimulus-based, or response-based. In this article, the authors contribute to this debate by contrasting response- and stimulus-based learning by manipulating them selectively and simultaneously. Results show that (a) participants learned response sequences in the absence of stimulus-specific perceptual sequence information but (b) not stimulus sequences without corresponding response information. In a third condition, response sequence and stimulus frequency information were in conflict, and each effect decreased learning in the other domain. Overall, our findings show that learning in these tasks is primarily motor-based, but it is also constrained by relatively salient perceptual information. Together with earlier findings in the literature, the findings also suggest a task and stimulus-arrangement-specific interaction between motor and perceptual learning, where relevance and salience of the specific information plays a crucial role.

  1. Amount of mental practice and performance of a simple motor task.

    PubMed

    Kremer, Peter; Spittle, Michael; McNeil, Dominic; Shinners, Cassandra

    2009-10-01

    The effects of different amounts of mental practice on the performance of a motor skill were studied. Research supports the effectiveness of mental practice on performance; however, little is known about how much practice is needed and whether there is an optimal amount for these practice effects. Participants, 209 students ages 18 to 44 years (M=20.5, SD=2.9), completed a pre- and posttest of dart throwing with the nonpreferred hand. In the practice phase, participants completed either 25 (Mental Practice 25), 50 (Mental Practice 50), or 100 (Mental Practice 100) trials of the darts task or 50 trials of a catching task (Catching Task). Performance for all groups improved from pre- to posttest. Improvements for the three mental practice groups were greater than for the Catching Task group; however, there were no differences for the three Mental Practice groups. The findings support the positive effect of mental practice over a control condition and suggest that small amounts of mental practice may be sufficient for performance improvements, at least for a simple motor skill.

  2. Individual variation in sleep and motor activity in rats.

    PubMed

    Tang, Xiangdong; Yang, Linghui; Sanford, Larry D

    2007-06-04

    We examined individual differences in sleep and motor activity across 2 consecutive days in rats. EEG and motor activity were recorded via telemetry in Wistar rats (n=29) for 48h under well-habituated conditions. Rats were grouped based on sleep amounts and stability across days (short [SS, n=7], intermediate [IS, n=15] and long [LS, n=7] sleep) and comparisons were conducted to determine group differences for measures of sleep and motor activity. We found that correlations across recording days were significant for all selected sleep measures and motor activity counts. Rankings for 24h total sleep time and non-rapid eye movement sleep (NREM) were SSmotor activity counts (per waking min) were greater (32-38%) in SS compared to LS rats on both recording days. The results indicate that individual differences in sleep and motor activity in Wistar rats are stable across days. Differences between SS and LS rats have parallels to those reported for short and long sleep humans.

  3. Short-term adaptation to a simple motor task: a physiological process preserved in multiple sclerosis.

    PubMed

    Mancini, L; Ciccarelli, O; Manfredonia, F; Thornton, J S; Agosta, F; Barkhof, F; Beckmann, C; De Stefano, N; Enzinger, C; Fazekas, F; Filippi, M; Gass, A; Hirsch, J G; Johansen-Berg, H; Kappos, L; Korteweg, T; Manson, S C; Marino, S; Matthews, P M; Montalban, X; Palace, J; Polman, C; Rocca, M; Ropele, S; Rovira, A; Wegner, C; Friston, K; Thompson, A; Yousry, T

    2009-04-01

    Short-term adaptation indicates the attenuation of the functional MRI (fMRI) response during repeated task execution. It is considered to be a physiological process, but it is unknown whether short-term adaptation changes significantly in patients with brain disorders, such as multiple sclerosis (MS). In order to investigate short-term adaptation during a repeated right-hand tapping task in both controls and in patients with MS, we analyzed the fMRI data collected in a large cohort of controls and MS patients who were recruited into a multi-centre European fMRI study. Four fMRI runs were acquired for each of the 55 controls and 56 MS patients at baseline and 33 controls and 26 MS patients at 1-year follow-up. The externally cued (1 Hz) right hand tapping movement was limited to 3 cm amplitude by using at all sites (7 at baseline and 6 at follow-up) identically manufactured wooden frames. No significant differences in cerebral activation were found between sites. Furthermore, our results showed linear response adaptation (i.e. reduced activation) from run 1 to run 4 (over a 25 minute period) in the primary motor area (contralateral more than ipsilateral), in the supplementary motor area and in the primary sensory cortex, sensory-motor cortex and cerebellum, bilaterally. This linear activation decay was the same in both control and patient groups, did not change between baseline and 1-year follow-up and was not influenced by the modest disease progression observed over 1 year. These findings confirm that the short-term adaptation to a simple motor task is a physiological process which is preserved in MS.

  4. Impaired Functional Connectivity Unmasked by Simple Repetitive Motor Task in Early Relapsing-Remitting Multiple Sclerosis.

    PubMed

    Petsas, Nikolaos; Tomassini, Valentina; Filippini, Nicola; Sbardella, Emilia; Tona, Francesca; Piattella, Maria Cristina; Pozzilli, Carlo; Wise, Richard G; Pantano, Patrizia

    2015-07-01

    Resting brain activity can be modulated by motor tasks to adapt to function. In multiple sclerosis (MS) patients, altered resting-state functional connectivity (RS-FC) has been reported and associated with impaired function and disability; little is known on how RS-FC is modulated by a simple repetitive motor task. To assess changes in RS-FC in early relapsing-remitting MS (RRMS) patients associated with repetitive thumb flexions (RTFs). A total of 20 right-handed patients with early RRMS and 14 healthy controls underwent a resting functional magnetic resonance imaging (fMRI) scan, before and after 25 minutes of alternate 30-s blocks of right RTF and rest. Dual-regression analysis of resting fMRI data followed the independent component analysis. Individual spatial maps of coherence between brain areas for 2 networks of interest, sensorimotor and cerebellar, were compared at the group level and correlated with measures of both clinical impairment and brain damage. Significant RTF-induced differences in RS-FC were observed between groups in the cerebellar network because of increased RS-FC in patients but not in controls. In the sensorimotor network, the RS-FC after RTF increased in both groups, with no significant between-group differences. The sensorimotor and the cerebellar RS-FC were intercorrelated only in patients and only after the RTF. The sensorimotor RS-FC increase in patients correlated with structural MRI alterations. Our study unmasked RS-FC changes of motor-related networks occurring after a simple repetitive motor task in early RRMS patients only. Evaluation of altered RSN dynamics might prove useful for anticipating neuroplasticity and for MRI-informed neurorehabilitation. © The Author(s) 2014.

  5. Core stability exercise is as effective as task-oriented motor training in improving motor proficiency in children with developmental coordination disorder: a randomized controlled pilot study.

    PubMed

    Au, Mei K; Chan, Wai M; Lee, Lin; Chen, Tracy Mk; Chau, Rosanna Mw; Pang, Marco Yc

    2014-10-01

    To compare the effectiveness of a core stability program with a task-oriented motor training program in improving motor proficiency in children with developmental coordination disorder (DCD). Randomized controlled pilot trial. Outpatient unit in a hospital. Twenty-two children diagnosed with DCD aged 6-9 years were randomly allocated to the core stability program or the task-oriented motor program. Both groups underwent their respective face-to-face training session once per week for eight consecutive weeks. They were also instructed to carry out home exercises on a daily basis during the intervention period. Short Form of the Bruininks-Oseretsky Test of Motor Proficiency (Second Edition) and Sensory Organization Test at pre- and post-intervention. Intention-to-treat analysis revealed no significant between-group difference in the change of motor proficiency standard score (P=0.717), and composite equilibrium score derived from the Sensory Organization Test (P=0.100). Further analysis showed significant improvement in motor proficiency in both the core stability (mean change (SD)=6.3(5.4); p=0.008) and task-oriented training groups (mean change(SD)=5.1(4.0); P=0.007). The composite equilibrium score was significantly increased in the task-oriented training group (mean change (SD)=6.0(5.5); P=0.009), but not in the core stability group (mean change(SD) =0.0(9.6); P=0.812). In the task-oriented training group, compliance with the home program was positively correlated with change in motor proficiency (ρ=0.680, P=0.030) and composite equilibrium score (ρ=0.638, P=0.047). The core stability exercise program is as effective as task-oriented training in improving motor proficiency among children with DCD. © The Author(s) 2014.

  6. Recent seizure activity alters motor organization in frontal lobe epilepsy as revealed by task-based fMRI.

    PubMed

    Woodward, Kristine E; Gaxiola-Valdez, Ismael; Mainprize, David; Grossi, Matthew; Goodyear, Bradley G; Federico, Paolo

    2014-10-01

    Patients with frontal lobe epilepsy (FLE) commonly demonstrate motor impairments, suggesting that frontal lobe seizures affect motor function. However, the underlying mechanisms of these deficits are not known, nor has any study systematically examined motor organization in these patients. We therefore examined cortical motor organization in a group of adult patients with FLE, using task-based fMRI. Eleven right FLE patients, six left FLE patients, and ten control subjects underwent task-based fMRI. Two tasks were performed using the right and left hands separately, and both hands together. The first task was a finger-tapping task and the second task was a more complex coordination task. Functional MR data were compared between patient groups and controls. A laterality index of brain activation was also calculated between the epileptic and healthy hemisphere to determine hemispheric dominance during task performance to explore its relationship with a variety of patient-specific epilepsy factors. Overall, right FLE patients demonstrated decreased BOLD activity in the epileptic hemisphere and increased BOLD activity in the healthy hemisphere compared to controls (p<0.05). The comparison of left FLE patients to controls provided less conclusive differences, possibly due to the low number of left FLE patients studied. Laterality indices of the coordination task were positively correlated to the number of months since the last seizure in both patient groups (right FLE: rs=0.779, left FLE: rs=0.943). Patients that had experienced a recent seizure relied more on the sensorimotor cortex of the healthy hemisphere during task performance, compared to those that were relatively seizure free (p<0.05). Patients with FLE exhibited changes in motor BOLD activity that was dependent on the duration of seizure freedom. These results demonstrate the presence of seizure-related alteration of cortical motor organization in FLE, which may underlie the motor deficits seen in these

  7. Proprioceptive control of human wrist extensor motor units during an attention-demanding task.

    PubMed

    Nafati, Gilel; Rossi-Durand, Christiane; Schmied, Annie

    2004-08-27

    The responsiveness of the tonically firing single motor units (SMU) to Ia afferent volleys elicited by either mechanical (T-reflex) or electrical nerve stimulation (H-reflex) was tested in the extensor carpi radialis muscle (ECR) while the subjects were maintaining a steady wrist extension force using visual feedback set either at low or high gain. The aim was to determine whether the proprioceptive control of tonic motoneuronal activity depends on the level of attentiveness required by the behavioural context. The response probability of the SMUs to tendon taps was significantly higher (p<0.0001) and that to electrical nerve stimulation was lower (p<0.001) during the more demanding task. Since these changes in SMU responsiveness were not accompanied by any differences in either the motor unit firing patterns or the mean levels of EMG muscle activity, it can be concluded that there were no attention-related changes in the net excitatory drive to the ECR motoneurons. These results are consistent with the idea that fusimotor sensitization of the muscle spindle may have occurred in the more demanding task: an increase in the mechanical sensitivity of the muscle spindles would certainly account for both the T-reflex facilitation and the H-reflex depression observed. The attention-demanding task therefore seemed to involve an independent fusimotor drive activation process. The results of this study suggest that an adaptation of the fusimotor system occurs in humans, depending on the levels of attention and accuracy required to perform the ongoing motor task, as previously reported to occur in animals.

  8. Short-term motor learning through non-immersive virtual reality task in individuals with down syndrome.

    PubMed

    de Mello Monteiro, Carlos Bandeira; da Silva, Talita Dias; de Abreu, Luiz Carlos; Fregni, Felipe; de Araujo, Luciano Vieira; Ferreira, Fernando Henrique Inocêncio Borba; Leone, Claudio

    2017-04-14

    Down syndrome (DS) has unique physical, motor and cognitive characteristics. Despite cognitive and motor difficulties, there is a possibility of intervention based on the knowledge of motor learning. However, it is important to study the motor learning process in individuals with DS during a virtual reality task to justify the use of virtual reality to organize intervention programs. The aim of this study was to analyze the motor learning process in individuals with DS during a virtual reality task. A total of 40 individuals participated in this study, 20 of whom had DS (24 males and 8 females, mean age of 19 years, ranging between 14 and 30 yrs.) and 20 typically developing individuals (TD) who were matched by age and gender to the individuals with DS. To examine this issue, we used software that uses 3D images and reproduced a coincidence-timing task. The results showed that all individuals improved performance in the virtual task, but the individuals with DS that started the task with worse performance showed higher difference from the beginning. Besides that, they were able to retain and transfer the performance with increase of speed of the task. Individuals with DS are able to learn movements from virtual tasks, even though the movement time was higher compared to the TD individuals. The results showed that individuals with DS who started with low performance improved coincidence- timing task with virtual objects, but were less accurate than typically developing individuals. ClinicalTrials.gov Identifier: NCT02719600 .

  9. Decreased Modulation of EEG Oscillations in High-Functioning Autism during a Motor Control Task

    PubMed Central

    Ewen, Joshua B.; Lakshmanan, Balaji M.; Pillai, Ajay S.; McAuliffe, Danielle; Nettles, Carrie; Hallett, Mark; Crone, Nathan E.; Mostofsky, Stewart H.

    2016-01-01

    Autism spectrum disorders (ASD) are thought to result in part from altered cortical excitatory-inhibitory balance; this pathophysiology may impact the generation of oscillations on electroencephalogram (EEG). We investigated premotor-parietal cortical physiology associated with praxis, which has strong theoretical and empirical associations with ASD symptomatology. Twenty five children with high-functioning ASD (HFA) and 33 controls performed a praxis task involving the pantomiming of tool use, while EEG was recorded. We assessed task-related modulation of signal power in alpha and beta frequency bands. Compared with controls, subjects with HFA showed 27% less left central (motor/premotor) beta (18–22 Hz) event-related desynchronization (ERD; p = 0.030), as well as 24% less left parietal alpha (7–13 Hz) ERD (p = 0.046). Within the HFA group, blunting of central ERD attenuation was associated with impairments in clinical measures of praxis imitation (r = −0.4; p = 0.04) and increased autism severity (r = 0.48; p = 0.016). The modulation of central beta activity is associated, among other things, with motor imagery, which may be necessary for imitation. Impaired imitation has been associated with core features of ASD. Altered modulation of oscillatory activity may be mechanistically involved in those aspects of motor network function that relate to the core symptoms of ASD. PMID:27199719

  10. Peripheral neuropathy reduces asymmetries in inter-limb transfer in a visuo-motor task.

    PubMed

    Pan, Zhujun; Van Gemmert, Arend W A

    2016-01-01

    Asymmetry of inter-limb transfer has been associated with the specialization of the dominant and non-dominant motor system. Reductions of asymmetry have been interpreted as behavioural evidence showing a decline of hemispheric lateralization. A previous study showed that ageing did not qualitatively change the inter-limb transfer asymmetry of a visuo-motor task. The current study elaborates on these findings; it examines whether diminished somatosensory information as a result of peripheral neuropathy (PN) adversely affects inter-limb transfer asymmetry. Twenty individuals affected by PN and 20 older controls were recruited and divided equally across two groups. One group trained a visuo-motor task with the right hand while the other group trained it with the left hand. Performance (initial direction error) of the untrained hand before and after training was collected to determine learning effects from inter-limb transfer. Similar to previous studies, the current study showed asymmetric inter-limb transfer in older controls. In contrast, PN showed inter-limb transfer in both directions indicating that PN reduces inter-limb transfer asymmetry. Increased bilateral hemispheric recruitment is suggested to be responsible for this reduced asymmetry which may compensate for deteriorated tactile and/or proprioceptive inputs in PN. Two possible hypotheses are discussed explaining the relationship between declined somatosensory information and increases in bilateral hemispheric recruitment.

  11. Valence and arousal of emotional stimuli impact cognitive-motor performance in an oddball task.

    PubMed

    Lu, Yingzhi; Jaquess, Kyle J; Hatfield, Bradley D; Zhou, Chenglin; Li, Hong

    2017-04-01

    It is widely recognized that emotions impact an individual's ability to perform in a given task. However, little is known about how emotion impacts the various aspects of cognitive -motor performance. We recorded event-related potentials (ERPs) and chronometric responses from twenty-six participants while they performed a cognitive-motor oddball task in regard to four categories of emotional stimuli (high-arousing positive-valence, low-arousing positive-valence, high-arousing negative-valence, and low-arousing negative-valence) as "deviant" stimuli. Six chronometric responses (reaction time, press time, return time, choice time, movement time, and total time) and three ERP components (P2, N2 and late positive potential) were measured. Results indicated that reaction time was significantly affected by the presentation of emotional stimuli. Also observed was a negative relationship between N2 amplitude and elements of performance featuring reaction time in the low-arousing positive-valence condition. This study provides further evidence that emotional stimuli influence cognitive-motor performance in a specific manner. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Inhibitory motor control in apneic and insomniac patients: a stop task study.

    PubMed

    Sagaspe, Patricia; Philip, Pierre; Schwartz, Sophie

    2007-12-01

    The aim of this study was to assess with a stop task the inhibitory motor control efficiency--a major component of executive control functions--in patients suffering from sleep disorders. Twenty-two patients with untreated obstructive sleep apnea syndrome (OSAS) (mean age 46 +/- 9 years; mean apnea-hypopnea index, AHI = 30 +/- 20) and 13 patients with psychophysiological insomnia (mean age 47 +/- 12 years) were compared with individually matched healthy controls. Sleep disturbances in the patient populations were clinically and polysomnographically diagnosed. The stop task has a frequent visual 'Go' stimulus to set up a response tendency and a less frequent auditory 'Stop' signal to withhold the planned or prepotent response. The stop signal reaction time (SSRT) reflects the time to internally suppress the ongoing response. SSRT was slower for the apneic patients than for their respective controls (248 +/- 107 versus 171 +/- 115 ms, anova, P < 0.05) but not for the insomniac patients compared with their controls (235 +/- 112 versus 194 +/- 109 ms, NS). Moreover, in apneic patients, slower SSRT was associated with lower nocturnal oxygen saturation (r = -0.477, P < 0.05). By contrast, neither apneics nor insomniacs differed from their matched controls for reaction times on Go trials. To conclude, unlike insomniacs, OSAS patients present an impaired inhibitory motor control, an executive function which is required in many common everyday life situations. Inhibitory motor control relies on the integrity of the inferior prefrontal cortex, which could be affected by nocturnal oxyhemoglobin desaturation in apneic patients.

  13. Changes in the theta band coherence during motor task after hand immobilization.

    PubMed

    Brauns, Igor; Teixeira, Silmar; Velasques, Bruna; Bittencourt, Juliana; Machado, Sergio; Cagy, Mauricio; Gongora, Mariana; Bastos, Victor Hugo; Machado, Dionis; Sandoval-Carrillo, Ada; Salas-Pacheco, Jose; Piedade, Roberto; Ribeiro, Pedro; Arias-Carrión, Oscar

    2014-01-01

    Many different factors can temporarily or permanently impair movement and impairs cortical organization, e.g. hand immobilization. Such changes have been widely studied using electroencephalography. Within this context, we have investigated the immobilization effects through the theta band coherence analysis, in order to find out whether the immobilization period causes any changes in the inter and intra-hemispheric coherence within the cerebral cortex, as well as to observe whether the theta band provides any information about the neural mechanisms involved during the motor act. We analyzed the cortical changes that occurred after 48 hours of hand immobilization. The theta band coherence was study through electroencephalography in 30 healthy subjects, divided into two groups (control and experimental). Within both groups, the subjects executed a task involving flexion and extension of the index finger, before and after 48 hours. The experimental group, however, was actually submitted to hand immobilization. We were able to observe an increase in the coupling within the experimental group in the frontal, parietal and temporal regions, and a decrease in the motor area. In order to execute manual tasks after some time of movement restriction, greater coherence is present in areas related to attention, movement preparation and sensorimotor integration processes. These results may contribute to a detailed assessment of involved neurophysiological mechanism in motor act execution.

  14. EEG Source Imaging Enhances the Decoding of Complex Right Hand Motor Imagery Tasks

    PubMed Central

    Edelman, Bradley J.; Baxter, Bryan

    2015-01-01

    Goal Sensorimotor-based brain-computer interfaces (BCIs) have achieved successful control of real and virtual devices in up to three dimensions; however, the traditional sensor-based paradigm limits the intuitive use of these systems. Many control signals for state-of-the-art BCIs involve imagining the movement of body parts that have little to do with the output command, revealing a cognitive disconnection between the user’s intent and the action of the end effector. Therefore, there is a need to develop techniques which can identify with high spatial resolution the self-modulated neural activity reflective of the actions of a helpful output device. Methods We extend previous EEG source imaging (ESI) work to decoding natural hand/wrist manipulations by applying a novel technique to classifying four complex motor imaginations of the right hand: flexion, extension, supination and pronation. Results We report an increase of up to 18.6% for individual task classification and 12.7% for overall classification using the proposed ESI approach over the traditional sensor-based method. Conclusion ESI is able to enhance BCI performance of decoding complex right hand motor imagery tasks. Significance The present work may lead to the development of BCI systems with naturalistic and intuitive motor imaginations, thus facilitating broad use of non-invasive BCIs. PMID:26276986

  15. Putamen neurons process both sensory and motor information during a complex task.

    PubMed

    Vicente, Ana F; Bermudez, Maria A; Romero, Maria Del Carmen; Perez, Rogelio; Gonzalez, Francisco

    2012-07-23

    The putamen has classically been considered to be primarily a motor structure. It is involved in a broad range of roles and its neurons have been postulated to function as pattern classifiers of behaviourally significant events. However, its specific role in motor and sensory processing is still unclear. For the purpose of better categorizing putamen neurons, we trained two rhesus monkeys to perform multisensory operant tasks by using complex stimuli such as short videoclips. Trials involved image or soundtrack or both. Some stimuli required a motor response associated to reward, whereas others did not require response and produced no reward. We found that neurons in the putamen showed pure visual responses, action-related activity, and reward responses. Insofar as action-related activity, preparation of movement, movement execution, and withholding of movement involved three different putamen neuron populations. Moreover, our data suggest an involvement of putamen neurons in processing primary rewards and visual events in a complex task, which may contribute to reinforcement learning through stimulus-reward association.

  16. Impaired motor inhibition in adults who stutter - evidence from speech-free stop-signal reaction time tasks.

    PubMed

    Markett, Sebastian; Bleek, Benjamin; Reuter, Martin; Prüss, Holger; Richardt, Kirsten; Müller, Thilo; Yaruss, J Scott; Montag, Christian

    2016-10-01

    Idiopathic stuttering is a fluency disorder characterized by impairments during speech production. Deficits in the motor control circuits of the basal ganglia have been implicated in idiopathic stuttering but it is unclear how these impairments relate to the disorder. Previous work has indicated a possible deficiency in motor inhibition in children who stutter. To extend these findings to adults, we designed two experiments to probe executive motor control in people who stutter using manual reaction time tasks that do not rely on speech production. We used two versions of the stop-signal reaction time task, a measure for inhibitory motor control that has been shown to rely on the basal ganglia circuits. We show increased stop-signal reaction times in two independent samples of adults who stutter compared to age- and sex-matched control groups. Additional measures involved simple reaction time measurements and a task-switching task where no group difference was detected. Results indicate a deficiency in inhibitory motor control in people who stutter in a task that does not rely on overt speech production and cannot be explained by general deficits in executive control or speeded motor execution. This finding establishes the stop-signal reaction time as a possible target for future experimental and neuroimaging studies on fluency disorders and is a further step towards unraveling the contribution of motor control deficits to idiopathic stuttering. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Cathodal Transcranial Direct Current Stimulation Over Left Dorsolateral Prefrontal Cortex Area Promotes Implicit Motor Learning in a Golf Putting Task.

    PubMed

    Zhu, Frank F; Yeung, Andrew Y; Poolton, Jamie M; Lee, Tatia M C; Leung, Gilberto K K; Masters, Rich S W

    2015-01-01

    Implicit motor learning is characterized by low dependence on working memory and stable performance despite stress, fatigue, or multi-tasking. However, current paradigms for implicit motor learning are based on behavioral interventions that are often task-specific and limited when applied in practice. To investigate whether cathodal transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) area during motor learning suppressed working memory activity and reduced explicit verbal-analytical involvement in movement control, thereby promoting implicit motor learning. Twenty-seven healthy individuals practiced a golf putting task during a Training Phase while receiving either real cathodal tDCS stimulation over the left DLPFC area or sham stimulation. Their performance was assessed during a Test phase on another day. Verbal working memory capacity was assessed before and after the Training Phase, and before the Test Phase. Compared to sham stimulation, real stimulation suppressed verbal working memory activity after the Training Phase, but enhanced golf putting performance during the Training Phase and the Test Phase, especially when participants were required to multi-task. Cathodal tDCS over the left DLPFC may foster implicit motor learning and performance in complex real-life motor tasks that occur during sports, surgery or motor rehabilitation. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Transfer of Short-Term Motor Learning across the Lower Limbs as a Function of Task Conception and Practice Order

    ERIC Educational Resources Information Center

    Stockel, Tino; Wang, Jinsung

    2011-01-01

    Interlimb transfer of motor learning, indicating an improvement in performance with one limb following training with the other, often occurs asymmetrically (i.e., from non-dominant to dominant limb or vice versa, but not both). In the present study, we examined whether interlimb transfer of the same motor task could occur asymmetrically and in…

  19. Transfer of Short-Term Motor Learning across the Lower Limbs as a Function of Task Conception and Practice Order

    ERIC Educational Resources Information Center

    Stockel, Tino; Wang, Jinsung

    2011-01-01

    Interlimb transfer of motor learning, indicating an improvement in performance with one limb following training with the other, often occurs asymmetrically (i.e., from non-dominant to dominant limb or vice versa, but not both). In the present study, we examined whether interlimb transfer of the same motor task could occur asymmetrically and in…

  20. Effect of Modality and Task Type on Interlanguage Variation

    ERIC Educational Resources Information Center

    Kim, Hye Yeong

    2017-01-01

    An essential component for assessing the accuracy and fluency of language learners is understanding how mode of communication and task type affect performance in second-language (L2) acquisition. This study investigates how text-based synchronous computer-mediated communication (SCMC) and face-to-face (F2F) oral interaction can influence the…

  1. Reading Rate, Readability and Variations in Task-Induced Processing.

    ERIC Educational Resources Information Center

    Coke, Esther U.

    This study examined the adaptability of reading rate to passage difficulty under different conditions of task-induced processing. Sixteen experimental passages varying in subject matter and ranging from 85 to 171 words were selected from a set of 32 texts rated for comprehensibility. The eight easiest and eight hardest texts were selected. Another…

  2. Differences in motor variability among individuals performing a standardized short-cycle manual task.

    PubMed

    Sandlund, Jonas; Srinivasan, Divya; Heiden, Marina; Mathiassen, Svend Erik

    2017-01-01

    Motor variability (MV) has been suggested to be a determinant of the risk for developing musculoskeletal disorders in repetitive work. In this study we examined whether individuals consistently differed in the extent of motor variability when performing a standardized short-cycle manual task. On three separate days, arm kinematics was recorded in 14 healthy subjects performing a pipetting task, transferring liquid from a pick-up tube to eight target tubes with a cycle time of 2.8s. Cycle-to-cycle standard deviations (SD) of a large selection of shoulder and elbow kinematic variables, were processed using principal component analysis (PCA). Thereafter, between-subjects and between-days (within-subject) variance components were calculated using a random effects model for each of four extracted principal components. The results showed that MV differed consistently between subjects (95% confidence intervals of the between-subjects variances did not include zero) and that subjects differed consistently in MV between days. Thus, our results support the notion that MV may be a consistent personal trait, even though further research is needed to verify whether individuals rank consistently in MV even across tasks. If so, MV may be a candidate determinant of the risk of developing fatigue and musculoskeletal disorders in repetitive occupational work.

  3. Task-Based Mirror Therapy Augmenting Motor Recovery in Poststroke Hemiparesis: A Randomized Controlled Trial.

    PubMed

    Arya, Kamal Narayan; Pandian, Shanta; Kumar, Dharmendra; Puri, Vinod

    2015-08-01

    To establish the effect of the task-based mirror therapy (TBMT) on the upper limb recovery in stroke. A pilot, randomized, controlled, assessor-blinded trial was conducted in a rehabilitation institute. A convenience sample of 33 poststroke (mean duration, 12.5 months) hemiparetic subjects was randomized into 2 groups (experimental, 17; control, 16). The subjects were allocated to receive either TBMT or standard motor rehabilitation-40 sessions (5/week) for a period of 8 weeks. The TBMT group received movements using various goal-directed tasks and a mirror box. The movements were performed by the less-affected side superimposed on the affected side. The main outcome measures were Brunnstrom recovery stage (BRS) and Fugl-Meyer assessment (FMA)-FMA of upper extremity (FMA-UE), including upper arm (FMA-UA) and wrist-hand (FMA-WH). The TBMT group exhibited highly significant improvement on mean scores of FMA-WH (P < .001) and FMA-UE (P < .001) at postassessment in comparison to the control group. Furthermore, there was a 12% increase in the number of subjects at BRS stage 5 (out of synergy movement) in the experimental group as compared to a 0% rise at the same stage in the control group. This pilot trial confirmed the role of TBMT in improving the wrist-hand motor recovery in poststroke hemiparesis. MT using tasks may be used as an adjunct in stroke rehabilitation. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  4. Motor learning in children with spina bifida: intact learning and performance on a ballistic task.

    PubMed

    Dennis, Maureen; Jewell, Derryn; Edelstein, Kim; Brandt, Michael E; Hetherington, Ross; Blaser, Susan E; Fletcher, Jack M

    2006-09-01

    Learning and performance on a ballistic task were investigated in children with spina bifida meningomyelocele (SBM), with either upper level spinal lesions (n = 21) or lower level spinal lesions (n = 81), and in typically developing controls (n = 35). Participants completed three phases (20 trials each) of an elbow goniometer task that required a ballistic arm movement to move a cursor to one of two target positions on a screen, including (1) an initial learning phase, (2) an adaptation phase with a gain change such that recalibration of the ballistic arm movement was required, and (3) a learning reactivation phase under the original gain condition. Initial error rate, asymptotic error rate, and learning rate did not differ significantly between the SBM and control groups. Relative to controls, the SBM group had reduced volumes in the cerebellar hemispheres and pericallosal gray matter (the region including the basal ganglia), although only the pericallosal gray matter was significantly correlated with motor adaptation. Congenital cerebellar dysmorphology is associated with preserved motor skill learning on voluntary, nonreflexive tasks in children with SBM, in whom the relative roles of the cerebellum and basal ganglia may differ from those in the adult brain.

  5. Coherent oscillations in monkey motor cortex and hand muscle EMG show task-dependent modulation.

    PubMed Central

    Baker, S N; Olivier, E; Lemon, R N

    1997-01-01

    1. Recordings were made of local field potential (slow waves) and pyramidal tract neurone (PTN) discharge from pairs of sites separated by a horizontal distance of up to 1.5 mm in the primary motor cortex of two conscious macaque monkeys performing a precision grip task. 2. In both monkeys, the slow wave recordings showed bursts of oscillations in the 20-30 Hz range. Spectral analysis revealed that the oscillations were coherent between the two simultaneously recorded cortical sites. In the monkey from which most data were recorded, the mean frequency of peak coherence was 23.4 Hz. 3. Coherence in this frequency range was also seen between cortical slow wave recordings and rectified EMG of hand and forearm muscles active during the task, and between pairs of rectified EMGs. 4. The dynamics of the coherence were investigated by analysing short, quasi-stationary data segments aligned relative to task performance. This revealed that the 20-30 Hz coherent oscillations were present mainly during the hold phase of the precision grip task. 5. The spikes of identified PTNs were used to compile spike-triggered averages of the slow wave recordings. Oscillations were seen in 11/17 averages of the slow wave recorded on the same electrode as the triggering spike, and 11/17 averages of the slow wave recorded on the distant electrode. The mean period of these oscillations was 45.8 ms. 6. It is concluded that oscillations in the range 20-30 Hz are present in monkey motor cortex, are coherent between spatially separated cortical sites, and encompass the pyramidal tract output neurones. They are discernable in the EMG of active muscles, and show a consistent task-dependent modulation. Images Figure 3 Figure 6 Figure 7 PMID:9175005

  6. Adaptation of task difficulty in rehabilitation exercises based on the user's motor performance and physiological responses.

    PubMed

    Shirzad, Navid; Van der Loos, H F Machiel

    2013-06-01

    Although robot-assisted rehabilitation regimens are as effective, functionally, as conventional therapies, they still lack features to increase patients' engagement in the regimen. Providing rehabilitation tasks at a "desirable difficulty" is one of the ways to address this issue and increase the motivation of a patient to continue with the therapy program. Then the problem is to design a system that is capable of estimating the user's desirable difficulty, and ultimately, modifying the task based on this prediction. In this paper we compared the performance of three machine learning algorithms in predicting a user's desirable difficulty during a typical reaching motion rehabilitation task. Different levels of error amplification were used as different levels of task difficulty. We explored the usefulness of using participants' motor performance and physiological signals during the reaching task in prediction of their desirable difficulties. Results showed that a Neural Network approach gives higher prediction accuracy in comparison with models based on k-Nearest Neighbor and Discriminant Analysis methods.

  7. Effect of a Task-Oriented Rehabilitation Program on Upper Extremity Recovery Following Motor Stroke

    PubMed Central

    Winstein, Carolee J.; Wolf, Steven L.; Dromerick, Alexander W.; Lane, Christianne J.; Nelsen, Monica A.; Lewthwaite, Rebecca; Cen, Steven Yong; Azen, Stanley P.

