Best practice for motor imagery: a systematic literature review on motor imagery training elements in five different disciplines

Implicit and explicit motor imagery ability after SCI: Moving the elbow makes the difference

Cervical spinal cord injury (SCI) causes dramatic sensorimotor deficits that restrict both activity and participation. Restoring activity and participation requires extensive upper limb rehabilitation focusing elbow and wrist movements, which can include motor imagery. Yet, it remains unclear whether MI ability is impaired or spared after SCI. We investigated implicit and explicit MI ability in individuals with C6 or C7 SCI (SCIC6 and SCIC7 groups), as well as in age- and gender-matched controls without SCI. Inspired by previous studies, implicit MI evaluations involved hand laterality judgments, hand orientation judgments (HOJT) and hand-object interaction judgments. Explicit MI evaluations involved mental chronometry assessments of physically possible or impossible movements due to the paralysis of upper limb muscles in both groups of participants with SCI. HOJT was the paradigm in which implicit MI ability profiles differed the most between groups, particularly in the SCIC6 group who had impaired elbow movements in the horizontal plane. MI ability profiles were similar between groups for explicit MI evaluations, but reflected task familiarity with higher durations in the case of unfamiliar movements in controls or attempt to perform movements which were no longer possible in persons with SCI. Present results, obtained from a homogeneous population of individuals with SCI, suggest that people with long-term SCI rely on embodied cognitive motor strategies, similar to controls. Differences found in behavioral response pattern during implicit MI mirrored the actual motor deficit, particularly during tasks that involved internal representations of affected body parts.

Actual and imagined music-cued gait training for people with multiple sclerosis: a multicentre qualitative study

OBJECTIVES

To explore the experiences and acceptability of music-cued motor imagery (MCMI), music-cued gait training (MCGT), and combined MCMI and MCGT (MCMI-MCGT) in people with multiple sclerosis (pwMS). We also aimed to explore participants' self-rated health status postintervention and gather recommendations for further programme development.

DESIGN

Qualitative study alongside the double-blind randomised controlled real and imagined gait training with music-cueing (RIGMUC) multicentre trial of MCMI, MCGT and MCMI-MCGT.

SETTING

PwMS recruited for the RIGMUC trial from Departments of Neurology at Medical Universities of Innsbruck and Graz and Clinic for Rehabilitation Muenster, Austria.

PARTICIPANTS

All 132 pwMS with mild to moderate disability randomised into the trial were included in the analysis.

METHODS

Participants practised home-based MCMI, MCGT or MCMI-MCGT for 30 min, 4×/week, for 4 weeks. Three trained researchers conducted weekly semistructured telephone interviews during the intervention period, supporting adherence, addressing problems, sharing experiences and assessing intervention acceptability. Follow-up interviews at 4-week postintervention aimed to understand participants' self-rated changes in walking, fatigue and overall health compared with their prestudy condition. Investigator triangulation was employed among the researchers to enhance trustworthiness and credibility.

RESULTS

Using thematic analysis, we identified five themes: (1) empowerment, (2) remaining in sync, (3) interconnection between imagined and actual walking, (4) sustaining focus and (5) real-world transfer. Participants appreciated and found the imagined and actual MCGT innovative. Problems included concentration issues, early fatigue in advanced disability and difficulty synchronising with music cues. Positive changes in walking, fatigue and overall health postinterventions were reported offering valuable insights for programme development.

CONCLUSIONS

A participatory study to codevelop a music-cued exercise programme for pwMS seems appropriate as participants appreciated the innovation and effectiveness of both imagined and actual MCGT. Future studies should also investigate pwMS' potential and limitations in enhancing their MCMI abilities with intensive therapist-supported practice.

TRIAL REGISTRATION NUMBER

DRKS00023978.

Assessment of the Educational and Training Modalities in Point-of-Care Ultrasound (POCUS) for Anesthesiologists

Point-of-care ultrasound (POCUS) has been developed as a critical tool for diagnostic patient evaluation and clinical management. Its transcendence into anesthesiology necessitates appropriate and effective educational strategies to assist in the development of anesthesia POCUS learners. Several professional societies, including the American Society of Anesthesiologists (ASA), American Society of Regional Anesthesia (ASRA), and Accreditation Council for Graduate Medical Education (ACGME) for anesthesiology have established minimum training standards for POCUS education for anesthesiologists, residents, and fellows.1,4 The article at hand aims to summarize and provide insight into the various educational modalities utilized in POCUS training, incorporate these strategies in the established "Indication, Acquisition, Interpretation, and Medical decision-making" (I-AIM) framework, and include recommendations on the minimum number of POCUS exams to aid in achieving competency. 3.

Motor imagery of finger movements: Effects on cortical and muscle activities

PURPOSE

The purpose of the current study was to explore the immediate effect of motor imagery (MI) involving finger movement of a given limb on cortical response and muscle activity in healthy subjects.

METHODS

Twenty healthy right-handed adults (7 females and 13 males) with a mean + SD age of 22.05 + 6.08 years participated in the study. The beta-band event-related desynchronization (ERD) at the sensorimotor cortex and muscle activity during finger movement tasks using either the index, middle, or thumb digits on the non-dominant left hand were compared before and after an MI training session. Subjects underwent a pre-MI, MI training, and finally a post-MI session where they either performed or imagined performing a button-pushing action 50 times per session with each of the three digits.

RESULTS

The ERD power in the beta frequency band was lower in pre-MI compared to post-MI and was significantly different between the pre- and post-MI sessions for both the index and middle fingers, but not the thumb. A significant decrease was seen in the mean muscle activity during post-MI compared to pre-MI for all the digits except the thumb.

CONCLUSIONS

The results from the current study suggest that complex MI can result in motor learning and improvement in motor performance, thereby requiring less effort during motion.

The Development and Evaluation of the Kinesthetic Motor Imagery of Pelvic Floor Muscle Contraction Questionnaire (KMI-PFQ) in Spanish Women

Practitioners have begun using motor imagery (MI) for preventing and treating some pelvic floor disorders. Due to requirements for imagining before performing a MI intervention and because there are few instruments available for assessing this specific ability in the pelvic floor musculature, we sought to develop and test a new MI questionnaire, the Kinesthetic Motor Imagery of Pelvic Floor Muscle Contraction Questionnaire (KMI-PFQ). We focused in this study on the development and analysis of the instrument's factorial structure and internal reliability in a participant sample of 162 healthy Spanish women (M age = 20.1, SD = 2.2 years). We developed and evaluated the KMI-PFQ's psychometric properties, finding it to have good internal consistency, with Cronbach's α = .838, ω coefficient = .839, and an intraclass correlation coefficient = .809, with two factors ("ability" and "mental effort") explaining 58.36% of response variance. The standard error of measurement was 3.58, and the minimal detectable change was 9.92. No floor or ceiling effects were identified. There was also good convergent validity as seen by statistically significant positive correlations between KMI-PFQ scores and the revised-Movement Image Questionnaire and Vividness of Visual Imagery Questionnaire. There were no statistically significant correlations between KMI-PFQ scores and the Orientation to Life Questionnaire. The KMI-PFQ is a valid and reliable instrument for measuring kinesthetic ability to feel/imagine pelvic floor muscle contractions in healthy Spanish women.

