Freely Moving Visuomotor Learning Assay with Reversal Learning v1

The goal of this protocol is to assess visuomotor learning and motor flexibility in freely-moving mice, using the Visiomode touchscreen platform. Water-restricted mice first learn to associate touching a visual stimulus on the screen with a water reward. They then learn to discriminate between different visual stimuli on the touchscreen by nose-poking, before asked to switch their motor strategy to forelimb reaching.

Freely Moving Visual Discrimination Assay with Visiomode v2

The goal of this protocol is to assess visuomotor learning and motor flexibility in freely-moving mice, using the Visiomode touchscreen platform. Water-restricted mice first learn to associate touching a visual stimulus on the screen with a water reward. They then learn to discriminate between different visual stimuli on the touchscreen by nose-poking, before asked to switch their motor strategy to forelimb reaching. Version 1 of the protocol uses traditional water deprivation and water rewards in the task as a means of motivating mice to perform the task. Version 2 of the protocol uses Citric Acid for water restriction and sucrose as rewards in the task instead of the traditional water deprivation protocol.

Motor Learning in Response to Different Experimental Pain Models among Healthy Individuals: A Systematic Review

Learning new movement patterns is a normal part of daily life, but of critical importance in both sport and rehabilitation. A major question is how different sensory signals are integrated together to give rise to motor adaptation and learning. More specifically, there is growing evidence that pain can give rise to alterations in the learning process. Despite a number of studies investigating the role of pain on the learning process, there is still no systematic review to summarize and critically assess investigations regarding this topic in the literature. Here in this systematic review, we summarize and critically evaluate studies that examined the influence of experimental pain on motor learning. Seventeen studies that exclusively assessed the effect of experimental pain models on motor learning among healthy individuals were included for this systematic review, carried out based on the PRISMA statement. The results of the review revealed there is no consensus regarding the effect of pain on the skill learning acquisition and retention. However, several studies demonstrated that participants who experienced pain continued to express a changed motor strategy to perform a motor task even one week after training under the pain condition. The results highlight a need for further studies in this area of research, and specifically to investigate whether pain has different effects on motor learning depending on the type of motor task.

Ecological design of augmentation improves helicopter ship landing maneuvers: An approach in augmented virtuality

Helicopter landing on a ship is a visually regulated "rendezvous" task during which pilots must use fine control to land a powerful rotorcraft on the deck of a moving ship tossed by the sea while minimizing the energy at impact. Although augmented reality assistance can be hypothesized to improve pilots’ performance and the safety of landing maneuvers by guiding action toward optimal behavior in complex and stressful situations, the question of the optimal information to be displayed to feed the pilots’ natural information-movement coupling remains to be investigated. Novice participants were instructed to land a simplified helicopter on a ship in a virtual reality simulator while minimizing energy at impact and landing duration. The wave amplitude and related ship heave were manipulated. We compared the benefits of two types of visual augmentation whose design was based on either solving cockpit-induced visual occlusion problems or strengthening the online regulation of the deceleration by keeping the current τ˙ variable around an ideal value of -0.5 to conduct smooth and efficient landing. Our results showed that the second augmentation, ecologically grounded, offers benefits at several levels of analysis. It decreases the landing duration, improves the control of the helicopter displacement, and sharpens the sensitivity to changes in τ˙. This underlines the importance for designers of augmented reality systems to collaborate with psychologists to identify the relevant perceptual-motor strategy that must be encouraged before designing an augmentation that will enhance it.

Cortical correlates in upright dynamic and static balance in the elderly

Falls are the second most frequent cause of injury in the elderly. Physiological processes associated with aging affect the elderly’s ability to respond to unexpected balance perturbations, leading to increased fall risk. Every year, approximately 30% of adults, 65 years and older, experiences at least one fall. Investigating the neurophysiological mechanisms underlying the control of static and dynamic balance in the elderly is an emerging research area. The study aimed to identify cortical and muscular correlates during static and dynamic balance tests in a cohort of young and old healthy adults. We recorded cortical and muscular activity in nine elderly and eight younger healthy participants during an upright stance task in static and dynamic (core board) conditions. To simulate real-life dual-task postural control conditions, the second set of experiments incorporated an oddball visual task. We observed higher electroencephalographic (EEG) delta rhythm over the anterior cortex in the elderly and more diffused fast rhythms (i.e., alpha, beta, gamma) in younger participants during the static balance tests. When adding a visual oddball, the elderly displayed an increase in theta activation over the sensorimotor and occipital cortices. During the dynamic balance tests, the elderly showed the recruitment of sensorimotor areas and increased muscle activity level, suggesting a preferential motor strategy for postural control. This strategy was even more prominent during the oddball task. Younger participants showed reduced cortical and muscular activity compared to the elderly, with the noteworthy difference of a preferential activation of occipital areas that increased during the oddball task. These results support the hypothesis that different strategies are used by the elderly compared to younger adults during postural tasks, particularly when postural and cognitive tasks are combined. The knowledge gained in this study could inform the development of age-specific rehabilitative and assistive interventions.