    2016-01-01

    IMPORTANCE Clinical trials suggest that higher doses of task-oriented training are superior to current clinical practice for patients with stroke with upper extremity motor deficits. OBJECTIVE To compare the efficacy of a structured, task-oriented motor training program vs usual and customary occupational therapy (UCC) during stroke rehabilitation. DESIGN, SETTING, AND PARTICIPANTS Phase 3, pragmatic, single-blind randomized trial among 361 participants with moderate motor impairment recruited from 7 US hospitals over 44 months, treated in the outpatient setting from June 2009 to March 2014. INTERVENTIONS Structured, task-oriented upper extremity training (Accelerated Skill Acquisition Program[ASAP]; n = 119); dose-equivalent occupational therapy (DEUCC; n = 120); or monitoring-only occupational therapy (UCC; n = 122). The DEUCC group was prescribed 30 one-hour sessions over 10 weeks; the UCC group was only monitored, without specification of dose. MAIN OUTCOMES AND MEASURES The primary outcome was 12-month change in log-transformed Wolf Motor Function Test time score (WMFT, consisting of a mean of 15 timed arm movements and hand dexterity tasks). Secondary outcomes were change in WMFT time score (minimal clinically important difference [MCID] = 19 seconds) and proportion of patients improving ≥25 points on the Stroke Impact Scale (SIS) hand function score (MCID = 17.8 points). RESULTS Among the 361 randomized patients (mean age, 60.7 years; 56% men; 42% African American; mean time since stroke onset, 46 days), 304 (84%) completed the 12-month primary outcome assessment; in intention-to-treat analysis, mean group change scores (log WMFT, baseline to 12 months) were, for the ASAP group, 2.2 to 1.4 (difference, 0.82); DEUCC group, 2.0 to 1.2 (difference, 0.84); and UCC group, 2.1 to 1.4 (difference, 0.75), with no significant between-group differences (ASAP vs DEUCC:0.14; 95% CI, −0.05 to 0.33; P = .16; ASAP vs UCC: −0.01; 95% CI, −0.22 to 0.21; P = .94; and

  8. Task-specific contribution of the human striatum to perceptual-motor skill learning.

    PubMed

    Cavaco, Sara; Anderson, Steven W; Correia, Manuel; Magalhaes, Marina; Pereira, Claudia; Tuna, Assuncao; Taipa, Ricardo; Pinto, Pedro; Pinto, Claudia; Cruz, Romeu; Lima, Antonio Bastos; Castro-Caldas, Alexandre; da Silva, Antonio Martins; Damasio, Hanna

    2011-01-01

    Acquisition of new perceptual-motor skills depends on multiple brain areas, including the striatum. However, the specific contribution of each structure to this type of learning is still poorly understood. Focusing on the striatum, we proposed (a) to replicate the finding of impaired rotary pursuit (RP) and preserved mirror tracing (MT) in Huntington's disease (HD); and (b) to further explore this putative learning dissociation with other human models of striatal dysfunction (i.e., Parkinson's disease and focal vascular damage) and two new paradigms (i.e., Geometric Figures, GF, and Control Stick, CS) of skill learning. Regardless of the etiology, participants with damage to the striatum showed impaired learning of visuomotor tracking skills (i.e., RP and GF), whereas the ability to learn skills that require motor adaptation (i.e., MT and CS) was not affected. These results suggest a task-specific involvement of the striatum in the early stages of skill learning.

  9. Extracting motor synergies from random movements for low-dimensional task-space control of musculoskeletal robots.

    PubMed

    Fu, Kin Chung Denny; Dalla Libera, Fabio; Ishiguro, Hiroshi

    2015-10-08

    In the field of human motor control, the motor synergy hypothesis explains how humans simplify body control dimensionality by coordinating groups of muscles, called motor synergies, instead of controlling muscles independently. In most applications of motor synergies to low-dimensional control in robotics, motor synergies are extracted from given optimal control signals. In this paper, we address the problems of how to extract motor synergies without optimal data given, and how to apply motor synergies to achieve low-dimensional task-space tracking control of a human-like robotic arm actuated by redundant muscles, without prior knowledge of the robot. We propose to extract motor synergies from a subset of randomly generated reaching-like movement data. The essence is to first approximate the corresponding optimal control signals, using estimations of the robot's forward dynamics, and to extract the motor synergies subsequently. In order to avoid modeling difficulties, a learning-based control approach is adopted such that control is accomplished via estimations of the robot's inverse dynamics. We present a kernel-based regression formulation to estimate the forward and the inverse dynamics, and a sliding controller in order to cope with estimation error. Numerical evaluations show that the proposed method enables extraction of motor synergies for low-dimensional task-space control.

  10. The effect of dual-task difficulty on the inhibition of the motor cortex.

    PubMed

    Corp, Daniel T; Rogers, Mark A; Youssef, George J; Pearce, Alan J

    2016-02-01

    Dual-tasking is intrinsic to many daily activities, including walking and driving. However, the activity of the primary motor cortex (M1) in response to dual-tasks (DT) is still not well characterised. A recent meta-analysis (Corp in Neurosci Biobehav Rev 43:74-87, 2014) demonstrated a reduction in M1 inhibition during dual-tasking, yet responses were not consistent between studies. It was suggested that DT difficulty might account for some of this between-study variability. The aim of this study was to investigate whether corticospinal excitability and M1 inhibition differed between an easier and more difficult dual-task. Transcranial magnetic stimulation (TMS) was applied to participants' abductor pollicis brevis muscle representation during a concurrent pincer grip task and stationary bike-riding. The margin of error in which to maintain pincer grip force was reduced to increase task difficulty. Compared to ST conditions, significantly increased M1 inhibition was demonstrated for the easier, but not more difficult, DT. However, there was no significant difference in M1 inhibition between easy and difficult DTs. The difference in difficulty between the two tasks may not have been wide enough to result in significant differences in M1 inhibition. Increased M1 inhibition for the easy DT condition was in opposition to the reduction in M1 inhibition found in our meta-analysis (Corp in Neurosci Biobehav Rev 43:74-87, 2014). We propose that this may be partially explained by differences in the timing of the TMS pulse between DT studies.

  11. Task-specificity of unilateral anodal and dual-M1 tDCS effects on motor learning.

    PubMed

    Karok, Sophia; Fletcher, David; Witney, Alice G

    2017-01-08

    Task-specific effects of transcranial direct current stimulation (tDCS) on motor learning were investigated in 30 healthy participants. In a sham-controlled, mixed design, participants trained on 3 different motor tasks (Purdue Pegboard Test, Visuomotor Grip Force Tracking Task and Visuomotor Wrist Rotation Speed Control Task) over 3 consecutive days while receiving either unilateral anodal over the right primary motor cortex (M1), dual-M1 or sham stimulation. Retention sessions were administered 7 and 28 days after the end of training. In the Purdue Pegboard Test, both anodal and dual-M1 stimulation reduced average completion time approximately equally, an improvement driven by online learning effects and maintained for about 1 week. The Visuomotor Grip Force Tracking Task and the Visuomotor Wrist Rotation Speed Control Task were associated with an advantage of dual-M1 tDCS in consolidation processes both between training sessions and when testing at long-term retention; both were maintained for at least 1 month. This study demonstrates that M1-tDCS enhances and sustains motor learning with different electrode montages. Stimulation-induced effects emerged at different learning phases across the tasks, which strongly suggests that the influence of tDCS on motor learning is dynamic with respect to the functional recruitment of the distributed motor system at the time of stimulation. Divergent findings regarding M1-tDCS effects on motor learning may partially be ascribed to task-specific consequences and the effects of offline consolidation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Temporal Accumulation and Decision Processes in the Duration Bisection Task Revealed by Contingent Negative Variation

    PubMed Central

    Ng, Kwun Kei; Tobin, Simon; Penney, Trevor B.

    2011-01-01

    The duration bisection paradigm is a classic task used to examine how humans and other animals perceive time. Typically, participants first learn short and long anchor durations and are subsequently asked to classify probe durations as closer to the short or long anchor duration. However, the specific representations of time and the decision rules applied in this task remain the subject of debate. For example, researchers have questioned whether participants actually use representations of the short and long anchor durations in the decision process rather than merely a response threshold that is derived from those anchor durations. Electroencephalographic (EEG) measures, like the contingent negative variation (CNV), can provide information about the perceptual and cognitive processes that occur between the onset of the timing stimulus and the motor response. The CNV has been implicated as an electrophysiological marker of interval timing processes such as temporal accumulation, representation of the target duration, and the decision that the target duration has been attained. We used the CNV to investigate which durations are involved in the bisection categorization decision. The CNV increased in amplitude up to the value of the short anchor, remained at a constant level until about the geometric mean (GM) of the short and long anchors, and then began to resolve. These results suggest that the short anchor and the GM of the short and long anchors are critical target durations used in the bisection categorization decision process. In addition, larger mean N1P2 amplitude differences were associated with larger amplitude CNVs, which may reflect the participant’s precision in initiating timing on each trial across a test session. Overall, the results demonstrate the value of using scalp-recorded EEG to address basic questions about interval timing. PMID:22144952

  13. Development of Vestibular Stochastic Resonance as a Sensorimotor Countermeasure: Improving Otolith Ocular and Motor Task Responses

    NASA Technical Reports Server (NTRS)

    Mulavara, Ajitkumar; Fiedler, Matthew; DeDios,Yiri E.; Galvan, Raquel; Bloomberg, Jacob; Wood, Scott

    2011-01-01

    Astronauts experience disturbances in sensorimotor function after spaceflight during the initial introduction to a gravitational environment, especially after long-duration missions. Stochastic resonance (SR) is a mechanism by which noise can assist and enhance the response of neural systems to relevant, imperceptible sensory signals. We have previously shown that imperceptible electrical stimulation of the vestibular system enhances balance performance while standing on an unstable surface. The goal of our present study is to develop a countermeasure based on vestibular SR that could improve central interpretation of vestibular input and improve motor task responses to mitigate associated risks.

  14. Subcortical neuronal ensembles: an analysis of motor task association, tremor, oscillations, and synchrony in human patients.

    PubMed

    Hanson, Timothy L; Fuller, Andrew M; Lebedev, Mikhail A; Turner, Dennis A; Nicolelis, Miguel A L

    2012-06-20

    Deep brain stimulation (DBS) has expanded as an effective treatment for motor disorders, providing a valuable opportunity for intraoperative recording of the spiking activity of subcortical neurons. The properties of these neurons and their potential utility in neuroprosthetic applications are not completely understood. During DBS surgeries in 25 human patients with either essential tremor or Parkinson's disease, we acutely recorded the single-unit activity of 274 ventral intermediate/ventral oralis posterior motor thalamus (Vim/Vop) neurons and 123 subthalamic nucleus (STN) neurons. These subcortical neuronal ensembles (up to 23 neurons sampled simultaneously) were recorded while the patients performed a target-tracking motor task using a cursor controlled by a haptic glove. We observed that modulations in firing rate of a substantial number of neurons in both Vim/Vop and STN represented target onset, movement onset/direction, and hand tremor. Neurons in both areas exhibited rhythmic oscillations and pairwise synchrony. Notably, all tremor-associated neurons exhibited synchrony within the ensemble. The data further indicate that oscillatory (likely pathological) neurons and behaviorally tuned neurons are not distinct but rather form overlapping sets. Whereas previous studies have reported a linear relationship between power spectra of neuronal oscillations and hand tremor, we report a nonlinear relationship suggestive of complex encoding schemes. Even in the presence of this pathological activity, linear models were able to extract motor parameters from ensemble discharges. Based on these findings, we propose that chronic multielectrode recordings from Vim/Vop and STN could prove useful for further studying, monitoring, and even treating motor disorders.

  15. Dramatic effects of speech task on motor and linguistic planning in severely dysfluent parkinsonian speech

    PubMed Central

    Van Lancker Sidtis, Diana; Cameron, Krista; Sidtis, John J.

    2015-01-01

    In motor speech disorders, dysarthric features impacting intelligibility, articulation, fluency, and voice emerge more saliently in conversation than in repetition, reading, or singing. A role of the basal ganglia in these task discrepancies has been identified. Further, more recent studies of naturalistic speech in basal ganglia dysfunction have revealed that formulaic language is more impaired than novel language. This descriptive study extends these observations to a case of severely dysfluent dysarthria due to a parkinsonian syndrome. Dysfluencies were quantified and compared for conversation, two forms of repetition, reading, recited speech, and singing. Other measures examined phonetic inventories, word forms, and formulaic language. Phonetic, syllabic, and lexical dysfluencies were more abundant in conversation than in other task conditions. Formulaic expressions in conversation were reduced compared to normal speakers. A proposed explanation supports the notion that the basal ganglia contribute to formulation of internal models for execution of speech. PMID:22774929

  16. Mental workload and motor performance dynamics during practice of reaching movements under various levels of task difficulty.

    PubMed

    Shuggi, Isabelle M; Oh, Hyuk; Shewokis, Patricia A; Gentili, Rodolphe J

    2017-09-30

    The assessment of mental workload can inform attentional resource allocation during task performance that is essential for understanding the underlying principles of human cognitive-motor behavior. While many studies have focused on mental workload in relation to human performance, a modest body of work has examined it in a motor practice/learning context without considering individual variability. Thus, this work aimed to examine mental workload by employing the NASA TLX as well as the changes in motor performance resulting from the practice of a novel reaching task. Two groups of participants practiced a reaching task at a high and low nominal difficulty during which a group-level analysis assessed the mental workload, motor performance and motor improvement dynamics. A secondary cluster analysis was also conducted to identify specific individual patterns of cognitive-motor responses. Overall, both group- and cluster-level analyses revealed that: (i) all participants improved their performance throughout motor practice, and (ii) an increase in mental workload was associated with a reduction of the quality of motor performance along with a slower rate of motor improvement. The results are discussed in the context of the optimal challenge point framework and in particular it is proposed that under the experimental conditions employed here, functional task difficulty: (i) would possibly depend on an individuals' information processing capabilities, and (ii) could be indexed by the level of mental workload which, when excessively heightened can decrease the quality of performance and more generally result in delayed motor improvements. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  17. The Effects of Material and Task Variations on a Brief Cognitive Learning Strategies Training Program.

    ERIC Educational Resources Information Center

    Weinstein, Claire E.; And Others

    Two studies were performed to investigate the effects of material and task variations in the acquisition of cognitive learning strategies. Groups of undergraduate students were taught to use mental imagery, meaningful elaboration, and grouping. The type of training task or the order of training and test materials differed for each of the…

  18. Optimization of jaw muscle activity and fine motor control during repeated biting tasks.

    PubMed

    Kumar, Abhishek; Svensson, Krister G; Baad-Hansen, Lene; Trulsson, Mats; Isidor, Flemming; Svensson, Peter

    2014-12-01

    To investigate if repeated holding and splitting of food morsel change the variability of force and jaw muscle activity in participants with natural dentition. Twenty healthy volunteers (mean age=26.2±3.9 years) participated in a single session divided into six series. Each series consisted of ten trials of a standardized behavioural task (total 60 trials) involving holding and splitting a flat-faced tablet (8mm, 180mg) placed on a bite force transducer with the anterior teeth. The hold and split forces along with the electromyographic (EMG) activity of the left and right masseter (MAL and MAR), left anterior temporalis (TAL) and digastric (DIG) muscles were recorded. A series (ten trials) of natural biting tasks was also performed before and after the six series of the behavioural task. The mean hold force (P<0.001) but not the mean split force (P=0.590) showed significant effect of number of series. No significant effect of series was seen on the variability of hold and split force and the EMG activity except for the variability of EMG activity for MAL during the hold phase (P=0.021) and DIG during the split phase (P<0.001). The behavioural task had no effect on the EMG activity of the natural biting task. There was no evident optimization of jaw motor function in terms of reduction in the variability of bite force values and muscle activity, when this simple task was repeated up to sixty times in participants with normal intact periodontium. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Sonification and haptic feedback in addition to visual feedback enhances complex motor task learning.

    PubMed

    Sigrist, Roland; Rauter, Georg; Marchal-Crespo, Laura; Riener, Robert; Wolf, Peter

    2015-03-01

    Concurrent augmented feedback has been shown to be less effective for learning simple motor tasks than for complex tasks. However, as mostly artificial tasks have been investigated, transfer of results to tasks in sports and rehabilitation remains unknown. Therefore, in this study, the effect of different concurrent feedback was evaluated in trunk-arm rowing. It was then investigated whether multimodal audiovisual and visuohaptic feedback are more effective for learning than visual feedback only. Naïve subjects (N = 24) trained in three groups on a highly realistic virtual reality-based rowing simulator. In the visual feedback group, the subject's oar was superimposed to the target oar, which continuously became more transparent when the deviation between the oars decreased. Moreover, a trace of the subject's trajectory emerged if deviations exceeded a threshold. The audiovisual feedback group trained with oar movement sonification in addition to visual feedback to facilitate learning of the velocity profile. In the visuohaptic group, the oar movement was inhibited by path deviation-dependent braking forces to enhance learning of spatial aspects. All groups significantly decreased the spatial error (tendency in visual group) and velocity error from baseline to the retention tests. Audiovisual feedback fostered learning of the velocity profile significantly more than visuohaptic feedback. The study revealed that well-designed concurrent feedback fosters complex task learning, especially if the advantages of different modalities are exploited. Further studies should analyze the impact of within-feedback design parameters and the transferability of the results to other tasks in sports and rehabilitation.

  20. [Neuromodulatory effects of bromazepam when individuals were exposed to a motor learning task: quantitative electroencephalography (qEEG)].

    PubMed

    Salles, José Inácio; Bastos, Victor Hugo; Cunha, Marlo; Machado, Dionis; Cagy, Maurício; Furtado, Vernon; Basile, Luis Fernando; Piedade, Roberto; Ribeiro, Pedro

    2006-03-01

    The sedative effects of bromazepam on cognitive and performance have been widely investigated. A number of different approaches have assessed the influence of bromazepam when individuals are engaged to a motor task. In this context, the present study aimed to investigate electrophysiological changes when individuals were exposed to a typewriting task after taking 6 mg of bromazepam. qEEG data were simultaneously recorded during the task. In particular, relative power in delta band (0.5-3.5 Hz) was analyzed. Time of execution and errors during the task were registered as behavioral variables. The experimental group, bromazepam 6 mg, showed a better motor performance and higher relative power than control individuals (placebo). These results suggest that the use of bromazepam reduces anxiety levels as expected and thus, produces an increment in motor performance.

  1. Manipulation gesture effect in visual and auditory presentations: the link between tools in perceptual and motor tasks

    PubMed Central

    Rey, Amandine E.; Roche, Kévin; Versace, Rémy; Chainay, Hanna

    2015-01-01

    There is much behavioral and neurophysiological evidence in support of the idea that seeing a tool activates motor components of action related to the perceived object (e.g., grasping, use manipulation). However, the question remains as to whether the processing of the motor components associated with the tool is automatic or depends on the situation, including the task and the modality of tool presentation. The present study investigated whether the activation of motor components involved in tool use in response to the simple perception of a tool is influenced by the link between prime and target tools, as well as by the modality of presentation, in perceptual or motor tasks. To explore this issue, we manipulated the similarity of gesture involved in the use of the prime and target (identical, similar, different) with two tool presentation modalities of the presentation tool (visual or auditory) in perceptual and motor tasks. Across the experiments, we also manipulated the relevance of the prime (i.e., associated or not with the current task). The participants saw a first tool (or heard the sound it makes), which was immediately followed by a second tool on which they had to perform a perceptual task (i.e., indicate whether the second tool was identical to or different from the first tool) or a motor task (i.e., manipulate the second tool as if it were the first tool). In both tasks, the similarity between the gestures employed for the first and the second tool was manipulated (Identical, Similar or Different gestures). The results showed that responses were faster when the manipulation gestures for the two tools were identical or similar, but only in the motor task. This effect was observed irrespective of the modality of presentation of the first tool, i.e., visual or auditory. We suggest that the influence of manipulation gesture on response time depends on the relevance of the first tool in motor tasks. We discuss these motor activation results in terms of the

  2. How task complexity and stimulus modality affect motor execution: target accuracy, response timing and hesitations.

    PubMed

    Parrington, Lucy; MacMahon, Clare; Ball, Kevin

    2015-01-01

    Elite sports players are characterized by the ability to produce successful outcomes while attending to changing environmental conditions. Few studies have assessed whether the perceptual environment affects motor skill execution. To test the effect of changing task complexity and stimulus conditions, the authors examined response times and target accuracy of 12 elite Australian football players using a passing-based laboratory test. Data were assessed using mixed modeling and chi-square analyses. No differences were found in target accuracy for changes in complexity or stimulus condition. Decision, movement and total disposal time increased with complexity and decision hesitations were greater when distractions were present. Decision, movement and disposal time were faster for auditory in comparison to visual signals, and when free to choose, players passed more frequently to auditory rather than visual targets. These results provide perspective on how basic motor control processes such as reaction and response to stimuli are influenced in a complex motor skill. Findings suggest auditory stimuli should be included in decision-making studies and may be an important part of a decision-training environment.

  3. Multisensory Integration in Non-Human Primates during a Sensory-Motor Task.

    PubMed

    Lanz, Florian; Moret, Véronique; Rouiller, Eric Michel; Loquet, Gérard

    2013-01-01

    Daily our central nervous system receives inputs via several sensory modalities, processes them and integrates information in order to produce a suitable behavior. The amazing part is that such a multisensory integration brings all information into a unified percept. An approach to start investigating this property is to show that perception is better and faster when multimodal stimuli are used as compared to unimodal stimuli. This forms the first part of the present study conducted in a non-human primate's model (n = 2) engaged in a detection sensory-motor task where visual and auditory stimuli were displayed individually or simultaneously. The measured parameters were the reaction time (RT) between stimulus and onset of arm movement, successes and errors percentages, as well as the evolution as a function of time of these parameters with training. As expected, RTs were shorter when the subjects were exposed to combined stimuli. The gains for both subjects were around 20 and 40 ms, as compared with the auditory and visual stimulus alone, respectively. Moreover the number of correct responses increased in response to bimodal stimuli. We interpreted such multisensory advantage through redundant signal effect which decreases perceptual ambiguity, increases speed of stimulus detection, and improves performance accuracy. The second part of the study presents single-unit recordings derived from the premotor cortex (PM) of the same subjects during the sensory-motor task. Response patterns to sensory/multisensory stimulation are documented and specific type proportions are reported. Characterization of bimodal neurons indicates a mechanism of audio-visual integration possibly through a decrease of inhibition. Nevertheless the neural processing leading to faster motor response from PM as a polysensory association cortical area remains still unclear.

  4. No Effect of Anodal Transcranial Direct Current Stimulation Over the Motor Cortex on Response-Related ERPs during a Conflict Task

    PubMed Central

    Conley, Alexander C.; Fulham, W. R.; Marquez, Jodie L.; Parsons, Mark W.; Karayanidis, Frini

    2016-01-01

    Anodal transcranial direct current stimulation (tDCS) over the motor cortex is considered a potential treatment for motor rehabilitation following stroke and other neurological pathologies. However, both the context under which this stimulation is effective and the underlying mechanisms remain to be determined. In this study, we examined the mechanisms by which anodal tDCS may affect motor performance by recording event-related potentials (ERPs) during a cued go/nogo task after anodal tDCS over dominant primary motor cortex (M1) in young adults (Experiment 1) and both dominant and non-dominant M1 in older adults (Experiment 2). In both experiments, anodal tDCS had no effect on either response time (RT) or response-related ERPs, including the cue-locked contingent negative variation (CNV) and both target-locked and response-locked lateralized readiness potentials (LRP). Bayesian model selection analyses showed that, for all measures, the null effects model was stronger than a model including anodal tDCS vs. sham. We conclude that anodal tDCS has no effect on RT or response-related ERPs during a cued go/nogo task in either young or older adults. PMID:27547180

  5. Comprehension of handwriting development: Pen-grip kinetics in handwriting tasks and its relation to fine motor skills among school-age children.

    PubMed

    Lin, Yu-Chen; Chao, Yen-Li; Wu, Shyi-Kuen; Lin, Ho-Hsio; Hsu, Chieh-Hsiang; Hsu, Hsiao-Man; Kuo, Li-Chieh

    2017-05-16

    Numerous tools have been developed to evaluate handwriting performances by analysing written products. However, few studies have directly investigated kinetic performances of digits when holding a pen. This study thus attempts to investigate pen-grip kinetics during writing tasks of school-age children and explore the relationship between the kinetic factors and fine motor skills. This study recruited 181 children aged from 5 to 12 years old and investigated the effects of age on handwriting kinetics and the relationship between these and fine motor skills. The forces applied from the digits and pen-tip were measured during writing tasks via a force acquisition pen, and the children's fine motor performances were also evaluated. The results indicate that peak force and average force might not be direct indicators of handwriting performance for normally developing children at this age. Younger children showed larger force variation and lower adjustment frequency during writing, which might indicate they had poorer force control than the older children. Force control when handling a pen is significantly correlated with fine motor performance, especially in relation to the manual dexterity. A novel system is proposed for analysing school-age children's force control while handwriting. We observed the development of force control in relation to pen grip among the children with different ages in this study. The findings suggested that manipulation skill may be crucial when children are establishing their handwriting capabilities. © 2017 Occupational Therapy Australia.

  6. Hemodynamic Response of the Supplementary Motor Area during Locomotor Tasks with Upright versus Horizontal Postures in Humans

    PubMed Central

    Obayashi, Shigeru; Nakajima, Katsumi; Hara, Yukihiro

    2016-01-01

    To understand cortical mechanisms related to truncal posture control during human locomotion, we investigated hemodynamic responses in the supplementary motor area (SMA) with quadrupedal and bipedal gaits using functional near-infrared spectroscopy in 10 healthy adults. The subjects performed three locomotor tasks where the degree of postural instability varied biomechanically, namely, hand-knee quadrupedal crawling (HKQuad task), upright quadrupedalism using bilateral Lofstrand crutches (UpQuad task), and typical upright bipedalism (UpBi task), on a treadmill. We measured the concentration of oxygenated hemoglobin (oxy-Hb) during the tasks. The oxy-Hb significantly decreased in the SMA during the HKQuad task, whereas it increased during the UpQuad task. No significant responses were observed during the UpBi task. Based on the degree of oxy-Hb responses, we ranked these locomotor tasks as UpQuad > UpBi > HKQuad. The order of the different tasks did not correspond with postural instability of the tasks. However, qualitative inspection of oxy-Hb time courses showed that oxy-Hb waveform patterns differed between upright posture tasks (peak-plateau-trough pattern for the UpQuad and UpBi tasks) and horizontal posture task (downhill pattern for the HKQuad task). Thus, the SMA may contribute to the control of truncal posture accompanying locomotor movements in humans. PMID:27413555

  7. Action dynamics in multitasking: the impact of additional task factors on the execution of the prioritized motor movement

    PubMed Central

    Scherbaum, Stefan; Gottschalk, Caroline; Dshemuchadse, Maja; Fischer, Rico

    2015-01-01

    In multitasking, the execution of a prioritized task is in danger of crosstalk by the secondary task. Task shielding allows minimizing this crosstalk. However, the locus and temporal dynamics of crosstalk effects and further sources of influence on the execution of the prioritized task are to-date only vaguely understood. Here we combined a dual-task paradigm with an action dynamics approach and studied how and according to which temporal characteristics crosstalk, previously experienced interference and previously executed responses influenced participants' mouse movements in the prioritized task's execution. Investigating continuous mouse movements of the prioritized task, our results indicate a continuous crosstalk from secondary task processing until the endpoint of the movement was reached, although the secondary task could only be executed after finishing execution of the prioritized task. The motor movement in the prioritized task was further modulated by previously experienced interference between the prioritized and the secondary task. Furthermore, response biases from previous responses of the prioritized and the secondary task in movements indicate different sources of such biases. The bias by previous responses to the prioritized task follows a sustained temporal pattern typical for a contextual reactivation, while the bias by previous responses to the secondary task follows a decaying temporal pattern indicating residual activation of previously activated spatial codes. PMID:26217267

  8. The effect of exercise on motor performance tasks used in the neurological assessment of sports-related concussion.

    PubMed

    Schneiders, A G; Sullivan, S J; McCrory, P R; Gray, A; Maruthayanar, S; Singh, P; Ranhotigammage, P; Van der Salm, R

    2008-12-01

    Sports-related concussion is assessed using both cognitive and motor performance tasks. There is limited understanding of how exercise affects these measures. The purpose of this study was to investigate the effect of moderate-intensity exercise on three selected measures of motor performance. A repeated measures design was used to compare baseline motor performance scores with post-exercise scores with an exercise intervention modelled on the physiological demands of a team sport. 30 physically active subjects performed timed motor performance tasks: Finger-to-Nose (FTN), Tandem Gait (TG) and Single Leg Stance (SLS). The tasks were administered twice pre-exercise and twice post-exercise. FTN, TG and SLS demonstrated high test-retest reliability (ICC values >0.8). 15 minutes of moderate-intensity exercise caused a significant improvement in FTN (T2 = 2.66 (SD 0.38), T3 = 2.49 (0.32); p<0.001) and TG (T2 = 13.08 (2.84), T3 = 12.23 (2.22); p = 0.001), but not in SLS (T2 = 5.94 (4.99), T3 = 5.91 (5.54); p = 0.507). Improvement in the performance of motor tasks after exercise has implications for the immediate assessment of sports-related concussion, given that measures of motor performance are utilised in concussion assessment instruments.

  9. Learning better by repetition or variation? Is transfer at odds with task specific training?

    PubMed

    Bonney, Emmanuel; Jelsma, Lemke Dorothee; Ferguson, Gillian D; Smits-Engelsman, Bouwien C M

    2017-01-01

    Transfer of motor skills is the ultimate goal of motor training in rehabilitation practice. In children with Developmental Coordination Disorder (DCD), very little is known about how skills are transferred from training situations to real life contexts. In this study we examined the influence of two types of practice on transfer of motor skills acquired in a virtual reality (VR) environment. One hundred and eleven children with DCD and their typically developing (TD) peers, aged 6-10 years (M = 8.0 SD = 1.0) were randomly assigned to either variable (n = 56) or repetitive practice (n = 55). Participants in the repetitive practice played the same exergame (ski slalom) twice weekly for 20 minutes, over a period of 5 weeks, while those in the variable group played 10 different games. Motor skills such as balance tasks (hopping), running and agility tasks, ball skills and functional activities were evaluated before and after 5 weeks of training. ANOVA repeated measures indicated that both DCD and TD children demonstrated transfer effects to real life skills with identical and non-identical elements at exactly the same rate, irrespective of the type of practice they were assigned to. Based on these findings, we conclude that motor skills acquired in the VR environment, transfers to real world contexts in similar proportions for both TD and DCD children. The type of practice adopted does not seem to influence children's ability to transfer skills acquired in an exergame to life situations but the number of identical elements does.

  10. Stability of age-related deficits in the mnemonic similarity task across task variations.

    PubMed

    Stark, Shauna M; Stevenson, Rebecca; Wu, Claudia; Rutledge, Samantha; Stark, Craig E L

    2015-06-01

    Several studies in our lab and others have demonstrated age-related declines in mnemonic discrimination during a recognition memory paradigm using repeated items, similar lures, and novel foils. In particular, older adults exhibit a shift in lure discriminability, identifying similar lures as old items at a greater rate than young adults. This shift likely reflects deficits in pattern separation processing as a result of underlying changes in the dentate gyrus of the hippocampus. Here, we explored whether alterations in the task design could rescue the age-related impairment or whether it was ubiquitous as one might expect if the neurobiological mechanisms were truly disturbed by typical aging. Despite overt instructions to study item details during encoding, we replicated the age-related deficit in mnemonic discrimination. We established reliable effects with short lists of stimuli and with repeated testing. Altering the task design from a study/test to a continuous recognition paradigm replicated the age-related shift in lure discrimination as well. Modifying the task to an old/new response (rather than old/similar/new) showed the same effect and a d' analysis showed that lure items were more akin to target items in older adults. Finally, we varied the test instructions in order to promote gist or veridical responses in the old/new task. Even these overt veridical test instructions did not ameliorate older adults' lure discrimination problems. Together, these findings demonstrate the robust nature of this age-related deficit and support the hypothesis that typical aging results in neurobiological changes that underlie this impairment.

  11. The influence of catch trials on the consolidation of motor memory in force field adaptation tasks.

    PubMed

    Focke, Anne; Stockinger, Christian; Diepold, Christina; Taubert, Marco; Stein, Thorsten

    2013-01-01

    In computational neuroscience it is generally accepted that human motor memory contains neural representations of the physics of the musculoskeletal system and the objects in the environment. These representations are called "internal models". Force field studies, in which subjects have to adapt to dynamic perturbations induced by a robotic manipulandum, are an established tool to analyze the characteristics of such internal models. The aim of the current study was to investigate whether catch trials during force field learning could influence the consolidation of motor memory in more complex tasks. Thereby, the force field was more than double the force field of previous studies (35 N·s/m). Moreover, the arm of the subjects was not supported. A total of 46 subjects participated in this study and performed center-out movements at a robotic manipulandum in two different force fields. Two control groups learned force field A on day 1 and were retested in the same force field on day 3 (AA). Two test groups additionally learned an interfering force field B (= -A) on day 2 (ABA). The difference between the two test and control groups, respectively, was the absence (0%) or presence (19%) of catch trials, in which the force field was turned-off suddenly. The results showed consolidation of force field A on day 3 for both control groups. Test groups showed no consolidation of force field A (19% catch trials) and even poorer performance on day 3 (0% catch trials). In conclusion, it can be stated that catch trials seem to have a positive effect on the performance on day 3 but do not trigger a consolidation process as shown in previous studies that used a lower force field viscosity with supported arm. These findings indicate that the results of previous studies in which less complex tasks were analyzed, cannot be fully transferred to more complex tasks. Moreover, the effects of catch trials in these situations are insufficiently understood and further research is needed.