Changes in spinal motoneuron excitability during the improvement of fingertip dexterity by actual execution combined with motor imagery practice

Since there is an upper limit to skill improvement through the repetition of actual execution, we examined whether motor imagery could be used in combination with actual execution to maximize motor skill improvement. Fingertip dexterity was evaluated in 25 healthy participants performing a force adjustment task using a pinch movement with the left thumb and index finger. In the intervention condition, six sets of repetitions of combined actual execution and motor imagery were performed, while in the control condition, the same flow was performed, but with motor imagery replaced by rest. Changes in the excitability of spinal motoneurons during motor imagery compared to rest were compared in terms of the F/M amplitude ratio. Motor skill changes were compared before and after repeated practice and between the conditions, respectively, using the absolute amount of adjustment error between the target pinch force value and the delivered pinch force value (absolute error) as an index. The results showed that the repetition of exercise practice and motor imagery decreased the absolute error, which was greater than that of exercise practice alone in terms of motor skill improvement. The F/M amplitude ratio for motor imagery compared to rest did not increase. This suggests that motor imagery is involved in the degree of the increase of spinal motoneuron excitability based on the real-time prediction of motor execution and that there may be no need for an increase in excitability during motor skill control.

The Effect of Motor Imagery Practice on an Aiming Task with Attentional Focus Cues

When one directs their attention to an intended effect (external focus of attention, EFOA), motor performance is generally better than when one directs their attention to their own body movements (internal focus of attention, IFOA). However, the effect of attentional focus is unclear when a skill is practiced through motor imagery (MI) in the absence of physical trials. Participants (N = 30, M = 22.33 yrs, SD = 2.69) in the present study completed three physical trials of a reciprocal aiming task before and (24-h) after MI practice. During MI practice, the EFOA (n = 15) and IFOA (n = 15) groups mentally practiced the task with no physical practice with EFOA-MI or IFOA-MI, respectively, for three consecutive days. Our results showed that both groups significantly improved in accuracy (F1,28 = 6.49, p = .017), supporting the benefit of MI in motor skill acquisition. However, a significant effect of attentional focus was not observed (F1.,28 = 0.445, p = 0.51). We discussed two potential explanations: EFOA/IFOA requires physical trials to affect performance, or individuals must use both EFOA and IFOA in the process of creating imagery of the environment and movements, which may obscure the effect of EFOA and IFOA.

Influence of Motor Imagery Modality on First-Serve Performance in Tennis Players

Motor imagery (MI) is frequently used in tennis players. This pilot study aimed to assess whether the MI modality and preference of skilled tennis players could influence their service performance when using MI before serving first balls. Twenty expert players (Mage = 18.6 years) completed the movement imagery questionnaire (third version) to assess their MI modality scores (internal visual, external visual, and kinesthetic) and their MI preference. Participants completed 4 experimental counterbalanced sessions spread over 4 weeks, each including the completion of 20 first-serve balls in match condition. The sessions included a control condition (i.e., only physical practice trials) and three MI conditions during which the players had to mentally imagine themselves performing a serve according to one of the imagery modalities, either internal visual, external visual, or kinesthetic, before serving. The percentage of success, the speed of the service balls (measured by a tablet with SWING VISION and a radar gun), and an efficiency score were recorded and then evaluated by experts and served as performance indicators and dependent variables. The results of this study showed that players benefited from MI before serving and that almost a third of the participants achieved a higher percentage of success and efficiency scores when using their preferred MI modality. These results lead us, in an applied way, to suggest to skilled tennis players to determine their MI preference and to have recourse to the mental simulation of a successful serve before serving the first balls in match condition.

Anodal transcranial direct current stimulation does not enhance the effects of motor imagery training of a sequential finger-tapping task in young adults

When applied over the primary motor cortex (M1), anodal transcranial direct current stimulation (a-tDCS) could enhance the effects of a single motor imagery training (MIt) session on the learning of a sequential finger-tapping task (SFTT). This study aimed to investigate the effect of a-tDCS on the learning of an SFTT during multiple MIt sessions. Two groups of 16 healthy young adults participated in three consecutive MIt sessions over 3 days, followed by a retention test 1 week later. They received active or sham a-tDCS during a MIt session in which they mentally rehearsed an eight-item complex finger sequence with their left hand. Before and after each session, and during the retention test, they physically repeated the sequence as quickly and accurately as possible. Both groups (i) improved their performance during the first two sessions, showing online learning; (ii) stabilised the level they reached during all training sessions, reflecting offline consolidation; and (iii) maintained their performance level one week later, showing retention. However, no significant difference was found between the groups, regardless of the MSL stage. These results emphasise the importance of performing several MIt sessions to maximise performance gains, but they do not support the additional effects of a-tDCS.

Effectiveness of synchronous action observation and mental practice on upper extremity motor recovery after stroke

The purpose of this quasi-experimental pretest-posttest control group study was to examine the effect of group synchronous action observation/mental practice intervention compared to usual rehabilitation care on upper extremity motor recovery after stroke. The intervention group (n = 25) received usual care, consisting of a minimum of 3 hours of rehabilitation services per day, 5 days a week, plus group synchronous action observation/mental practice sessions 3 times per week and the control group (n = 26) received usual care. Outcome measures included the Kinesthetic and Visual Imagery Questionnaire Short Version (KVIQ-10), the Fugl-Meyer Assessment (FMA-UE) of affected upper extremity motor function only and The Box and Block Test (BBT). Although there were no statistically significant differences in upper extremity motor function between the two groups, a subgroup analysis of the intervention group identified statistically significant (FMA-UE: p < .001; BBT: p = .04) and Minimally Important Clinical Differences on upper extremity motor recovery between patients with behaviors demonstrating more versus less commitment to the intervention. Group synchronous action observation/mental practice is a promising intervention for patients demonstrating commitment to actively participating in the intervention to improve outcomes on upper extremity motor recovery after stroke.

