The effects of postural threat induced by a virtual environment on performance of a walking balance task

ABSTRACTRapid motor learning may occur in situations where individuals perceive a threat of injury if they do not perform a task well. This rapid motor learning may be facilitated by improved motor performance and, consequently, more errorless practice. As a first step towards understanding the role of perceived threat on rapid motor learning, the purpose of this study was to determine how performance of a motor task is affected in situations where perceived threat of injury is high. We hypothesized that perceived threat of injury in a virtual environment would result in improved performance of a walking task (i.e., walking on a narrow beam). Results demonstrated that increased perceived threat of injury yielded slightly greater, but not statistically significant, balance performance in virtual environments (median percentage of successful steps: 78.8%, 48.3%, and 55.2% in the real low-threat, virtual low-threat, and virtual high-threat environments, respectively). These results may be partially attributed to habituation to threat over time and practice. If implemented carefully, virtual reality technology can be an effective tool for investigating walking balance in environments that are perceived as threatening.

Download Full-text

The effects of postural threat induced by a virtual environment on performance of a walking balance task

Human Movement Science ◽

10.1016/j.humov.2020.102712 ◽

2020 ◽

Vol 74 ◽

pp. 102712

Author(s):

Amir Boroomand-Tehrani ◽

Andrew H. Huntley ◽

David Jagroop ◽

Jennifer L. Campos ◽

Kara K. Patterson ◽

...

Keyword(s):

Virtual Environment ◽

Postural Threat ◽

Balance Task ◽

Walking Balance

Download Full-text

Gait and Balance Changes with Investigational Peripheral Nerve Cell Therapy during Deep Brain Stimulation in People with Parkinson’s Disease

Brain Sciences ◽

10.3390/brainsci11040500 ◽

2021 ◽

Vol 11 (4) ◽

pp. 500

Author(s):

Geetanjali Gera ◽

Zain Guduru ◽

Tritia Yamasaki ◽

Julie A. Gurwell ◽

Monica J. Chau ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Deep Brain Stimulation ◽

Peripheral Nerve ◽

Brain Stimulation ◽

Step Length ◽

Gait Velocity ◽

Balance Performance ◽

Improved Performance ◽

Deep Brain

Background: The efficacy of deep brain stimulation (DBS) and dopaminergic therapy is known to decrease over time. Hence, a new investigational approach combines implanting autologous injury-activated peripheral nerve grafts (APNG) at the time of bilateral DBS surgery to the globus pallidus interna. Objectives: In a study where APNG was unilaterally implanted into the substantia nigra, we explored the effects on clinical gait and balance assessments over two years in 14 individuals with Parkinson’s disease. Methods: Computerized gait and balance evaluations were performed without medication, and stimulation was in the off state for at least 12 h to best assess the role of APNG implantation alone. We hypothesized that APNG might improve gait and balance deficits associated with PD. Results: While people with a degenerative movement disorder typically worsen with time, none of the gait parameters significantly changed across visits in this 24 month study. The postural stability item in the UPDRS did not worsen from baseline to the 24-month follow-up. However, we measured gait and balance improvements in the two most affected individuals, who had moderate PD. In these two individuals, we observed an increase in gait velocity and step length that persisted over 6 and 24 months. Conclusions: Participants did not show worsening of gait and balance performance in the off therapy state two years after surgery, while the two most severely affected participants showed improved performance. Further studies may better address the long-term maintanenace of these results.

Download Full-text

Neurophysiological changes in the visuomotor network after practicing a motor task

Journal of Neurophysiology ◽

10.1152/jn.00020.2018 ◽

2018 ◽

Vol 120 (1) ◽

pp. 239-249 ◽

Cited By ~ 10

Author(s):

James E. Gehringer ◽

David J. Arpin ◽

Elizabeth Heinrichs-Graham ◽

Tony W. Wilson ◽

Max J. Kurz

Keyword(s):