  12. Geographic variations in mortality from motor vehicle crashes.

    PubMed

    Baker, S P; Whitfield, R A; O'Neill, B

    1987-05-28

    Using a new technique to study the mortality associated with motor vehicle crashes, we calculated population-based death rates of occupants of motor vehicles during the period 1979 through 1981 and mapped them according to county for the 48 contiguous states of the United States. Mortality was highest in counties of low population density (r = 0.57; P less than 0.0001) and was also inversely correlated with per capita income (r = 0.23; P less than 0.0001). Death rates varied more than 100-fold; for example, Esmeralda County, Nevada, with 0.2 residents per square mile (2.6 km2), had a death rate of 558 per 100,000 population, as compared with Manhattan, New York, with 64,000 residents per square mile and a death rate of 2.5 per 100,000. Differences in road characteristics, travel speeds, seat-belt use, types of vehicles, and availability of emergency care may have been major contributors to these relations.

  13. Intermanual transfer and bilateral cortical plasticity is maintained in older adults after skilled motor training with simple and complex tasks

    PubMed Central

    Dickins, Daina S. E.; Sale, Martin V.; Kamke, Marc R.

    2015-01-01

    Intermanual transfer refers to the phenomenon whereby unilateral motor training induces performance gains in both the trained limb and in the opposite, untrained limb. Evidence indicates that intermanual transfer is attenuated in older adults following training on a simple ballistic movement task, but not after training on a complex task. This study investigated whether differences in plasticity in bilateral motor cortices underlie these differential intermanual transfer effects in older adults. Twenty young (<35 years-old) and older adults (>65 years) trained on a simple (repeated ballistic thumb abduction) and complex (sequential finger-thumb opposition) task in separate sessions. Behavioral performance was used to quantify intermanual transfer between the dominant (trained) and non-dominant (untrained) hands. The amplitude of motor-evoked potentials induced by single pulse transcranial magnetic stimulation was used to investigate excitability changes in bilateral motor cortices. Contrary to predictions, both age groups exhibited performance improvements in both hands after unilateral skilled motor training with simple and complex tasks. These performance gains were accompanied by bilateral increases in cortical excitability in both groups for the simple but not the complex task. The findings suggest that advancing age does not necessarily influence the capacity for intermanual transfer after training with the dominant hand. PMID:25999856

  14. Neuroanatomical variations as a function of experience in a complex daily task: A VBM and DTI study on driving experience.

    PubMed

    Megías, Alberto; Petrova, D; Navas, J F; Cándido, A; Maldonado, A; Catena, A

    2017-04-26

    Complex tasks require the learning and integration of multiple cognitive, sensory, and psychomotor skills for correct execution. Driving-related skills are developed step by step through the increase of mileage driven and the accumulation of practice in different traffic situations. The acquisition of these skills should be reflected in the brain structure. However, no previous studies have explored brain structural variations associated with driving experience. The aim of the present study was to investigate whether driving frequency, defined as average annual driving mileage, is related to neuroanatomical variations in gray matter (GM) volume and white matter (WM) integrity using voxel-based morphometry (VBM) and DTI-based fractional anisotropy (FA), respectively. We recruited 83 drivers with variable range of annual driving mileage and controlled for age, sex, handedness, IQ, time since the acquisition of driving license, use of motorcycles/mopeds and bicycles, perceived driving skills, and subjective probability of having an accident. Our results showed variations in white matter FA as a function of mileage driven. Driving experience was related to a significant increase of FA in parts of the right hemisphere superior and inferior longitudinal fasciculus, anterior thalamic radiation, forceps majors, inferior fronto-occipital fasciculus, and corticospinal tract. No significant differences were observed in gray matter volumes. FA variations were found in brain regions that have been associated with cognitive, visual, and motor processes necessary for skilled performance in driving. These results suggest that variations in white matter diffusivity can underlie the development of driving skills and safer driving.

  15. Mind wandering and motor control: off-task thinking disrupts the online adjustment of behavior.

    PubMed

    Kam, Julia W Y; Dao, Elizabeth; Blinn, Patricia; Krigolson, Olav E; Boyd, Lara A; Handy, Todd C

    2012-01-01

    Mind wandering episodes have been construed as periods of "stimulus-independent" thought, where our minds are decoupled from the external sensory environment. In two experiments, we used behavioral and event-related potential (ERP) measures to determine whether mind wandering episodes can also be considered as periods of "response-independent" thought, with our minds disengaged from adjusting our behavioral outputs. In the first experiment, participants performed a motor tracking task and were occasionally prompted to report whether their attention was "on-task" or "mind wandering." We found greater tracking error in periods prior to mind wandering vs. on-task reports. To ascertain whether this finding was due to attenuation in visual perception per se vs. a disruptive effect of mind wandering on performance monitoring, we conducted a second experiment in which participants completed a time-estimation task. They were given feedback on the accuracy of their estimations while we recorded their EEG, and were also occasionally asked to report their attention state. We found that the sensitivity of behavior and the P3 ERP component to feedback signals were significantly reduced just prior to mind wandering vs. on-task attentional reports. Moreover, these effects co-occurred with decreases in the error-related negativity elicited by feedback signals (fERN), a direct measure of behavioral feedback assessment in cortex. Our findings suggest that the functional consequences of mind wandering are not limited to just the processing of incoming stimulation per se, but extend as well to the control and adjustment of behavior.

  16. Oscillations in the power spectra of motor unit signals caused by refractoriness variations

    NASA Astrophysics Data System (ADS)

    Hu, X. L.; Tong, K. Y.; Hung, L. K.

    2004-09-01

    The refractory period of a motor unit is an important mechanism that regulates the motor unit firing, and its variation has been found in many physiological cases. In this study, a new observation that an increase in the motor unit refractoriness results in an enhancement of oscillations, or ripple effects, in the motor unit output power density spectra (PDS) has been identified and studied. The effects of the refractoriness variation on the PDS of motor unit firing were investigated on three levels: theoretical modeling, simulation and electromyographic (EMG) experimentation on human subjects. Both theoretical modeling and simulation showed the enhanced oscillations, ripple effects, in MUAPT PDS, given the increase in the refractoriness. It was also found that the extent of the increment in output PDS oscillation could be related to the motor unit size and the mean firing rate of the stimulation. A needle EMG experiment on biceps brachii muscles of five healthy human subjects was carried out during isometric contraction at 20% maximum voluntary contraction (MVC) for 20 s with a fatigue effort proceeded by MVC. The increased oscillations in the PDS of the real MUAPTs were observed with the rising of the motor unit refractoriness due to fatigue. The study gives new information for EMG spectra interpretation, and also provides a potential method for accessing neuromuscular transmission failure (NTF) due to fatigue during voluntary contraction.

  17. Signal, Noise, and Variation in Neural and Sensory-Motor Latency.

    PubMed

    Lee, Joonyeol; Joshua, Mati; Medina, Javier F; Lisberger, Stephen G

    2016-04-06

    Analysis of the neural code for sensory-motor latency in smooth pursuit eye movements reveals general principles of neural variation and the specific origin of motor latency. The trial-by-trial variation in neural latency in MT comprises a shared component expressed as neuron-neuron latency correlations and an independent component that is local to each neuron. The independent component arises heavily from fluctuations in the underlying probability of spiking, with an unexpectedly small contribution from the stochastic nature of spiking itself. The shared component causes the latency of single-neuron responses in MT to be weakly predictive of the behavioral latency of pursuit. Neural latency deeper in the motor system is more strongly predictive of behavioral latency. A model reproduces both the variance of behavioral latency and the neuron-behavior latency correlations in MT if it includes realistic neural latency variation, neuron-neuron latency correlations in MT, and noisy gain control downstream of MT.

  18. Signal, noise, and variation in neural and sensory-motor latency

    PubMed Central

    Lee, Joonyeol; Joshua, Mati; Medina, Javier F.; Lisberger, Stephen G.

    2016-01-01

    Analysis of the neural code for sensory-motor latency in smooth pursuit eye movements reveals general principles of neural variation and the specific origin of motor latency. The trial-by-trial variation in neural latency in MT comprises: a shared component expressed as neuron-neuron latency correlations; and an independent component that is local to each neuron. The independent component arises heavily from fluctuations in the underlying probability of spiking with an unexpectedly small contribution from the stochastic nature of spiking itself. The shared component causes the latency of single neuron responses in MT to be weakly predictive of the behavioral latency of pursuit. Neural latency deeper in the motor system is more strongly predictive of behavioral latency. A model reproduces both the variance of behavioral latency and the neuron-behavior latency correlations in MT if it includes realistic neural latency variation, neuron-neuron latency correlations in MT, and noisy gain control downstream from MT. PMID:26971946

  19. Unimodal Versus Bimodal EEG-fMRI Neurofeedback of a Motor Imagery Task

    PubMed Central

    Perronnet, Lorraine; Lécuyer, Anatole; Mano, Marsel; Bannier, Elise; Lotte, Fabien; Clerc, Maureen; Barillot, Christian

    2017-01-01

    Neurofeedback is a promising tool for brain rehabilitation and peak performance training. Neurofeedback approaches usually rely on a single brain imaging modality such as EEG or fMRI. Combining these modalities for neurofeedback training could allow to provide richer information to the subject and could thus enable him/her to achieve faster and more specific self-regulation. Yet unimodal and multimodal neurofeedback have never been compared before. In the present work, we introduce a simultaneous EEG-fMRI experimental protocol in which participants performed a motor-imagery task in unimodal and bimodal NF conditions. With this protocol we were able to compare for the first time the effects of unimodal EEG-neurofeedback and fMRI-neurofeedback versus bimodal EEG-fMRI-neurofeedback by looking both at EEG and fMRI activations. We also propose a new feedback metaphor for bimodal EEG-fMRI-neurofeedback that integrates both EEG and fMRI signal in a single bi-dimensional feedback (a ball moving in 2D). Such a feedback is intended to relieve the cognitive load of the subject by presenting the bimodal neurofeedback task as a single regulation task instead of two. Additionally, this integrated feedback metaphor gives flexibility on defining a bimodal neurofeedback target. Participants were able to regulate activity in their motor regions in all NF conditions. Moreover, motor activations as revealed by offline fMRI analysis were stronger during EEG-fMRI-neurofeedback than during EEG-neurofeedback. This result suggests that EEG-fMRI-neurofeedback could be more specific or more engaging than EEG-neurofeedback. Our results also suggest that during EEG-fMRI-neurofeedback, participants tended to regulate more the modality that was harder to control. Taken together our results shed first light on the specific mechanisms of bimodal EEG-fMRI-neurofeedback and on its added-value as compared to unimodal EEG-neurofeedback and fMRI-neurofeedback. PMID:28473762

  20. How is a motor skill learned? Change and invariance at the levels of task success and trajectory control.

    PubMed

    Shmuelof, Lior; Krakauer, John W; Mazzoni, Pietro

    2012-07-01

    The public pays large sums of money to watch skilled motor performance. Notably, however, in recent decades motor skill learning (performance improvement beyond baseline levels) has received less experimental attention than motor adaptation (return to baseline performance in the setting of an external perturbation). Motor skill can be assessed at the levels of task success and movement quality, but the link between these levels remains poorly understood. We devised a motor skill task that required visually guided curved movements of the wrist without a perturbation, and we defined skill learning at the task level as a change in the speed-accuracy trade-off function (SAF). Practice in restricted speed ranges led to a global shift of the SAF. We asked how the SAF shift maps onto changes in trajectory kinematics, to establish a link between task-level performance and fine motor control. Although there were small changes in mean trajectory, improved performance largely consisted of reduction in trial-to-trial variability and increase in movement smoothness. We found evidence for improved feedback control, which could explain the reduction in variability but does not preclude other explanations such as an increased signal-to-noise ratio in cortical representations. Interestingly, submovement structure remained learning invariant. The global generalization of the SAF across a wide range of difficulty suggests that skill for this task is represented in a temporally scalable network. We propose that motor skill acquisition can be characterized as a slow reduction in movement variability, which is distinct from faster model-based learning that reduces systematic error in adaptation paradigms.

  1. How is a motor skill learned? Change and invariance at the levels of task success and trajectory control

    PubMed Central

    Krakauer, John W.; Mazzoni, Pietro

    2012-01-01

    The public pays large sums of money to watch skilled motor performance. Notably, however, in recent decades motor skill learning (performance improvement beyond baseline levels) has received less experimental attention than motor adaptation (return to baseline performance in the setting of an external perturbation). Motor skill can be assessed at the levels of task success and movement quality, but the link between these levels remains poorly understood. We devised a motor skill task that required visually guided curved movements of the wrist without a perturbation, and we defined skill learning at the task level as a change in the speed–accuracy trade-off function (SAF). Practice in restricted speed ranges led to a global shift of the SAF. We asked how the SAF shift maps onto changes in trajectory kinematics, to establish a link between task-level performance and fine motor control. Although there were small changes in mean trajectory, improved performance largely consisted of reduction in trial-to-trial variability and increase in movement smoothness. We found evidence for improved feedback control, which could explain the reduction in variability but does not preclude other explanations such as an increased signal-to-noise ratio in cortical representations. Interestingly, submovement structure remained learning invariant. The global generalization of the SAF across a wide range of difficulty suggests that skill for this task is represented in a temporally scalable network. We propose that motor skill acquisition can be characterized as a slow reduction in movement variability, which is distinct from faster model-based learning that reduces systematic error in adaptation paradigms. PMID:22514286

  2. The interaction of spatial ability and motor learning in the transfer of training from a simulator to a real task.

    PubMed

    Tracey, M R; Lathan, C E

    2001-01-01

    Virtual Reality (VR) based simulators have been used as a training tool in many settings, although very few studies examine transfer of training from simulators to a real world task, particularly for manipulation tasks. Simulators could play a key role as an enabling technology for manipulation tasks related to teleoperation, and medical procedure training. We investigated the relationship between motor tasks and participants' spatial abilities. This relationship was further examined with respect to learning in a simulator and to transfer of training from the simulator to the real world on a pick-and-place task. Spatial abilities were characterized using a battery of recognition and manipulation figural tests. Subjects with lower spatial abilities demonstrated significant positive transfer from a simulator based training task to a similar real world robotic operation task. Subjects with higher spatial skills did not respond as positively from training in a simulated environment.

  3. Performance on a functional motor task is enhanced by sleep in middle-aged and older adults.

    PubMed

    Al-Sharman, Alham; Siengsukon, Catherine F

    2014-07-01

    Although sleep has been shown to enhance motor skill learning, it remains unclear whether sleep enhances learning of a functional motor task in middle-aged and older individuals. The purpose of this study was to examine whether sleep enhances motor learning of a functional motor task in middle-aged and older adults. Twenty middle-aged and 20 older individuals were randomly assigned to either the sleep condition or the no-sleep condition. Participants in the sleep condition practiced a novel walking task in the evening, and returned the following morning for retesting. Participants in the no-sleep condition practiced the walking task in the morning and returned the same day in the evening for a retest. Outcome measures included time around the walking path and spatiotemporal gait parameters. Only the middle-aged and older adults in the sleep condition demonstrated significant off-line improvement in performance, measured as a decline in time to walk around the novel path and improvement in spatiotemporal gait parameters. The middle-aged and older adults in the no-sleep condition failed to demonstrate off-line improvements in performance of this functional task. This is the first study to provide evidence that sleep facilitates learning a clinically relevant functional motor task in middle-aged and older adults. Because many neurologic conditions occur in the middle-aged and older adults and sleep issues are very prevalent in many neurologic conditions, it is imperative that physical therapists consider sleep as a factor that may impact motor learning and recovery in these individuals. (See Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A73) for more insights from the authors.

  4. Mind wandering and motor control: off-task thinking disrupts the online adjustment of behavior

    PubMed Central

    Kam, Julia W. Y.; Dao, Elizabeth; Blinn, Patricia; Krigolson, Olav E.; Boyd, Lara A.; Handy, Todd C.

    2012-01-01

    Mind wandering episodes have been construed as periods of “stimulus-independent” thought, where our minds are decoupled from the external sensory environment. In two experiments, we used behavioral and event-related potential (ERP) measures to determine whether mind wandering episodes can also be considered as periods of “response-independent” thought, with our minds disengaged from adjusting our behavioral outputs. In the first experiment, participants performed a motor tracking task and were occasionally prompted to report whether their attention was “on-task” or “mind wandering.” We found greater tracking error in periods prior to mind wandering vs. on-task reports. To ascertain whether this finding was due to attenuation in visual perception per se vs. a disruptive effect of mind wandering on performance monitoring, we conducted a second experiment in which participants completed a time-estimation task. They were given feedback on the accuracy of their estimations while we recorded their EEG, and were also occasionally asked to report their attention state. We found that the sensitivity of behavior and the P3 ERP component to feedback signals were significantly reduced just prior to mind wandering vs. on-task attentional reports. Moreover, these effects co-occurred with decreases in the error-related negativity elicited by feedback signals (fERN), a direct measure of behavioral feedback assessment in cortex. Our findings suggest that the functional consequences of mind wandering are not limited to just the processing of incoming stimulation per se, but extend as well to the control and adjustment of behavior. PMID:23248596

  5. Constrained motor-perceptual task in infancy: effects of sensory modality.

    PubMed

    Tiernan, Chad W; Angulo-Barroso, Rosa M

    2008-03-01

    The authors examined the relative success of varying sensory stimulation modalities that they presented via a mobile reinforcement procedure for promoting left-knee extensions in 3-month-old infants. They separated 53 infants into 5 groups. Four groups received contingent unimodal auditory, enhanced auditory, or visual reinforcement or contingent bimodal auditory plus visual (aud + vis) reinforcement. One group (controls) received aud + vis noncontingent reinforcement. The group that received aud + vis contingent reinforcement was most successful in learning the motor task and maintained the highest attention levels. The authors observed few differences in learning and attention within the unimodal groups. The present findings confirm the effectiveness of contingent multisensory stimulation for promoting perception-action coupling in infancy.

  6. Multiscale AM-FM methods on EEG signals for motor task classification.

    PubMed

    Flores Vega, Christian; Murray, Victor

    2015-01-01

    In this manuscript, we present the use of customized, multiscale amplitude-modulation frequency-modulation (AMFM) methods on electroencephalography (EEG) brain signals during the subject development a motor task: right hand and left hand. This approach is compared to various non-linear patterns and methods that have been applied in order to characterize and understand the dynamic behavior of the EEG signals. The AM-FM methods have been optimized in terms of multiscale filters for the mu band (8-12 Hz). The instantaneous AM-FM values are processed using their probability density function and classified using multiple layer perceptron (MLP) and the partial least squares regression (PLS). The system is tested using the standard BCI dataset with results with a precision to 89% and an area under the ROC to 91%.

  7. Improving posture-motor dual-task with a supraposture-focus strategy in young and elderly adults.

    PubMed

    Yu, Shu-Han; Huang, Cheng-Ya

    2017-01-01

    In a postural-suprapostural task, appropriate prioritization is necessary to achieve task goals and maintain postural stability. A "posture-first" principle is typically favored by elderly people in order to secure stance stability, but this comes at the cost of reduced suprapostural performance. Using a postural-suprapostural task with a motor suprapostural goal, this study investigated differences between young and older adults in dual-task cost across varying task prioritization paradigms. Eighteen healthy young (mean age: 24.8 ± 5.2 years) and 18 older (mean age: 68.8 ± 3.7 years) adults executed a designated force-matching task from a stabilometer board using either a stabilometer stance (posture-focus strategy) or force-matching (supraposture-focus strategy) as the primary task. The dual-task effect (DTE: % change in dual-task condition; positive value: dual-task benefit, negative value: dual-task cost) of force-matching error and reaction time (RT), posture error, and approximate entropy (ApEn) of stabilometer movement were measured. When using the supraposture-focus strategy, young adults exhibited larger DTE values in each behavioral parameter than when using the posture-focus strategy. The older adults using the supraposture-focus strategy also attained larger DTE values for posture error, stabilometer movement ApEn, and force-matching error than when using the posture-focus strategy. These results suggest that the supraposture-focus strategy exerted an increased dual-task benefit for posture-motor dual-tasking in both healthy young and elderly adults. The present findings imply that the older adults should make use of the supraposture-focus strategy for fall prevention during dual-task execution.

  8. Improving posture-motor dual-task with a supraposture-focus strategy in young and elderly adults

    PubMed Central

    Yu, Shu-Han

    2017-01-01

    In a postural-suprapostural task, appropriate prioritization is necessary to achieve task goals and maintain postural stability. A “posture-first” principle is typically favored by elderly people in order to secure stance stability, but this comes at the cost of reduced suprapostural performance. Using a postural-suprapostural task with a motor suprapostural goal, this study investigated differences between young and older adults in dual-task cost across varying task prioritization paradigms. Eighteen healthy young (mean age: 24.8 ± 5.2 years) and 18 older (mean age: 68.8 ± 3.7 years) adults executed a designated force-matching task from a stabilometer board using either a stabilometer stance (posture-focus strategy) or force-matching (supraposture-focus strategy) as the primary task. The dual-task effect (DTE: % change in dual-task condition; positive value: dual-task benefit, negative value: dual-task cost) of force-matching error and reaction time (RT), posture error, and approximate entropy (ApEn) of stabilometer movement were measured. When using the supraposture-focus strategy, young adults exhibited larger DTE values in each behavioral parameter than when using the posture-focus strategy. The older adults using the supraposture-focus strategy also attained larger DTE values for posture error, stabilometer movement ApEn, and force-matching error than when using the posture-focus strategy. These results suggest that the supraposture-focus strategy exerted an increased dual-task benefit for posture-motor dual-tasking in both healthy young and elderly adults. The present findings imply that the older adults should make use of the supraposture-focus strategy for fall prevention during dual-task execution. PMID:28151943

  9. Motor adaptations to unilateral quadriceps fatigue during a bilateral pedaling task.

    PubMed

    Brøchner Nielsen, N-P; Hug, F; Guével, A; Fohanno, V; Lardy, J; Dorel, S

    2016-12-20

    This study was designed to investigate how motor coordination adapts to unilateral fatigue of the quadriceps during a constant-load bilateral pedaling task. We first hypothesized that this local fatigue would not be compensated within the fatigued muscles leading to a decreased knee extension power. Then, we aimed to determine whether this decrease would be compensated by between-joints compensations within the ipsilateral leg and/or an increased contribution of the contralateral leg. Fifteen healthy volunteers were tested during pedaling at 350 W before and after a fatigue protocol consisting of 15 minutes of electromyostimulation on the quadriceps muscle. Motor coordination was assessed from myoelectrical activity (22 muscles) and joint powers calculated through inverse dynamics. Maximal knee extension torque decreased by 28.3%±6.8% (P<.0005) immediately after electromyostimulation. A decreased knee extension power produced by the ipsilateral leg was observed during pedaling (-22.8±12.3 W, -17.0%±9.4%; P<.0005). To maintain the task goal, participants primarily increased the power produced by the non-fatigued contralateral leg during the flexion phase. This was achieved by an increase in hip flexion power confirmed by a higher activation of the tensor fascia latae. These results suggest no adjustment of neural drive to the fatigued muscles and demonstrate no concurrent ipsilateral compensation by the non-fatigued muscles involved in the extension pedaling phase. Although interindividual variability was observed, findings provide evidence that participants predominantly adapted by compensating with the contralateral leg during its flexion phase. Both neural (between legs) and mechanical (between pedals) couplings and the minimization of cost functions might explain these results.

  10. Explicit knowledge enhances motor vigor and performance: motivation versus practice in sequence tasks

    PubMed Central

    Lindquist, Martin A.; Haith, Adrian M.; Krakauer, John W.

    2015-01-01

    Motor skill learning involves a practice-induced improvement in the speed and/or accuracy of a discrete movement. It is often thought that paradigms involving repetitive practice of discrete movements performed in a fixed sequence result in a further enhancement of skill beyond practice of the individual movements in a random order. Sequence-specific performance improvements could, however, arise without practice as a result of knowledge of the sequence order; knowledge could operate by either enabling advanced motor planning of the known sequence elements or by increasing overall motivation. Here, we examined how knowledge and practice contribute to performance of a sequence of movements. We found that explicit knowledge provided through instruction produced practice-independent improvements in reaction time and execution quality. These performance improvements occurred even for random elements within a partially known sequence, indicative of a general motivational effect rather than a sequence-specific effect of advanced planning. This motivational effect suggests that knowledge influences performance in a manner analogous to reward. Additionally, practice led to similar improvements in execution quality for both known and random sequences. The lack of interaction between knowledge and practice suggests that any skill acquisition occurring during discrete sequence tasks arises solely from practice of the individual movement elements, independent of their order. We conclude that performance improvements in discrete sequence tasks arise from the combination of knowledge-based motivation and sequence-independent practice; investigating this interplay between cognition and movement may facilitate a greater understanding of the acquisition of skilled behavior. PMID:25904709

  11. Explicit knowledge enhances motor vigor and performance: motivation versus practice in sequence tasks.

    PubMed

    Wong, Aaron L; Lindquist, Martin A; Haith, Adrian M; Krakauer, John W

    2015-07-01

    Motor skill learning involves a practice-induced improvement in the speed and/or accuracy of a discrete movement. It is often thought that paradigms involving repetitive practice of discrete movements performed in a fixed sequence result in a further enhancement of skill beyond practice of the individual movements in a random order. Sequence-specific performance improvements could, however, arise without practice as a result of knowledge of the sequence order; knowledge could operate by either enabling advanced motor planning of the known sequence elements or by increasing overall motivation. Here, we examined how knowledge and practice contribute to performance of a sequence of movements. We found that explicit knowledge provided through instruction produced practice-independent improvements in reaction time and execution quality. These performance improvements occurred even for random elements within a partially known sequence, indicative of a general motivational effect rather than a sequence-specific effect of advanced planning. This motivational effect suggests that knowledge influences performance in a manner analogous to reward. Additionally, practice led to similar improvements in execution quality for both known and random sequences. The lack of interaction between knowledge and practice suggests that any skill acquisition occurring during discrete sequence tasks arises solely from practice of the individual movement elements, independent of their order. We conclude that performance improvements in discrete sequence tasks arise from the combination of knowledge-based motivation and sequence-independent practice; investigating this interplay between cognition and movement may facilitate a greater understanding of the acquisition of skilled behavior. Copyright © 2015 the American Physiological Society.

  12. Proactive and retroactive transfer of middle age adults in a sequential motor learning task.

    PubMed

    Verneau, Marion; van der Kamp, John; Savelsbergh, Geert J P; de Looze, Michiel P

    2015-03-01

    We assessed the effects of aging in the transfer of motor learning in a sequential manual assembly task that is representative for real working conditions. On two different days, young (18-30 years) and middle-aged adults (50-65 years) practiced to build two products that consisted of the same six components but which had to be assembled in a partly different order. Assembly accuracy and movement time during tests, which were performed before and after the practice sessions, were compared to determine proactive and retroactive transfer. The results showed proactive facilitation (i.e., benefits from having learned the first product on learning the second one) in terms of an overall shortening of movement time in both age-groups. In addition, only the middle-aged adults were found to show sequence-specific proactive facilitation, in which the shortening of movement time was limited to components that had the same the order in the two products. Most likely, however, the sequence-specific transfer was an epiphenomenon of the comparatively low rate of learning among the middle-aged adults. The results, however, did reveal genuine differences between the groups for retroactive transfer (i.e., effects from learning the second product on performance of the first). Middle-aged adults tended to show more pronounced retroactive interference in terms of a general decrease in accuracy, while younger adults showed sequence-specific retroactive facilitation (i.e., shortening of movement times for components that had the same order in the two products), but only when they were fully accurate. Together this suggests that in the learning of sequential motor tasks the effects of age are more marked for retroactive transfer than for proactive transfer.

  13. Keeping an eye on the violinist: motor experts show superior timing consistency in a visual perception task.

    PubMed

    Wöllner, Clemens; Cañal-Bruland, Rouwen

    2010-11-01

    Common coding theory states that perception and action may reciprocally induce each other. Consequently, motor expertise should map onto perceptual consistency in specific tasks such as predicting the exact timing of a musical entry. To test this hypothesis, ten string musicians (motor experts), ten non-string musicians (visual experts), and ten non-musicians were asked to watch progressively occluded video recordings of a first violinist indicating entries to fellow members of a string quartet. Participants synchronised with the perceived timing of the musical entries. Results revealed significant effects of motor expertise on perception. Compared to visual experts and non-musicians, string players not only responded more accurately, but also with less timing variability. These findings provide evidence that motor experts' consistency in movement execution-a key characteristic of expert motor performance-is mirrored in lower variability in perceptual judgements, indicating close links between action competence and perception.

  14. Keeping an eye on the violinist: motor experts show superior timing consistency in a visual perception task

    PubMed Central

    Cañal-Bruland, Rouwen

    2010-01-01

    Common coding theory states that perception and action may reciprocally induce each other. Consequently, motor expertise should map onto perceptual consistency in specific tasks such as predicting the exact timing of a musical entry. To test this hypothesis, ten string musicians (motor experts), ten non-string musicians (visual experts), and ten non-musicians were asked to watch progressively occluded video recordings of a first violinist indicating entries to fellow members of a string quartet. Participants synchronised with the perceived timing of the musical entries. Results revealed significant effects of motor expertise on perception. Compared to visual experts and non-musicians, string players not only responded more accurately, but also with less timing variability. These findings provide evidence that motor experts’ consistency in movement execution—a key characteristic of expert motor performance—is mirrored in lower variability in perceptual judgements, indicating close links between action competence and perception. PMID:20300943

  15. Transcranial Direct Current Stimulation of the Motor Cortex Biases Action Choice in a Perceptual Decision Task.

    PubMed

    Javadi, Amir-Homayoun; Beyko, Angeliki; Walsh, Vincent; Kanai, Ryota

    2015-11-01

    One of the multiple interacting systems involved in the selection and execution of voluntary actions is the primary motor cortex (PMC). We aimed to investigate whether the transcranial direct current stimulation (tDCS) of this area can modulate hand choice. A perceptual decision-making task was administered. Participants were asked to classify rectangles with different height-to-width ratios into horizontal and vertical rectangles using their right and left index fingers while their PMC was stimulated either bilaterally or unilaterally. Two experiments were conducted with different stimulation conditions: the first experiment (n = 12) had only one stimulation condition (bilateral stimulation), and the second experiment (n = 45) had three stimulation conditions (bilateral, anodal unilateral, and cathodal unilateral stimulations). The second experiment was designed to confirm the results of the first experiment and to further investigate the effects of anodal and cathodal stimulations alone in the observed effects. Each participant took part in two sessions. The laterality of stimulation was reversed over the two sessions. Our results showed that anodal stimulation of the PMC biases participants' responses toward using the contralateral hand whereas cathodal stimulation biases responses toward the ipsilateral hand. Brain stimulation also modulated the RT of the left hand in all stimulation conditions: Responses were faster when the response bias was in favor of the left hand and slower when the response bias was against it. We propose two possible explanations for these findings: the perceptual bias account (bottom-up effects of stimulation on perception) and the motor-choice bias account (top-down modulation of the decision-making system by facilitation of response in one hand over the other). We conclude that motor responses and the choice of hand can be modulated using tDCS.

  16. Functional somatotopy revealed across multiple cortical regions using a model of complex motor task

    PubMed Central

    Cunningham, David A.; Machado, Andre; Yue, Guang H.; Carey, Jim R.; Plow, Ela B.

    2014-01-01

    The primary motor cortex (M1) possesses a functional somatotopic structure -representations of adjacent within-limb joints overlap to facilitate coordination while maintaining discrete centers for individuated movement. We examined whether similar organization exists across other sensorimotor cortices. Twenty-four right-handed healthy subjects underwent functional Magnetic Resonance Imaging (fMRI) while tracking complex targets with flexion/extension at right finger, elbow and ankle separately. Activation related to each joint at false discovery rate of .005 served as its representation across multiple regions. Within each region, we identified the Center of Mass (COM) for each representation, and overlap between representations of within-limb (finger and elbow) and between-limb joints (finger and ankle). Somatosensory (S1) and premotor cortices (PMC) demonstrated greater distinction of COM and minimal overlap for within- and between-limb representations. Contrarily, M1 and supplementary motor area (SMA) showed more integrative somatotopy with higher sharing for within-limb representations. Superior and inferior parietal lobule (SPL and IPL) possessed both types of structure. Some clusters exhibited extensive overlap of within- and between-limb representations, while others showed discrete COMs for within-limb representations. Our results help infer hierarchy in motor control. Areas as S1 may be associated with individuated movements, while M1 may be more integrative for coordinated motion; parietal associative regions may allow switch between both modes of control. Such hierarchy creates redundant opportunities to exploit in stroke rehabilitation. Use of complex rather than traditionally used simple movements was integral to illustrating comprehensive somatotopic structure; complex tasks can potentially help understand cortical representation of skill and learning-related plasticity. PMID:23920009

  17. Re-examining sleep׳s effect on motor skills: How to access performance on the finger tapping task?

    PubMed Central

    Ribeiro Pereira, Sofia Isabel; Beijamini, Felipe; Vincenzi, Roberta Almeida; Louzada, Fernando Mazzilli

    2015-01-01

    Here our goal was to determine the magnitude of sleep-related motor skill enhancement. Performance on the finger tapping task (FTT) was evaluated after a 90 min daytime nap (n=15) or after quiet wakefulness (n=15). By introducing a slight modification in the formula used to calculate the offline gains we were able to refine the estimated magnitude of sleep׳s effect on motor skills. The raw value of improvement after a nap decreased after this correction (from ~15% to ~5%), but remained significantly higher than the control. These results suggest that sleep does indeed play a role in motor skill consolidation. PMID:26483936

  18. Ensemble Fractional Sensitivity: A Quantitative Approach to Neuron Selection for Decoding Motor Tasks

    PubMed Central

    Singhal, Girish; Aggarwal, Vikram; Acharya, Soumyadipta; Aguayo, Jose; He, Jiping; Thakor, Nitish

    2010-01-01

    A robust method to help identify the population of neurons used for decoding motor tasks is developed. We use sensitivity analysis to develop a new metric for quantifying the relative contribution of a neuron towards the decoded output, called “fractional sensitivity.” Previous model-based approaches for neuron ranking have been shown to largely depend on the collection of training data. We suggest the use of an ensemble of models that are trained on random subsets of trials to rank neurons. For this work, we tested a decoding algorithm on neuronal data recorded from two male rhesus monkeys while they performed a reach to grasp a bar at three orientations (45°, 90°, or 135°). An ensemble approach led to a statistically significant increase of 5% in decoding accuracy and 25% increase in identification accuracy of simulated noisy neurons, when compared to a single model. Furthermore, ranking neurons based on the ensemble fractional sensitivities resulted in decoding accuracies 10%–20% greater than when randomly selecting neurons or ranking based on firing rates alone. By systematically reducing the size of the input space, we determine the optimal number of neurons needed for decoding the motor output. This selection approach has practical benefits for other BMI applications where limited number of electrodes and training datasets are available, but high decoding accuracies are desirable. PMID:20169103

  19. Selective effects of motor expertise in mental body rotation tasks: comparing object-based and perspective transformations.