Motor learning in golf-a systematic review

Golf is a sport that consists of complex movement skills that need to be executed with utmost precision. Consequently, motor skill learning plays a crucial role in golf, and large numbers of studies address various methods of motor learning. In the present review, we give a systematic overview of randomized controlled trials (RCTs) on motor learning of golf-specific motor skills. Three electronic databases were searched for RCTs looking at the effect of at least one learning method on performance in a golf-specific motor task. We grouped the studies depending on the learning strategies "cognitive training", "practice scheduling", "augmented feedback", "implicit and explicit learning" and "focus of attention". Fifty-two RCTs met the eligibility criteria and were included in the systematic review. Superior methods within their respective strategies were an external focus of attention and increasing contextual interference, as well as errorless learning. For "cognitive training" and "augmented feedback", no single method can be considered the most favorable. The overall biggest limitations were the lack of statistical power for more than half of the RCTs, and the fact that most studies of the present review investigated simple putting tasks in novices only. Although we have shown superiority of specific learning methods, transferability of the recommendations that can be derived from simple golf tasks in novices to sport-specific tasks in advanced players still has to be demonstrated and require study designs with the intention to provide practical recommendations for coaches and athletes in the sport of golf.

A commentary on Eaves et al. with a special focus on clinical neurorehabilitation

We very much appreciate the theoretical foundations and considerations of AO, MI, and their combination AO + MI by Eaves et al. In their exploratory review, the authors highlight the beneficial effects of the combined use of AO and MI, with a particular focus on synchronous AO and MI. From a neurorehabilitation perspective, different processes may apply to patients, particularly after a stroke. As suggested by Eaves et al., the cognitive load might prevent the use of synchronous AO + MI and the asynchronous application of AO and MI might be indicated. Furthermore, some aspects should be considered when applying AO + MI in rehabilitation: screening for the patients' cognitive capabilities and MI ability, and a familiarisation programme for AO and MI, before starting with an AO + MI training. With their review, Eaves et al. propose a number of research questions in the field of neurorehabilitation that urgently need to be addressed: the use of asynchronous vs. synchronous AOMI, observation and imagination with or without errors, or use of different MI perspectives and modes in different learning stages. This commentary provides some additional suggestions on patients' MI ability and cognitive level, MI familiarisation and detailed reporting recommendations to transfer Eaves et al. findings into clinical practice.

Different pedagogical approaches to motor imagery both demonstrate individualized movement patterns to achieve improved performance outcomes when learning a complex motor skill

Cognitive training techniques such as motor imagery (MI)-cognitive simulation of movement, has been found to successfully facilitate skill acquisition. The MI literature emphasizes the need to accurately imitate key elements of motor execution to facilitate improved performance outcomes. However, there is a scarcity of MI research investigating how contemporary approaches to motor learning, such as nonlinear pedagogy (NLP), can be integrated into MI practice. Grounded in an ecological dynamics approach to human movement, NLP proposes that skilled action is an emergent process that results from continuous interactions between perceptual information of the environment and movement. This emergent process can be facilitated by the manipulation of key task constraints that aim to encourage learners to explore movement solutions that satisfy individual constraints (e.g., height and weight) and achieve successful performance outcomes. The aim of the present study was to explore the application of a NLP approach to MI approach for skill acquisition. Fourteen weightlifting beginners (two female and 12 male) participated in a 4-week intervention involving either NLP (i.e. analogy-based instructions and manipulation of task constraints) or a linear pedagogy (LP; prescriptive instructions of optimal technique, repetition of same movement form) to learn a complex weightlifting derivative. Performance accuracy, movement criterion (barbell trajectory type), kinematic data, and quantity of exploration/exploitation were measured pre-mid-post intervention. No significant differences (p = .438) were observed in the amount of exploration between LP (EER = 0.41) and NLP (EER = 0.26) conditions. Equivalent changes in rearward displacement (R×D) were observed with no significant differences between conditions for technique assessments 1, 2, or 3 (p = .13 - .67). Both NLP and LP conditions were found to primarily demonstrate 'sub-optimal' type 3 barbell trajectories (NLP = 72%; LP = 54%). These results suggest that MI instructions prescribing a specific movement form (i.e., LP condition) are ineffective in restricting available movements to a prescribed technique but rather the inherent task constraints appear to 'force' learners to explore alternative movement solutions to achieve successful performance outcomes. Although MI instructions prescribing specific techniques have previously supported improved skill development, the current findings indicate that learners may self-organise their movements regardless of MI instructions to satisfy individual and task constraints while achieving improved performance. Therefore, it may be beneficial to consider scripts that are more outcome focused and incorporate task constraints to facilitate learners' inherent exploration of individual task solutions.

From tradition to innovation: a comparison of the traditional 4-step approach versus a blended learning modification for technical skills teaching

BACKGROUND

This experimental study was performed to evaluate the role of blended learning for technical skill teaching on the European Trauma Course (ETC). While online modules are extensively used for theoretical teaching, their role in skills training remains less well explored. The ETC currently relies on the established 4-step technique for teaching technical skills. However, the required large cohort of skilled instructors and the time intensity prove increasingly challenging in a current climate of staff shortages and funding constraints. This study assesses if blended learning, combining pre-course online elements with face-to-face training matches the effectiveness of the traditional 4-step approach whilst being more time-efficient.

METHODS

In a randomised, multi-centre trial, the conventional face-to-face 4-step technique for teaching a skill of medium complexity, the application of a pelvic binder, was compared with an innovative blended approach. It was hypothesised that the blended approach was non-inferior for skill performance measured after the teaching session and after two days (skill retention) with the time needed for teaching and student/teacher satisfaction as secondary outcomes.

RESULTS

Ninety participants, divided into 44 traditional and 46 blended method students, were analysed. Independent-samples t-test showed no significant difference in performance scores and non-inferiority of the blended approach with a half of one standard deviation margin. A statistically significant difference in mean retention scores favored the blended approach. A Mann-Whitney U Test revealed no significant difference in candidate satisfaction levels but a statistically significant difference in instructors' satisfaction levels in favour of the blended approach. Analysis with Welch' t-test demonstrated that the face-to-face teaching time needed for the blended approach was significantly shorter (by 6 min).

CONCLUSIONS

The integration of a blended approach with the 4-step technique for teaching pelvic binder application in the ETC streamlined teaching without compromising skill acquisition quality. This innovative approach addresses traditional limitations and shows promise in adapting medical education to modern learning and teaching demands. We suggest that blended learning could also be applied for other skills taught on life support courses.

