scholarly journals Sensorized Assessment of Dynamic Locomotor Imagery in People with Stroke and Healthy Subjects

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4545
Author(s):  
Daniela De Bartolo ◽  
Valeria Belluscio ◽  
Giuseppe Vannozzi ◽  
Giovanni Morone ◽  
Gabriella Antonucci ◽  
...  
Keyword(s):  
Motor Imagery ◽  
Lower Limbs ◽  
Imagery Task ◽  
Experimental Conditions ◽  
Significant Information ◽  
Imagery Training ◽  
Mental Chronometry ◽  
Sinusoidal Waveform ◽  
Reaction Forces ◽  
Measurement Units

Dynamic motor imagery (dMI) is a motor imagery task associated with movements partially mimicking those mentally represented. As well as conventional motor imagery, dMI has been typically assessed by mental chronometry tasks. In this paper, an instrumented approach was proposed for quantifying the correspondence between upper and lower limb oscillatory movements performed on the spot during the dMI of walking vs. during actual walking. Magneto-inertial measurement units were used to measure limb swinging in three different groups: young adults, older adults and stroke patients. Participants were tested in four experimental conditions: (i) simple limb swinging; (ii) limb swinging while imagining to walk (dMI-task); (iii) mental chronometry task, without any movement (pure MI); (iv) actual level walking at comfortable speed. Limb swinging was characterized in terms of the angular velocity, frequency of oscillations and sinusoidal waveform. The dMI was effective at reproducing upper limb oscillations more similar to those occurring during walking for all the three groups, but some exceptions occurred for lower limbs. This finding could be related to the sensory feedback, stretch reflexes and ground reaction forces occurring for lower limbs and not for upper limbs during walking. In conclusion, the instrumented approach through wearable motion devices adds significant information to the current dMI approach, further supporting their applications in neurorehabilitation for monitoring imagery training protocols in patients with stroke.

scholarly journals Slowing of Motor Imagery after a Right Hemispheric Stroke

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Francine Malouin ◽  
Carol L. Richards ◽  
Anne Durand
Keyword(s):  
Working Memory ◽  
Motor Imagery ◽  
Memory Deficits ◽  
Mental Practice ◽  
Visuospatial Working Memory ◽  
Hemispheric Stroke ◽  
Imagery Training ◽  
Mental Chronometry ◽  
Temporal Congruence ◽  
Movement Representation

The temporal congruence between real and imagined movements is not always preserved after stroke. We investigated the dependence of temporal incongruence on the side of the hemispheric lesion and its link with working memory deficits. Thirty-seven persons with a chronic stroke after a right or left hemispheric lesion (RHL : n=19; LHL : n=18) and 32 age-matched healthy persons (CTL) were administered a motor imagery questionnaire, mental chronometry and working memory tests. In contrast to persons in the CTL group and LHL subgroup, persons with a RHL had longer movement times during the imagination than the physical execution of stepping movements on both sides, indicating a reduced ability to predict movement duration (temporal incongruence). While motor imagery vividness was good in both subgroups, the RHL group had greater visuospatial working memory deficits. The bilateral slowing of stepping movements in the RHL group indicates that temporal congruence during motor imagery is impaired after a right hemispheric stroke and is also associated with greater visuospatial working memory deficits. Findings emphasize the need to use mental chronometry to control for movement representation during motor imagery training and may indicate that mental practice through motor imagery will have limitations in patients with a right hemispheric stroke.

scholarly journals Scale-Dependent Signal Identification in Low-Dimensional Subspace: Motor Imagery Task Classification

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Qingshan She ◽  
Haitao Gan ◽  
Yuliang Ma ◽  
Zhizeng Luo ◽  
Tom Potter ◽  
...  
Keyword(s):  
Motor Imagery ◽  
Clustering Algorithm ◽  
Gaussian Mixture ◽  
Dimensional Subspace ◽  
Support Vector ◽  
Imagery Task ◽  
Common Spatial Pattern ◽  
Significant Information ◽  
Low Dimensional ◽  
Composite Data

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.

scholarly journals Optimal Combination of Anodal Transcranial Direct Current Stimulations and Motor Imagery Interventions