    PubMed

    Steggemann, Yvonne; Engbert, Kai; Weigelt, Matthias

    2011-06-01

    Brain imaging studies provide strong evidence for the involvement of the human mirror system during the observation of complex movements, depending on the individual's motor expertise. Here, we ask the question whether motor expertise not only affects perception while observing movements, but also benefits perception while solving mental rotation tasks. Specifically, motor expertise should only influence the performance in mental body rotation tasks (MBRT) with left-right judgment, evoking a perspective transformation, whereas motor expertise should not affect the MBRT with same-different judgment, evoking an object-related transformation. Participants with and without motor expertise for rotational movements were tested in these two conditions in the MBRT. Results showed that motor experience selectively affected performance in the MBRT with the left-right judgment, but not with same-different judgment. More precisely, motor expertise only benefited performance when human figures were presented in (for non-experts) unfamiliar, upside-down body orientations. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. The Effect of an Acute Bout of Moderate-Intensity Aerobic Exercise on Motor Learning of a Continuous Tracking Task

    PubMed Central

    Snow, Nicholas J.; Mang, Cameron S.; Roig, Marc; Boyd, Lara A.

    2016-01-01

    Introduction There is evidence for beneficial effects of acute and long-term exercise interventions on several forms of memory, including procedural motor learning. In the present study we examined how performing a single bout of continuous moderate intensity aerobic exercise would impact motor skill acquisition and retention in young healthy adults, compared to a period of rest. We hypothesized that exercise would improve motor skill acquisition and retention, compared to motor practice alone. Materials and Methods Sixteen healthy adults completed sessions of aerobic exercise or seated rest that were immediately followed by practice of a novel motor task (practice). Exercise consisted of 30 minutes of continuous cycling at 60% peak O2 uptake. Twenty-four hours after practice, we assessed motor learning with a no-exercise retention test (retention). We also quantified changes in offline motor memory consolidation, which occurred between practice and retention (offline). Tracking error was separated into indices of temporal precision and spatial accuracy. Results There were no differences between conditions in the timing of movements during practice (p = 0.066), at retention (p = 0.761), or offline (p = 0.966). However, the exercise condition enabled participants to maintain spatial accuracy during practice (p = 0.477); whereas, following rest performance diminished (p = 0.050). There were no significant differences between conditions at retention (p = 0.532) or offline (p = 0.246). Discussion An acute bout of moderate-intensity aerobic exercise facilitated the maintenance of motor performance during skill acquisition, but did not influence motor learning. Given past work showing that pairing high intensity exercise with skilled motor practice benefits learning, it seems plausible that intensity is a key modulator of the effects of acute aerobic exercise on changes in complex motor behavior. Further work is necessary to establish a dose-response relationship between

  1. The Effect of an Acute Bout of Moderate-Intensity Aerobic Exercise on Motor Learning of a Continuous Tracking Task.

    PubMed

    Snow, Nicholas J; Mang, Cameron S; Roig, Marc; McDonnell, Michelle N; Campbell, Kristin L; Boyd, Lara A

    2016-01-01

    There is evidence for beneficial effects of acute and long-term exercise interventions on several forms of memory, including procedural motor learning. In the present study we examined how performing a single bout of continuous moderate intensity aerobic exercise would impact motor skill acquisition and retention in young healthy adults, compared to a period of rest. We hypothesized that exercise would improve motor skill acquisition and retention, compared to motor practice alone. Sixteen healthy adults completed sessions of aerobic exercise or seated rest that were immediately followed by practice of a novel motor task (practice). Exercise consisted of 30 minutes of continuous cycling at 60% peak O2 uptake. Twenty-four hours after practice, we assessed motor learning with a no-exercise retention test (retention). We also quantified changes in offline motor memory consolidation, which occurred between practice and retention (offline). Tracking error was separated into indices of temporal precision and spatial accuracy. There were no differences between conditions in the timing of movements during practice (p = 0.066), at retention (p = 0.761), or offline (p = 0.966). However, the exercise condition enabled participants to maintain spatial accuracy during practice (p = 0.477); whereas, following rest performance diminished (p = 0.050). There were no significant differences between conditions at retention (p = 0.532) or offline (p = 0.246). An acute bout of moderate-intensity aerobic exercise facilitated the maintenance of motor performance during skill acquisition, but did not influence motor learning. Given past work showing that pairing high intensity exercise with skilled motor practice benefits learning, it seems plausible that intensity is a key modulator of the effects of acute aerobic exercise on changes in complex motor behavior. Further work is necessary to establish a dose-response relationship between aerobic exercise and motor learning.

  2. Activation of the arousal response can impair performance on a simple motor task.

    PubMed

    Noteboom, J T; Fleshner, M; Enoka, R M

    2001-08-01

    The purpose of this study was to determine the effect of arousal in men and women on the moment-to-moment performance of a simple motor task. We examined the control of a precision task in the presence and absence of imposed stressors. Twenty-nine subjects (14 men, 15 women; 18--44 yr) were randomly assigned to either a control group or one of two stressor groups, Mental Math or Electric Shock. Subjects presented with Math and Shock stressors, which lasted 10 min, experienced significant increases in cognitive and physiological arousal compared with baseline and control subjects. Heart rate, systolic blood pressure, and electrodermal activity were elevated 5--80% with presentation of the stressors, whereas diastolic blood pressure and salivary cortisol were unchanged. The greater levels of cognitive and physiological arousal were associated with reductions in steadiness of a pinch grip for the Shock subjects (approximately 130% reduction from baseline) but not for the subjects in the Math group, who experienced heightened arousal but no change in steadiness (10% reduction from baseline). Although women exhibited more of a reduction in steadiness than men, the effect was largely unrelated to the magnitude of the change in arousal.

  3. Application of ensemble classifier in EEG-based motor imagery tasks

    NASA Astrophysics Data System (ADS)

    Liu, Bianhong; Hao, Hongwei

    2007-12-01

    Electroencephalogram (EEG) recorded during motor imagery tasks can be used to move a cursor to a target on a computer screen. Such an EEG-based brain-computer interface (BCI) can provide a new communication channel for the subjects with neuromuscular disorders. To achieve higher speed and more accuracy to enhance the practical applications of BCI in computer aid medical systems, the ensemble classifier is used for the single classification. The ERDs at the electrodes C3 and C4 are calculated and then stacked together into the feature vector for the ensemble classifier. The ensemble classifier is based on Linear Discriminant Analysis (LDA) and Nearest Neighbor (NN). Furthermore, it considers the feedback. This method is successfully used in the 2003 international data analysis competition on BCI-tasks (data set III). The results show that the ensemble classifier succeed with a recognition as 90%, on average, which is 5% and 3% higher than that of using the LDA and NN separately. Moreover, the ensemble classifier outperforms LDA and NN in the whole time course. With adequate recognition, ease of use and clearly understood, the ensemble classifier can meet the need of time-requires for single classification.

  4. Task-based mirror therapy enhances ipsilesional motor functions in stroke: A pilot study.

    PubMed

    Arya, Kamal Narayan; Pandian, Shanta; Kumar, Dharmendra

    2017-04-01

    To examine the effect of Mirror therapy (MT) on dexterity, coordination, and muscle strength of the less-affected upper limb in stroke. Pre-test post-test, single group, experimental design. Rehabilitation institute. Post-stroke hemiparetic chronic subjects (N = 21). Forty sessions of MT using various tasks in addition to the conventional rehabilitation. Tasks such as lifting a glass, ball-squeezing, and picking-up objects were performed by the less-affected side in front of the mirror-box creating an illusion for the affected side. Minnesota Manual Dexterity Test (MMDT), Purdue Peg Board Test (PPBT), and Manual Muscle Testing (MMT) were used to measure the deficits of the less-affected side. Post-intervention, the less-affected side of the participants exhibited significant improvement on MMDT (p < 0.001), PPBT (p < 0.001), and MMT (shoulder flexors, wrist extensors and deviators, and finger flexors-extensors; p = 0.005-0.046). In post-stroke hemiparesis, MT also led to the improvement in dexterity, coordination, and strength of the less-affected side. In addition to the affected side, the technique may augment the subtle motor deficits of the less-affected side. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Balancing cognitive control: how observed movements influence motor performance in a task with balance constraints.

    PubMed

    Verrel, Julius; Lisofsky, Nina; Kühn, Simone

    2014-07-01

    We investigated the influence of observed movements on executed movements in a task requiring lifting one foot from the floor while maintaining whole-body balance. Sixteen young participants (20-30 years) performed foot lift movements, which were either cued symbolically by a letter (L/R, indicating to lift the left/right foot) or by a short movie showing a foot lift movement. In the symbol cue condition, stimuli from the movie cue condition were used as distractors, and vice versa. Anticipatory postural adjustments (APAs) and actual foot lifts were recorded using force plates and optical motion capture. Foot lift responses were generally faster in response to the movie compared to the symbol cue condition. Moreover, incongruent movement distractors interfered with performance in the symbol cue condition, as shown by longer response times and increased number of APAs. Latencies of the first (potentially wrong) APA in a trial were shorter for movie compared to symbol cues but were not affected by cue-distractor congruency. Amplitude of the first APA was smaller when it was followed by additional APAs compared to trials with a single APA. Our results show that automatic imitation tendencies are integrated with postural control in a task with balance constraints. Analysis of the number, timing and amplitude of APAs indicates that conflicts between intended and observed movements are not resolved at a purely cognitive level but directly influence overt motor performance, emphasizing the intimate link between perception, cognition and action.

  6. Effect of a repeated tongue-lift motor task for tongue function.

    PubMed

    Honki, Hisae; Iida, Takashi; Komiyama, Osamu; Masuda, Manabu; Svensson, Peter; Kawara, Misao

    2016-12-01

    This study investigated the effect of repeated tongue motor tasks on suprahyoid muscle activity and tongue pressure. Fourteen participants performed three series of a standardized tongue-lift training (TLT) task on each of five consecutive days. Electromyographic (EMG) activity from suprahyoid muscles and tongue pressure were recorded. In the first and third TLT series, participants were instructed only to target different force levels. During the second TLT series, visual feedback of the force level was given. One series consisted of three measurements [at 10%, 20%, and 40% of maximum voluntary contraction (MVC), respectively]. The coefficient of determination of the target force level-EMG curve and the target force level-tongue pressure curve was calculated from all series. There were no statistically significant day-to-day differences in EMG-root mean square (RMS) values and tongue pressure during MVC. The coefficients of determination of tongue pressure in the first series on day 1 were statistically significantly lower than the coefficients of determination in the first series on day 5. These findings suggest that the control of tongue pressure improved, while the maximum force remained constant. These results could have implications for treatment paradigms related to learning for patients with compromised tongue function, such as swallowing disorders or dysphagia.

  7. Motor learning: changes in the structure of variability in a redundant task.

    PubMed

    Müller, Hermann; Sternad, Dagmar

    2009-01-01

    Although variability is a fundamental and ubiquitous feature of movement in all biological systems, skilled performance is typically associated with a low level of variability and, implicitly, random noise. Hence, during practice performance variability undergoes changes leading to an overall reduction. However, learning manifests itself through more than just a reduction of random noise. To better understand the processes underlying acquisition and control of movements we show how the examination of variability and its changes with practice provides a suitable window to shed light on this phenomenon. We present one route into this problem that is particularly suited for tasks with redundant degrees of freedom: task performance is parsed into execution and result variables that are related by some function which provides a set of equivalent executions for a given result. Variability over repeated performances is analyzed with a view to this solution manifold. We present a method that parses the structure of variability into four conceptually motivated components and review three methods that are currently used in motor control research. Their advantages and limitations are discussed.

  8. The influence of catch trials on the consolidation of motor memory in force field adaptation tasks

    PubMed Central

    Focke, Anne; Stockinger, Christian; Diepold, Christina; Taubert, Marco; Stein, Thorsten

    2013-01-01

    In computational neuroscience it is generally accepted that human motor memory contains neural representations of the physics of the musculoskeletal system and the objects in the environment. These representations are called “internal models”. Force field studies, in which subjects have to adapt to dynamic perturbations induced by a robotic manipulandum, are an established tool to analyze the characteristics of such internal models. The aim of the current study was to investigate whether catch trials during force field learning could influence the consolidation of motor memory in more complex tasks. Thereby, the force field was more than double the force field of previous studies (35 N·s/m). Moreover, the arm of the subjects was not supported. A total of 46 subjects participated in this study and performed center-out movements at a robotic manipulandum in two different force fields. Two control groups learned force field A on day 1 and were retested in the same force field on day 3 (AA). Two test groups additionally learned an interfering force field B (= −A) on day 2 (ABA). The difference between the two test and control groups, respectively, was the absence (0%) or presence (19%) of catch trials, in which the force field was turned-off suddenly. The results showed consolidation of force field A on day 3 for both control groups. Test groups showed no consolidation of force field A (19% catch trials) and even poorer performance on day 3 (0% catch trials). In conclusion, it can be stated that catch trials seem to have a positive effect on the performance on day 3 but do not trigger a consolidation process as shown in previous studies that used a lower force field viscosity with supported arm. These findings indicate that the results of previous studies in which less complex tasks were analyzed, cannot be fully transferred to more complex tasks. Moreover, the effects of catch trials in these situations are insufficiently understood and further research is

  9. Brain-computer interface analysis of a dynamic visuo-motor task.

    PubMed

    Logar, Vito; Belič, Aleš

    2011-01-01

    The area of brain-computer interfaces (BCIs) represents one of the more interesting fields in neurophysiological research, since it investigates the development of the machines that perform different transformations of the brain's "thoughts" to certain pre-defined actions. Experimental studies have reported some successful implementations of BCIs; however, much of the field still remains unexplored. According to some recent reports the phase coding of informational content is an important mechanism in the brain's function and cognition, and has the potential to explain various mechanisms of the brain's data transfer, but it has yet to be scrutinized in the context of brain-computer interface. Therefore, if the mechanism of phase coding is plausible, one should be able to extract the phase-coded content, carried by brain signals, using appropriate signal-processing methods. In our previous studies we have shown that by using a phase-demodulation-based signal-processing approach it is possible to decode some relevant information on the current motor action in the brain from electroencephalographic (EEG) data. In this paper the authors would like to present a continuation of their previous work on the brain-information-decoding analysis of visuo-motor (VM) tasks. The present study shows that EEG data measured during more complex, dynamic visuo-motor (dVM) tasks carries enough information about the currently performed motor action to be successfully extracted by using the appropriate signal-processing and identification methods. The aim of this paper is therefore to present a mathematical model, which by means of the EEG measurements as its inputs predicts the course of the wrist movements as applied by each subject during the task in simulated or real time (BCI analysis). However, several modifications to the existing methodology are needed to achieve optimal decoding results and a real-time, data-processing ability. The information extracted from the EEG could

  10. Behavioral, Cognitive, and Motor Preparation Deficits in a Visual Cued Spatial Attention Task in Autism Spectrum Disorder

    PubMed Central

    Sokhadze, Estate M.; Tasman, Allan; Sokhadze, Guela E.; El-Baz, Ayman S.; Casanova, Manuel F.

    2015-01-01

    Abnormalities in motor skills have been regarded as part of the symptomatology characterizing autism spectrum disorder (ASD). It has been estimated that 80% of subjects with autism display “motor dyspraxia” or clumsiness that are not readily identified in a routine neurological examination. In this study we used behavioral measures, event-related potentials (ERP), and lateralized readiness potential (LRP) to study cognitive and motor preparation deficits contributing to the dyspraxia of autism. A modified Posner cueing task was used to analyze motor preparation abnormalities in children with autism and in typically developing children (N=30/per group). In this task, subjects engage in preparing motor response based on a visual cue, and then execute a motor movement based on the subsequent imperative stimulus. The experimental conditions, such as the validity of the cue and the spatial location of the target stimuli were manipulated to influence motor response selection, preparation, and execution. Reaction time and accuracy benefited from validly cued targets in both groups, while main effects of target spatial position were more obvious in the autism group. The main ERP findings were prolonged and more negative early frontal potentials in the ASD in incongruent trials in both types of spatial location. The LRP amplitude was larger in incongruent trials and had stronger effect in the children with ASD. These effects were better expressed at the earlier stages of LRP, specifically those related to response selection, and showed difficulties at the cognitive phase of stimulus processing rather that at the motor execution stage. The LRP measures at different stages reflect the chronology of cognitive aspects of movement preparation and are sensitive to manipulations of cue correctness, thus representing very useful biomarker in autism dyspraxia research. Future studies may use more advance and diverse manipulations of movement preparation demands in testing more

  11. Behavioral, Cognitive, and Motor Preparation Deficits in a Visual Cued Spatial Attention Task in Autism Spectrum Disorder.

    PubMed

    Sokhadze, Estate M; Tasman, Allan; Sokhadze, Guela E; El-Baz, Ayman S; Casanova, Manuel F

    2016-03-01

    Abnormalities in motor skills have been regarded as part of the symptomatology characterizing autism spectrum disorder (ASD). It has been estimated that 80 % of subjects with autism display "motor dyspraxia" or clumsiness that are not readily identified in a routine neurological examination. In this study we used behavioral measures, event-related potentials (ERP), and lateralized readiness potential (LRP) to study cognitive and motor preparation deficits contributing to the dyspraxia of autism. A modified Posner cueing task was used to analyze motor preparation abnormalities in children with autism and in typically developing children (N = 30/per group). In this task, subjects engage in preparing motor response based on a visual cue, and then execute a motor movement based on the subsequent imperative stimulus. The experimental conditions, such as the validity of the cue and the spatial location of the target stimuli were manipulated to influence motor response selection, preparation, and execution. Reaction time and accuracy benefited from validly cued targets in both groups, while main effects of target spatial position were more obvious in the autism group. The main ERP findings were prolonged and more negative early frontal potentials in the ASD in incongruent trials in both types of spatial location. The LRP amplitude was larger in incongruent trials and had stronger effect in the children with ASD. These effects were better expressed at the earlier stages of LRP, specifically those related to response selection, and showed difficulties at the cognitive phase of stimulus processing rather that at the motor execution stage. The LRP measures at different stages reflect the chronology of cognitive aspects of movement preparation and are sensitive to manipulations of cue correctness, thus representing very useful biomarker in autism dyspraxia research. Future studies may use more advance and diverse manipulations of movement preparation demands in testing more

  12. Task-dependent modification of leg motor neuron synaptic input underlying changes in walking direction and walking speed.

    PubMed

    Rosenbaum, Philipp; Schmitz, Josef; Schmidt, Joachim; Büschges, Ansgar

    2015-08-01

    Animals modify their behavior constantly to perform adequately in their environment. In terrestrial locomotion many forms of adaptation exist. Two tasks are changes of walking direction and walking speed. We investigated these two changes in motor output in the stick insect Cuniculina impigra to see how they are brought about at the level of leg motor neurons. We used a semi-intact preparation in which we can record intracellularly from leg motor neurons during walking. In this single-leg preparation the middle leg of the animal steps in a vertical plane on a treadwheel. Stimulation of either abdomen or head reliably elicits fictive forward or backward motor activity, respectively, in the fixed and otherwise deafferented thorax-coxa joint. With a change of walking direction only thorax-coxa-joint motor neurons protractor and retractor changed their activity. The protractor switched from swing activity during forward to stance activity during backward walking, and the retractor from stance to swing. This phase switch was due to corresponding change of phasic synaptic inputs from inhibitory to excitatory and vice versa at specific phases of the step cycle. In addition to phasic synaptic input a tonic depolarization of the motor neurons was present. Analysis of changes in stepping velocity during stance showed only a significant correlation to flexor motor neuron activity, but not to that of retractor and depressor motor neurons during forward walking. These results show that different tasks in the stick insect walking system are generated by altering synaptic inputs to specific leg joint motor neurons only. Copyright © 2015 the American Physiological Society.

  13. Task-dependent modification of leg motor neuron synaptic input underlying changes in walking direction and walking speed

    PubMed Central

    Rosenbaum, Philipp; Schmitz, Josef; Schmidt, Joachim

    2015-01-01

    Animals modify their behavior constantly to perform adequately in their environment. In terrestrial locomotion many forms of adaptation exist. Two tasks are changes of walking direction and walking speed. We investigated these two changes in motor output in the stick insect Cuniculina impigra to see how they are brought about at the level of leg motor neurons. We used a semi-intact preparation in which we can record intracellularly from leg motor neurons during walking. In this single-leg preparation the middle leg of the animal steps in a vertical plane on a treadwheel. Stimulation of either abdomen or head reliably elicits fictive forward or backward motor activity, respectively, in the fixed and otherwise deafferented thorax-coxa joint. With a change of walking direction only thorax-coxa-joint motor neurons protractor and retractor changed their activity. The protractor switched from swing activity during forward to stance activity during backward walking, and the retractor from stance to swing. This phase switch was due to corresponding change of phasic synaptic inputs from inhibitory to excitatory and vice versa at specific phases of the step cycle. In addition to phasic synaptic input a tonic depolarization of the motor neurons was present. Analysis of changes in stepping velocity during stance showed only a significant correlation to flexor motor neuron activity, but not to that of retractor and depressor motor neurons during forward walking. These results show that different tasks in the stick insect walking system are generated by altering synaptic inputs to specific leg joint motor neurons only. PMID:26063769

  14. Levodopa medication does not influence motor inhibition or conflict resolution in a conditional stop-signal task in Parkinson's disease.

    PubMed

    Obeso, Ignacio; Wilkinson, Leonora; Jahanshahi, Marjan

    2011-09-01

    Evidence from animal, clinical, and imaging studies suggests that the basal ganglia and their frontal connections mediate motor inhibition, but the role of dopamine remains unclear. The aim of our study was to investigate, for the first time, whether levodopa medication influences motor inhibition and conflict resolution on the conditional stop-signal reaction time task in patients with Parkinson's disease (PD) tested on or off their medication. Sixteen PD patients and 17 healthy controls performed the conditional stop-signal reaction time (SSRT) task, which requires inhibition of responses when a stop signal is presented on "critical" trials. Additionally, on "non-critical" trials, participants are instructed to ignore the stop signal and respond, thus generating conflict between motor inhibition and initiation; and conflict-induced slowing (CIS) on these "non-critical" trials. Levodopa medication did not significantly influence response initiation, inhibition (SSRT) or the measure of conflict resolution (CIS). Compared to healthy controls, PD patients showed significantly worse response initiation and inhibition both on and off their levodopa medication. Our results suggest that motor inhibition or conflict-induced slowing on the conditional stop-signal RT task are not altered by dopamine replacement in PD. This conclusion is consistent with evidence from animal studies and clinical pharmacological investigations suggesting a role for noradrenaline in motor inhibition and impulsivity.

  15. Perceptual, premotor and motor factors in the performance of a delayed-reaching task by subjects with unilateral spatial neglect.

    PubMed

    Shimodozono, M; Matsumoto, S; Miyata, R; Etoh, S; Tsujio, S; Kawahira, K

    2006-01-01

    We used a computerized delayed-reaching task with a simple reaction time (RT) to investigate the visuo-motor and spatio-temporal performance of right brain-damaged (RBD) patients with unilateral spatial neglect (USN). Fifty-three RBD patients (22 with and 31 without USN) and 25 controls performed the tasks. We recorded the following data: the first RT (RT-1), which is thought to reflect the detection of the target position (the perceptual factor); the second RT (RT-2), which represents the initiation of reaching (the motor initiation aspect of premotor factors); the movement time (MT), which is hypothesized to reflect the "pure" motor component of the task. RBD patients with both USN and hemianopia demonstrated significantly longer RTs towards the left than towards the right for both the RT-1 and the RT-2. Among the RBD patients without hemianopia, the laterality index (left side/right side) of the RT-1 in those with USN was significantly greater than in those without USN or the controls. Among the three groups, there were no significant differences between the laterality indices of either the RT-2s or the MTs. These results suggest that the impairment of leftward movement in RBD patients with USN might be caused primarily by a perceptual impairment rather than an impairment in motor initiation, and is certainly not a "pure" motor impairment.

  16. Learning better by repetition or variation? Is transfer at odds with task specific training?

    PubMed Central

    Bonney, Emmanuel; Ferguson, Gillian D.; Smits-Engelsman, Bouwien C. M.

    2017-01-01

    Objective Transfer of motor skills is the ultimate goal of motor training in rehabilitation practice. In children with Developmental Coordination Disorder (DCD), very little is known about how skills are transferred from training situations to real life contexts. In this study we examined the influence of two types of practice on transfer of motor skills acquired in a virtual reality (VR) environment. Method One hundred and eleven children with DCD and their typically developing (TD) peers, aged 6–10 years (M = 8.0 SD = 1.0) were randomly assigned to either variable (n = 56) or repetitive practice (n = 55). Participants in the repetitive practice played the same exergame (ski slalom) twice weekly for 20 minutes, over a period of 5 weeks, while those in the variable group played 10 different games. Motor skills such as balance tasks (hopping), running and agility tasks, ball skills and functional activities were evaluated before and after 5 weeks of training. Results ANOVA repeated measures indicated that both DCD and TD children demonstrated transfer effects to real life skills with identical and non-identical elements at exactly the same rate, irrespective of the type of practice they were assigned to. Conclusion Based on these findings, we conclude that motor skills acquired in the VR environment, transfers to real world contexts in similar proportions for both TD and DCD children. The type of practice adopted does not seem to influence children’s ability to transfer skills acquired in an exergame to life situations but the number of identical elements does. PMID:28333997

  17. Acquisition of Internal Models of Motor Tasks in Children with Autism

    ERIC Educational Resources Information Center

    Gidley Larson, Jennifer C.; Bastian, Amy J.; Donchin, Opher; Shadmehr, Reza; Mostofsky, Stewart H.

    2008-01-01

    Children with autism exhibit a host of motor disorders including poor coordination, poor tool use and delayed learning of complex motor skills like riding a tricycle. Theory suggests that one of the crucial steps in motor learning is the ability to form internal models: to predict the sensory consequences of motor commands and learn from errors to…

  18. Acquisition of Internal Models of Motor Tasks in Children with Autism

    ERIC Educational Resources Information Center

    Gidley Larson, Jennifer C.; Bastian, Amy J.; Donchin, Opher; Shadmehr, Reza; Mostofsky, Stewart H.

    2008-01-01

    Children with autism exhibit a host of motor disorders including poor coordination, poor tool use and delayed learning of complex motor skills like riding a tricycle. Theory suggests that one of the crucial steps in motor learning is the ability to form internal models: to predict the sensory consequences of motor commands and learn from errors to…

  19. Distribution of Practice and Metacognition in Learning and Long-Term Retention of a Discrete Motor Task

    ERIC Educational Resources Information Center

    Dail, Teresa K.; Christina, Robert W.

    2004-01-01

    This study examined judgments of learning and the long-term retention of a discrete motor task (golf putting) as a function of practice distribution. The results indicated that participants in the distributed practice group performed more proficiently than those in the massed practice group during both acquisition and retention phases. No…

  20. Relationships between Task-Oriented Postural Control and Motor Ability in Children and Adolescents with Down Syndrome

    ERIC Educational Resources Information Center

    Wang, Hui-Yi; Long, I-Man; Liu, Mei-Fang

    2012-01-01

    Individuals with Down syndrome (DS) have been characterized by greater postural sway in quiet stance and insufficient motor ability. However, there is a lack of studies to explore the properties of dynamic postural sway, especially under conditions of task-oriented movement. The purpose of this study was to investigate the relationships between…

  1. The effects of bromazepam over the central and frontal areas during a motor task: an EEG study.

    PubMed

    Fortunato, Suzete; Tanaka, Guaraci Ken; Araújo, Fernanda; Bittencourt, Juliana; Aprigio, Danielle; Gongora, Mariana; Teixeira, Silmar; Pompeu, Fernando Augusto Monteiro Saboia; Cagy, Mauricio; Basile, Luis F; Ribeiro, Pedro; Velasques, Bruna

    2015-04-01

    The present study investigates the influence of bromazepam while executing a motor task. Specifically, we intend to analyze the changes in alpha absolute power under two experimental conditions, bromazepam and placebo. We also included analyses of theta and beta frequencies. We collected electroencephalographic data before, during, and after motor task execution. We used a Two Way ANOVA to investigate the condition (PL × Br6 mg) and moment (pre and post) variables for the following electrodes: Fp1, Fp2, F7, F3, Fz, F4, F8, C3, CZ and C4. We found a main effect for condition on the electrodes FP1, F7, F3, Fz, F4, C3 and CZ, for alpha and beta bands. For beta band we also found a main effect for condition on the electrodes Fp2, F8 and C4; for theta band we identified a main effect for condition on C3, Cz and C4 electrodes. This finding suggests that the motor task did not have any influence on the electrocortical activity in alpha, and that the existing modifications were a consequence due merely to the drug use. Despite its anxiolytic and sedative action, bromazepam did not show any significant changes when the individuals executed a finger extension motor task.

  2. Relationships between Task-Oriented Postural Control and Motor Ability in Children and Adolescents with Down Syndrome

    ERIC Educational Resources Information Center

    Wang, Hui-Yi; Long, I-Man; Liu, Mei-Fang

    2012-01-01

    Individuals with Down syndrome (DS) have been characterized by greater postural sway in quiet stance and insufficient motor ability. However, there is a lack of studies to explore the properties of dynamic postural sway, especially under conditions of task-oriented movement. The purpose of this study was to investigate the relationships between…

  3. The Effect of Motor Difficulty on the Acquisition of a Computer Task: A Comparison between Young and Older Adults

    ERIC Educational Resources Information Center

    Fezzani, K.; Albinet, C.; Thon, B.; Marquie, J. -C.

    2010-01-01

    The present study investigated the extent to which the impact of motor difficulty on the acquisition of a computer task varies as a function of age. Fourteen young and 14 older participants performed 352 sequences of 10 serial pointing movements with a wireless pen on a digitiser tablet. A conditional probabilistic structure governed the…

  4. The Influence of Parkinson's Disease Motor Symptom Asymmetry on Hand Performance: An Examination of the Grooved Pegboard Task.

    PubMed

    Scharoun, Sara M; Bryden, Pamela J; Sage, Michael D; Almeida, Quincy J; Roy, Eric A

    2015-01-01

    This study examined the influence of motor symptom asymmetry in Parkinson's disease (PD) on Grooved Pegboard (GP) performance in right-handed participants. The Unified Parkinson's Disease Rating Scale was used to assess motor symptoms and separate participants with PD into two groups (right-arm affected, left-arm affected) for comparison with a group of healthy older adults. Participants completed the place and replace GP tasks two times with both hands. Laterality quotients were computed to quantify performance differences between the two hands. Comparisons among the three groups indicated that when the nonpreferred hand is affected by PD motor symptoms, superior preferred hand performance (as seen in healthy older adults) is further exaggerated in tasks that require precision (i.e., place task). Regardless of the task, when the preferred hand is affected, there is an evident shift to superior left-hand performance, which may inevitably manifest as a switch in hand preference. Results add to the discussion of the relationship between handedness and motor symptom asymmetry in PD.

  5. Within-session and one-week practice effects on a motor task in amnestic mild cognitive impairment.

    PubMed

    Schaefer, Sydney Y; Duff, Kevin

    2016-10-03

    Practice effects on neuropsychological tests, which are improvements in test scores due to repeated exposure to testing materials, are robust in healthy elders, but muted in older adults with cognitive disorders. Conversely, few studies have investigated practice effects on motor tasks involving procedural memory, particularly across test-retest periods exceeding 24 hours. The current study examined one-week practice effects on a novel upper extremity motor task in 54 older adults with amnestic mild cognitive impairment. Results indicate that these individuals with primary memory deficits did improve on this motor task within a brief training session as well as across one week. These practice effects were unrelated to demographic characteristics or global cognition. One-week practice effects were, however, negatively related to delayed memory function, with larger practice effects being associated with poorer delayed memory and potentially better visuospatial ability. The presence of longer term practice effects on a procedural motor task not only has implications for how longitudinal assessments with similar measures involving implicit memory might be interpreted, but may also inform future rehabilitative strategies for patients with more severe declarative memory deficits.

  6. The Effect of Motor Difficulty on the Acquisition of a Computer Task: A Comparison between Young and Older Adults

    ERIC Educational Resources Information Center

    Fezzani, K.; Albinet, C.; Thon, B.; Marquie, J. -C.