TRIAL REGISTRATION

University of Dundee (Schools of Medicine and Life sciences Research Ethics Committee, REC number 22/59, 28th June 2022).

The effect of movement representation techniques on ankle function and performance in persons with or without a lateral ankle sprain: a systematic review and meta-analysis

BACKGROUND

Lateral ankle sprains are highly prevalent and result in tissue damage, impairments of muscle strength, instability, and muscle activation. Up to 74% will experience ongoing symptoms after a lateral ankle sprain. In healthy subjects, motor imagery might induce neural changes in the somatosensory and motor areas of the brain, yielding favourable enhancements in muscular force. However, during motor imagery, difficulties in building a motor image, no somatosensory feedback, and the absence of structural changes at the level of the muscle might explain the differences found between motor imagery and physical practice. In rehabilitation, motor imagery might be supportive in rebuilding motor networks or creating new networks to restore impairments in muscle activation and movement patterns. This systematic review was undertaken to summarize the current body of evidence about the effect on motor imagery, or action observation, on lower leg strength, muscle performance, ankle range of motion, balance, and edema in persons with, and without, a lateral ankle sprain compared to usual care, a placebo intervention, or no intervention.

METHODS

A systematic review with meta-analysis of randomized controlled trials was conducted in healthy participants and participants with a lateral ankle sprain. Motor imagery or action observation in isolation, or in combination with usual care were compared to a placebo intervention, or no intervention. An electronic search of MEDLINE, EMBASE, Cinahl, Psychinfo, Sportdiscus, Web of Science, Cochrane and Google Scholar was conducted, and articles published up to 7th June 2023 were included. Two reviewers individually screened titles and abstracts for relevancy using the inclusion criteria. Variables related to muscle strength, muscle function, range of motion, balance, return to sports tests, or questionnaires on self-reported function or activities were extracted. A risk of bias assessment was done using the Cochrane Risk-of-Bias tool II by two reviewers. Meta-analysis using a random effects model was performed when two or more studies reported the same outcome measures. The Standardized Mean Difference (SMD) was calculated over the change from baseline scores. Review manager 5.4 was used to perform analysis of subgroup differences and test for statistically significant differences. Confidence intervals were visually checked for overlap between subgroups.

RESULTS

Nine studies, six examining healthy participants and three examining participants with an acute lateral ankle sprain, were included. All studies were rated with moderate to high risk of bias overall. Quality of the motor imagery interventions differed largely between studies. Meta-analysis showed a large and significant effect of motor imagery on lower leg strength (SMD 1.47, 95% CI 0.44 to 2.50); however, the evidence was downgraded to very low certainty due to substantial heterogeneity (I2 = 73%), limitations in the studies (some concerns in risk of bias in all studies), and imprecision (n =  < 300). Evidence showed no association with ankle range of motion (SMD 0.25, 95% CI -0.43 to 0.93), edema (SMD -1.11, 95% CI -1.60 to 3.81), the anterior reach direction of the Star Excursion Balance Test (SEBT) (SMD 0.73, 95% CI -0.62 to 2.08), the posterolateral direction (SMD 0.32, 95% CI -0.94 to 1.57), and the posteromedial direction (SMD 0.52, 95% CI -0.07 to 1.10). The certainty of evidence for the different comparisons was very low.

CONCLUSIONS

There is a low certainty, significant, positive effect for motor imagery being able to improve lower leg muscle strength in healthy participants. The effect on balance, range of motion and edema was uncertain and of very low certainty.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021243258.

Motor learning without physical practice: The effects of combined action observation and motor imagery practice on cup-stacking speed

In this study we explored training effects for combined action observation and motor imagery (AO + MI) instructions on a complex cup-stacking task, without physical practice. Using a Graeco-Latin Square design, we randomly assigned twenty-six participants into four groups. This counterbalanced the within-participant factor of practice condition (AO + MI, AO, MI, Control) across four cup-stacking tasks, which varied in their complexity. On each of the three consecutive practice days participants experienced twenty trials under each of the three mental practice conditions. On each trial, a first-person perspective video depicted bilateral cup-stacking performed by an experienced model. During AO, participants passively observed this action, responding only to occasional colour cues. For AO + MI, participants imagined performing the observed action and synchronised their concurrent MI with the display. For MI, a sequence of pictures cued imagery of each stage of the task. Analyses revealed a significant main effect of practice condition both at the 'surprise' post-test (Day 3) and at the one-week retention test. At both time points movement execution times were significantly shorter for AO + MI compared with AO, MI and the Control. Execution times were also shorter overall at the retention compared with the post-test. These results demonstrate that a complex novel motor task can be acquired without physical training. Practitioners can therefore use AO + MI practice to supplement physical practice and optimise skill learning.

Inter-task transfer of force gains is facilitated by motor imagery

Introduction

There is compelling evidence that motor imagery (MI) contributes to improve muscle strength. While strong effects have been observed for finger muscles, only few experiments with moderate benefits were conducted within applied settings targeting large upper or lower limb muscles. The aim of the present study was therefore to extend the investigation of embedded MI practice designed to improve maximal voluntary strength on a multi-joint dynamic exercise involving the lower limbs. Additionally, we tested whether targeting the content of MI on another movement than that physically performed and involving the same body parts might promote inter-task transfer of strength gains.

Methods

A total of 75 participants were randomly assigned into three groups who underwent a physical training on back squat. During inter-trial recovery periods, a first MI group (n = 25) mentally rehearsed the back squat, while a second MI group (n = 25) performed MI of a different movement involving the lower limbs (deadlift). Participants from the control group (n = 25) completed a neutral cognitive task during equivalent time. Strength and power gains were assessed ecologically using a velocity transducer device at 4 different time periods.

Results

Data first revealed that participants who engaged in MI of the back squat improved their back squat performance (p < 0.03 and p < 0.01, respectively), more than the control group (p < 0.05), hence supporting the positive effects of MI on strength. Data further supported the inter-task transfer of strength gains when MI targeted a movement that was not physically trained (p = 0.05).

Discussion

These findings provide experimental support for the use of MI during physical training sessions to improve and transfer force development.