Sensor Network for Analyzing Upper Body Strategies in Parkinson’s Disease versus Normative Kinematic Patterns

In rehabilitation, the upper limb function is generally assessed using clinical scales and functional motor tests. Although the Box and Block Test (BBT) is commonly used for its simplicity and ease of execution, it does not provide a quantitative measure of movement quality. This study proposes the integration of an ecological Inertial Measurement Units (IMUs) system for analysis of the upper body kinematics during the execution of a targeted version of BBT, by able-bodied persons with subjects with Parkinson’s disease (PD). Joint angle parameters (mean angle and range of execution) and hand trajectory kinematic indices (mean velocity, mean acceleration, and dimensionless jerk) were calculated from the data acquired by a network of seven IMUs. The sensors were applied on the trunk, head, and upper limb in order to characterize the motor strategy used during the execution of BBT. Statistics revealed significant differences (p < 0.05) between the two groups, showing compensatory strategies in subjects with PD. The proposed IMU-based targeted BBT protocol allows to assess the upper limb function during manual dexterity tasks and could be used in the future for assessing the efficacy of rehabilitative treatments.

Freely Moving Visual Discrimination Assay with Visiomode v2

The goal of this protocol is to assess visuomotor learning and motor flexibility in freely-moving mice, using the Visiomode touchscreen platform. Water-restricted mice first learn to associate touching a visual stimulus on the screen with a water reward. They then learn to discriminate between different visual stimuli on the touchscreen by nose-poking, before asked to switch their motor strategy to forelimb reaching.

Pursuing Artful Movement Science in Music Performance: Single Subject Motor Analysis With Two Elite Pianists

Piano performance motor learning research requires more “artful” methodologies if it is to meaningfully address music performance as a corporeal art. To date, research has been sparse and it has typically constrained multiple performance variables in order to isolate specific phenomena. This approach has denied the fundamental ethos of music performance which, for elite performers, is an act of interpretation, not mere reproduction. Piano performances are intentionally manipulated for artistic expression. We documented motor movements in the complex task of performance of the first six measures of Chopin’s “Revolutionary” Etude by two anthropometrically different elite pianists. We then discussed their motor strategy selections as influenced by anthropometry and the composer’s musical directives. To quantify the joint angles of the trunk, shoulders, elbows, and wrists, we used a VICON 3 D motion capture system and biomechanical modeling. A Kistler force plate (1 N, Swiss) quantified center of gravity (COG) shifts. Changes in COG and trunk angles had considerable influence on the distal segments of the upper limbs. The shorter pianist used an anticipatory strategy, employing larger shifts in COG and trunk angles to produce dynamic stability as compensation for a smaller stature. Both pianists took advantage of low inertial left shoulder internal rotation and adduction to accommodate large leaps in the music. For the right arm, motor strategizing was confounded by rests in the music. These two cases illustrated, in principle, that expert pianists’ individualized motor behaviors can be explained as compensatory efforts to accommodate both musical goals and anthropometric constraints. Motor learning among piano students can benefit from systematic attention to motor strategies that consider both of these factors.

Motor strategy during postural control is not muscle fatigue joint-dependent, but muscle fatigue increases postural asymmetry

The aim of this study was to investigate the effects of ankle and hip muscle fatigue on motor adjustments (experiment 1) and symmetry (experiment 2) of postural control during a quiet standing task. Twenty-three young adults performed a bipedal postural task on separate force platforms, before and after a bilateral ankle and hip muscle fatigue protocol (randomized). Ankle and hip muscles were fatigued separately using a standing calf raise protocol (ankle fatigue) on a step and flexion and extension of the hip (hip fatigue) sitting on a chair, at a controlled movement frequency (0.5Hz), respectively. In both experiments, force, center of pressure, and electromyography parameters were measured. The symmetry index was used in experiment 2 to analyze the postural asymmetry in the parameters. Our main findings showed that muscle fatigue impaired postural stability, regardless of the fatigued muscle region (i.e., ankle or hip). In addition, young adults used an ankle motor strategy (experiment 1) before and after both the ankle and hip muscle fatigue protocols. Moreover, we found increased asymmetry between the lower limbs (experiment 2) during the quiet standing task after muscle fatigue. Thus, we can conclude that the postural motor strategy is not muscle fatigue joint-dependent and a fatigue task increases postural asymmetry, regardless of the fatigued region (hip or ankle). These findings could be applied in sports training and rehabilitation programs with the objective of reducing the fatigue effects on asymmetry and improving balance.