    2010-01-01

    The present study investigated the extent to which the impact of motor difficulty on the acquisition of a computer task varies as a function of age. Fourteen young and 14 older participants performed 352 sequences of 10 serial pointing movements with a wireless pen on a digitiser tablet. A conditional probabilistic structure governed the…

  7. Effects of short-term training on behavioral learning and skill acquisition during intraoral fine motor task.

    PubMed

    Kumar, A; Grigoriadis, J; Trulsson, M; Svensson, P; Svensson, K G

    2015-10-15

    Sensory information from the orofacial mechanoreceptors are used by the nervous system to optimize the positioning of food, determine the force levels, and force vectors involved in biting of food morsels. Moreover, practice resulting from repetition could be a key to learning and acquiring a motor skill. Hence, the aim of the experiment was to test the hypothesis that repeated splitting of a food morsel during a short-term training with an oral fine motor task would result in increased performance and optimization of jaw movements, in terms of reduction in duration of various phases of the jaw movements. Thirty healthy volunteers were asked to intraorally manipulate and split a chocolate candy, into two equal halves. The participants performed three series (with 10 trials) of the task before and after a short-term (approximately 30 min) training. The accuracy of the split and vertical jaw movement during the task were recorded. The precision of task performance improved significantly after training (22% mean deviation from ideal split after vs. 31% before; P<0.001). There was a significant decrease in the total duration of jaw movements during the task after the training (1.21 s total duration after vs. 1.56 s before; P<0.001). Further, when the jaw movements were divided into different phases, the jaw opening phase and contact phase were significantly shorter after training than before training (P=0.001, P=0.002). The results indicate that short-term training of an oral fine motor task induces behavior learning, skill acquisition and optimization of jaw movements in terms of better performance and reduction in the duration of jaw movements, during the task. The finding of the present study provides insights into how humans learn oral motor behaviors or the kind of adaptation that takes place after a successful prosthetic rehabilitation. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  8. Motor intensive anti-gravity training improves performance in dynamic balance related tasks in persons with Parkinson's disease.

    PubMed

    Malling, Anne Sofie B; Jensen, Bente R

    2016-01-01

    Recent studies indicate that the effect of training on motor performance in persons with Parkinson's disease (PDP) is dependent on motor intensity. However, training of high motor intensity can be hard to apply in PDP due to e.g. bradykinesia, rigidity, tremor and postural instability. Therefore, the aim was to study the effect of motor intensive training performed in a safe anti-gravity environment using lower-body positive pressure (LBPP) technology on performance during dynamic balance related tasks. Thirteen male PDP went through an 8-week control period followed by 8 weeks of motor intensive antigravity training. Seventeen healthy males constituted a control group (CON). Performance during a five repetition sit-to-stand test (STS; sagittal plane) and a dynamic postural balance test (DPB; transversal plane) was evaluated. Effect measures were completion time, functional rates of force development, directional changes and force variance. STS completion time improved by 24% to the level of CON which was explained by shorter sitting-time and standing-time and larger numeric rate of force change during lowering to the chair, indicating faster vertical directional change and improved relaxation. DPB completion time tended to improve and was accompanied by improvements of functional medial and lateral rates of force development and higher vertical force variance during DPB. Our results suggest that the performance improvements may relate to improved inter-limb coordination. It is concluded that 8 weeks of motor intensive training in a safe LBPP environment improved performance during dynamic balance related tasks in PDP.

  9. Performance variation in motor imagery brain-computer interface: a brief review.

    PubMed

    Ahn, Minkyu; Jun, Sung Chan

    2015-03-30

    Brain-computer interface (BCI) technology has attracted significant attention over recent decades, and has made remarkable progress. However, BCI still faces a critical hurdle, in that performance varies greatly across and even within subjects, an obstacle that degrades the reliability of BCI systems. Understanding the causes of these problems is important if we are to create more stable systems. In this short review, we report the most recent studies and findings on performance variation, especially in motor imagery-based BCI, which has found that low-performance groups have a less-developed brain network that is incapable of motor imagery. Further, psychological and physiological states influence performance variation within subjects. We propose a possible strategic approach to deal with this variation, which may contribute to improving the reliability of BCI. In addition, the limitations of current work and opportunities for future studies are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Can stereotype threat affect motor performance in the absence of explicit monitoring processes? Evidence using a strength task.

    PubMed

    Chalabaev, Aïna; Brisswalter, Jeanick; Radel, Rémi; Coombes, Stephen A; Easthope, Christopher; Clément-Guillotin, Corentin

    2013-04-01

    Previous evidence shows that stereotype threat impairs complex motor skills through increased conscious monitoring of task performance. Given that one-step motor skills may not be susceptible to these processes, we examined whether performance on a simple strength task may be reduced under stereotype threat. Forty females and males performed maximum voluntary contractions under stereotypical or nullified-stereotype conditions. Results showed that the velocity of force production within the first milliseconds of the contraction decreased in females when the negative stereotype was induced, whereas maximal force did not change. In males, the stereotype induction only increased maximal force. These findings suggest that stereotype threat may impair motor skills in the absence of explicit monitoring processes, by influencing the planning stage of force production.

  11. Motor adaptations to local muscle pain during a bilateral cyclic task.

    PubMed

    Brøchner Nielsen, Niels-Peter; Tucker, Kylie; Dorel, Sylvain; Guével, Arnaud; Hug, François

    2017-02-01

    The aim of this study was to determine how unilateral pain, induced in two knee extensor muscles, affects muscle coordination during a bilateral pedaling task. Fifteen participants performed a 4-min pedaling task at 130 W in two conditions (Baseline and Pain). Pain was induced by injection of hypertonic saline into the vastus medialis (VM) and vastus lateralis (VL) muscles of one leg. Force applied throughout the pedaling cycle was measured using an instrumented pedal and used to calculate pedal power. Surface electromyography (EMG) was recorded bilaterally from eight muscles to assess changes in muscle activation strategies. Compared to Baseline, during the Pain condition, EMG amplitude of muscles of the painful leg (VL and VM-the painful muscles, and RF-another quadriceps muscle with no pain) was lower during the extension phase [(mean ± SD): VL: -22.5 ± 18.9%; P < 0.001; VM: -28.8 ± 19.9%; P < 0.001, RF: -20.2 ± 13.9%; P < 0.001]. Consistent with this, pedal power applied by the painful leg was also lower during the extension phase (-16.8 ± 14.2 W, P = 0.001) during Pain compared to Baseline. This decrease was compensated for by an 11.3 ± 8.1 W increase in pedal power applied by the non-painful leg during its extension phase (P = 0.04). These results support pain adaptation theories, which suggest that when there is a clear opportunity to compensate, motor adaptations to pain occur to decrease load within the painful tissue. Although the pedaling task offered numerous possibilities for compensation, only between-leg compensations were systematically observed. This finding is discussed in relation to the mechanical and neural constraints of the pedaling task.

  12. Increased brain cortical activity during parabolic flights has no influence on a motor tracking task.

    PubMed

    Schneider, Stefan; Brümmer, Vera; Mierau, Andreas; Carnahan, Heather; Dubrowski, Adam; Strüder, Heiko K

    2008-03-01

    Previous studies showed that changing forces of gravity as they typically occur during parabolic flights might be responsible for adaptional processes of the CNS. However, until now it has not been differentiated between primary influences of weightlessness and secondary influences due to psycho-physiological factors (e.g., physical or mental strain). With the aim of detecting parabolic flight related changes in central cortical activity, a resting EEG was deduced in 16 subjects before, during and after parabolic flights. After subdividing EEG into alpha-, beta-,delta- and theta-wave bands, an increase in beta-power was noticeable inflight, whereas alpha(1)-power was increased postflight. No changes could be observed for the control group. To control possible effects of cortical activation, a manual tracking task with mirror inversion was performed during either the phase of weightlessness or during the normal gravity phase of a parabolic flight. No differences in performance nor in adaptation could be observed between both groups. A third group, performing under normal and stress-free conditions in a lab showed similar tracking values. We assume that the specific increase in brain activity is a sign of an increase in arousal inflight. This does support previous assumptions of non-specific stressors during parabolic flights and has to be considered as a relevant factor for experiments on central nerve adaptation. Although no influences of stress and/or weightlessness on motor performance and adaptation could be observed, we suggest that an "inflight" control group seems to be more adequate than a laboratory control group to investigate gravity-dependent changes in motor control.

  13. An analysis of physiological signals as a measure of task engagement in a multi-limb-coordination motor-learning task.

    PubMed

    Murray, Spencer A; Goldfarb, Michael

    2015-01-01

    There is widespread agreement in the physical rehabilitation community that task engagement is essential to effective neuromuscular recovery. Despite this, there are no clear measures of such task engagement. This paper assesses the extent to which certain physiological measurements might provide a measure of task engagement. In previous studies, correlations between mental focus and certain physiological measurements have been observed in subjects performing tasks requiring mental effort. In this study, the authors analyzed whether these signals showed similar correlation when subjects performed a multi-limb-coordination motor-learning task. Subjects played a video game which required the use of both arms and one leg to play a simplified electronic drum set with varying difficulty. Heart rate (HR), skin conductance level (SCL), and facial electromyogram (EMG) were recorded while the subjects played. Analysis of the recordings showed statistically significant correlations relating task difficulty to SCL, HR and EMG amplitude in corrugator supercilii. No statistically significant correlation was observed between task difficulty and EMG in frontalis.

  14. Modulation of manual preference induced by lateralized practice diffuses over distinct motor tasks: age-related effects

    PubMed Central

    Souza, Rosana M.; Coelho, Daniel B.; Teixeira, Luis A.

    2014-01-01

    In this study we investigated the effect of use of the non-preferred left hand to practice different motor tasks on manual preference in children and adults. Manual preference was evaluated before, immediately after and 20 days following practice. Evaluation was made with tasks of distinct levels of complexity requiring reaching and manipulation of cards at different eccentricities in the workspace. Results showed that left hand use in adults induced increased preference of that hand at the central position when performing the simple task, while left hand use by the children induced increased preference of the left hand at the rightmost positions in the performance of the complex task. These effects were retained over the rest period following practice. Kinematic analysis showed that left hand use during practice did not lead to modification of intermanual performance asymmetry. These results indicate that modulation of manual preference was a consequence of higher frequency of use of the left hand during practice rather than of change in motor performance. Findings presented here support the conceptualization that confidence on successful performance when using a particular limb generates a bias in hand selection, which diffuses over distinct motor tasks. PMID:25538656

  15. Variation among Developmental Dyslexics: Evidence from a Printed-Word-Learning Task

    ERIC Educational Resources Information Center

    Bailey, Caroline E.; Manis, Franklin R.; Pedersen, William C.; Seidenberg, Mark S.

    2004-01-01

    A word-learning task was used to investigate variation among developmental dyslexics classified as phonological and surface dyslexics. Dyslexic children and chronological age (CA)- and reading level (RL)-matched normal readers were taught to pronounce novel nonsense words such as "veep." Words were assigned either a regular (e.g., ''veep'') or an…

  16. Variation among Developmental Dyslexics: Evidence from a Printed-Word-Learning Task

    ERIC Educational Resources Information Center

    Bailey, Caroline E.; Manis, Franklin R.; Pedersen, William C.; Seidenberg, Mark S.

    2004-01-01

    A word-learning task was used to investigate variation among developmental dyslexics classified as phonological and surface dyslexics. Dyslexic children and chronological age (CA)- and reading level (RL)-matched normal readers were taught to pronounce novel nonsense words such as "veep." Words were assigned either a regular (e.g., ''veep'') or an…

  17. Interrelationships among Age, Sex, and Depth of Sport Experience on a Complex Motor Task by 4- to 9-Year Old Children.

    ERIC Educational Resources Information Center

    Kuhlman, Jolynn S.; Beitel, Patricia A.

    Age, gender, and/or previous experience seem to be related to the performance/learning of new perceptual motor tasks. This study sought to determine the relative interrelationships of age, gender, and the depth of sport experience on initial practice of a complex perceptual motor soccer task for 46 children 4- to 9-years-old who were enrolled in a…

  18. Primary Motor Cortex Activation during Action Observation of Tasks at Different Video Speeds Is Dependent on Movement Task and Muscle Properties

    PubMed Central

    Moriuchi, Takefumi; Matsuda, Daiki; Nakamura, Jirou; Matsuo, Takashi; Nakashima, Akira; Nishi, Keita; Fujiwara, Kengo; Iso, Naoki; Nakane, Hideyuki; Higashi, Toshio

    2017-01-01

    The aim of the present study was to investigate how the video speed of observed action affects the excitability of the primary motor cortex (M1), as assessed by the size of motor-evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS). Twelve healthy subjects observed a video clip of a person catching a ball (Experiment 1: rapid movement) and another 12 healthy subjects observed a video clip of a person reaching to lift a ball (Experiment 2: slow movement task). We played each video at three different speeds (slow, normal and fast). The stimulus was given at two points of timing in each experiment. These stimulus points were locked to specific frames of the video rather than occurring at specific absolute times, for ease of comparison across different speeds. We recorded MEPs from the first dorsal interosseous muscle (FDI) and abductor digiti minimi muscle (ADM) of the right hand. MEPs were significantly different for different video speeds only in the rapid movement task. MEPs for the rapid movement task were higher when subjects observed an action played at slow speed than normal or fast speed condition. There was no significant change for the slow movement task. Video speed was effective only in the ADM. Moreover, MEPs in the ADM were significantly higher than in the FDI in a rapid movement task under the slow speed condition. Our findings suggest that the M1 becomes more excitable when subjects observe the video clip at the slow speed in a rapid movement, because they could recognize the elements of movement in others. Our results suggest the effects of manipulating the speed of the viewed task on the excitability of the M1 during passive observation differ depending on the type of movement task observed. It is likely that rehabilitation in the clinical setting will be more efficient if the video speed is changed to match the task’s characteristics. PMID:28163678

  19. When Affordances Climb into Your Mind: Advantages of Motor Simulation in a Memory Task Performed by Novice and Expert Rock Climbers

    ERIC Educational Resources Information Center

    Pezzulo, Giovanni; Barca, Laura; Bocconi, Alessandro Lamberti; Borghi, Anna M.

    2010-01-01

    Does the sight of multiple climbing holds laid along a path activate a motor simulation of climbing that path? One way of testing whether multiple affordances and their displacement influence the formation of a motor simulation is to study acquired motor skills. We used a behavioral task in which expert and novice rock climbers were shown three…

  20. Effects of aripiprazole and haloperidol on neural activation during a simple motor task in healthy individuals: A functional MRI study.

    PubMed

    Goozee, Rhianna; O'Daly, Owen; Handley, Rowena; Reis Marques, Tiago; Taylor, Heather; McQueen, Grant; Hubbard, Kathryn; Pariante, Carmine; Mondelli, Valeria; Reinders, Antje A T S; Dazzan, Paola

    2017-04-01

    The dopaminergic system plays a key role in motor function and motor abnormalities have been shown to be a specific feature of psychosis. Due to their dopaminergic action, antipsychotic drugs may be expected to modulate motor function, but the precise effects of these drugs on motor function remain unclear. We carried out a within-subject, double-blind, randomized study of the effects of aripiprazole, haloperidol and placebo on motor function in 20 healthy men. For each condition, motor performance on an auditory-paced task was investigated. We entered maps of neural activation into a random effects general linear regression model to investigate motor function main effects. Whole-brain imaging revealed a significant treatment effect in a distributed network encompassing posterior orbitofrontal/anterior insula cortices, and the inferior temporal and postcentral gyri. Post-hoc comparison of treatments showed neural activation after aripiprazole did not differ significantly from placebo in either voxel-wise or region of interest analyses, with the results above driven primarily by haloperidol. We also observed a simple main effect of haloperidol compared with placebo, with increased task-related recruitment of posterior cingulate and precentral gyri. Furthermore, region of interest analyses revealed greater activation following haloperidol compared with placebo in the precentral and post-central gyri, and the putamen. These diverse modifications in cortical motor activation may relate to the different pharmacological profiles of haloperidol and aripiprazole, although the specific mechanisms underlying these differences remain unclear. Evaluating healthy individuals can allow investigation of the effects of different antipsychotics on cortical activation, independently of either disease-related pathology or previous treatment. Hum Brain Mapp 38:1833-1845, 2017. © 2017 Wiley Periodicals, Inc.

  1. Consecutive learning of opposing unimanual motor tasks using the right arm followed by the left arm causes intermanual interference

    PubMed Central

    Thürer, Benjamin; Stein, Thorsten

    2017-01-01

    Intermanual transfer (motor memory generalization across arms) and motor memory interference (impairment of retest performance in consecutive motor learning) are well-investigated motor learning phenomena. However, the interplay of these phenomena remains elusive, i.e., whether intermanual interference occurs when two unimanual tasks are consecutively learned using different arms. Here, we examine intermanual interference when subjects consecutively adapt their right and left arm movements to novel dynamics. We considered two force field tasks A and B which were of the same structure but mirrored orientation (B = -A). The first test group (ABA-group) consecutively learned task A using their right arm and task B using their left arm before being retested for task A with their right arm. Another test group (AAA-group) learned only task A in the same right-left-right arm schedule. Control subjects learned task A using their right arm without intermediate left arm learning. All groups were able to adapt their right arm movements to force field A and both test groups showed significant intermanual transfer of this initial learning to the contralateral left arm of 21.9% (ABA-group) and 27.6% (AAA-group). Consecutively, both test groups adapted their left arm movements to force field B (ABA-group) or force field A (AAA-group). For the ABA-group, left arm learning caused significant intermanual interference of the initially learned right arm task (68.3% performance decrease). The performance decrease of the AAA-group (10.2%) did not differ from controls (15.5%). These findings suggest that motor control and learning of right and left arm movements involve partly similar neural networks or underlie a vital interhemispheric connectivity. Moreover, our results suggest a preferred internal task representation in extrinsic Cartesian-based coordinates rather than in intrinsic joint-based coordinates because interference was absent when learning was performed in extrinsically

  2. Consecutive learning of opposing unimanual motor tasks using the right arm followed by the left arm causes intermanual interference.

    PubMed

    Stockinger, Christian; Thürer, Benjamin; Stein, Thorsten

    2017-01-01

    Intermanual transfer (motor memory generalization across arms) and motor memory interference (impairment of retest performance in consecutive motor learning) are well-investigated motor learning phenomena. However, the interplay of these phenomena remains elusive, i.e., whether intermanual interference occurs when two unimanual tasks are consecutively learned using different arms. Here, we examine intermanual interference when subjects consecutively adapt their right and left arm movements to novel dynamics. We considered two force field tasks A and B which were of the same structure but mirrored orientation (B = -A). The first test group (ABA-group) consecutively learned task A using their right arm and task B using their left arm before being retested for task A with their right arm. Another test group (AAA-group) learned only task A in the same right-left-right arm schedule. Control subjects learned task A using their right arm without intermediate left arm learning. All groups were able to adapt their right arm movements to force field A and both test groups showed significant intermanual transfer of this initial learning to the contralateral left arm of 21.9% (ABA-group) and 27.6% (AAA-group). Consecutively, both test groups adapted their left arm movements to force field B (ABA-group) or force field A (AAA-group). For the ABA-group, left arm learning caused significant intermanual interference of the initially learned right arm task (68.3% performance decrease). The performance decrease of the AAA-group (10.2%) did not differ from controls (15.5%). These findings suggest that motor control and learning of right and left arm movements involve partly similar neural networks or underlie a vital interhemispheric connectivity. Moreover, our results suggest a preferred internal task representation in extrinsic Cartesian-based coordinates rather than in intrinsic joint-based coordinates because interference was absent when learning was performed in extrinsically

  3. The influence of stress and energy level on learning muscle relaxation during gross-motor task performance using electromyographic feedback.

    PubMed

    van Dijk, H; Voerman, G E; Hermens, H J

    2006-09-01

    The aim was to investigate the influence of mood on learning muscle relaxation. Self-reported mood (assessed by the Stress-Energy Checklist) at baseline was related to learning muscle relaxation induced by electromyographic feedback training during performance of a gross-motor task. Feedback training was provided either intermittently (Intermittent Feedback Task, IF, n=12) or continuously (Continuous Feedback Task, CF, n=9). Results reveal a negative correlation between the learning effect at short-term and energy dimension for the IF Task. It can be concluded that mood experienced prior to a learning task is relevant for the learning effect and this effect may be dependent on the schedule of feedback used.

  4. Characterization of cognitive and motor performance during dual-tasking in healthy older adults and patients with Parkinson's disease.

    PubMed

    Wild, Lucia Bartmann; de Lima, Daiane Borba; Balardin, Joana Bisol; Rizzi, Luana; Giacobbo, Bruno Lima; Oliveira, Henrique Bianchi; de Lima Argimon, Irani Iracema; Peyré-Tartaruga, Leonardo Alexandre; Rieder, Carlos R M; Bromberg, Elke

    2013-02-01

    The primary purpose of this study was to investigate the effect of dual-tasking on cognitive performance and gait parameters in patients with idiopathic Parkinson's disease (PD) without dementia. The impact of cognitive task complexity on cognition and walking was also examined. Eighteen patients with PD (ages 53-88, 10 women; Hoehn and Yahr stage I-II) and 18 older adults (ages 61-84; 10 women) completed two neuropsychological measures of executive function/attention (the Stroop Test and Wisconsin Card Sorting Test). Cognitive performance and gait parameters related to functional mobility of stride were measured under single (cognitive task only) and dual-task (cognitive task during walking) conditions with different levels of difficulty and different types of stimuli. In addition, dual-task cognitive costs were calculated. Although cognitive performance showed no significant difference between controls and PD patients during single or dual-tasking conditions, only the patients had a decrease in cognitive performance during walking. Gait parameters of patients differed significantly from controls at single and dual-task conditions, indicating that patients gave priority to gait while cognitive performance suffered. Dual-task cognitive costs of patients increased with task complexity, reaching significantly higher values then controls in the arithmetic task, which was correlated with scores on executive function/attention (Stroop Color-Word Page). Baseline motor functioning and task executive/attentional load affect the performance of cognitive tasks of PD patients while walking. These findings provide insight into the functional strategies used by PD patients in the initial phases of the disease to manage dual-task interference.

  5. Effect of volitional relaxation and motor imagery on F wave and MEP: do these tasks affect excitability of the spinal or cortical motor neurons?

    PubMed

    Fujisawa, R; Kimura, J; Taniguchi, S; Ichikawa, H; Hara, M; Shimizu, H; Iida, H; Yamada, T; Tani, T

    2011-07-01

    To test if simple motor imagery, like thumb abduction, preferentially influences the excitability of the spinal or cortical motoneurons. Ten healthy subjects underwent two separate experiments, each consisting of recording F waves and MEPs from abductor pollicis brevis (APB) in three consecutive sessions: (1) baseline, (2) after immobilizing APB for 3 h, and (3) after brief muscle exercise. During the immobilization, the subjects were instructed to volitionally relax APB in experiment 1 (relaxation task), and mentally simulate thumb abduction without actual movement in experiment 2 (imagery task). Relaxation task suppressed both MEPs and F waves. Motor imagery reduced this suppression, restoring F waves nearly completely (94%) and MEPs only partially (77%). Hence, the rest-induced decline of MEPs in part results from cortical modulation. In contrast, statistical analysis revealed no differences in imagery-induced recovery of motoneuron excitabilities whether assessed by F wave or MEP. Thus, increased excitability of spinal motoneurons responsible for F-wave changes also accounts for recovery of MEPs. Volitional relaxation depresses the spinal and cortical motoneurons, whereas mental simulation counters rest-induced suppression primarily by restoring spinal excitability. The present findings help elucidate physiologic mechanisms underlying motor imagery. Copyright © 2010 International Federation of Clinical Neurophysiology. All rights reserved.

  6. Disrupted implicit motor sequence learning in schizophrenia and bipolar disorder revealed with ambidextrous Serial Reaction Time Task.

    PubMed

    Chrobak, Adrian Andrzej; Siuda-Krzywicka, Katarzyna; Siwek, Grzegorz Przemysław; Tereszko, Anna; Janeczko, Weronika; Starowicz-Filip, Anna; Siwek, Marcin; Dudek, Dominika

    2017-10-03

    Impairment of implicit motor sequence learning was shown in schizophrenia (SZ) and, most recently, in bipolar disorder (BD), and was connected to cerebellar abnormalities. The goal of this study was to compare implicit motor sequence learning in BD and SZ. We examined 33 patients with BD, 33 patients with SZ and 31 healthy controls with a use of ambidextrous Serial Reaction Time Task (SRTT), which allows exploring asymmetries in performance depending on the hand used. BD and SZ patients presented impaired implicit motor sequence learning, although the pattern of their impairments was different. While BD patients showed no signs of implicit motor sequence learning for both hands, the SZ group presented some features of motor learning when performing with the right, but not with the left hand. To our best knowledge this is the first study comparing implicit motor sequence learning in BD and SZ. We show that both diseases share impairments in this domain, however in the case of SZ this impairment differs dependently on the hand performing SRTT. We propose that implicit motor sequence learning impairments constitute an overlapping symptom in BD and SZ and suggest further neuroimaging studies to verify cerebellar underpinnings as its cause. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. An investigation of fMRI time series stationarity during motor sequence learning foot tapping tasks.

    PubMed

    Muhei-aldin, Othman; VanSwearingen, Jessie; Karim, Helmet; Huppert, Theodore; Sparto, Patrick J; Erickson, Kirk I; Sejdić, Ervin

    2014-04-30

    Understanding complex brain networks using functional magnetic resonance imaging (fMRI) is of great interest to clinical and scientific communities. To utilize advanced analysis methods such as graph theory for these investigations, the stationarity of fMRI time series needs to be understood as it has important implications on the choice of appropriate approaches for the analysis of complex brain networks. In this paper, we investigated the stationarity of fMRI time series acquired from twelve healthy participants while they performed a motor (foot tapping sequence) learning task. Since prior studies have documented that learning is associated with systematic changes in brain activation, a sequence learning task is an optimal paradigm to assess the degree of non-stationarity in fMRI time-series in clinically relevant brain areas. We predicted that brain regions involved in a "learning network" would demonstrate non-stationarity and may violate assumptions associated with some advanced analysis approaches. Six blocks of learning, and six control blocks of a foot tapping sequence were performed in a fixed order. The reverse arrangement test was utilized to investigate the time series stationarity. Our analysis showed some non-stationary signals with a time varying first moment as a major source of non-stationarity. We also demonstrated a decreased number of non-stationarities in the third block as a result of priming and repetition. Most of the current literature does not examine stationarity prior to processing. The implication of our findings is that future investigations analyzing complex brain networks should utilize approaches robust to non-stationarities, as graph-theoretical approaches can be sensitive to non-stationarities present in data. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Gaze motor asymmetries in the perception of faces during a memory task.

    PubMed

    Mertens, I; Siegmund, H; Grüsser, O J

    1993-09-01

    In 33 male and female adult volunteers, eye position recordings were performed by means of an infrared reflection technique. Slides of randomly shuffled black-and-white photographs (7.5 x 10 degrees) of faces and vases were projected for 6 or 20 sec respectively in a visual memory task. In each series, 10 slides of art nouveau vases and of the "inner part" of masked Caucasian faces were used. During recording the head was fixed by a bite-board. (a) For faces the preferred targets of the centre of gaze were the eyes, the mouth and nose region, for vases the contours and some prominent ornaments. (b) Left-right asymmetries in the gaze-movement sampling strategy appeared with faces, but not with vases. In faces, the overall time that the centre of gaze remained in the left half of the field of gaze was significantly longer than in the right half. (c) When, however, the amplitude of the gaze excursions into the left and right halves of the inspected items was taken as a measure and normalized, a preference for the right gaze field was observed. (d) The relative left-right bias during face inspection was stronger with the 6 sec than with the 20 sec inspection period and significantly stronger in female than in male subjects for the 6 sec tasks. (e) Left/right inversion of the face stimuli did not abolish the side bias. Thus the asymmetric sampling strategy when faces were inspected as compared to vases was due to "internal" factors on the part of the subjects. It is hypothesized that a left-right asymmetry in hemispheric visual data processing for face stimuli was the cause of a left-right asymmetry in gaze motor strategies when faces were inspected.

  9. Discriminative methods for classification of asynchronous imaginary motor tasks from EEG data.

    PubMed

    Delgado Saa, Jaime F; Çetin, Müjdat

    2013-09-01

    In this work, two methods based on statistical models that take into account the temporal changes in the electroencephalographic (EEG) signal are proposed for asynchronous brain-computer interfaces (BCI) based on imaginary motor tasks. Unlike the current approaches to asynchronous BCI systems that make use of windowed versions of the EEG data combined with static classifiers, the methods proposed here are based on discriminative models that allow sequential labeling of data. In particular, the two methods we propose for asynchronous BCI are based on conditional random fields (CRFs) and latent dynamic CRFs (LDCRFs), respectively. We describe how the asynchronous BCI problem can be posed as a classification problem based on CRFs or LDCRFs, by defining appropriate random variables and their relationships. CRF allows modeling the extrinsic dynamics of data, making it possible to model the transitions between classes, which in this context correspond to distinct tasks in an asynchronous BCI system. On the other hand, LDCRF goes beyond this approach by incorporating latent variables that permit modeling the intrinsic structure for each class and at the same time allows modeling extrinsic dynamics. We apply our proposed methods on the publicly available BCI competition III dataset V as well as a data set recorded in our laboratory. Results obtained are compared to the top algorithm in the BCI competition as well as to methods based on hierarchical hidden Markov models (HHMMs), hierarchical hidden CRF (HHCRF), neural networks based on particle swarm optimization (IPSONN) and to a recently proposed approach based on neural networks and fuzzy theory, the S-dFasArt. Our experimental analysis demonstrates the improvements provided by our proposed methods in terms of classification accuracy.

  10. An investigation of fMRI time series stationarity during motor sequence learning foot tapping tasks

    PubMed Central

    Muhei-aldin, Othman; VanSwearingen, Jessie; Karim, Helmet; Huppert, Theodore; Sparto, Patrick J.; Erickson, Kirk I.; Sejdić, Ervin

    2014-01-01

    Background: Understanding complex brain networks using functional magnetic resonance imaging (fMRI) is of great interest to clinical and scientific communities. To utilize advanced analysis methods such as graph theory for these investigations, the stationarity of fMRI time series needs to be understood as it has important implications on the choice of appropriate approaches for the analysis of complex brain networks. New Method: In this paper, we investigated the stationarity of fMRI time series acquired from twelve healthy participants while they performed a motor (foot tapping sequence) learning task. Since prior studies have documented that learning is associated with systematic changes in brain activation, a sequence learning task is an optimal paradigm to assess the degree of non-stationarity in fMRI time-series in clinically relevant brain areas. We predicted that brain regions involved in a “learning network” would demonstrate non-stationarity and may violate assumptions associated with some advanced analysis approaches. Six blocks of learning, and six control blocks of a foot tapping sequence were performed in a fixed order. The reverse arrangement test was utilized to investigate the time series stationarity. Results: Our analysis showed some non-stationary signals with a time varying first moment as a major source of non-stationarity. We also demonstrated a decreased number of non-stationarities in the third block as a result of priming and repetition. Comparison with Existing Methods: Most of the current literature does not examine stationarity prior to processing. Conclusions: The implication of our findings is that future investigations analyzing complex brain networks should utilize approaches robust to non-stationarities, as graph-theoretical approaches can be sensitive to non-stationarities present in data. PMID:24530436

  11. Hybrid EEG-fNIRS Asynchronous Brain-Computer Interface for Multiple Motor Tasks

    PubMed Central

    Buccino, Alessio Paolo; Keles, Hasan Onur; Omurtag, Ahmet

    2016-01-01

    Non-invasive Brain-Computer Interfaces (BCI) have demonstrated great promise for neuroprosthetics and assistive devices. Here we aim to investigate methods to combine Electroencephalography (EEG) and functional Near-Infrared Spectroscopy (fNIRS) in an asynchronous Sensory Motor rhythm (SMR)-based BCI. We attempted to classify 4 different executed movements, namely, Right-Arm—Left-Arm—Right-Hand—Left-Hand tasks. Previous studies demonstrated the benefit of EEG-fNIRS combination. However, since normally fNIRS hemodynamic response shows a long delay, we investigated new features, involving slope indicators, in order to immediately detect changes in the signals. Moreover, Common Spatial Patterns (CSPs) have been applied to both EEG and fNIRS signals. 15 healthy subjects took part in the experiments and since 25 trials per class were available, CSPs have been regularized with information from the entire population of participants and optimized using genetic algorithms. The different features have been compared in terms of performance and the dynamic accuracy over trials shows that the introduced methods diminish the fNIRS delay in the detection of changes. PMID:26730580

  12. Learning a throwing task is associated with differential changes in the use of motor abundance.

    PubMed

    Yang, J-F; Scholz, J P

    2005-05-01

    This study sought to characterize changes in the synergy of joint motions related to learning a Frisbee throwing task and, in particular, how the use of abundant solutions to joint coordination changed during the course of learning for successful performance. The latter information was helpful in determining the relative importance of different performance-related variables (PVs) to performance improvement. Following a pre-test, the main experiment consisted of six subjects practicing a Frisbee throw to a laterally-placed target for five days, 150 throws per day, followed by a post-test. A subgroup of three subjects continued to practice for an extended period of extensive practice amounting to 1800-2700 additional throws each, followed by a second post-test. Motor abundance was addressed through the uncontrolled manifold approach (UCM), which was used to partition the variance of joint configurations into two components with respect to relevant PVs, one component leading to a consistent value of the PV across repetitions, and a reflection of motor abundance, and a second component resulting in unstable values of the relevant PV. The method was used to test hypotheses about the relative importance of controlling the PVs that have an impact on successful task performance: movement extent, movement direction, hand path velocity, and the hand's orientation to the target. In addition, the amount of self-motion, or apparently extraneous joint motion having no effect on the hand's motion, compared to joint motion that does affect the hand's motion, was determined. After a week of practice, all subjects showed improvement in terms of targeting accuracy. Hand movement variability also decreased with practice and this was associated with a decrease in overall joint configuration variance. This trend continued to a greater extent in the three subjects who participated in extended practice. Although the component of joint configuration variance that was consistent with a

  13. Hippocampal negative event-related potential recorded in humans during a simple sensorimotor task occurs independently of motor execution.