A Quantitative Investigation of Mental Fatigue Elicited during Motor Imagery Practice: Selective Effects on Maximal Force Performance and Imagery Ability

In the present study, we examined the development of mental fatigue during the kinesthetic motor imagery (MI) of isometric force contractions performed with the dominant upper limb. Participants (n = 24) underwent four blocks of 20 MI trials of isometric contractions at 20% of the maximal voluntary contraction threshold (20% MVC_MI) and 20 MI trials of maximal isometric contractions (100% MVC_MI). Mental fatigue was assessed after each block using a visual analogue scale (VAS). We assessed maximal isometric force before, during and after MI sessions. We also assessed MI ability from self-report ratings and skin conductance recordings. Results showed a logarithmic pattern of increase in mental fatigue over the course of MI, which was superior during 100% MVC_MI. Unexpectedly, maximal force improved during 100% MVC_MI between the 1st and 2nd evaluations but remained unchanged during 20% MVC_MI. MI ease and vividness improved during 100% MVC_MI, with a positive association between phasic skin conductance and VAS mental fatigue scores. Conversely, subjective measures revealed decreased MI ability during 20% MVC_MI. Mental fatigue did not hamper the priming effects of MI on maximal force performance, nor MI's ability for tasks involving high physical demands. By contrast, mental fatigue impaired MI vividness and elicited boredom effects in the case of motor tasks with low physical demands.

Cross-subject aesthetic preference recognition of Chinese dance posture using EEG

Due to the differences in knowledge, experience, background, and social influence, people have subjective characteristics in the process of dance aesthetic cognition. To explore the neural mechanism of the human brain in the process of dance aesthetic preference, and to find a more objective determining criterion for dance aesthetic preference, this paper constructs a cross-subject aesthetic preference recognition model of Chinese dance posture. Specifically, Dai nationality dance (a classic Chinese folk dance) was used to design dance posture materials, and an experimental paradigm for aesthetic preference of Chinese dance posture was built. Then, 91 subjects were recruited for the experiment, and their EEG signals were collected. Finally, the transfer learning method and convolutional neural networks were used to identify the aesthetic preference of the EEG signals. Experimental results have shown the feasibility of the proposed model, and the objective aesthetic measurement in dance appreciation has been implemented. Based on the classification model, the accuracy of aesthetic preference recognition is 79.74%. Moreover, the recognition accuracies of different brain regions, different hemispheres, and different model parameters were also verified by the ablation study. Additionally, the experimental results reflected the following two facts: (1) in the visual aesthetic processing of Chinese dance posture, the occipital and frontal lobes are more activated and participate in dance aesthetic preference; (2) the right brain is more involved in the visual aesthetic processing of Chinese dance posture, which is consistent with the common knowledge that the right brain is responsible for processing artistic activities.

Mental training in dentistry: A scoping review

INTRODUCTION

Clinical motor skills are essential to train dental students. There is evidence that imagery serves to acquire and improve motor skills, but there is scarce information on its application in dental education. In order to broadly map the available evidence and to detect knowledge gaps in the mental training used to develop motor skills in dentistry, a scoping review was conducted.

MATERIALS AND METHODS

A structured search was conducted to identify relevant references from the Web of Science, Scopus and MEDLINE/PubMed databases for studies addressing mental training methods applied to develop motor skills in dentistry.

RESULTS

A total of 758 articles were screened and four were selected, all of which were randomized clinical trials. Three studies investigated the effectiveness of visual imagery, and one investigated kinesthetic imagery. The research theme identified was motor skill acquisition.

CONCLUSION

The reviewed studies indicate the usefulness of mental training for skill acquisition in dentistry. To improve the generalizability of the results, further research with standardized mental training on motor skills in dentistry is needed.

Enhancing upper-limb neurorehabilitation in chronic stroke survivors using combined action observation and motor imagery therapy

Introduction

For people who have had a stroke, recovering upper-limb function is a barrier to independence. When movement is difficult, mental practice can be used to complement physical therapy. In this within-participants study we investigated the effects of combined action observation and motor imagery (AO + MI) therapy on upper-limb recovery in chronic stroke survivors.

Methods

A Graeco-Latin Square design was used to counterbalance four mental practice conditions (AO + MI, AO, MI, Control) across four cup-stacking tasks of increasing complexity. Once a week, for five consecutive weeks, participants (n = 10) performed 16 mental practice trials under each condition. Each trial displayed a 1st person perspective of a cup-stacking task performed by an experienced model. For AO, participants watched each video and responded to an occasional color cue. For MI, participants imagined the effort and sensation of performing the action; cued by a series of still-images. For combined AO + MI, participants observed a video of the action while they simultaneously imagined performing the same action in real-time. At three time points (baseline; post-test; two-week retention test) participants physically executed the three mentally practiced cup-stacking tasks, plus a fourth unpractised sequence (Control), as quickly and accurately as possible.

Results

Mean movement execution times were significantly reduced overall in the post-test and the retention test compared to baseline. At retention, movement execution times were significantly shorter for combined AO + MI compared to both MI and the Control. Individual participants reported clinically important changes in quality of life (Stroke Impact Scale) and positive qualitative experiences of AO + MI (social validation).

Discussion

These results indicate that when physical practice is unsuitable, combined AO + MI therapy could offer an effective adjunct for neurorehabilitation in chronic stroke survivors.

Factors and strategies affecting motor imagery ability in people with multiple sclerosis: a systematic review

BACKGROUND

Although growing evidence has shown beneficial effects of motor imagery (MI) training in different populations including people with multiple sclerosis (pwMS), not all patients with neurological diseases may benefit from MI.

OBJECTIVES

To investigate factors and strategies affecting and enhancing MI ability in pwMS.

DATA SOURCES

MEDLINE/PubMed, PsycINFO, Cochrane Library, Scopus, EMBASE, EBSCOhost, Web of Science and REHABDATA databases, clinical trials registries, dissertation repositories, study bibliographies and internet search engines were searched through August 2021.

STUDY SELECTION

Any study type but single case studies investigating factors or strategies contributing to MI ability in pwMS.

STUDY APPRAISAL AND SYNTHESIS METHODS

Risk of bias (RoB) was assessed using the Joanna Briggs Institute Checklist for Case-Control and Analytical Cross-Sectional Studies and Cochrane RoB-2.0 tool for randomised trials. A qualitative synthesis was performed summarising main results.

RESULTS

Eight databases, 4 trial registries, 9 dissertation repositories, and 1 internet search engine were searched. Fourteen studies including 366 pwMS and 236 healthy controls were included. Most frequently, cognitive impairment was reported as a negative factor influencing MI ability in pwMS. Other negative factors were cognitive fatigue and disability. Inconsistent evidence was found on the contribution of MS phenotype, anxiety, and depression. Using a theory-based MI framework and familiarisation to MI and external cueing may enhance MI ability.