Motor Learning ◽

Motor Planning ◽

Motor Task ◽

Force Production ◽

Oscillatory Activity ◽

Matching Task ◽

Force Output ◽

Motor Action ◽

Visuomotor Transformations ◽

Target Matching

Although it is well appreciated that practicing a motor task updates the associated internal model, it is still unknown how the cortical oscillations linked with the motor action change with practice. The present study investigates the short-term changes (e.g., fast motor learning) in the α- and β-event-related desynchronizations (ERD) associated with the production of a motor action. To this end, we used magnetoencephalography to identify changes in the α- and β-ERD in healthy adults after participants practiced a novel isometric ankle plantarflexion target-matching task. After practicing, the participants matched the targets faster and had improved accuracy, faster force production, and a reduced amount of variability in the force output when trying to match the target. Parallel with the behavioral results, the strength of the β-ERD across the motor-planning and execution stages was reduced after practice in the sensorimotor and occipital cortexes. No pre/postpractice changes were found in the α-ERD during motor planning or execution. Together, these outcomes suggest that fast motor learning is associated with a decrease in β-ERD power. The decreased strength likely reflects a more refined motor plan, a reduction in neural resources needed to perform the task, and/or an enhancement of the processes that are involved in the visuomotor transformations that occur before the onset of the motor action. These results may augment the development of neurologically based practice strategies and/or lead to new practice strategies that increase motor learning. NEW & NOTEWORTHY We aimed to determine the effects of practice on the movement-related cortical oscillatory activity. Following practice, we found that the performance of the ankle plantarflexion target-matching task improved and the power of the β-oscillations decreased in the sensorimotor and occipital cortexes. These novel findings capture the β-oscillatory activity changes in the sensorimotor and occipital cortexes that are coupled with behavioral changes to demonstrate the effects of motor learning.

Download Full-text

Dual contributions of cerebellar-thalamic networks to learning and offline consolidation of a complex motor task

10.1101/2020.08.27.270330 ◽

2020 ◽

Author(s):

Andres P Varani ◽

Romain W Sala ◽

Caroline Mailhes-Hamon ◽

Jimena L Frontera ◽

Clément Léna ◽

...

Keyword(s):

Motor Learning ◽

Motor Task ◽

Cerebellar Nuclei ◽

Specific Inhibition ◽

Thalamic Nuclei ◽

Related Information ◽

Midline Thalamus ◽

Ventral Thalamus ◽

Complex Motor ◽

Offline Processing

SUMMARYThe contribution of cerebellum to motor learning is often considered to be limited to adaptation, a short-timescale tuning of reflexes and previous learned skills. Yet, the cerebellum is reciprocally connected to two main players of motor learning, the motor cortex and the basal ganglia, via the ventral and midline thalamus respectively. Here, we evaluated the contribution of cerebellar neurons projecting to these thalamic nuclei in a skilled locomotion task in mice. In the cerebellar nuclei, we found task-specific neuronal activities during the task, and lasting changes after the task suggesting an offline processing of task-related information. Using pathway-specific inhibition, we found that dentate neurons projecting to the midline thalamus contribute to learning and retrieval, while interposed neurons projecting to the ventral thalamus contribute to the offline consolidation of savings. Our results thus show that two parallel cerebello-thalamic pathways perform distinct computations operating on distinct timescales in motor learning.

Download Full-text

Motor learning and transfer: from feedback to feedforward control

10.1101/845933 ◽

2019 ◽

Author(s):

Rodrigo S. Maeda ◽

Paul L. Gribble ◽

J. Andrew Pruszynski

Keyword(s):

Motor Learning ◽

Muscle Activity ◽

Shoulder Joint ◽

Stretch Reflex ◽

Feedforward Control ◽

Motor Task ◽

Joint Torques ◽

Motor Commands ◽

Shoulder Muscle ◽

Long Latency

AbstractPrevious work has demonstrated that when learning a new motor task, the nervous system modifies feedforward (ie. voluntary) motor commands and that such learning transfers to fast feedback (ie. reflex) responses evoked by mechanical perturbations. Here we show the inverse, that learning new feedback responses transfers to feedforward motor commands. Sixty human participants (34 females) used a robotic exoskeleton and either 1) received short duration mechanical perturbations (20 ms) that created pure elbow rotation or 2) generated self-initiated pure elbow rotations. They did so with the shoulder joint free to rotate (normal arm dynamics) or locked (altered arm dynamics) by the robotic manipulandum. With the shoulder unlocked, the perturbation evoked clear shoulder muscle activity in the long-latency stretch reflex epoch (50-100ms post-perturbation), as required for countering the imposed joint torques, but little muscle activity thereafter in the so-called voluntary response. After locking the shoulder joint, which alters the required joint torques to counter pure elbow rotation, we found a reliable reduction in the long-latency stretch reflex over many trials. This reduction transferred to feedforward control as we observed 1) a reduction in shoulder muscle activity during self-initiated pure elbow rotation trials and 2) kinematic errors (ie. aftereffects) in the direction predicted when failing to compensate for normal arm dynamics, even though participants never practiced self-initiated movements with the shoulder locked. Taken together, our work shows that transfer between feedforward and feedback control is bidirectional, furthering the notion that these processes share common neural circuits that underlie motor learning and transfer.