    PubMed

    Roman, Robert; Brázdil, Milan; Chládek, Jan; Rektor, Ivan; Jurák, Pavel; Světlák, Miroslav; Damborská, Alena; Shaw, Daniel J; Kukleta, Miloslav

    2013-12-01

    A hippocampal-prominent event-related potential (ERP) with a peak latency at around 450 ms is consistently observed as a correlate of hippocampal activity during various cognitive tasks. Some intracranial EEG studies demonstrated that the amplitude of this hippocampal potential was greater in response to stimuli requiring an overt motor response, in comparison with stimuli for which no motor response is required. These findings could indicate that hippocampal-evoked activity is related to movement execution as well as stimulus evaluation and associated memory processes. The aim of the present study was to investigate the temporal relationship between the hippocampal negative potential latency and motor responses. We analyzed ERPs recorded with 22 depth electrodes implanted into the hippocampi of 11 epileptic patients. Subjects were instructed to press a button after the presentation of a tone. All investigated hippocampi generated a prominent negative ERP peaking at ~420 ms. In 16 from 22 cases, we found that the ERP latency did not correlate with the reaction time; in different subjects, this potential could either precede or follow the motor response. Our results indicate that the hippocampal negative ERP occurs independently of motor execution. We suggest that hippocampal-evoked activity, recorded in a simple sensorimotor task, is related to the evaluation of stimulus meaning within the context of situation.

  14. Single session motor learning demonstrated using a visuomotor task: Evidence from fMRI and behavioural analysis.

    PubMed

    Boe, Shaun G; Cassidy, Ryan J; McIlroy, William E; Graham, Simon J

    2012-08-15

    There is a continuing need to improve understanding of the central nervous system control of learning. Specifically, there is a need to examine the characteristics of cortical and sub-cortical activity linked to the stages of motor learning, including those occurring within a single-session. In this study we sought to design and investigate a visuomotor task to determine its ability to assess the component of motor learning occurring during a single session of fMRI (i.e., the 'online' improvement in motor performance). Fourteen healthy control subjects performed a visuomotor task requiring a combination of bilateral grip force to accurately move a cursor towards a target. We assessed online motor learning by comparing behavioural measures (accuracy and error magnitude) and the extent of spatial activation in specific brain regions of interest (ROIs) using fMRI pre- and post-training. Results showed a training-related improvement in performance based on increased accuracy (p<0.0125) and decreased error magnitude (p<0.0125) from pre- to post-training. Decreases in the extent of spatial activation from pre- to post-training in the majority of ROIs supported a training-related attenuation in brain activity associated with online motor learning. Importantly, decreases in error magnitude across conditions (p<0.05) confirmed that improvements in performance continued over the entire course of the experiment. Establishing this task may permit more extensive study of the neural correlates of single-session, online learning in healthy individuals and those with motor control challenges. Information obtained from such studies may provide an opportunity to improve interventions in neurological rehabilitation. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Why Do Fine Motor Skills Predict Mathematics? Construct Validity of the Design Copying Task

    ERIC Educational Resources Information Center

    Murrah, William M.; Chen, Wei-Bing; Cameron, Claire E.

    2013-01-01

    Recent educational studies have found evidence that measures of fine motor skills are predictive of educational outcomes. However, the precise nature of fine motor skills has received little attention in these studies. With evidence mounting that fine motor skills are an important indicator of school readiness, investigating the nature of this…

  16. Decreased Connectivity and Cerebellar Activity in Autism during Motor Task Performance

    ERIC Educational Resources Information Center

    Mostofsky, Stewart H.; Powell, Stephanie K.; Simmonds, Daniel J.; Goldberg, Melissa C.; Caffo, Brian; Pekar, James J.

    2009-01-01

    Although motor deficits are common in autism, the neural correlates underlying the disruption of even basic motor execution are unknown. Motor deficits may be some of the earliest identifiable signs of abnormal development and increased understanding of their neural underpinnings may provide insight into autism-associated differences in parallel…

  17. Decreased Connectivity and Cerebellar Activity in Autism during Motor Task Performance

    ERIC Educational Resources Information Center

    Mostofsky, Stewart H.; Powell, Stephanie K.; Simmonds, Daniel J.; Goldberg, Melissa C.; Caffo, Brian; Pekar, James J.

    2009-01-01

    Although motor deficits are common in autism, the neural correlates underlying the disruption of even basic motor execution are unknown. Motor deficits may be some of the earliest identifiable signs of abnormal development and increased understanding of their neural underpinnings may provide insight into autism-associated differences in parallel…

  18. Evolution of brain activation after stroke in a constant-effort versus constant-output motor task.

    PubMed

    Bönstrup, Marlene; Schulz, Robert; Cheng, Bastian; Feldheim, Jan; Zimerman, Máximo; Thomalla, Götz; Hummel, Friedhelm C; Gerloff, Christian

    2015-01-01

    Recovery of hand function after stroke has been associated with transient overactivation of the cerebral sensorimotor network. One open question has been as to how much this transient overactivation is related to 'true' reorganisation of the network or reflecting the fact that a simple motor task is difficult to perform for a patient with a motor deficit, i.e. reflecting 'effort'. To address this, we combined a constant-output (varying effort) and constant-effort (varying output) task in a longitudinal (T1 = 3-5 days, T2 = 6 weeks, T3 = 3 months after stroke) multimodal (functional magnetic resonance imaging (FMRI), electroencephalography (EEG)) study of 12 (EEG)/8 (FMRI) patients (7 male, age 67 ± 9 years) showing significant recovery from a hand motor deficit. The reduction of sensorimotor activation from T1 to T3 was significant (p = 0.012). But task effort did not exhibit any significant impact on the evolution of task-related brain activation over time. This proved to be equally applicable to FMRI and EEG data. We conclude that initial up-regulation of brain activity after stroke is not simply a consequence of enhanced effort early after stroke but rather reflects neural processes involved in reorganisation and recovery of function.

  19. The Effect of a Six-Month Dancing Program on Motor-Cognitive Dual-Task Performance in Older Adults.

    PubMed

    Hamacher, Dennis; Hamacher, Daniel; Rehfeld, Kathrin; Hökelmann, Anita; Schega, Lutz

    2015-10-01

    Dancing is a complex sensorimotor activity involving physical and mental elements which have positive effects on cognitive functions and motor control. The present randomized controlled trial aims to analyze the effects of a dancing program on the performance on a motor-cognitive dual task. Data of 35 older adults, who were assigned to a dancing group or a health-related exercise group, are presented in the study. In pretest and posttest, we assessed cognitive performance and variability of minimum foot clearance, stride time, and stride length while walking. Regarding the cognitive performance and the stride-to-stride variability of minimum foot clearance, interaction effects have been found, indicating that dancing lowers gait variability to a higher extent than conventional health-related exercise. The data show that dancing improves minimum foot clearance variability and cognitive performance in a dual-task situation. Multi-task exercises (like dancing) might be a powerful tool to improve motor-cognitive dual-task performance.

  20. The anaesthetic combination of ketamine/midazolam does not alter the acquisition of spatial and motor tasks in adult mice.

    PubMed

    Valentim, A M; Olsson, I A S; Antunes, L M

    2013-01-01

    The ketamine/midazolam association of a dissociative with a sedative agent is used for the induction and maintenance of anaesthesia in laboratory animals. Anaesthesia may interfere with research results through side-effects on the nervous system, such as memory impairment. It is known that ketamine and midazolam affect cognition; however, their effects have not been clarified when used in a context of balanced anaesthesia. Thus, this study evaluated the effects of ketamine/midazolam on the acquisition of motor and of a spatial memory task in adult mice. Twenty-eight C57BL/6 adult male mice were divided into three groups: untreated control, treated with ketamine/midazolam (75 mg/kg / 10 mg/kg) and treated with midazolam (10 mg/kg) groups. Respiratory rate, heart rate and systolic pressure were measured every 5 min in the animals treated with ketamine/midazolam, as this was the only group that exhibited loss of the righting reflex. One day after treatment, animals were tested in the open field, rotarod and radial arm maze. There were no differences between treatments regarding open-field activity, rotarod performance or number of working and reference memory errors in the radial arm maze task. In conclusion, the learning process of spatial and motor tasks was not disrupted by the anaesthetic combination of ketamine/midazolam. These results suggest its safe use in adult mice in projects where acquisition of a spatial and motor task is necessary.

  1. Strategic Variations in Fitts’ Task: Comparison of Healthy Older Adults and Cognitively Impaired Patients

    PubMed Central

    Poletti, Céline; Sleimen-Malkoun, Rita; Decker, Leslie Marion; Retornaz, Frédérique; Lemaire, Patrick; Temprado, Jean-Jacques

    2017-01-01

    The present study aimed at investigating how healthy older adults (HOA) and cognitively impaired patients (CIP) differ in a discrete Fitts’ aiming task. Four levels of task difficulty were used, resulting from the simultaneous manipulation of the size of the target and its distance from home position. We found that movement times (MTs) followed Fitts’ law in both HOA and CIP, with the latter being significantly slower and more affected by increased task difficulty. Moreover, correlation analyses suggest that lower information processing speed (IPS) and deficits in executive functions (EFs) are associated with decline of sensorimotor performance in Fitts’ task. Analyses of strategic variations showed that HOA and CIP differed in strategy repertoire (which strategies they used), strategy distribution (i.e., how often they used each available strategy), and strategy execution (i.e., how quick they were with each available strategy). These findings further our understanding of how strategic variations used in a sensorimotor task are affected by cognitive impairment in older adults. PMID:28163682

  2. Resting state connectivity immediately following learning correlates with subsequent sleep-dependent enhancement of motor task performance.

    PubMed

    Gregory, Michael D; Agam, Yigal; Selvadurai, Chindhuri; Nagy, Amanda; Vangel, Mark; Tucker, Matthew; Robertson, Edwin M; Stickgold, Robert; Manoach, Dara S

    2014-11-15

    There is ongoing debate concerning the functions of resting-state brain activity. Prior work demonstrates that memory encoding enhances subsequent resting-state functional connectivity within task-relevant networks and that these changes predict better recognition. Here, we used functional connectivity MRI (fcMRI) to examine whether task-induced changes in resting-state connectivity correlate with performance improvement after sleep. In two separate sessions, resting-state scans were acquired before and after participants performed a motor task. In one session participants trained on the motor sequence task (MST), a well-established probe of sleep-dependent memory consolidation, and were tested the next day, after a night of sleep. In the other session they performed a motor control task (MCT) that minimized learning. In an accompanying behavioral control study, participants trained on the MST and were tested after either a night of sleep or an equivalent interval of daytime wake. Both the fcMRI and the sleep control groups showed significant improvement of MST performance, while the wake control group did not. In the fcMRI group, increased connectivity in bilateral motor cortex following MST training correlated with this next-day improvement. This increased connectivity did not appear to reflect initial learning since it did not correlate with learning during training and was not greater after MST training than MCT performance. Instead, we hypothesize that this increased connectivity processed the new memories for sleep-dependent consolidation. Our findings demonstrate that physiological processes immediately after learning correlate with sleep-dependent performance improvement and suggest that the wakeful resting brain prepares memories of recent experiences for later consolidation during sleep.

  3. Bilateral motor tasks involve more brain regions and higher neural activation than unilateral tasks: an fMRI study.

    PubMed

    Noble, Jeremy W; Eng, Janice J; Boyd, Lara A

    2014-09-01

    Movements that involve simultaneous coordination of muscles of the right and left lower limbs form a large part of our daily activities (e.g., standing, rising from a chair). This study used functional magnetic resonance imaging to determine which brain areas are used to control coordinated lower-limb movements, specifically comparing regions that are activated during bilateral exertions to those performed unilaterally. Plantarflexor exertions were produced at a target force level of 15% of the participants' maximum voluntary contraction, in three conditions, with their right (dominant) foot, with their left foot, and with both feet simultaneously. A voxel-wise analysis determined which regions were active in the bilateral, but not in the unilateral conditions. In addition, a region of interest (ROI) approach was used to determine differences in the percent signal change (PSC) between the conditions within motor areas. The voxel-wise analysis showed a large number of regions (cortical, subcortical, and cerebellar) that were active during the bilateral condition, but not during either unilateral condition. The ROI analysis showed several motor regions with higher activation in the bilateral condition than unilateral conditions; further, the magnitude of bilateral PSC was more than the sum of the two unilateral conditions in several of these regions. We postulate that the greater levels of activation during bilateral exertions may arise from interhemispheric inhibition, as well as from the greater need for motor coordination (e.g., synchronizing the two limbs to activate together) and visual processing (e.g., monitoring of two visual stimuli).

  4. Transfer of short-term motor learning across the lower limbs as a function of task conception and practice order.

    PubMed

    Stöckel, Tino; Wang, Jinsung

    2011-11-01

    Interlimb transfer of motor learning, indicating an improvement in performance with one limb following training with the other, often occurs asymmetrically (i.e., from non-dominant to dominant limb or vice versa, but not both). In the present study, we examined whether interlimb transfer of the same motor task could occur asymmetrically and in opposite directions (i.e., from right to left leg vs. left to right leg) depending on individuals' conception of the task. Two experimental conditions were tested: In a dynamic control condition, the process of learning was facilitated by providing the subjects with a type of information that forced them to focus on dynamic features of a given task (force impulse); and in a spatial control condition, it was done with another type of information that forced them to focus on visuomotor features of the same task (distance). Both conditions employed the same leg extension task. In addition, a fully-crossed transfer paradigm was used in which one group of subjects initially practiced with the right leg and were tested with the left leg for a transfer test, while the other group used the two legs in the opposite order. The results showed that the direction of interlimb transfer varied depending on the condition, such that the right and the left leg benefited from initial training with the opposite leg only in the spatial and the dynamic condition, respectively. Our finding suggests that manipulating the conception of a leg extension task has a substantial influence on the pattern of interlimb transfer in such a way that the direction of transfer can even be opposite depending on whether the task is conceived as a dynamic or spatial control task.

  5. A robot-based behavioural task to quantify impairments in rapid motor decisions and actions after stroke.

    PubMed

    Bourke, Teige C; Lowrey, Catherine R; Dukelow, Sean P; Bagg, Stephen D; Norman, Kathleen E; Scott, Stephen H

    2016-10-10

    Stroke can affect our ability to perform daily activities, although it can be difficult to identify the underlying functional impairment(s). Recent theories highlight the importance of sensory feedback in selecting future motor actions. This selection process can involve multiple processes to achieve a behavioural goal, including selective attention, feature/object recognition, and movement inhibition. These functions are often impaired after stroke, but existing clinical measures tend to explore these processes in isolation and without time constraints. We sought to characterize patterns of post-stroke impairments in a dynamic situation where individuals must identify and select spatial targets rapidly in a motor task engaging both arms. Impairments in generating rapid motor decisions and actions could guide functional rehabilitation targets, and identify potential of individuals to perform daily activities such as driving. Subjects were assessed in a robotic exoskeleton. Subjects used virtual paddles attached to their hands to hit away 200 virtual target objects falling towards them while avoiding 100 virtual distractors. The inclusion of distractor objects required subjects to rapidly assess objects located across the workspace and make motor decisions about which objects to hit. As many as 78 % of the 157 subjects with subacute stroke had impairments in individual global, spatial, temporal, or hand-specific task parameters relative to the 95 % performance bounds for 309 non-disabled control subjects. Subjects with stroke and neglect (Behavioural Inattention Test score <130; n = 28) were more often impaired in task parameters than other subjects with stroke. Approximately half of subjects with stroke hit proportionally more distractor objects than 95 % of controls, suggesting they had difficulty in attending to and selecting appropriate objects. This impairment was observed for affected and unaffected limbs including some whose motor performance was

  6. Simple motor tasks independently predict extubation failure in critically ill neurological patients.

    PubMed

    Kutchak, Fernanda Machado; Rieder, Marcelo de Mello; Victorino, Josué Almeida; Meneguzzi, Carla; Poersch, Karla; Forgiarini, Luiz Alberto; Bianchin, Marino Muxfeldt

    2017-01-01

    To evaluate the usefulness of simple motor tasks such as hand grasping and tongue protrusion as predictors of extubation failure in critically ill neurological patients. This was a prospective cohort study conducted in the neurological ICU of a tertiary care hospital in the city of Porto Alegre, Brazil. Adult patients who had been intubated for neurological reasons and were eligible for weaning were included in the study. The ability of patients to perform simple motor tasks such as hand grasping and tongue protrusion was evaluated as a predictor of extubation failure. Data regarding duration of mechanical ventilation, length of ICU stay, length of hospital stay, mortality, and incidence of ventilator-associated pneumonia were collected. A total of 132 intubated patients who had been receiving mechanical ventilation for at least 24 h and who passed a spontaneous breathing trial were included in the analysis. Logistic regression showed that patient inability to grasp the hand of the examiner (relative risk = 1.57; 95% CI: 1.01-2.44; p < 0.045) and protrude the tongue (relative risk = 6.84; 95% CI: 2.49-18.8; p < 0.001) were independent risk factors for extubation failure. Acute Physiology and Chronic Health Evaluation II scores (p = 0.02), Glasgow Coma Scale scores at extubation (p < 0.001), eye opening response (p = 0.001), MIP (p < 0.001), MEP (p = 0.006), and the rapid shallow breathing index (p = 0.03) were significantly different between the failed extubation and successful extubation groups. The inability to follow simple motor commands is predictive of extubation failure in critically ill neurological patients. Hand grasping and tongue protrusion on command might be quick and easy bedside tests to identify neurocritical care patients who are candidates for extubation. Avaliar a utilidade de tarefas motoras simples, tais como preensão de mão e protrusão da língua, para predizer extubação malsucedida em pacientes neurológicos críticos. Estudo

  7. Functional near-infrared spectroscopy-based correlates of prefrontal cortical dynamics during a cognitive-motor executive adaptation task

    PubMed Central

    Gentili, Rodolphe J.; Shewokis, Patricia A.; Ayaz, Hasan; Contreras-Vidal, José L.

    2013-01-01

    This study investigated changes in brain hemodynamics, as measured by functional near infrared spectroscopy, during performance of a cognitive-motor adaptation task. The adaptation task involved the learning of a novel visuomotor transformation (a 60° counterclockwise screen-cursor rotation), which required inhibition of a prepotent visuomotor response. A control group experienced a familiar transformation and thus, did not face any executive challenge. Analysis of the experimental group hemodynamic responses revealed that the performance enhancement was associated with a monotonic reduction in the oxygenation level in the prefrontal cortex. This finding confirms and extends functional magnetic resonance imaging and electroencephalography studies of visuomotor adaptation and learning. The changes in prefrontal brain activation suggest an initial recruitment of frontal executive functioning to inhibit prepotent visuomotor mappings followed by a progressive de-recruitment of the same prefrontal regions. The prefrontal hemodynamic changes observed in the experimental group translated into enhanced motor performance revealed by a reduction in movement time, movement extent, root mean square error and the directional error. These kinematic adaptations are consistent with the acquisition of an internal model of the novel visuomotor transformation. No comparable change was observed in the control group for either the hemodynamics or for the kinematics. This study (1) extends our understanding of the frontal executive processes from the cognitive to the cognitive-motor domain and (2) suggests that optical brain imaging can be employed to provide hemodynamic based-biomarkers to assess and monitor the level of adaptive cognitive-motor performance. PMID:23847489

  8. Assessment of fine motor skill in musicians and nonmusicians: differences in timing versus sequence accuracy in a bimanual fingering task.

    PubMed

    Kincaid, Anthony E; Duncan, Scott; Scott, Samuel A

    2002-08-01

    While professional musicians are generally considered to possess better control of finger movements than nonmusicians, relatively few reports have experimentally addressed the nature of this discrepancy in fine motor skills. For example, it is unknown whether musicians perform with greater skill than control subjects in all aspects of different types of fine motor activities. More specifically, it is not known whether musicians perform better than control subjects on a fine motor task that is similar, but not identical, to the playing of their primary instrument. The purpose of this study was to examine the accuracy of finger placement and accuracy of timing in professional musicians and nonmusicians using a simple, rhythmical, bilateral fingering pattern and the technology that allowed separate assessment of these two parameters. Professional musicians (other than pianists) and nonmusicians were given identical, detailed and explicit instructions but not allowed physically to practice the finger pattern. After verbally repeating the correct pattern for the investigator, subjects performed the task on an electric keyboard with both hands simultaneously. Each subject's performance was then converted to a numerical score. While musicians clearly demonstrated better accuracy in timing, no significant difference was found between the groups in their finger placement scores. These findings were not correlated with subjects' age, sex, limb dominance, or primary instrument (for the professional musicians). This study indicates that professional musicians perform better in timing accuracy but not spatial accuracy while executing a simple, novel, bimanual motor sequence.

  9. Task-dependent differences in corticobulbar excitability of the submental motor projections: Implications for neural control of swallowing.

    PubMed

    Doeltgen, Sebastian H; Ridding, Michael C; Dalrymple-Alford, John; Huckabee, Maggie-Lee

    2011-01-15

    It has been suggested that the primary motor cortex plays a substantial role in the neural circuitry that controls swallowing. Although its role in the voluntary oral phase of swallowing is undisputed, its precise role in motor control of the more reflexive, pharyngeal phase of swallowing is unclear. The contribution of the primary motor cortex to the pharyngeal phase of swallowing was examined using transcranial magnetic stimulation (TMS) to evoke motor evoked potentials (MEPs) in the anterior hyomandibular muscle group during either volitional submental muscle contraction or contraction during the pharyngeal phase of both volitionally, and reflexively, initiated swallowing. For each subject, in all three conditions, TMS was triggered when submental surface EMG (sEMG) reached 75% of the mean maximal submental sEMG amplitude measured during 10 volitional swallows. MEPs recorded during volitional submental muscle contraction were elicited in 22 of the 35 healthy subjects examined (63%). Only 16 of these 22 subjects (45.7%) also displayed MEPs recorded during volitional swallowing, but their MEP amplitudes were larger when triggered by submental muscle contraction than when triggered by volitional swallowing. Additionally, only 7 subjects (of 19 tested) showed MEPs triggered by submental muscle contraction during a reflexively triggered pharyngeal swallow. These differences indicate differing levels of net M1 excitability during execution of the investigated tasks, possibly brought about by task-dependent changes in the balance of excitatory and inhibitory neural activity. Copyright © 2010 Elsevier Inc. All rights reserved.

  10. Dual-Task Interference during Initial Learning of a New Motor Task Results from Competition for the Same Brain Areas

    ERIC Educational Resources Information Center

    Remy, Florence; Wenderoth, Nicole; Lipkens, Karen; Swinnen, Stephan P.

    2010-01-01

    Cerebral patterns of activity elicited by dual-task performance throughout the learning of a complex bimanual coordination pattern were addressed. Subjects (N = 12) were trained on the coordination pattern and scanned using fMRI at early (PRE) and late (POST) learning stages. During scanning, the coordination pattern was performed either as a…

  11. Dual-Task Interference during Initial Learning of a New Motor Task Results from Competition for the Same Brain Areas

    ERIC Educational Resources Information Center

    Remy, Florence; Wenderoth, Nicole; Lipkens, Karen; Swinnen, Stephan P.

    2010-01-01

    Cerebral patterns of activity elicited by dual-task performance throughout the learning of a complex bimanual coordination pattern were addressed. Subjects (N = 12) were trained on the coordination pattern and scanned using fMRI at early (PRE) and late (POST) learning stages. During scanning, the coordination pattern was performed either as a…

  12. Age-related changes of the functional architecture of the cortico-basal ganglia circuitry during motor task execution.

    PubMed

    Marchand, William R; Lee, James N; Suchy, Yana; Garn, Cheryl; Johnson, Susanna; Wood, Nicole; Chelune, Gordon

    2011-03-01

    Normal human aging is associated with declining motor control and function. It is thought that dysfunction of the cortico-basal ganglia circuitry may contribute to age-related sensorimotor impairment, however the underlying mechanisms are poorly characterized. The aim of this study was to enhance our understanding of age-related changes in the functional architecture of these circuits. Fifty-nine subjects, consisting of a young, middle and old group, were studied using functional MRI and a motor activation paradigm. Functional connectivity analyses and examination of correlations of connectivity strength with performance on the activation task as well as neurocognitive tasks completed outside of magnet were conducted. Results indicated that increasing age is associated with changes in the functional architecture of the cortico-basal ganglia circuitry. Connectivity strength increased between subcortical nuclei and cortical motor and sensory regions but no changes were found between subcortical components of the circuitry. Further, increased connectivity was correlated with poorer performance on a neurocognitive task independently of age. This result suggests that increased connectivity reflects a decline in brain function rather than a compensatory process. These findings advance our understanding of the normal aging process. Further, the methods employed will likely be useful for future studies aimed at disambiguating age-related versus illness progression changes associated with neuropsychiatric disorders that involve the cortico-basal ganglia circuitry.

  13. Bilateral motor tasks involve more brain regions and higher neural activation than unilateral tasks: an fMRI study

    PubMed Central

    Noble, Jeremy W.; Eng, Janice J.; Boyd, Lara A.

    2015-01-01

    Movements that involve simultaneous coordination of muscles of the right and left lower limbs form a large part of our daily activities (e.g., standing, rising from a chair). This study used functional magnetic resonance imaging (fMRI) to determine which brain areas are used to control coordinated lower limb movements, specifically comparing regions that are activated during bilateral exertions to those performed unilaterally. Plantarflexor exertions were produced at a target force level of 15% of the participants’ maximum voluntary contraction, in three conditions, with their right (dominant) foot, with their left foot and with both feet simultaneously. A voxel-wise analysis determined which regions were active in the bilateral, but not in the unilateral conditions. In addition, a regions of interest (ROI) approach was used to determine differences in the percent signal change (PSC) between the conditions within motor areas. The voxel-wise analysis showed a large number of regions (cortical, subcortical and cerebellar) that were active during the bilateral condition, but not during either unilateral condition. The ROI analysis showed several motor regions with higher activation in the bilateral condition than unilateral conditions; further, the magnitude of bilateral PSC was more than the sum of the two unilateral conditions in several of these regions. We postulate that the greater levels of activation during bilateral exertions may arise from interhemispheric inhibition, as well as from the greater need for motor coordination (e.g., synchronizing the two limbs to activate together) and visual processing (e.g., monitoring of two visual stimuli). PMID:24770862

  14. EEG-Based Brain-Computer Interface for Decoding Motor Imagery Tasks within the Same Hand Using Choi-Williams Time-Frequency Distribution

    PubMed Central

    Alwanni, Hisham; Baslan, Yara; Alnuman, Nasim; Daoud, Mohammad I.

    2017-01-01

    This paper presents an EEG-based brain-computer interface system for classifying eleven motor imagery (MI) tasks within the same hand. The proposed system utilizes the Choi-Williams time-frequency distribution (CWD) to construct a time-frequency representation (TFR) of the EEG signals. The constructed TFR is used to extract five categories of time-frequency features (TFFs). The TFFs are processed using a hierarchical classification model to identify the MI task encapsulated within the EEG signals. To evaluate the performance of the proposed approach, EEG data were recorded for eighteen intact subjects and four amputated subjects while imagining to perform each of the eleven hand MI tasks. Two performance evaluation analyses, namely channel- and TFF-based analyses, are conducted to identify the best subset of EEG channels and the TFFs category, respectively, that enable the highest classification accuracy between the MI tasks. In each evaluation analysis, the hierarchical classification model is trained using two training procedures, namely subject-dependent and subject-independent procedures. These two training procedures quantify the capability of the proposed approach to capture both intra- and inter-personal variations in the EEG signals for different MI tasks within the same hand. The results demonstrate the efficacy of the approach for classifying the MI tasks within the same hand. In particular, the classification accuracies obtained for the intact and amputated subjects are as high as 88.8% and 90.2%, respectively, for the subject-dependent training procedure, and 80.8% and 87.8%, respectively, for the subject-independent training procedure. These results suggest the feasibility of applying the proposed approach to control dexterous prosthetic hands, which can be of great benefit for individuals suffering from hand amputations. PMID:28832513

  15. Intra-Auditory Integration Improves Motor Performance and Synergy in an Accurate Multi-Finger Pressing Task

    PubMed Central

    Koh, Kyung; Kwon, Hyun Joon; Park, Yang Sun; Kiemel, Tim; Miller, Ross H.; Kim, Yoon Hyuk; Shin, Joon-Ho; Shim, Jae Kun

    2016-01-01

    Humans detect changes in the air pressure and understand the surroundings through the auditory system. The sound humans perceive is composed of two distinct physical properties, frequency and intensity. However, our knowledge is limited how the brain perceives and combines these two properties simultaneously (i.e., intra-auditory integration), especially in relation to motor behaviors. Here, we investigated the effect of intra-auditory integration between the frequency and intensity components of auditory feedback on motor outputs in a constant finger-force production task. The hierarchical variability decomposition model previously developed was used to decompose motor performance into mathematically independent components each of which quantifies a distinct motor behavior such as consistency, repeatability, systematic error, within-trial synergy, or between-trial synergy. We hypothesized that feedback on two components of sound as a function of motor performance (frequency and intensity) would improve motor performance and multi-finger synergy compared to feedback on just one component (frequency or intensity). Subjects were instructed to match the reference force of 18 N with the sum of all finger forces (virtual finger or VF force) while listening to auditory feedback of their accuracy. Three experimental conditions were used: (i) condition F, where frequency changed; (ii) condition I, where intensity changed; (iii) condition FI, where both frequency and intensity changed. Motor performance was enhanced for the FI conditions as compared to either the F or I condition alone. The enhancement of motor performance was achieved mainly by the improved consistency and repeatability. However, the systematic error remained unchanged across conditions. Within- and between-trial synergies were also improved for the FI condition as compared to either the F or I condition alone. However, variability of individual finger forces for the FI condition was not significantly

  16. Fine motor skills in adult Tourette patients are task-dependent

    PubMed Central

    2012-01-01

    Background Tourette syndrome is a neuropsychiatric disorder characterized by motor and phonic tics. Deficient motor inhibition underlying tics is one of the main hypotheses in its pathophysiology. Therefore the question arises whether this supposed deficient motor inhibition affects also voluntary movements. Despite severe motor tics, different personalities who suffer from Tourette perform successfully as neurosurgeon, pilot or professional basketball player. Methods For the investigation of fine motor skills we conducted a motor performance test battery in an adult Tourette sample and an age matched group of healthy controls. Results The Tourette patients showed a significant lower performance in the categories steadiness of both hands and aiming of the right hand in comparison to the healthy controls. A comparison of patients’ subgroup without comorbidities or medication and healthy controls revealed a significant difference in the category steadiness of the right hand. Conclusions Our results show that steadiness and visuomotor integration of fine motor skills are altered in our adult sample but not precision and speed of movements. This alteration pattern might be the clinical vignette of complex adaptations in the excitability of the motor system on the basis of altered cortical and subcortical components. The structurally and functionally altered neuronal components could encompass orbitofrontal, ventrolateral prefrontal and parietal cortices, the anterior cingulate, amygdala, primary motor and sensorimotor areas including altered corticospinal projections, the corpus callosum and the basal ganglia. PMID:23057645

  17. Fine motor skills in adult Tourette patients are task-dependent.

    PubMed

    Neuner, Irene; Arrubla, Jorge; Ehlen, Corinna; Janouschek, Hildegard; Nordt, Carlos; Fimm, Bruno; Schneider, Frank; Shah, N Jon; Kawohl, Wolfram

    2012-10-11

    Tourette syndrome is a neuropsychiatric disorder characterized by motor and phonic tics. Deficient motor inhibition underlying tics is one of the main hypotheses in its pathophysiology. Therefore the question arises whether this supposed deficient motor inhibition affects also voluntary movements. Despite severe motor tics, different personalities who suffer from Tourette perform successfully as neurosurgeon, pilot or professional basketball player. For the investigation of fine motor skills we conducted a motor performance test battery in an adult Tourette sample and an age matched group of healthy controls. The Tourette patients showed a significant lower performance in the categories steadiness of both hands and aiming of the right hand in comparison to the healthy controls. A comparison of patients' subgroup without comorbidities or medication and healthy controls revealed a significant difference in the category steadiness of the right hand. Our results show that steadiness and visuomotor integration of fine motor skills are altered in our adult sample but not precision and speed of movements. This alteration pattern might be the clinical vignette of complex adaptations in the excitability of the motor system on the basis of altered cortical and subcortical components. The structurally and functionally altered neuronal components could encompass orbitofrontal, ventrolateral prefrontal and parietal cortices, the anterior cingulate, amygdala, primary motor and sensorimotor areas including altered corticospinal projections, the corpus callosum and the basal ganglia.

  18. Variation in U.S. traffic safety policy environments and motor vehicle fatalities 1980-2010.

    PubMed

    Silver, D; Macinko, J; Bae, J Y; Jimenez, G; Paul, M

    2013-12-01

    To examine the impact of variation in state laws governing traffic safety on motor vehicle fatalities. Repeated cross sectional time series design. Fixed effects regression models estimate the relationship between state motor vehicle fatality rates and the strength of the state law environment for 50 states, 1980-2010. The strength of the state policy environment is measured by calculating the proportion of a set of 27 evidence-based laws in place each year. The effect of alcohol consumption on motor vehicle fatalities is estimated using a subset of alcohol laws as instrumental variables. Once other risk factors are controlled in statistical models, states with stronger regulation of safer driving and driver/passenger protections had significantly lower motor vehicle fatality rates for all ages. Alcohol consumption was strongly associated with higher MVC death rates, as were state unemployment rates. Encouraging laggard states to adopt the full range of available laws could significantly reduce preventable traffic-related deaths in the U.S. - especially those among younger individuals. Estimating the relationship between different policy environments and health outcomes can quantify the result of policy gaps. Copyright © 2013 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  19. Dynamic analysis of a BLDC motor with mechanical and electromagnetic interaction due to air gap variation

    NASA Astrophysics Data System (ADS)

    Im, Hyungbin; Yoo, Hong Hee; Chung, Jintai

    2011-04-01

    In this study, the dynamic behaviors of a BLDC motor are analyzed, when the motor undergoes mechanical and electromagnetic interaction due to an air gap variation between the stator and rotor. When considering the air gap variation caused by the translational motion of the rotor relative to the stator, the kinetic and potential energies, Rayleigh dissipation function, and the magnetic coenergy are expressed in terms of the rotor displacements and stator currents. With these energies and function, new equations of motion are derived using Lagrange's equation. The equations for the proposed model are nonlinear equations in which the displacements and currents are coupled. The time responses for the displacements and currents are computed for the proposed and previous models. Furthermore, the effects of rotor eccentricity are also investigated. It is found that, when the air gap varies with time, the time responses for the proposed and previous models have small differences in the stator currents, electromagnetic torques, and rotating speeds. However, the time responses have large differences in the rotor displacements. Therefore, this paper claims that the proposed model describes the dynamic behaviors of the motor more accurately than the previous model. It is also shown that rotor eccentricity increases the stator current period and the electromagnetic torque, while it decreases the rotating speed of the rotor.