LIMITATIONS

Eligible studies were highly heterogeneous.

CONCLUSION AND IMPLICATIONS OF KEY FINDINGS

Cognitive impairment, cognitive fatigue and disability negatively influence MI ability in pwMS. Visual and/or auditory cueing of MI are strategies for facilitating MI ability.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42020173081 CONTRIBUTION OF THE PAPER.

Motor imagery as an intervention to improve activities of daily living post-stroke: A systematic review of randomized controlled trials

Introduction:

Motor imagery (MI) may be an effective tool for improving activities of daily living (ADL) post-stroke. However, no review to date has examined ADL independence when investigating training effectiveness. This review aimed to evaluate the quality of evidence and the effectiveness of MI training for improving ADL independence post-stroke.

Method:

Randomized controlled trial (RCT) studies comparing MI to conventional therapies were reviewed. Methodological quality was assessed using the Physiotherapy Evidence Database (PEDro) scale.

Results:

Thirteen articles met inclusion criteria. The overall quality was considered moderate to good, with a PEDro score ranging from 3 to 8. Most studies (9 out of 13) were considered good quality, with one rating of poor quality and three of fair quality. The primary findings suggest that MI training is a low-risk tool that may facilitate ADL independence. Audio-based MI training seems to improve ADL independence when paired with other rehabilitation methods, but the results should be interpreted with caution.

Conclusion:

To our knowledge, this is the first systematic review to examine RCTs investigating MI effectiveness in improving ADL post-stroke. Results support the use of MI to facilitate ADL independence. However, more research is needed to establish practice guidelines for implementing MI training post-stroke.

Motor imagery training to improve language processing: What are the arguments?

Studies showed that motor expertise was found to induce improvement in language processing. Grounded and situated approaches attributed this effect to an underlying automatic simulation of the motor experience elicited by action words, similar to motor imagery (MI), and suggest shared representations of action conceptualization. Interestingly, recent results also suggest that the mental simulation of action by MI training induces motor-system modifications and improves motor performance. Consequently, we hypothesize that, since MI training can induce motor-system modifications, it could be used to reinforce the functional connections between motor and language system, and could thus lead to improved language performance. Here, we explore these potential interactions by reviewing recent fundamental and clinical literature in the action-language and MI domains. We suggested that exploiting the link between action language and MI could open new avenues for complementary language improvement programs. We summarize the current literature to evaluate the rationale behind this novel training and to explore the mechanisms underlying MI and its impact on language performance.

The Effects of Subthreshold Vibratory Noise on Cortical Activity During Motor Imagery

Previous studies have demonstrated that both visual and proprioceptive feedback play vital roles in mental practice of movements. Tactile sensation has been shown to improve with peripheral sensory stimulation via imperceptible vibratory noise by stimulating the sensorimotor cortex. With both proprioception and tactile sensation sharing the same population of posterior parietal neurons encoding within high-level spatial representations, the effect of imperceptible vibratory noise on motor imagery-based brain-computer interface is unknown. The objective of this study was to investigate the effects of this sensory stimulation via imperceptible vibratory noise applied to the index fingertip in improving motor imagery-based brain-computer interface performance. Fifteen healthy adults (nine males and six females) were studied. Each subject performed three motor imagery tasks, namely drinking, grabbing, and flexion-extension of the wrist, with and without sensory stimulation while being presented a rich immersive visual scenario through a virtual reality headset. Results showed that vibratory noise increased event-related desynchronization during motor imagery compared with no vibration. Furthermore, the task classification percentage was higher with vibration when the tasks were discriminated using a machine learning algorithm. In conclusion, subthreshold random frequency vibration affected motor imagery-related event-related desynchronization and improved task classification performance.

Enhancing motor imagery practice using synchronous action observation

In this paper, we discuss a variety of ways in which practising motor actions by means of motor imagery (MI) can be enhanced via synchronous action observation (AO), that is, by AO + MI. We review the available research on the (mostly facilitatory) behavioural effects of AO + MI practice in the early stages of skill acquisition, discuss possible theoretical explanations, and consider several issues related to the choice and presentation schedules of suitable models. We then discuss considerations related to AO + MI practice at advanced skill levels, including expertise effects, practical recommendations such as focussing attention on specific aspects of the observed action, using just-ahead models, and possible effects of the perspective in which the observed action is presented. In section "Coordinative AO + MI", we consider scenarios where the observer imagines performing an action that complements or responds to the observed action, as a promising and yet under-researched application of AO + MI training. In section "The dual action simulation hypothesis of AO + MI", we review the neurocognitive hypothesis that AO + MI practice involves two parallel action simulations, and we consider opportunities for future research based on recent neuroimaging work on parallel motor representations. In section "AO + MI training in motor rehabilitation", we review applications of AO, MI, and AO + MI training in the field of neurorehabilitation. Taken together, this evidence-based, exploratory review opens a variety of avenues for future research and applications of AO + MI practice, highlighting several clear advantages over the approaches of purely AO- or MI-based practice.

Imagining the way forward: A review of contemporary motor imagery theory

Over the past few decades, researchers have become interested in the mechanisms behind motor imagery (i.e., the mental rehearsal of action). During this time several theories of motor imagery have been proposed, offering diverging accounts of the processes responsible for motor imagery and its neural overlap with movement. In this review, we summarize the core claims of five contemporary theories of motor imagery: motor simulation theory, motor emulation theory, the motor-cognitive model, the perceptual-cognitive model, and the effects imagery model. Afterwards, we identify the key testable differences between them as well as their various points of overlap. Finally, we discuss potential future directions for theories of motor imagery.

Mental practice for laparoscopic salpingectomy

Mental practice (MP) is a method of enhancing surgical training by rehearsal of a task without physical action. The primary objective of the study was to develop and validate a MP tool for laparoscopic salpingectomy (LS). An imagery script for LS was developed and used to facilitate a structured MP session for trainees in Obstetrics and Gynaecology and expert gynaecologists across three teaching hospitals in the UK. A virtual platform was used for one trainee group to assess its feasibility compared to a face-to-face approach. Pre- and post-session assessments were conducted to evaluate the impact of the script on motivation, confidence, preparedness and quality of imagery and demonstrated a significant improvement in global imagery scores for both novice groups. The expert group scored significantly higher than the face-to-face novice group on all items both before and after MP, indicating construct validity. There were no significant differences demonstrated between the two novice groups, thus demonstrating the virtual platform to be a non-inferior approach - an important consideration in the current COVID era.