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Elodie Saruco ◽  
Franck Di Rienzo ◽  
Susana Nunez-Nagy ◽  
Miguel A. Rubio-Gonzalez ◽  
Ursula Debarnot ◽  
...  
Keyword(s):  
Postural Control ◽  
Motor Imagery ◽  
Direct Current ◽  
Primary Motor Cortex ◽  
Cortical Excitability ◽  
Homeostatic Plasticity ◽  
Experimental Conditions ◽  
Beneficial Effects ◽  
Imagery Training ◽  
Before And After

Motor imagery contributes to enhance the (re)learning of motor skills through remapping of cortical networks. Combining motor imagery with anodal transcranial direct-current stimulation (a-tDCS) over the primary motor cortex has further been shown to promote its beneficial effects on postural control. Whether motor imagery should be performed concomitantly to a-tDCS (over depolarized membrane) or consecutively (over changing neurotransmitters activity) remains to be elucidated. In the present study, we measured the performance in a postural control task before and after three experimental conditions. Participants received a-tDCS before (tDCSBefore), during (tDCSDuring), or both before and during motor imagery training (tDCSBefore + During). Performance was improved after tDCSDuring, but not after both the tDCSBefore and tDCSBefore + During conditions. These results support that homeostatic plasticity is likely to operate following a-tDCS through decreasing cortical excitability and that motor imagery should be performed during anodal stimulation for optimum gains.

Effectiveness of Motor Imagery Training for Children with Developmental Coordination Disorder Among Indian Children- A Pilot Study

2020 ◽  
Vol 11 (4) ◽  
pp. 6522-6525
Author(s):  
Ganapathy Sankar U ◽  
Monisha R
Keyword(s):  
Motor Imagery ◽  
Developmental Coordination Disorder ◽  
Treatment Protocol ◽  
Imagery Task ◽  
Indian Children ◽  
Cross Model ◽  
Imagery Training ◽  
Group A ◽  
Group B ◽  
Coordination Disorder

Children with developmental coordination disorder (DCD) experiences difficulty in performing coordinated movement task as there is a defect in the internal of movements. The of DCD has been examined in several studies which reveal several viable hypotheses including reduced processing speed, problems in executive functioning, poor cross-model integration and low perceptual-motor coupling. Researchers well documented that the predictive control of movements is impaired in children with Developmental Coordination Disorder (DCD), it was examined that impaired control of movements was due to a deficit in the internal of movements. Motor imagery training has been used to test this internal deficit. Motor imagery training is useful for children with DCD as it focuses on internal of movements. The current study aims to examine the effectiveness of Motor imagery training focused on mental imagery task to enhance the movement coordination abilities of children with DCD. By random sampling, 20 children with DCD were randomly divided into two groups, Group A received MI training, and Group B received COOP- Cognitive orientation to daily occupational performance. Both groups received intervention for nine sessions of 45 minutes. The results provided by the current study will help to describe treatment protocol for children with DCD with evidence. Both children and therapist will be benefited from the study.

Experience Influences Brain Mechanisms of Watching Dance

2011 ◽  
Vol 29 (supplement) ◽  
pp. 352-377 ◽  
Author(s):  
Seon Hee Jang ◽  
Frank E Pollick
Keyword(s):  
Motor Imagery ◽  
Visual Experience ◽  
Primary Motor Cortex ◽  
Action Observation ◽  
Brain Area ◽  
Retrosplenial Cortex ◽  
Imagery Task ◽  
Temporoparietal Junction ◽  
Action Observation Network ◽  
Viewing Experience