  20. Task-dependent changes of motor cortical network excitability during precision grip compared to isolated finger contraction.

    PubMed

    Kouchtir-Devanne, Nezha; Capaday, Charles; Cassim, François; Derambure, Philippe; Devanne, Hervé

    2012-03-01

    The purpose of this study was to determine whether task-dependent differences in corticospinal pathway excitability occur in going from isolated contractions of the index finger to its coordinated activity with the thumb. Focal transcranial magnetic stimulation (TMS) was used to measure input-output (I/O) curves--a measure of corticospinal pathway excitability--of the contralateral first dorsal interosseus (FDI) muscle in 21 healthy subjects performing two isometric motor tasks: index abduction and precision grip. The level of FDI electromyographic (EMG) activity was kept constant across tasks. The amplitude of the FDI motor evoked potentials (MEPs) and the duration of FDI silent period (SP) were plotted against TMS stimulus intensity and fitted, respectively, to a Boltzmann sigmoidal function. The plateau level of the FDI MEP amplitude I/O curve increased by an average of 40% during the precision grip compared with index abduction. Likewise, the steepness of the curve, as measured by the value of the maximum slope, increased by nearly 70%. By contrast, all I/O curve parameters [plateau, stimulus intensity required to obtain 50% of maximum response (S(50)), and slope] of SP duration were similar between the two tasks. Short- and long-latency intracortical inhibitions (SICI and LICI, respectively) were also measured in each task. Both measures of inhibition decreased during precision grip compared with the isolated contraction. The results demonstrate that the motor cortical circuits controlling index and thumb muscles become functionally coupled when the muscles are used synergistically and this may be due, at least in part, to a decrease of intracortical inhibition and an increase of recurrent excitation.

  1. Attention during functional tasks is associated with motor performance in children with developmental coordination disorder: A cross-sectional study.

    PubMed

    Fong, Shirley S M; Chung, Joanne W Y; Cheng, Yoyo T Y; Yam, Timothy T T; Chiu, Hsiu-Ching; Fong, Daniel Y T; Cheung, C Y; Yuen, Lily; Yu, Esther Y T; Hung, Yeung Sam; Macfarlane, Duncan J; Ng, Shamay S M

    2016-09-01

    This cross-sectional and exploratory study aimed to compare motor performance and electroencephalographic (EEG) attention levels in children with developmental coordination disorder (DCD) and those with typical development, and determine the relationship between motor performance and the real-time EEG attention level in children with DCD.Eighty-six children with DCD [DCD: n = 57; DCD and attention deficit hyperactivity disorder (ADHD): n = 29] and 99 children with typical development were recruited. Their motor performance was assessed with the Movement Assessment Battery for Children (MABC) and attention during the tasks of the MABC was evaluated by EEG.All children with DCD had higher MABC impairment scores and lower EEG attention scores than their peers (P < 0.05). After accounting for age, sex, body mass index, and physical activity level, the attention index remained significantly associated with the MABC total impairment score and explained 14.1% of the variance in children who had DCD but not ADHD (P = 0.009) and 17.5% of the variance in children with both DCD and ADHD (P = 0.007). Children with DCD had poorer motor performance and were less attentive to movements than their peers. Their poor motor performance may be explained by inattention.

  2. Walking in School-Aged Children in a Dual-Task Paradigm Is Related to Age But Not to Cognition, Motor Behavior, Injuries, or Psychosocial Functioning

    PubMed Central

    Hagmann-von Arx, Priska; Manicolo, Olivia; Lemola, Sakari; Grob, Alexander

    2016-01-01

    Age-dependent gait characteristics and associations with cognition, motor behavior, injuries, and psychosocial functioning were investigated in 138 typically developing children aged 6.7–13.2 years (M = 10.0 years). Gait velocity, normalized velocity, and variability were measured using the walkway system GAITRite without an additional task (single task) and while performing a motor or cognitive task (dual task). Assessment of children’s cognition included tests for intelligence and executive functions; parents reported on their child’s motor behavior, injuries, and psychosocial functioning. Gait variability (an index of gait regularity) decreased with increasing age in both single- and dual-task walking. Dual-task gait decrements were stronger when children walked in the motor compared to the cognitive dual-task condition and decreased with increasing age in both dual-task conditions. Gait alterations from single- to dual-task conditions were not related to children’s cognition, motor behavior, injuries, or psychosocial functioning. PMID:27014158

  3. Motor learning in a complex balance task and associated neuroplasticity: a comparison between endurance athletes and nonathletes.

    PubMed

    Seidel, Oliver; Carius, Daniel; Kenville, Rouven; Ragert, Patrick

    2017-09-01

    Studies suggested that motor expertise is associated with functional and structural brain alterations, which positively affect sensorimotor performance and learning capabilities. The purpose of the present study was to unravel differences in motor skill learning and associated functional neuroplasticity between endurance athletes (EA) and nonathletes (NA). For this purpose, participants had to perform a multimodal balance task (MBT) training on 2 sessions, which were separated by 1 wk. Before and after MBT training, a static balance task (SBT) had to be performed. MBT-induced functional neuroplasticity and neuromuscular alterations were assessed by means of functional near-infrared spectroscopy (fNIRS) and electromyography (EMG) during SBT performance. We hypothesized that EA would showed superior initial SBT performance and stronger MBT-induced improvements in SBT learning rates compared with NA. On a cortical level, we hypothesized that MBT training would lead to differential learning-dependent functional changes in motor-related brain regions [such as primary motor cortex (M1)] during SBT performance. In fact, EA showed superior initial SBT performance, whereas learning rates did not differ between groups. On a cortical level, fNIRS recordings (time × group interaction) revealed a stronger MBT-induced decrease in left M1 and inferior parietal lobe (IPL) for deoxygenated hemoglobin in EA. Even more interesting, learning rates were correlated with fNIRS changes in right M1/IPL. On the basis of these findings, we provide novel evidence for superior MBT training-induced functional neuroplasticity in highly trained athletes. Future studies should investigate these effects in different sports disciplines to strengthen previous work on experience-dependent neuroplasticity.NEW & NOTEWORTHY Motor expertise is associated with functional/structural brain plasticity. How such neuroplastic reorganization translates into altered motor learning processes remains elusive. We

  4. Differences in Motor Imagery Time when Predicting Task Duration in Alpine Skiers and Equestrian Riders

    ERIC Educational Resources Information Center

    Louis, Magali; Collet, Christian; Champely, Stephane; Guillot, Aymeric

    2012-01-01

    Athletes' ability to use motor imagery (MI) to predict the speed at which they could perform a motor sequence has received little attention. In this study, 21 alpine skiers and 16 equestrian riders performed MI based on a prediction of actual performance time (a) after the course inspection, (b) before the start, and (c) after the actual…

  5. Differences in Motor Imagery Time when Predicting Task Duration in Alpine Skiers and Equestrian Riders

    ERIC Educational Resources Information Center

    Louis, Magali; Collet, Christian; Champely, Stephane; Guillot, Aymeric

    2012-01-01

    Athletes' ability to use motor imagery (MI) to predict the speed at which they could perform a motor sequence has received little attention. In this study, 21 alpine skiers and 16 equestrian riders performed MI based on a prediction of actual performance time (a) after the course inspection, (b) before the start, and (c) after the actual…

  6. EEG μ rhythm in virtual reality reveals that motor coding of visual objects in peripersonal space is task dependent.

    PubMed

    Wamain, Yannick; Gabrielli, François; Coello, Yann

    2016-01-01

    Previous fMRI studies have shown that the visual perception of manipulable objects spontaneously involves the sensorimotor system, especially when the objects are located in peripersonal space. However, it has also been suggested that the motor coding of manipulable objects perceived in peripersonal space depends on an anticipation to interact with them. The present study aims at clarifying this issue by analyzing healthy adults' EEG activity on the centro-parietal region while perceptually judging intrinsic (prototypical or distorted shape) or extrinsic (reachable or not reachable location) properties of visual objects. In both the object identification and reachability judgment tasks, time-frequency decomposition of EEG signals was performed across the first 1000 ms following object presentation for trials on which no post-stimulus response was required (90% of the trials). Event-Related-(De)Synchronization (ERD/S) of μ rhythm was computed using the 150 ms pre-stimulus period as baseline. In the reachability judgment task, EEG analysis showed a desynchronization of μ rhythm starting 300 ms after object presentation, but only when the objects were presented with a prototypical shape in peripersonal space. For those objects, desynchronization of μ rhythm diminished progressively from peripersonal to extrapersonal space. By contrast, no such gradient was observed in the object identification task. On the whole, these data indicate that motor coding of visual objects expressed in the μ rhythm depends on an object's shape and location in space, but also on the goal of the perceptual task.

  7. Single-trial classification of motor imagery differing in task complexity: a functional near-infrared spectroscopy study

    PubMed Central

    2011-01-01

    Background For brain computer interfaces (BCIs), which may be valuable in neurorehabilitation, brain signals derived from mental activation can be monitored by non-invasive methods, such as functional near-infrared spectroscopy (fNIRS). Single-trial classification is important for this purpose and this was the aim of the presented study. In particular, we aimed to investigate a combined approach: 1) offline single-trial classification of brain signals derived from a novel wireless fNIRS instrument; 2) to use motor imagery (MI) as mental task thereby discriminating between MI signals in response to different tasks complexities, i.e. simple and complex MI tasks. Methods 12 subjects were asked to imagine either a simple finger-tapping task using their right thumb or a complex sequential finger-tapping task using all fingers of their right hand. fNIRS was recorded over secondary motor areas of the contralateral hemisphere. Using Fisher's linear discriminant analysis (FLDA) and cross validation, we selected for each subject a best-performing feature combination consisting of 1) one out of three channel, 2) an analysis time interval ranging from 5-15 s after stimulation onset and 3) up to four Δ[O2Hb] signal features (Δ[O2Hb] mean signal amplitudes, variance, skewness and kurtosis). Results The results of our single-trial classification showed that using the simple combination set of channels, time intervals and up to four Δ[O2Hb] signal features comprising Δ[O2Hb] mean signal amplitudes, variance, skewness and kurtosis, it was possible to discriminate single-trials of MI tasks differing in complexity, i.e. simple versus complex tasks (inter-task paired t-test p ≤ 0.001), over secondary motor areas with an average classification accuracy of 81%. Conclusions Although the classification accuracies look promising they are nevertheless subject of considerable subject-to-subject variability. In the discussion we address each of these aspects, their limitations for

  8. Comparative study of environmental factors influencing motor task learning and memory retention in sighted and blind crayfish.

    PubMed

    Bierbower, Sonya M; Shuranova, Zhanna P; Viele, Kert; Cooper, Robin L

    2013-01-01

    In classical conditioning, an alteration in response occurs when two stimuli are regularly paired in close succession. An area of particular research interest is classical conditioning with a chemical signal and visual and/or tactile stimuli as the unconditional stimuli, to test manipulative and motor behaviors in a learning paradigm. A classical learning task chamber was developed to examine learning trends in a sighted surface-dwelling crayfish, Procambarus clarkii, and in a blind cave-dwelling crayfish, Orconectes australis packardi. We examined whether learning is influenced by environmental factors and/or reliance on different primary sensory modalities. Crayfish were trained to manipulate a large, cumbersome cheliped through a small access point to obtain a food reward. In both species, acquisition of the learning task was rapid when they were in nonstressed conditions. The blind crayfish tested in low white light did not successfully complete the task, suggesting a stress response.

  9. Comparative study of environmental factors influencing motor task learning and memory retention in sighted and blind crayfish

    PubMed Central

    Bierbower, Sonya M; Shuranova, Zhanna P; Viele, Kert; Cooper, Robin L

    2013-01-01

    In classical conditioning, an alteration in response occurs when two stimuli are regularly paired in close succession. An area of particular research interest is classical conditioning with a chemical signal and visual and/or tactile stimuli as the unconditional stimuli, to test manipulative and motor behaviors in a learning paradigm. A classical learning task chamber was developed to examine learning trends in a sighted surface-dwelling crayfish, Procambarus clarkii, and in a blind cave-dwelling crayfish, Orconectes australis packardi. We examined whether learning is influenced by environmental factors and/or reliance on different primary sensory modalities. Crayfish were trained to manipulate a large, cumbersome cheliped through a small access point to obtain a food reward. In both species, acquisition of the learning task was rapid when they were in nonstressed conditions. The blind crayfish tested in low white light did not successfully complete the task, suggesting a stress response. PMID:23408733

  10. Non-physical practice improves task performance in an unstable, perturbed environment: motor imagery and observational balance training.

    PubMed

    Taube, Wolfgang; Lorch, Michael; Zeiter, Sibylle; Keller, Martin

    2014-01-01

    For consciously performed motor tasks executed in a defined and constant way, both motor imagery (MI) and action observation (AO) have been shown to promote motor learning. It is not known whether these forms of non-physical training also improve motor actions when these actions have to be variably applied in an unstable and unpredictable environment. The present study therefore investigated the influence of MI balance training (MI_BT) and a balance training combining AO and MI (AO+MI_BT) on postural control of undisturbed and disturbed upright stance on unstable ground. As spinal reflex excitability after classical (i.e., physical) balance training (BT) is generally decreased, we tested whether non-physical BT also has an impact on spinal reflex circuits. Thirty-six participants were randomly allocated into an MI_BT group, in which participants imagined postural exercises, an AO+MI_BT group, in which participants observed videos of other people performing balance exercises and imagined being the person in the video, and a non-active control group (CON). Before and after 4 weeks of non-physical training, balance performance was assessed on a free-moving platform during stance without perturbation and during perturbed stance. Soleus H-reflexes were recorded during stable and unstable stance. The post-measurement revealed significantly decreased postural sway during undisturbed and disturbed stance after both MI_BT and AO+MI_BT. Spinal reflex excitability remained unchanged. This is the first study showing that non-physical training (MI_BT and AO+MI_BT) not only promotes motor learning of "rigid" postural tasks but also improves performance of highly variable and unpredictable balance actions. These findings may be relevant to improve postural control and thus reduce the risk of falls in temporarily immobilized patients.

  11. Non-physical practice improves task performance in an unstable, perturbed environment: motor imagery and observational balance training

    PubMed Central

    Taube, Wolfgang; Lorch, Michael; Zeiter, Sibylle; Keller, Martin

    2014-01-01

    For consciously performed motor tasks executed in a defined and constant way, both motor imagery (MI) and action observation (AO) have been shown to promote motor learning. It is not known whether these forms of non-physical training also improve motor actions when these actions have to be variably applied in an unstable and unpredictable environment. The present study therefore investigated the influence of MI balance training (MI_BT) and a balance training combining AO and MI (AO+MI_BT) on postural control of undisturbed and disturbed upright stance on unstable ground. As spinal reflex excitability after classical (i.e., physical) balance training (BT) is generally decreased, we tested whether non-physical BT also has an impact on spinal reflex circuits. Thirty-six participants were randomly allocated into an MI_BT group, in which participants imagined postural exercises, an AO+MI_BT group, in which participants observed videos of other people performing balance exercises and imagined being the person in the video, and a non-active control group (CON). Before and after 4 weeks of non-physical training, balance performance was assessed on a free-moving platform during stance without perturbation and during perturbed stance. Soleus H-reflexes were recorded during stable and unstable stance. The post-measurement revealed significantly decreased postural sway during undisturbed and disturbed stance after both MI_BT and AO+MI_BT. Spinal reflex excitability remained unchanged. This is the first study showing that non-physical training (MI_BT and AO+MI_BT) not only promotes motor learning of “rigid” postural tasks but also improves performance of highly variable and unpredictable balance actions. These findings may be relevant to improve postural control and thus reduce the risk of falls in temporarily immobilized patients. PMID:25538598

  12. The effect of voluntary modulation of the sensory-motor rhythm during different mental tasks on H reflex.

    PubMed

    Jarjees, M; Vučković, A

    2016-08-01

    The aim of this study was to explore the possibility of the short-term modulation of the soleus H reflex through self-induced modulation of the sensory-motor rhythm (SMR) as measured by electroencephalography (EEG) at Cz. Sixteen healthy participants took part in one session of neuromodulation. Motor imagery and mental math were strategies for decreasing SMR, while neurofeedback was used to increase SMR. H reflex of the soleus muscle was elicited by stimulating tibial nerve when SMR reached a pre-defined threshold and was averaged over 5 trials. Neurofeedback and mental math both resulted in the statistically significant increase of H reflex (p=1.04·10(-6) and p=5.47·10(-5) respectively) while motor imagery produced the inconsistent direction of H reflex modulation (p=0.57). The average relative increase of H reflex amplitude was for neurofeedback 19.0±5.4%, mental math 11.1±3.6% and motor imagery 2.6±1.0%. A significant negative correlation existed between SMR amplitude and H reflex for all tasks at Cz and C4. It is possible to achieve a short-term modulation of H reflex through short-term modulation of SMR. Various mental tasks dominantly facilitate H reflex irrespective of direction of SMR modulation. Improving understanding of the influence of sensory-motor cortex on the monosynaptic reflex through the self-induced modulation of cortical activity. Copyright © 2016. Published by Elsevier B.V.

  13. Changes in the inhibitory control exerted by the antagonist Ia afferents on human wrist extensor motor units during an attention-demanding motor task.

    PubMed

    Nafati, Gilel; Schmied, Annie; Rossi-Durand, Christiane

    2005-04-01

    The aim of this study was to determine the extent to which an attention-demanding visuomotor task affects the strength of the inhibitory control exerted by the wrist flexor group Ia afferents on the wrist extensor motoneurons. Effects of median nerve stimulation on the tonic activity of wrist extensor single motor units were analyzed in terms of the interspike interval (ISI) lengthening. Results show that the inhibitory effects exerted by the antagonistic group Ia afferents were significantly enhanced when the wrist extensor motoneurons were involved in an attention-demanding task. Enhanced inhibition from antagonist afferents may reflect task-related changes in the excitability of the di- and/or polysynaptic pathways mediating reciprocal inhibition due to either the action of descending inputs and/or an increase in the efficiency of the Ia inputs to the premotoneuronal inhibitory interneurons. Modulation of the inhibition exerted by proprioceptive antagonist afferents may be one of the processes which contribute to the fine adjustment of the wrist muscle force output required in fine handling tasks.

  14. Motor dual-task Timed Up & Go test better identifies prefrailty individuals than single-task Timed Up & Go test.

    PubMed

    Tang, Pei-Fang; Yang, Hao-Jan; Peng, Ya-Chi; Chen, Hui-Ya

    2015-02-01

    The present study investigated whether dual-task Timed Up & Go tests (TUG) could identify prefrail individuals more sensitively than the single-task TUG (TUGsingle ) in community-dwelling middle-aged and older adults. This cross-sectional study recruited adults aged 50 years and older who actively participated in local community programs. Time taken to complete single-task TUG and dual-task TUG, carrying a cup of water (TUGmanual ) or carrying out serial-3 subtraction (TUGcognitive ) while executing TUG, was measured. Prefrailty status was defined based on Fried's phenotypic definition. Of the 65 participants (mean age 71.5±8.1 years), 33.3% of the 12 middle-aged (50-64 years) and 62.3% of the 53 older (≥65 years) adults were prefrail, mainly as a result of weak grip strength. The receiver operating characteristic curve analyses for differentiating prefrailty from non-frailty showed that the area under the curve (AUC) for TUGmanual (0.73, 95% CI 0.60-0.86) was better than that for TUGsingle (0.67, 95% CI 0.54-0.80), whereas the AUC value was not significant for TUGcognitive (0.60, 95% CI 0.46-0.74). The optimal cut-off points for detecting prefrailty using TUGsingle , TUGmanual and TUGcognitive were 7.7 s (sensitivity 68%), 8.2 s (sensitivity 83%), and 14.3 s (sensitivity 29%), respectively. After adjusting for age, logistic regression analyses showed that individuals with TUGmanual 8.2 s or slower were 7.2-fold more likely to have prefrailty than those with TUGmanual faster than 8.2 s. TUGmanual is more valid and sensitive than TUGsingle in identifying prefrail individuals. The TUGmanual thus could serve as a screening tool for early detection of individuals with prefrailty in community-dwelling middle-aged and older adults. © 2014 Japan Geriatrics Society.

  15. Effects of attention and precision of exerted force on beta range EEG-EMG synchronization during a maintained motor contraction task.

    PubMed

    Kristeva-Feige, Rumyana; Fritsch, Christoph; Timmer, Jens; Lücking, Carl-Hermann

    2002-01-01

    The present study was aimed at investigating the effect of attention and precision level of exerted force on beta range EEG-EMG synchronization. We simultaneously recorded cortical electrical activity (EEG) in a bipolar manner from the contralateral sensorimotor areas and surface electromyographic (EMG) activity from the flexor digitorum superficialis muscle in 10 healthy subjects during a maintained motor contraction task at 8% of the maximal voluntary contraction (MVC) force level. The coherence between oscillatory processes in the EEG and EMG was calculated. Three different conditions were investigated: (i) performing the task with high precision (HP); (ii) performing the task with high precision and simultaneously performing a mental arithmetic task (HPAT), i.e. attention was divided between the motor task and the mental arithmetic task; and (iii) performing the task with low precision (LP). We have found that the amount of beta range EEG-EMG synchronization decreases below the 95% confidence level when attention is divided between the motor task and the mental arithmetic task. The results also show that the frequency of beta range synchronization is higher with a higher level of precision but still lies within the beta frequency range (15-30 Hz). The data indicate that beta range synchronization represents a state of the cortico-muscular network when attention is directed towards the motor task. The frequency of synchronization of this network is associated with, and possibly encodes, precision in force production.

  16. Multiple Language Use Influences Oculomotor Task Performance: Neurophysiological Evidence of a Shared Substrate between Language and Motor Control.

    PubMed

    Heidlmayr, Karin; Doré-Mazars, Karine; Aparicio, Xavier; Isel, Frédéric

    2016-01-01

    In the present electroencephalographical study, we asked to which extent executive control processes are shared by both the language and motor domain. The rationale was to examine whether executive control processes whose efficiency is reinforced by the frequent use of a second language can lead to a benefit in the control of eye movements, i.e. a non-linguistic activity. For this purpose, we administrated to 19 highly proficient late French-German bilingual participants and to a control group of 20 French monolingual participants an antisaccade task, i.e. a specific motor task involving control. In this task, an automatic saccade has to be suppressed while a voluntary eye movement in the opposite direction has to be carried out. Here, our main hypothesis is that an advantage in the antisaccade task should be observed in the bilinguals if some properties of the control processes are shared between linguistic and motor domains. ERP data revealed clear differences between bilinguals and monolinguals. Critically, we showed an increased N2 effect size in bilinguals, thought to reflect better efficiency to monitor conflict, combined with reduced effect sizes on markers reflecting inhibitory control, i.e. cue-locked positivity, the target-locked P3 and the saccade-locked presaccadic positivity (PSP). Moreover, effective connectivity analyses (dynamic causal modelling; DCM) on the neuronal source level indicated that bilinguals rely more strongly on ACC-driven control while monolinguals rely on PFC-driven control. Taken together, our combined ERP and effective connectivity findings may reflect a dynamic interplay between strengthened conflict monitoring, associated with subsequently more efficient inhibition in bilinguals. Finally, L2 proficiency and immersion experience constitute relevant factors of the language background that predict efficiency of inhibition. To conclude, the present study provided ERP and effective connectivity evidence for domain-general executive

  17. Multiple Language Use Influences Oculomotor Task Performance: Neurophysiological Evidence of a Shared Substrate between Language and Motor Control

    PubMed Central

    Heidlmayr, Karin; Doré-Mazars, Karine; Aparicio, Xavier; Isel, Frédéric

    2016-01-01

    In the present electroencephalographical study, we asked to which extent executive control processes are shared by both the language and motor domain. The rationale was to examine whether executive control processes whose efficiency is reinforced by the frequent use of a second language can lead to a benefit in the control of eye movements, i.e. a non-linguistic activity. For this purpose, we administrated to 19 highly proficient late French-German bilingual participants and to a control group of 20 French monolingual participants an antisaccade task, i.e. a specific motor task involving control. In this task, an automatic saccade has to be suppressed while a voluntary eye movement in the opposite direction has to be carried out. Here, our main hypothesis is that an advantage in the antisaccade task should be observed in the bilinguals if some properties of the control processes are shared between linguistic and motor domains. ERP data revealed clear differences between bilinguals and monolinguals. Critically, we showed an increased N2 effect size in bilinguals, thought to reflect better efficiency to monitor conflict, combined with reduced effect sizes on markers reflecting inhibitory control, i.e. cue-locked positivity, the target-locked P3 and the saccade-locked presaccadic positivity (PSP). Moreover, effective connectivity analyses (dynamic causal modelling; DCM) on the neuronal source level indicated that bilinguals rely more strongly on ACC-driven control while monolinguals rely on PFC-driven control. Taken together, our combined ERP and effective connectivity findings may reflect a dynamic interplay between strengthened conflict monitoring, associated with subsequently more efficient inhibition in bilinguals. Finally, L2 proficiency and immersion experience constitute relevant factors of the language background that predict efficiency of inhibition. To conclude, the present study provided ERP and effective connectivity evidence for domain-general executive

  18. The primary motor cortex is associated with learning the absolute, but not relative, timing dimension of a task: A tDCS study.

    PubMed

    Apolinário-Souza, Tércio; Romano-Silva, Marco Aurélio; de Miranda, Débora Marques; Malloy-Diniz, Leandro Fernandes; Benda, Rodolfo Novellino; Ugrinowitsch, Herbert; Lage, Guilherme Menezes

    2016-06-01

    The functional role of the primary motor cortex (M1) in the production of movement parameters, such as length, direction and force, is well known; however, whether M1 is associated with the parametric adjustments in the absolute timing dimension of the task remains unknown. Previous studies have not applied tasks and analyses that could separate the absolute (variant) and relative (invariant) dimensions. We applied transcranial direct current stimulation (tDCS) to M1 before motor practice to facilitate motor learning. A sequential key-pressing task was practiced with two goals: learning the relative timing dimension and learning the absolute timing dimension. All effects of the stimulation of M1 were observed only in the absolute dimension of the task. Mainly, the stimulation was associated with better performance in the transfer test in the absolute dimension. Taken together, our results indicate that M1 is an important area for learning the absolute timing dimension of a motor sequence.

  19. Effects of Hand Orientation on Motor Imagery - Event Related Potentials Suggest Kinesthetic Motor Imagery to Solve the Hand Laterality Judgment Task

    PubMed Central

    Jongsma, Marijtje L. A.; Meulenbroek, Ruud G. J.; Okely, Judith; Baas, C. Marjolein; van der Lubbe, Rob H. J.; Steenbergen, Bert

    2013-01-01

    Motor imagery (MI) refers to the process of imagining the execution of a specific motor action without actually producing an overt movement. Two forms of MI have been distinguished: visual MI and kinesthetic MI. To distinguish between these forms of MI we employed an event related potential (ERP) study to measure interference effects induced by hand orientation manipulations in a hand laterality judgement task. We hypothesized that this manipulation should only affect kinesthetic MI but not visual MI. The ERPs elicited by rotated hand stimuli contained the classic rotation related negativity (RRN) with respect to palm view stimuli. We observed that laterally rotated stimuli led to a more marked RRN than medially rotated stimuli. This RRN effect was observed when participants had their hands positioned in either a straight (control) or an inward rotated posture, but not when their hands were positioned in an outward rotated posture. Posture effects on the ERP-RRN have not previously been studied. Apparently, a congruent hand posture (hands positioned in an outward rotated fashion) facilitates the judgement of the otherwise more demanding laterally rotated hand stimuli. These ERP findings support a kinesthetic interpretation of MI involved in solving the hand laterality judgement task. The RRN may be used as a non-invasive marker for kinesthetic MI and seems useful in revealing the covert behavior of MI in e.g. rehabilitation programs. PMID:24086747

  20. Effects of hand orientation on motor imagery--event related potentials suggest kinesthetic motor imagery to solve the hand laterality judgment task.

    PubMed

    Jongsma, Marijtje L A; Meulenbroek, Ruud G J; Okely, Judith; Baas, C Marjolein; van der Lubbe, Rob H J; Steenbergen, Bert

    2013-01-01

    Motor imagery (MI) refers to the process of imagining the execution of a specific motor action without actually producing an overt movement. Two forms of MI have been distinguished: visual MI and kinesthetic MI. To distinguish between these forms of MI we employed an event related potential (ERP) study to measure interference effects induced by hand orientation manipulations in a hand laterality judgement task. We hypothesized that this manipulation should only affect kinesthetic MI but not visual MI. The ERPs elicited by rotated hand stimuli contained the classic rotation related negativity (RRN) with respect to palm view stimuli. We observed that laterally rotated stimuli led to a more marked RRN than medially rotated stimuli. This RRN effect was observed when participants had their hands positioned in either a straight (control) or an inward rotated posture, but not when their hands were positioned in an outward rotated posture. Posture effects on the ERP-RRN have not previously been studied. Apparently, a congruent hand posture (hands positioned in an outward rotated fashion) facilitates the judgement of the otherwise more demanding laterally rotated hand stimuli. These ERP findings support a kinesthetic interpretation of MI involved in solving the hand laterality judgement task. The RRN may be used as a non-invasive marker for kinesthetic MI and seems useful in revealing the covert behavior of MI in e.g. rehabilitation programs.

  1. Do pursuit movement tasks lead to differential changes in early somatosensory evoked potentials related to motor learning compared with typing tasks?

    PubMed

    Andrew, Danielle; Yielder, Paul; Murphy, Bernadette

    2015-02-15

    Central nervous system (CNS) plasticity is essential for development; however, recent research has demonstrated its role in pathology, particularly following overuse and repetition. Previous studies investigating changes in sensorimotor integration (SMI) have used relatively simple paradigms resulting in minimal changes in neural activity, as determined through the use of somatosensory evoked potentials (SEPs). This study sought to utilize complex tasks and compare separate motor paradigms to determine which one best facilitates long-term learning. Spinal, brainstem, and cortical SEPs were recorded following median nerve stimulation at the wrist pre- and postinterventions. Eighteen participants performed the same paradigms, a control condition of 10 min of mental recitation and two interventions, one consisting of 10 min of tracing and the other 10 min of repetitive typing. Significant increases in the N13, N20, P25, and N30 SEP peaks were seen for both interventions. A significant decrease in the N24 SEP peak was observed for both interventions. Significant improvements in accuracy were seen for both interventions postacquisition but only for tracing during retention. The changes seen following motor learning were congruent with those associated with long-term learning, which was also reflected by significant increases in accuracy during retention. Tracing or the pursuit movement paradigm was shown to be a more effective learning tool. The identification of a task that is sufficiently novel and complex, leading to robust changes in SEP peaks, indicates a task that can be utilized in future work to study clinical populations and the effect of experimental interventions on SMI. Copyright © 2015 the American Physiological Society.

  2. Planning multiple movements within a fixed time limit: The cost of constrained time allocation in a visuo-motor task

    PubMed Central

    Zhang, Hang; Wu, Shih-Wei; Maloney, Laurence T.

    2010-01-01

    S.-W. Wu, M. F. Dal Martello, and L. T. Maloney (2009) evaluated subjects' performance in a visuo-motor task where subjects were asked to hit two targets in sequence within a fixed time limit. Hitting targets earned rewards and Wu et al. varied rewards associated with targets. They found that subjects failed to maximize expected gain; they failed to invest more time in the movement to the more valuable target. What could explain this lack of response to reward? We first considered the possibility that subjects require training in allocating time between two movements. In Experiment 1, we found that, after extensive training, subjects still failed: They did not vary time allocation with changes in payoff. However, their actual gains equaled or exceeded the expected gain of an ideal time allocator, indicating that constraining time itself has a cost for motor accuracy. In a second experiment, we found that movements made under externally imposed time limits were less accurate than movements made with the same timing freely selected by the mover. Constrained time allocation cost about 17% in expected gain. These results suggest that there is no single speed–accuracy tradeoff for movement in our task and that subjects pursued different motor strategies with distinct speed–accuracy tradeoffs in different conditions. PMID:20884550

  3. Exploration of joint redundancy but not task space variability facilitates supervised motor learning.

    PubMed

    Singh, Puneet; Jana, Sumitash; Ghosal, Ashitava; Murthy, Aditya

    2016-12-13

    The number of joints and muscles in a human arm is more than what is required for reaching to a desired point in 3D space. Although previous studies have emphasized how such redundancy and the associated flexibility may play an important role in path planning, control of noise, and optimization of motion, whether and how redundancy might promote motor learning has not been investigated. In this work, we quantify redundancy space and investigate its significance and effect on motor learning. We propose that a larger redundancy space leads to faster learning across subjects. We observed this pattern in subjects learning novel kinematics (visuomotor adaptation) and dynamics (force-field adaptation). Interestingly, we also observed differences in the redundancy space between the dominant hand and nondominant hand that explained differences in the learning of dynamics. Taken together, these results provide support for the hypothesis that redundancy aids in motor learning and that the redundant component of motor variability is not noise.