Anodal tDCS does not enhance the learning of the sequential finger-tapping task by motor imagery practice in healthy older adults

Background

Motor imagery practice (MIP) and anodal transcranial direct current stimulation (a-tDCS) are innovative methods with independent positive influence on motor sequence learning (MSL) in older adults.

Objective

The present study investigated the effect of MIP combined with a-tDCS over the primary motor cortex (M1) on the learning of a finger tapping sequence of the non-dominant hand in healthy older adults.

Methods

Thirty participants participated in this double-blind sham-controlled study. They performed three MIP sessions, one session per day over three consecutive days and a retention test 1 week after the last training session. During training / MIP, participants had to mentally rehearse an 8-element finger tapping sequence with their left hand, concomitantly to either real (a-tDCS group) or sham stimulation (sham-tDCS group). Before and after MIP, as well as during the retention test, participants had to physically perform the same sequence as fast and accurately as possible.

Results

Our main results showed that both groups (i) improved their performance during the first two training sessions, reflecting acquisition/on-line performance gains, (ii) stabilized their performance from one training day to another, reflecting off-line consolidation; as well as after 7 days without practice, reflecting retention, (iii) for all stages of MSL, there was no significant difference between the sham-tDCS and a-tDCS groups.

Conclusion

This study highlights the usefulness of MIP in motor sequence learning for older adults. However, 1.5 mA a-tDCS did not enhance the beneficial effects of MIP, which adds to the inconsistency of results found in tDCS studies. Future work is needed to further explore the best conditions of use of tDCS to improve motor sequence learning with MIP.

Mapping relational links between motor imagery, action observation, action-related language, and action execution

Actions can be physically executed, observed, imagined, or simply thought about. Unifying mental processes, such as simulation, emulation, or predictive processing, are thought to underlie different action types, whether they are mental states, as in the case of motor imagery and action observation, or involve physical execution. While overlapping brain activity is typically observed across different actions which indicates commonalities, research interest is also concerned with investigating the distinct functional components of these action types. Unfortunately, untangling subtleties associated with the neurocognitive bases of different action types is a complex endeavour due to the high dimensional nature of their neural substrate (e.g., any action process is likely to activate multiple brain regions thereby having multiple dimensions to consider when comparing across them). This has impeded progress in action-related theorising and application. The present study addresses this challenge by using the novel approach of multidimensional modeling to reduce the high-dimensional neural substrate of four action-related behaviours (motor imagery, action observation, action-related language, and action execution), find the least number of dimensions that distinguish or relate these action types, and characterise their neurocognitive relational links. Data for the model comprised brain activations for action types from whole-brain analyses reported in 53 published articles. Eighty-two dimensions (i.e., 82 brain regions) for the action types were reduced to a three-dimensional model, that mapped action types in ordination space where the greater the distance between the action types, the more dissimilar they are. A series of one-way ANOVAs and post-hoc comparisons performed on the mean coordinates for each action type in the model showed that across all action types, action execution and concurrent action observation (AO)-motor imagery (MI) were most neurocognitively similar, while action execution and AO were most dissimilar. Most action types were similar on at least one neurocognitive dimension, the exception to this being action-related language. The import of the findings are discussed in terms of future research and implications for application.

Motor imagery training of goal-directed reaching in relation to imagery of reaching and grasping in healthy people

The study aimed to determine whether four weeks of motor imagery training (MIT) of goal-directed reaching (reaching to grasp task) would affect the cortical activity during motor imagery of reaching (MIR) and grasping (MIG) in the same way. We examined cortical activity regarding event-related potentials (ERPs) in healthy young participants. Our study also evaluated the subjective vividness of the imagery. Furthermore, we aimed to determine the relationship between the subjective assessment of motor imagery (MI) ability to reach and grasp and the cortical activity during those tasks before and after training to understand the underlying neuroplasticity mechanisms. Twenty-seven volunteers participated in MIT of goal-directed reaching and two measurement sessions before and after MIT. During the sessions 128-channel electroencephalography (EEG) was recorded during MIR and MIG. Also, participants assessed the vividness of the MI tasks using a visual analog scale (VAS). The vividness of imagination improved significantly (P < .05) after MIT. A repeated measures ANOVA showed that the task (MIR/MIG) and the location of electrodes had a significant effect on the ERP's amplitude (P < .05). The interaction between the task, location, and session (before/after MIT) also had a significant effect on the ERP's amplitude (P < .05). Finally, the location of electrodes and the interaction between location and session had a significant effect on the ERP's latency (P < .05). We found that MIT influenced the EEG signal associated with reaching differently than grasping. The effect was more pronounced for MIR than for MIG. Correlation analysis showed that changes in the assessed parameters due to MIT reduced the relationship between the subjective evaluation of imagining and the EEG signal. This finding means that the subjective evaluation of imagining cannot be a simple, functional insight into the bioelectrical activity of the cerebral cortex expressed by the ERPs in mental training. The changes we noted in ERPs after MIT may benefit the use of non-invasive EEG in the brain-computer interface (BCI) context.Trial registration: NCT04048083.

Reliability of the Spanish Version of the Movement Imagery Questionnaire-3 (MIQ-3) and Characteristics of Motor Imagery in Institutionalized Elderly People

Motor imagery (MI) training is increasingly used to improve the performance of specific motor skills. The Movement Imagery Questionnaire-3 (MIQ-3) is an instrument for assessing MI ability validated in Spanish although its reliability has not yet been studied in the elderly population. The main objective of this study was to test its reliability in institutionalized elderly people. Secondarily, we studied whether there are differences according to gender and age in MI ability (measured by the MIQ-3) and in temporal congruency (measured by mental chronometry of elbow and knee flexion-extension and getting up and sitting down from chair movements). The subjects were 60 elderly, institutionalized, Spanish-speaking individuals without cognitive impairment or dementia, and aged between 70 and 100 years. Cronbach's alpha showed high internal consistency in the internal visual and external visual subscales and moderate in the kinesthetic subscale. The intraclass correlation coefficient showed good test-retest reliability for all three subscales. Mixed factorial analysis of variances (ANOVAs) showed that MI ability decreased with increasing age range, the imagery time decreased concerning the execution of the same movement, and there were no gender differences in either IM ability or temporal congruence. The Spanish version of the MIQ-3 is a reliable instrument for measuring MI ability in institutionalized elderly.