Download Full-text

Learning the same motor task twice impairs its retention in a time- and dose-dependent manner

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2020.2556 ◽

2021 ◽

Vol 288 (1942) ◽

pp. 20202556

Author(s):

R. Hamel ◽

L. Dallaire-Jean ◽

É. De La Fontaine ◽

J. F. Lepage ◽

P. M. Bernier

Keyword(s):

Motor Learning ◽

Refractory Period ◽

Motor Task ◽

Dependent Manner ◽

Learning Session ◽

Concurrent Learning ◽

Performance Improvements ◽

Dependent Process ◽

Initial Learning ◽

Dose Dependent

Anterograde interference emerges when two differing tasks are learned in close temporal proximity, an effect repeatedly attributed to a competition between differing task memories. However, recent development alternatively suggests that initial learning may trigger a refractory period that occludes neuroplasticity and impairs subsequent learning, consequently mediating interference independently of memory competition. Accordingly, this study tested the hypothesis that interference can emerge when the same motor task is being learned twice, that is when competition between memories is prevented. In a first experiment, the inter-session interval (ISI) between two identical motor learning sessions was manipulated to be 2 min, 1 h or 24 h. Results revealed that retention of the second session was impaired as compared to the first one when the ISI was 2 min but not when it was 1 h or 24 h, indicating a time-dependent process. Results from a second experiment replicated those of the first one and revealed that adding a third motor learning session with a 2 min ISI further impaired retention, indicating a dose-dependent process. Results from a third experiment revealed that the retention impairments did not take place when a learning session was preceded by simple rehearsal of the motor task without concurrent learning, thus ruling out fatigue and confirming that retention is impaired specifically when preceded by a learning session. Altogether, the present results suggest that competing memories is not the sole mechanism mediating anterograde interference and introduce the possibility that a time- and dose-dependent refractory period—independent of fatigue—also contributes to its emergence. One possibility is that learning transiently perturbs the homeostasis of learning-related neuronal substrates. Introducing additional learning when homeostasis is still perturbed may not only impair performance improvements, but also memory formation.

Download Full-text

Effects of balance training on balance performance in youth: role of training difficulty

BMC Sports Science Medicine and Rehabilitation ◽

10.1186/s13102-020-00218-4 ◽

2020 ◽

Vol 12 (1) ◽

Author(s):

Simon Schedler ◽

Florian Tenelsen ◽

Laura Wich ◽

Thomas Muehlbauer

Keyword(s):

Task Difficulty ◽

Balance Training ◽

Gait Velocity ◽

Balance Performance ◽

Timed Up And Go ◽

Balance Test ◽

Cross Sectional ◽

Time Dynamic ◽

Balance Task ◽

Functional Reach Test

Abstract Background Cross-sectional studies have shown that balance performance can be challenged by the level of task difficulty (e.g., varying stance conditions, sensory manipulations). However, it remains unclear whether the application of different levels of task difficulty during balance training (BT) leads to altered adaptations in balance performance. Thus, we examined the effects of BT conducted under a high versus a low level of task difficulty on balance performance. Methods Forty male adolescents were randomly assigned to a BT program using a low (BT-low: n = 20; age: 12.4 ± 2.0 yrs) or a high (BT-high: n = 20; age: 12.5 ± 2.5 yrs) level of balance task difficulty. Both groups trained for 7 weeks (2 sessions/week, 30–35 min each). Pre- and post-training assessments included measures of static (one-legged stance [OLS] time), dynamic (10-m gait velocity), and proactive (Y-Balance Test [YBT] reach distance, Functional Reach Test [FRT]; Timed-Up-and-Go Test [TUG]) balance. Results Significant main effects of Test (i.e., pre- to post-test improvements) were observed for all but one balance measure (i.e., 10-m gait velocity). Additionally, a Test x Group interaction was detected for the FRT in favor of the BT-high group (Δ + 8%, p < 0.001, d = 0.35). Further, tendencies toward significant Test x Group interactions were found for the YBT anterior reach (in favor of BT-high: Δ + 9%, p < 0.001, d = 0.60) and for the OLS with eyes opened and on firm surface (in favor of BT-low: Δ + 31%, p = 0.003, d = 0.67). Conclusions Following 7 weeks of BT, enhancements in measures of static, dynamic, and proactive balance were observed in the BT-high and BT-low groups. However, BT-high appears to be more effective for increasing measures of proactive balance, whereas BT-low seems to be more effective for improving proxies of static balance. Trial registration Current Controlled Trials ISRCTN83638708 (Retrospectively registered 19th June, 2020).