  4. Exploration of joint redundancy but not task space variability facilitates supervised motor learning

    PubMed Central

    Singh, Puneet; Jana, Sumitash; Ghosal, Ashitava; Murthy, Aditya

    2016-01-01

    The number of joints and muscles in a human arm is more than what is required for reaching to a desired point in 3D space. Although previous studies have emphasized how such redundancy and the associated flexibility may play an important role in path planning, control of noise, and optimization of motion, whether and how redundancy might promote motor learning has not been investigated. In this work, we quantify redundancy space and investigate its significance and effect on motor learning. We propose that a larger redundancy space leads to faster learning across subjects. We observed this pattern in subjects learning novel kinematics (visuomotor adaptation) and dynamics (force-field adaptation). Interestingly, we also observed differences in the redundancy space between the dominant hand and nondominant hand that explained differences in the learning of dynamics. Taken together, these results provide support for the hypothesis that redundancy aids in motor learning and that the redundant component of motor variability is not noise. PMID:27911808

  5. Potential Predictors of Changes in Gross Motor Function during Various Tasks for Children with Cerebral Palsy: A Follow-Up Study

    ERIC Educational Resources Information Center

    Chen, Chia-ling; Chen, Chung-yao; Chen, Hsieh-ching; Liu, Wen-yu; Shen, I-hsuan; Lin, Keh-chung

    2013-01-01

    Very few studies have investigated predictors of change in various gross motor outcomes in ambulatory children with cerebral palsy (CP). The aim of this study was to identify potential predictors for change in gross motor outcomes measured during various tasks in children with CP. A group of 45 children (age, 6-15 years) with CP and 7 potential…

  6. Potential Predictors of Changes in Gross Motor Function during Various Tasks for Children with Cerebral Palsy: A Follow-Up Study

    ERIC Educational Resources Information Center

    Chen, Chia-ling; Chen, Chung-yao; Chen, Hsieh-ching; Liu, Wen-yu; Shen, I-hsuan; Lin, Keh-chung

    2013-01-01

    Very few studies have investigated predictors of change in various gross motor outcomes in ambulatory children with cerebral palsy (CP). The aim of this study was to identify potential predictors for change in gross motor outcomes measured during various tasks in children with CP. A group of 45 children (age, 6-15 years) with CP and 7 potential…

  7. Shoulder motor performance assessment in the sagittal plane in children with hemiplegia during single joint pointing tasks.

    PubMed

    Formica, Domenico; Petrarca, Maurizio; Rossi, Stefano; Zollo, Loredana; Guglielmelli, Eugenio; Cappa, Paolo

    2014-07-29

    Pointing is a motor task extensively used during daily life activities and it requires complex visuo-motor transformation to select the appropriate movement strategy. The study of invariant characteristics of human movements has led to several theories on how the brain solves the redundancy problem, but the application of these theories on children affected by hemiplegia is limited. This study aims at giving a quantitative assessment of the shoulder motor behaviour in children with hemiplegia during pointing tasks. Eight children with hemiplegia were involved in the study and were asked to perform movements on the sagittal plane with both arms, at low and high speed. Subject movements were recorded using an optoelectronic system; a 4-DOF model of children arm has been developed to calculate kinematic and dynamic variables. A set of evaluation indexes has been extracted in order to quantitatively assess whether and how children modify their motor control strategies when perform movements with the more affected or less affected arm. In low speed movements, no differences can be seen in terms of movement duration and peak velocity between the More Affected arm (MA) and the Less Affected arm (LA), as well as in the main characteristics of movement kinematics and dynamics. As regards fast movements, remarkable differences in terms of strategies of motor control can be observed: while movements with LA did not show any significant difference in Dimensionless Jerk Index (JI) and Dimensionless Torque-change Cost index (TC) between the elevation and lowering phases, suggesting that motor control optimization is similar for movements performed with or against gravity, movements with MA showed a statistically significant increase of both JI and TC during lowering phase. Results suggest the presence of a different control strategy for fast movements in particular during lowering phase. Results suggest that motor control is not able to optimize Jerk and Torque-change cost

  8. Motor adaptation capacity as a function of age in carrying out a repetitive assembly task at imposed work paces.

    PubMed

    Gilles, Martine Annie; Guélin, Jean-Charles; Desbrosses, Kévin; Wild, Pascal

    2017-10-01

    The working population is getting older. Workers must adapt to changing conditions to respond to the efforts required by the tasks they have to perform. In this laboratory-based study, we investigated the capacities of motor adaptation as a function of age and work pace. Two phases were identified in the task performed: a collection phase, involving dominant use of the lower limbs; and an assembly phase, involving bi-manual motor skills. Results showed that senior workers were mainly limited during the collection phase, whereas they had less difficulty completing the assembly phase. However, senior workers did increase the vertical force applied while assembling parts, whatever the work pace. In younger and middle-aged subjects, vertical force was increased only for the faster pace. Older workers could adapt to perform repetitive tasks under different time constraints, but adaptation required greater effort than for younger workers. These results point towards a higher risk of developing musculoskeletal disorders among seniors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. A motorized pellet dispenser to deliver high intensity training of the single pellet reaching and grasping task in rats.

    PubMed

    Torres-Espín, Abel; Forero, Juan; Schmidt, Emma K A; Fouad, Karim; Fenrich, Keith K

    2017-08-25

    The single pellet reaching and grasping (SPG) task is widely used to study forelimb motor performance in rodents and to provide rehabilitation after neurological disorders. Nonetheless, the time necessary to train animals precludes its use in settings where high-intensity training is required. In the current study, we developed a novel high-intensity training protocol for the SPG task based on a motorized pellet dispenser and a dual-window enclosure. We tested the protocol in naive adult rats and found 1) an increase in the intensity of training without increasing the task time and without affecting the overall performance of the animals, 2) a reduction in the variability within and between experiments in comparison to manual SPG training, and 3) a reduction in the time required to conduct experiments. In summary, we developed and tested a novel protocol for SPG training that provides higher-intensity training while reducing the variability of results observed with other protocols. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Effect of a Task-Oriented Rehabilitation Program on Upper Extremity Recovery Following Motor Stroke: The ICARE Randomized Clinical Trial.

    PubMed

    Winstein, Carolee J; Wolf, Steven L; Dromerick, Alexander W; Lane, Christianne J; Nelsen, Monica A; Lewthwaite, Rebecca; Cen, Steven Yong; Azen, Stanley P

    2016-02-09

    Clinical trials suggest that higher doses of task-oriented training are superior to current clinical practice for patients with stroke with upper extremity motor deficits. To compare the efficacy of a structured, task-oriented motor training program vs usual and customary occupational therapy (UCC) during stroke rehabilitation. Phase 3, pragmatic, single-blind randomized trial among 361 participants with moderate motor impairment recruited from 7 US hospitals over 44 months, treated in the outpatient setting from June 2009 to March 2014. Structured, task-oriented upper extremity training (Accelerated Skill Acquisition Program [ASAP]; n = 119); dose-equivalent occupational therapy (DEUCC; n = 120); or monitoring-only occupational therapy (UCC; n = 122). The DEUCC group was prescribed 30 one-hour sessions over 10 weeks; the UCC group was only monitored, without specification of dose. The primary outcome was 12-month change in log-transformed Wolf Motor Function Test time score (WMFT, consisting of a mean of 15 timed arm movements and hand dexterity tasks). Secondary outcomes were change in WMFT time score (minimal clinically important difference [MCID] = 19 seconds) and proportion of patients improving ≥25 points on the Stroke Impact Scale (SIS) hand function score (MCID = 17.8 points). Among the 361 randomized patients (mean age, 60.7 years; 56% men; 42% African American; mean time since stroke onset, 46 days), 304 (84%) completed the 12-month primary outcome assessment; in intention-to-treat analysis, mean group change scores (log WMFT, baseline to 12 months) were, for the ASAP group, 2.2 to 1.4 (difference, 0.82); DEUCC group, 2.0 to 1.2 (difference, 0.84); and UCC group, 2.1 to 1.4 (difference, 0.75), with no significant between-group differences (ASAP vs DEUCC: 0.14; 95% CI, -0.05 to 0.33; P = .16; ASAP vs UCC: -0.01; 95% CI, -0.22 to 0.21; P = .94; and DEUCC vs UCC: -0.14; 95% CI, -0.32 to 0.05; P = .15). Secondary outcomes for the ASAP

  11. Specificity of transfer in basic and applied perceptual-motor tasks.

    PubMed

    Proctor, Robert W; Dunston, Phillip S; So, Joey C Y; Lopez-Santamaria, Bessy N; Yamaguchi, Motonori; Wang, Xiangyu

    2013-01-01

    We conducted research on transfer of skills using basic stimulus-response compatibility tasks and applied tasks requiring control of a hydraulic excavator simulator. The basic tasks show rapid acquisition of practiced spatial mappings, for which transfer is specific to the procedures used in training. The applied tasks show transfer across alternative control configurations that maintain practiced spatial mappings, as well as from part to whole practice. Transfer from simulated to real equipment also seems to occur; however, studies involving cooperation of academia and industry are needed to provide more definitive evidence on this question.

  12. Balance Training Enhances Motor Coordination During a Perturbed Side-Step Cutting Task.

    PubMed

    Oliveira, Anderson Souza; Silva, Priscila de Brito; Lund, Morten Enemark; Farina, Dario; Kersting, Uwe Gustav

    2017-09-23

    Study Design Controlled laboratory study. Background Balance training (BTR) may improve motor coordination, however little is known about the changes in motor coordination during unexpected perturbations to postural control following BTR. Objectives To study the effects of BTR on motor coordination and knee mechanics during perturbed side-step cutting maneuvers in healthy adults. Methods Twenty-six healthy men were randomly assigned to a training group (TG) or control (CG). Before BTR, subjects performed unperturbed, 90° side-step cutting maneuvers and one unexpected perturbed cut (10-cm translation of a moveable platform). The TG subjects participated in a 6-week BTR program while CG participants followed their regular activity schedule. Both groups were re-tested after a 6-week period. Surface electromyography was recorded from 16 muscles of the supporting limb and trunk, as well as kinematics, and ground reaction forces. Motor modules were extracted from the EMG by non-negative matrix factorization. External knee abduction moments were calculated using inverse dynamics equations. Results BTR resulted in a reduction of the external knee abduction moment (33 ± 25%, p<0.001, ŋp(2)=0.725), and increased the activation of trunk and proximal hip muscles in specific motor modules during perturbed cutting. BTR also increased burst duration for the motor module related to landing early in the perturbation phase (23 ± 11%, p<0.01, ŋp(2)=0.532). Conclusion BTR resulted in altered motor coordination and a reduction in the knee abduction moment during an unexpected perturbation. The previously reported reduction in injury incidence following BTR may be linked to changes in dynamic postural stability and neuromuscular control. J Orthop Sports Phys Ther, Epub 23 Sep 2017. doi:10.2519/jospt.2017.6980.

  13. Dynamic causal modelling of EEG and fMRI to characterize network architectures in a simple motor task.

    PubMed

    Bönstrup, Marlene; Schulz, Robert; Feldheim, Jan; Hummel, Friedhelm C; Gerloff, Christian

    2016-01-01

    Dynamic causal modelling (DCM) has extended the understanding of brain network dynamics in a variety of functional systems. In the motor system, DCM studies based on functional magnetic resonance imaging (fMRI) or on magneto-/electroencephalography (M/EEG) have demonstrated movement-related causal information flow from secondary to primary motor areas and have provided evidence for nonlinear cross-frequency interactions among motor areas. The present study sought to investigate to what extent fMRI- and EEG-based DCM might provide complementary and synergistic insights into neuronal network dynamics. Both modalities share principal similarities in the formulation of the DCM. Thus, we hypothesized that DCM based on induced EEG responses (DCM-IR) and on fMRI would reveal congruent task-dependent network dynamics. Brain electrical (63-channel surface EEG) and Blood Oxygenation Level Dependent (BOLD) signals were recorded in separate sessions from 14 healthy participants performing simple isometric right and left hand grips. DCM-IR and DCM-fMRI were used to estimate coupling parameters modulated by right and left hand grips within a core motor network of six regions comprising bilateral primary motor cortex (M1), ventral premotor cortex (PMv) and supplementary motor area (SMA). We found that DCM-fMRI and DCM-IR similarly revealed significant grip-related increases in facilitatory coupling between SMA and M1 contralateral to the active hand. A grip-dependent interhemispheric reciprocal inhibition between M1 bilaterally was only revealed by DCM-fMRI but not by DCM-IR. Frequency-resolved coupling analysis showed that the information flow from contralateral SMA to M1 was predominantly a linear alpha-to-alpha (9-13Hz) interaction. We also detected some cross-frequency coupling from SMA to contralateral M1, i.e., between lower beta (14-21Hz) at the SMA and higher beta (22-30Hz) at M1 during right hand grip and between alpha (9-13Hz) at SMA and lower beta (14-21Hz) at M1

  14. Caspr3-Deficient Mice Exhibit Low Motor Learning during the Early Phase of the Accelerated Rotarod Task

    PubMed Central

    Hirata, Haruna; Takahashi, Aki; Shimoda, Yasushi; Koide, Tsuyoshi

    2016-01-01

    Caspr3 (Contactin-associated protein-like 3, Cntnap3) is a neural cell adhesion molecule belonging to the Caspr family. We have recently shown that Caspr3 is expressed abundantly between the first and second postnatal weeks in the mouse basal ganglia, including the striatum, external segment of the globus pallidus, subthalamic nucleus, and substantia nigra. However, its physiological role remains largely unknown. In this study, we conducted a series of behavioral analyses on Capsr3-knockout (KO) mice and equivalent wild-type (WT) mice to investigate the role of Caspr3 in brain function. No significant differences were observed in most behavioral traits between Caspr3-KO and WT mice, but we found that Caspr3-KO mice performed poorly during the early phase of the accelerated rotarod task in which latency to falling off a rod rotating with increasing velocity was examined. In the late phase, the performance of the Caspr3-KO mice caught up to the level of WT mice, suggesting that the deletion of Caspr3 caused a delay in motor learning. We then examined changes in neural activity after training on the accelerated rotarod by conducting immunohistochemistry using antibody to c-Fos, an indirect marker for neuronal activity. Experience of the accelerated rotarod task caused increases in the number of c-Fos-positive cells in the dorsal striatum, cerebellum, and motor cortex in both Caspr3-KO and WT mice, but the number of c-Fos-positive cells was significantly lower in the dorsal striatum of Caspr3-KO mice than in that of WT mice. The expression of c-Fos in the ventral striatum of Caspr3-KO and WT mice was not altered by the training. Our findings suggest that reduced activation of neural cells in the dorsal striatum in Caspr3-KO mice leads to a decline in motor learning in the accelerated rotarod task. PMID:26807827

  15. Teaching a High-Avoidance Motor Task to a Retarded Child through Participant Modeling.

    ERIC Educational Resources Information Center

    Feltz, Deborah L.

    1980-01-01

    The study investigated the effectiveness of participant modeling as a technique for teaching an educable mentally retarded 12-year-old a task that was considered high in avoidance (a modified forward dive). Participant modeling with self-directed performance at each step was successful in teaching the student a high avoidance diving task. (SBH)

  16. Random motor generation in a finger tapping task: influence of spatial contingency and of cortical and subcortical hemispheric brain lesions

    PubMed Central

    Annoni, J.; Pegna, A.

    1997-01-01

    OBJECTIVE—To test the hypothesis that, during random motor generation, the spatial contingencies inherent to the task would induce additional preferences in normal subjects, shifting their performances farther from randomness. By contrast, perceptual or executive dysfunction could alter these task related biases in patients with brain damage.
METHODS—Two groups of patients, with right and left focal brain lesions, as well as 25 right handed subjects matched for age and handedness were asked to execute a random choice motor task—namely, to generate a random series of 180 button presses from a set of 10 keys placed vertically in front of them.
RESULTS—In the control group, as in the left brain lesion group, motor generation was subject to deviations from theoretical expected randomness, similar to those when numbers are generated mentally, as immediate repetitions (successive presses on the same key) are avoided. However, the distribution of button presses was also contingent on the topographic disposition of the keys: the central keys were chosen more often than those placed at extreme positions. Small distances were favoured, particularly with the left hand. These patterns were influenced by implicit strategies and task related contingencies.
 By contrast, right brain lesion patients with frontal involvement tended to show a more square distribution of key presses—that is, the number of key presses tended to be more equally distributed. The strategies were also altered by brain lesions: the number of immediate repetitions was more frequent when the lesion involved the right frontal areas yielding a random generation nearer to expected theoretical randomness. The frequency of adjacent key presses was increased by right anterior and left posterior cortical as well as by right subcortical lesions, but decreased by left subcortical lesions.
CONCLUSIONS—Depending on the side of the lesion and the degree of cortical-subcortical involvement, the

  17. Motor Cortical Correlates of Arm Resting in the Context of a Reaching Task and Implications for Prosthetic Control

    PubMed Central

    Kennedy, Scott D.; Schwartz, Andrew B.; Whitford, Andrew S.; Sohn, Jeong-Woo; McMorland, Angus J.C.

    2014-01-01

    Prosthetic devices are being developed to restore movement for motor-impaired individuals. A robotic arm can be controlled based on models that relate motor-cortical ensemble activity to kinematic parameters. The models are typically built and validated on data from structured trial periods during which a subject actively performs specific movements, but real-world prosthetic devices will need to operate correctly during rest periods as well. To develop a model of motor cortical modulation during rest, we trained monkeys (Macaca mulatta) to perform a reaching task with their own arm while recording motor-cortical single-unit activity. When a monkey spontaneously put its arm down to rest between trials, our traditional movement decoder produced a nonzero velocity prediction, which would cause undesired motion when applied to a prosthetic arm. During these rest periods, a marked shift was found in individual units' tuning functions. The activity pattern of the whole population during rest (Idle state) was highly distinct from that during reaching movements (Active state), allowing us to predict arm resting from instantaneous firing rates with 98% accuracy using a simple classifier. By cascading this state classifier and the movement decoder, we were able to predict zero velocity correctly, which would avoid undesired motion in a prosthetic application. Interestingly, firing rates during hold periods followed the Active pattern even though hold kinematics were similar to those during rest with near-zero velocity. These findings expand our concept of motor-cortical function by showing that population activity reflects behavioral context in addition to the direct parameters of the movement itself. PMID:24760860

  18. Fine and Gross Motor Task Performance When Using Computer-Based Video Models by Students with Autism and Moderate Intellectual Disability

    ERIC Educational Resources Information Center

    Mechling, Linda C.; Swindle, Catherine O.

    2013-01-01

    This investigation examined the effects of video modeling on the fine and gross motor task performance by three students with a diagnosis of moderate intellectual disability (Group 1) and by three students with a diagnosis of autism spectrum disorder (Group 2). Using a multiple probe design across three sets of tasks, the study examined the…

  19. Fine and Gross Motor Task Performance When Using Computer-Based Video Models by Students with Autism and Moderate Intellectual Disability

    ERIC Educational Resources Information Center

    Mechling, Linda C.; Swindle, Catherine O.

    2013-01-01

    This investigation examined the effects of video modeling on the fine and gross motor task performance by three students with a diagnosis of moderate intellectual disability (Group 1) and by three students with a diagnosis of autism spectrum disorder (Group 2). Using a multiple probe design across three sets of tasks, the study examined the…

  20. Learning, Not Adaptation, Characterizes Stroke Motor Recovery: Evidence From Kinematic Changes Induced by Robot-Assisted Therapy in Trained and Untrained Task in the Same Workspace

    PubMed Central

    Dipietro, L.; Krebs, H. I.; Volpe, B. T.; Stein, J.; Bever, C.; Mernoff, S. T.; Fasoli, S. E.; Hogan, N.

    2015-01-01

    Both the American Heart Association and the VA/DoD endorse upper-extremity robot-mediated rehabilitation therapy for stroke care. However, we do not know yet how to optimize therapy for a particular patient’s needs. Here, we explore whether we must train patients for each functional task that they must perform during their activities of daily living or alternatively capacitate patients to perform a class of tasks and have therapists assist them later in translating the observed gains into activities of daily living. The former implies that motor adaptation is a better model for motor recovery. The latter implies that motor learning (which allows for generalization) is a better model for motor recovery. We quantified trained and untrained movements performed by 158 recovering stroke patients via 13 metrics, including movement smoothness and submovements. Improvements were observed both in trained and untrained movements suggesting that generalization occurred. Our findings suggest that, as motor recovery progresses, an internal representation of the task is rebuilt by the brain in a process that better resembles motor learning than motor adaptation. Our findings highlight possible improvements for therapeutic algorithms design, suggesting sparse-activity-set training should suffice over exhaustive sets of task specific training. PMID:22186963

  1. Visual motor response of crewmen during a simulated 90 day space mission as measured by the critical task battery

    NASA Technical Reports Server (NTRS)

    Allen, R. W.; Jex, H. R.

    1972-01-01

    In order to test various components of a regenerative life support system and to obtain data on the physiological and psychological effects of long-duration exposure to confinement in a space station atmosphere, four carefully screened young men were sealed in space station simulator for 90 days. A tracking test battery was administered during the above experiment. The battery included a clinical test (critical instability task) related to the subject's dynamic time delay, and a conventional steady tracking task, during which dynamic response (describing functions) and performance measures were obtained. Good correlation was noted between the clinical critical instability scores and more detailed tracking parameters such as dynamic time delay and gain-crossover frequency. The comprehensive data base on human operator tracking behavior obtained in this study demonstrate that sophisticated visual-motor response properties can be efficiently and reliably measured over extended periods of time.

  2. Effect of task-oriented training and high-variability practice on gross motor performance and activities of daily living in children with spastic diplegia

    PubMed Central

    Kwon, Hae-Yeon; Ahn, So-Yoon

    2016-01-01

    [Purpose] This study investigates how a task-oriented training and high-variability practice program can affect the gross motor performance and activities of daily living for children with spastic diplegia and provides an effective and reliable clinical database for future improvement of motor performances skills. [Subjects and Methods] This study randomly assigned seven children with spastic diplegia to each intervention group including that of a control group, task-oriented training group, and a high-variability practice group. The control group only received neurodevelopmental treatment for 40 minutes, while the other two intervention groups additionally implemented a task-oriented training and high-variability practice program for 8 weeks (twice a week, 60 min per session). To compare intra and inter-relationships of the three intervention groups, this study measured gross motor performance measure (GMPM) and functional independence measure for children (WeeFIM) before and after 8 weeks of training. [Results] There were statistically significant differences in the amount of change before and after the training among the three intervention groups for the gross motor performance measure and functional independence measure. [Conclusion] Applying high-variability practice in a task-oriented training course may be considered an efficient intervention method to improve motor performance skills that can tune to movement necessary for daily livelihood through motor experience and learning of new skills as well as change of tasks learned in a complex environment or similar situations to high-variability practice. PMID:27821947

  3. Effect of task-oriented training and high-variability practice on gross motor performance and activities of daily living in children with spastic diplegia.

    PubMed

    Kwon, Hae-Yeon; Ahn, So-Yoon

    2016-10-01

    [Purpose] This study investigates how a task-oriented training and high-variability practice program can affect the gross motor performance and activities of daily living for children with spastic diplegia and provides an effective and reliable clinical database for future improvement of motor performances skills. [Subjects and Methods] This study randomly assigned seven children with spastic diplegia to each intervention group including that of a control group, task-oriented training group, and a high-variability practice group. The control group only received neurodevelopmental treatment for 40 minutes, while the other two intervention groups additionally implemented a task-oriented training and high-variability practice program for 8 weeks (twice a week, 60 min per session). To compare intra and inter-relationships of the three intervention groups, this study measured gross motor performance measure (GMPM) and functional independence measure for children (WeeFIM) before and after 8 weeks of training. [Results] There were statistically significant differences in the amount of change before and after the training among the three intervention groups for the gross motor performance measure and functional independence measure. [Conclusion] Applying high-variability practice in a task-oriented training course may be considered an efficient intervention method to improve motor performance skills that can tune to movement necessary for daily livelihood through motor experience and learning of new skills as well as change of tasks learned in a complex environment or similar situations to high-variability practice.

  4. Performing a reaching task with one arm while adapting to a visuomotor rotation with the other can lead to complete transfer of motor learning across the arms.

    PubMed

    Wang, Jinsung; Lei, Yuming; Binder, Jeffrey R

    2015-04-01

    The extent to which motor learning is generalized across the limbs is typically very limited. Here, we investigated how two motor learning hypotheses could be used to enhance the extent of interlimb transfer. According to one hypothesis, we predicted that reinforcement of successful actions by providing binary error feedback regarding task success or failure, in addition to terminal error feedback, during initial training would increase the extent of interlimb transfer following visuomotor adaptation (experiment 1). According to the other hypothesis, we predicted that performing a reaching task repeatedly with one arm without providing performance feedback (which prevented learning the task with this arm), while concurrently adapting to a visuomotor rotation with the other arm, would increase the extent of transfer (experiment 2). Results indicate that providing binary error feedback, compared with continuous visual feedback that provided movement direction and amplitude information, had no influence on the extent of transfer. In contrast, repeatedly performing (but not learning) a specific task with one arm while visuomotor adaptation occurred with the other arm led to nearly complete transfer. This suggests that the absence of motor instances associated with specific effectors and task conditions is the major reason for limited interlimb transfer and that reinforcement of successful actions during initial training is not beneficial for interlimb transfer. These findings indicate crucial contributions of effector- and task-specific motor instances, which are thought to underlie (a type of) model-free learning, to optimal motor learning and interlimb transfer. Copyright © 2015 the American Physiological Society.

  5. Speech Motor Programming in Apraxia of Speech: Evidence from a Delayed Picture-Word Interference Task

    ERIC Educational Resources Information Center

    Mailend, Marja-Liisa; Maas, Edwin

    2013-01-01

    Purpose: Apraxia of speech (AOS) is considered a speech motor programming impairment, but the specific nature of the impairment remains a matter of debate. This study investigated 2 hypotheses about the underlying impairment in AOS framed within the Directions Into Velocities of Articulators (DIVA; Guenther, Ghosh, & Tourville, 2006) model: The…

  6. Speech Motor Programming in Apraxia of Speech: Evidence from a Delayed Picture-Word Interference Task

    ERIC Educational Resources Information Center

    Mailend, Marja-Liisa; Maas, Edwin

    2013-01-01

    Purpose: Apraxia of speech (AOS) is considered a speech motor programming impairment, but the specific nature of the impairment remains a matter of debate. This study investigated 2 hypotheses about the underlying impairment in AOS framed within the Directions Into Velocities of Articulators (DIVA; Guenther, Ghosh, & Tourville, 2006) model: The…

  7. The Drawing of Squares and Diamonds: A Perceptual-Motor Task Analysis.

    ERIC Educational Resources Information Center

    Broderick, Pia; Laszlo, Judith I.

    1987-01-01

    Reports a study of 5- to 12-year-old children and adults regarding the role of perceptual motor factors in copying an equilateral four-sided "square" or "diamond" figure under five conditions. Developmental trends were found for copying both figures; the diamond was less well performed than the square at all ages tested.…

  8. Learning of a simple grapho-motor task by young children and adults: similar acquisition but age-dependent retention

    PubMed Central

    Julius, Mona S.; Adi-Japha, Esther

    2015-01-01

    Many new skills are acquired during early childhood. Typical laboratory skill learning tasks are not applicable for developmental studies that involve children younger than 8 years of age. It is not clear whether young children and adults share a basic underlying skill learning mechanism. In the present study, the learning and retention of a simple grapho-motor pattern were studied in three age groups: 5–6, 7–8, and 19–29 years. Each block of the task consists of identical patterns arranged in a spaced writing array. Progression across the block involves on-page movements while producing the pattern, and off-page movements between patterns. The participants practiced the production of the pattern using a digitizing tablet and were tested at 24 h and 2 weeks post-practice. All age groups produced the task blocks more quickly with practice, and the learning rate was inversely related to the initial production time. All groups exhibited additional gains 24 h post-practice that were well-retained 2 weeks later. The accuracy of the participants was maintained throughout the 2-weeks period. These findings suggest that young children and young adults use a similar mechanism when learning the task. Nevertheless, the 6-years-old spent more time off-page during retention testing than when tested at 24 h post-practice, thus supporting the notion that an age advantage may exists in the long-term retention of skills due to planning-dependent aspects. PMID:25798120

  9. An analysis of the processing requirements of a complex perceptual-motor task

    NASA Technical Reports Server (NTRS)

    Kramer, A. F.; Wickens, C. D.; Donchin, E.

    1983-01-01

    Current concerns in the assessment of mental workload are discussed, and the event-related brain potential (ERP) is introduced as a promising mental-workload index. Subjects participated in a series of studies in which they were required to perform a target acquisition task while also covertly counting either auditory or visual probes. The effects of several task-difficulty manipulations on the P300 component of the ERP elicited by the counted stimulus probes were investigated. With sufficiently practiced subjects the amplitude of the P300 was found to decrease with increases in task difficulty. The second experiment also provided evidence that the P300 is selectively sensitive to task-relevant attributes. A third experiment demonstrated a convergence in the amplitude of the P300s elicited in the simple and difficult versions of the tracking task. The amplitude of the P300 was also found to covary with the measures of tracking performance. The results of the series of three experiments illustrate the sensitivity of the P300 to the processing requirements of a complex target acquisition task. The findings are discussed in terms of the multidimensional nature of processing resources.

  10. Questioning implicit motor learning as instantiated by the pursuit-tracking task.

    PubMed

    Lang, Alexandre; Gapenne, Olivier; Rovira, Katia

    2011-10-01

    The effect of concurrent visual feedback on the implicit learning of repeated segments in a task of pursuit tracking has been tested. Although this feedback makes it possible to regulate the positional error during the movement, it could also induce negative guidance effects. To test this hypothesis, a first set of participants (N=42) were assigned to two groups, which performed either the standard pursuit-tracking task based on the experimental paradigm of Pew ( 1974 ; group F-ST), or a task called "movement reproduction" in which the feedback was suppressed (group noF-ST). A second set of participants (N=26) performed in the same feedback condition groups but in a dual-task situation (F-DT and noF-DT; Experiment 2). The results appear to confirm our predictions since the participants in groups without feedback, contrary to those in groups with feedback, succeeded with practice in differentiating their performances as a function of the nature of the segments (repeated or nonrepeated) both in simple (Experiment 1) and in dual-task (Experiment 2) situations. These experiments indicate that the feedback in the pursuit-tracking task induces a guidance function potentially resulting in an easiness tracking that prevents the participants from learning the repetition.

  11. An analysis of the processing requirements of a complex perceptual-motor task

    NASA Technical Reports Server (NTRS)

    Kramer, A. F.; Wickens, C. D.; Donchin, E.

    1983-01-01

    Current concerns in the assessment of mental workload are discussed, and the event-related brain potential (ERP) is introduced as a promising mental-workload index. Subjects participated in a series of studies in which they were required to perform a target acquisition task while also covertly counting either auditory or visual probes. The effects of several task-difficulty manipulations on the P300 component of the ERP elicited by the counted stimulus probes were investigated. With sufficiently practiced subjects the amplitude of the P300 was found to decrease with increases in task difficulty. The second experiment also provided evidence that the P300 is selectively sensitive to task-relevant attributes. A third experiment demonstrated a convergence in the amplitude of the P300s elicited in the simple and difficult versions of the tracking task. The amplitude of the P300 was also found to covary with the measures of tracking performance. The results of the series of three experiments illustrate the sensitivity of the P300 to the processing requirements of a complex target acquisition task. The findings are discussed in terms of the multidimensional nature of processing resources.

  12. On the interference of task-irrelevant hue variation on texture segmentation.

    PubMed

    Pearson, P M; Kingdom, F A

    2001-01-01

    Although natural images often include discordant information about object boundaries, the majority of research on texture segmentation has involved variation along a single dimension, e.g. colour, orientation, size. In this study, we examined orientation-based texture segmentation in the presence and absence of task-irrelevant colour variation. Previously, it had been shown that orientation-based texture segmentation was impaired if the elements, normally of one colour, were randomly allocated one of two colours (Morgan et al, 1992 Proceedings of the Royal Society of London, Series B 248 291-295). We found that this interference disappeared, however, when the spatial pattern of the colour variation was regular, as opposed to random, and when the elements were randomly positioned. We consider four models of how relevant and irrelevant texture information might combine to produce the interference effect, with special regard to these new findings. None of the models could account for the dependency of the interference effect on the spatial arrangement of colour and orientation in the texture. We suggest that inter-element separation and spatial-frequency selectivity are critical variables in the interference effect.

  13. Stereotype threat and lift effects in motor task performance: the mediating role of somatic and cognitive anxiety.

    PubMed

    Laurin, Raphael

    2013-01-01

    The aim of this investigation was to replicate the stereotype threat and lift effects in a motor task in a neutral sex-typed activity, using somatic and cognitive anxiety as key mediators of these phenomena. It was hypothesized that an ingroup/outgroup social categorization based on gender would have distinctive effects for female and male participants. A total of 161 French physical education students were randomly assigned to three threat conditions--no threat, female threat, and male threat--thus leading to a 3 x 2 (threat by gender) design. The analyses revealed a stereotype lift effect on the performances for both male and female participants, as well as a stereotype threat effect only for female participants. They also indicated that somatic anxiety had a mediating effect on the performance of female participants targeted by a negative stereotype, but that it had a facilitating effect on their performance. The stereotype threat and lift effects on motor tasks were replicated in a neutral sex-typed activity and somatic anxiety seems to have a facilitating mediating effect of the relationships between the gender-conditions (control or female threat) inter