The study of dance has been helpful to advance our understanding of how human brain networks of action observation are influenced by experience. However previous studies have not examined the effect of extensive visual experience alone: for example, an art critic or dance fan who has a rich experience of watching dance but negligible experience performing dance. To explore the effect of pure visual experience we performed a single experiment using functional Magnetic Resonance Imaging (fMRI) to compare the neural processing of dance actions in 3 groups: a) 14 ballet dancers, b) 10 experienced viewers, c) 12 novices without any extensive dance or viewing experience. Each of the 36 participants viewed short 2-second displays of ballet derived from motion capture of a professional ballerina. These displays represented the ballerina as only points of light at the major joints. We wished to study the action observation network broadly and thus included two different types of display and two different tasks for participants to perform. The two different displays were: a) brief movies of a ballet action and b) frames from the ballet movies with the points of lights connected by lines to show a ballet posture. The two different tasks were: a) passively observe the display and b) imagine performing the action depicted in the display. The two levels of display and task were combined factorially to produce four experimental conditions (observe movie, observe posture, motor imagery of movie, motor imagery of posture). The set of stimuli used in the experiment are available for download after this paper. A random effects ANOVA was performed on brain activity and an effect of experience was obtained in seven different brain areas including: right Temporoparietal Junction (TPJ), left Retrosplenial Cortex (RSC), right Primary Somatosensory Cortex (S1), bilateral Primary Motor Cortex (M1), right Orbitofrontal Cortex (OFC), right Temporal Pole (TP). The patterns of activation were plotted in each of these areas (TPJ, RSC, S1, M1, OFC, TP) to investigate more closely how the effect of experience changed across these areas. For this analysis, novices were treated as baseline and the relative effect of experience examined in the dancer and experienced viewer groups. Interpretation of these results suggests that both visual and motor experience appear equivalent in producing more extensive early processing of dance actions in early stages of representation (TPJ and RSC) and we hypothesise that this could be due to the involvement of autobiographical memory processes. The pattern of results found for dancers in S1 and M1 suggest that their perception of dance actions are enhanced by embodied processes. For example, the S1 results are consistent with claims that this brain area shows mirror properties. The pattern of results found for the experienced viewers in OFC and TP suggests that their perception of dance actions are enhanced by cognitive processes. For example, involving aspects of social cognition and hedonic processing – the experienced viewers find the motor imagery task more pleasant and have richer connections of dance to social memory. While aspects of our interpretation are speculative the core results clearly show common and distinct aspects of how viewing experience and physical experience shape brain responses to watching dance.

Bilateral Changes in Ground Reaction Forces in Patients with Unilateral Anterior Cruciate Ligament Deficiency During Stair Locomotion

2011 ◽  
Vol 27 (3) ◽  
pp. 437-445 ◽  
Author(s):  
H.-C. Lin ◽  
H.-C. Hsu ◽  
T.-W. Lu
Keyword(s):  
Cruciate Ligament ◽  
Ground Level ◽  
Rehabilitation Program ◽  
Lower Limbs ◽  
Control Group ◽  
Ground Reaction Forces ◽  
Acl Deficiency ◽  
Stair Ascent ◽  
Reaction Forces ◽  
Stair Locomotion

ABSTRACTStair locomotion is an important but challenging functional activity for people with lower limb pathology. This study aimed to investigate the bilateral changes in force-bearing on lower limbs during stair locomotion in patients with unilateral ACL deficiency. The ground reaction forces (GRF) were collected from three force platforms: One at ground level in front of a 5-step stair and two on the first two steps respectively. Parameters in vertical and anterior-posterior GRF were extracted and compared between the ACL-deficient (ACLD) and control groups. The ACLD group showed significantly slower stepping cadences in both stair ascent and stepping down to the ground (p < 0.05). The vertical GRF in the ACLD group demonstrated smaller peak forces but larger minimum forces between the two peaks than those in the control group during both stair ascent and descent. Significantly reduced anterior propulsive forces and push-off rates in the late stance were also found in both limbs of the ACLD group (p < 0.05). The slower cadences and reduced force-bearing on the affected limb suggested a protective strategy was adopted. However, the anterior loading parameters in the early stance on the unaffected limb demonstrated different adaptations with significantly larger magnitudes during stair ascent but reduced magnitudes during stair descent (p < 0.05). Similar results were also found in the weight- transferring strategies between legs in consecutive steps with a significantly larger percentage of lift-up forces but a smaller percentage of impact forces on the leading unaffected limb. The results of this study indicated a cautious force-bearing strategy and bilateral adaptation were apparent in the patients with unilateral ACL deficiency. This information may provide a safety guideline for the patients and be helpful for a better use of the stair tasks as part of a rehabilitation program.

Consolidation and retention of motor skill after motor imagery training

2020 ◽  
Vol 143 ◽  
pp. 107472 ◽  
Author(s):  
Gaia Bonassi ◽  
Giovanna Lagravinese ◽  
Ambra Bisio ◽  
Piero Ruggeri ◽  
Elisa Pelosin ◽  
...  
Keyword(s):  
Motor Imagery ◽  
Motor Skill ◽  
Imagery Training
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