Download Full-text

Effects of Multiple Sessions of Cathodal Priming and Anodal HD-tDCS on Visuo Motor Task Plateau Learning and Retention

Brain Sciences ◽

10.3390/brainsci10110875 ◽

2020 ◽

Vol 10 (11) ◽

pp. 875 ◽

Cited By ~ 1

Author(s):

Pierre Besson ◽

Makii Muthalib ◽

Christophe De Vassoigne ◽

Jonh Rothwell ◽

Stephane Perrey

Keyword(s):

Motor Learning ◽

Motor Task ◽

Controlled Study ◽

Anodal Tdcs ◽

Retention Performance ◽

Baseline Training ◽

Double Blind ◽

Trade Off ◽

The Impact ◽

Speed Accuracy

A single session of priming cathodal transcranial direct current stimulation (tDCS) prior to anodal tDCS (c-a-tDCS) allows cumulative effects on motor learning and retention. However, the impact of multiple sessions of c-a-tDCS priming on learning and retention remains unclear. Here, we tested whether multiple sessions of c-a-tDCS (over 3 consecutive days) applied over the left sensorimotor cortex can further enhance motor learning and retention of an already learned visuo-motor task as compared to anodal tDCS (a-tDCS) or sham. In a between group and randomized double-blind sham-controlled study design, 25 participants separated in 3 independent groups underwent 2 days of baseline training without tDCS followed by 3-days of training with both online and offline tDCS, and two retention tests (1 and 14 days later). Each training block consisted of five trials of a 60 s circular-tracing task intersected by 60 s rest, and performance was assessed in terms of speed–accuracy trade-off represented notably by an index of performance (IP). The main findings of this exploratory study were that multiple sessions of c-a-tDCS significantly further enhanced IP above baseline training levels over the 3 training days that were maintained over the 2 retention days, but these learning and retention performance changes were not significantly different from the sham group. Subtle differences in the changes in speed–accuracy trade-off (components of IP) between c-a-tDCS (maintenance of accuracy over increasing speed) and a-tDCS (increasing speed over maintenance of accuracy) provide preliminary insights to a mechanistic modulation of motor performance with priming and polarity of tDCS.

Download Full-text

Acupuncture Enhances Effective Connectivity between Cerebellum and Primary Sensorimotor Cortex in Patients with Stable Recovery Stroke

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2014/603909 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 7

Author(s):

Zijing Xie ◽

Fangyuan Cui ◽

Yihuai Zou ◽

Lijun Bai

Keyword(s):

Motor Learning ◽

Sensorimotor Cortex ◽

Effective Connectivity ◽

Motor Task ◽

Stroke Patients ◽

Movement Coordination ◽

Subacute Stroke ◽

Primary Sensorimotor Cortex ◽

Recovery Stroke ◽

Hemiparetic Stroke

Recent neuroimaging studies have demonstrated that stimulation of acupuncture at motor-implicated acupoints modulates activities of brain areas relevant to the processing of motor functions. This study aims to investigate acupuncture-induced changes in effective connectivity among motor areas in hemiparetic stroke patients by using the multivariate Granger causal analysis. A total of 9 stable recovery stroke patients and 8 healthy controls were recruited and underwent three runs of fMRI scan: passive finger movements and resting state before and after manual acupuncture stimuli. Stroke patients showed significantly attenuated effective connectivity between cortical and subcortical areas during passive motor task, which indicates inefficient information transmissions between cortical and subcortical motor-related regions. Acupuncture at motor-implicated acupoints showed specific modulations of motor-related network in stroke patients relative to healthy control subjects. This specific modulation enhanced bidirectionally effective connectivity between the cerebellum and primary sensorimotor cortex in stroke patients, which may compensate for the attenuated effective connectivity between cortical and subcortical areas during passive motor task and, consequently, contribute to improvement of movement coordination and motor learning in subacute stroke patients. Our results suggested that further efficacy studies of acupuncture in motor recovery can focus on the improvement of movement coordination and motor learning during motor rehabilitation.

Download Full-text