Mental rotation of hands and objects in ageing and Parkinson's disease: differentiating motor imagery and visuospatial ability

Motor imagery supports motor learning and performance and has the potential to be a useful strategy for neurorehabilitation. However, motor imagery ability may be impacted by ageing and neurodegeneration, which could limit its therapeutic effectiveness. Motor imagery can be assessed implicitly using a hand laterality task (HLT), whereby laterality judgements are slower for stimuli corresponding to physically more difficult postures, as indicated by a “biomechanical constraint” effect. Performance is also found to differ between back and palm views of the hand, which may differentially recruit visual and sensorimotor processes. Older adults and individuals with Parkinson’s disease (PD) have shown altered performance on the HLT; however, the effects of both ageing and PD on laterality judgements for the different hand views (back and palm) have not been directly examined. The present study compared healthy younger, healthy older, and PD groups on the HLT, an object-based mental rotation task, and an explicit motor imagery measure. The older and PD groups were slower than the younger group on the HLT, particularly when judging laterality from the back view, and exhibited increased biomechanical constraint effects for the palm. While response times were generally similar between older and PD groups, the PD group showed reduced accuracy for the back view. Letter rotation was slower and less accurate only in the PD group, while explicit motor imagery ratings did not differ significantly between groups. These results suggest that motor imagery may be slowed but relatively preserved in both typical ageing and neurodegeneration, while a PD-specific impairment in visuospatial processing may influence task performance. The findings have implications for the use of motor imagery in rehabilitation protocols.

Cerebellum regulating cerebral functional cortex through multiple pathways in complete thoracolumbar spinal cord injury

The previous studies have found significant brain structural and functional changes in cerebral regions after spinal cord injury (SCI), but few studies have explored the cerebellar–cerebral circuit changes in SCI. This study aims to study the brain structural changes of cerebellar subregions and its functional connectivity (FC) changes with cerebrum in complete thoracolumbar SCI (CTSCI), and screen out the regions that play relatively important roles in affecting sensorimotor function. Eighteen CTSCI patients and 18 age- and gender-matched healthy controls (HCs) were recruited. Voxel-based morphometry (VBM) was used to characterize the brain structural changes of cerebellar subregions [from the Anatomical Automatic Labeling (AAL116)], seed-based FC was used to evaluate the cerebellar–cerebral FC changes and support vector machine (SVM) analysis was used to search for sensitive imaging indicators. CTSCI patients showed slightly structural atrophy in vermis_3 (p = 0.046) and significantly decreased FC between cerebellum and cerebral sensorimotor-, visual-, cognitive-, and auditory-related regions (cluster-level FWE correction with p < 0.05). Additionally, SVM weight analysis showed that FC values between vermis_10 and right fusiform gyrus had the greatest weight in functional changes of CTSCI. In conclusion, different degrees of structural and functional changes occurred in each subregion of cerebellum following CTSCI, and FC change between vermis_10 and right fusiform gyrus plays the most important role in dysfunction and may become an important neural network index of rehabilitation therapy.

Neural Correlates of Motor Imagery during Action Observation in Affordance-based Actions: Preliminary Results

Object affordance, a characterization of the different functionalities of an object, refers to an object's numerous possibilities of interaction. It has a significant part to play in priming motoric actions which depends on the actor's spontaneous neurological behaviour. Action Observation (AO) and Motor Imagery (MI) also lead to the stimulation of motor system. In fact, AO and MI result in activation of overlapping brain areas as the actual motor task. AO combined with MI (referred to as AO+MI) initiates higher cortical activity in comparison with either MI or AO alone. In this paper, we investigate the influence of affordance driven motor priming during AO, MI and AO + MI. Source current density as an EEG parameter is estimated by Low Resolution Electromagnetic Tomography (LORETA). Our results demonstrate that affordance driven motor priming during AO+MI indicates stronger electrophysiological and behavioural changes. This is evident from the N2 ERP component. Further, the current source density (in brain regions associated with motor planning) during affordance driven AO+MI is found to be maximum.

Not all Forms of Muscle Hypertonia Worsen With Fatigue: A Pilot Study in Para Swimmers

In hypertonic muscles of patients with upper motor neuron syndrome (UMNS), investigation with surface electromyography (EMG) with the muscle in a shortened position and during passive muscle stretch allows to identify two patterns underlying hypertonia: spasticity and spastic dystonia. We recently observed in Para swimmers that the effect of fatigue on hypertonia can be different from subject to subject. Our goal was, therefore, to understand whether this divergent behavior may depend on the specific EMG pattern underlying hypertonia. We investigated eight UMNS Para swimmers (five men, mean age 23.25 ± 3.28 years), affected by cerebral palsy, who presented muscle hypertonia of knee flexors and extensors. Muscle tone was rated using the Modified Ashworth Scale (MAS). EMG patterns were investigated in rectus femoris (RF) and biceps femoris (BF) before and after two fatiguing motor tasks of increasing intensity. Before the fatiguing tasks, two subjects (#2 and 7) had spasticity and one subject (#5) had spastic dystonia in both RF and BF. Two subjects (#3 and 4) showed spasticity in RF and spastic dystonia in BF, whereas one subject (#1) had spasticity in RF and no EMG activity in BF. The remaining two subjects (#6 and 8) had spastic dystonia in RF and no EMG activity in BF. In all the 16 examined muscles, these EMG patterns persisted after the fatiguing tasks. Spastic dystonia increased (p &lt; 0.05), while spasticity did not change (p &gt; 0.05). MAS scores increased only in the muscles affected by spastic dystonia. Among the phenomena possibly underlying hypertonia, only spastic dystonia is fatigue-dependent. Technical staff and medical classifiers should be aware of this specificity, because, in athletes with spastic dystonia, intense and prolonged motor activity could negatively affect competitive performance, creating a situation of unfairness among Para athletes belonging to the same sports class.

Motor Imagery Combined With Physical Training Improves Response Inhibition in the Stop Signal Task

Background

Motor imagery training has a similar effect to that of physical training on motor performance. The objective of this study was to investigate the short-term effectiveness of motor imagery training on response inhibition using the stop signal task (SST).

Methods

Participants were divided into a physical training group (PT, n = 17), a motor imagery training group (MIT, n = 17), and a motor imagery combined with physical training group (MIPT, n = 17). All participants performed 10 SST training sessions over 5 days. Both stop signal reaction time (SSRT) and non-signal reaction time (NSRT) were measured before and after SST training.

Results

There were significant interaction (time × group) and time effects, although the group effect was not statistically significant. Bonferroni post hoc analysis showed that MIPT group revealed a significantly greater change in SSRT than PT and MIT groups, while there was no significant difference between PT and MIT groups. SSRT significantly decreased after training in all groups. In NSRT, there was a significant effect of time, but there was no significant interaction effect (time × group) or group effect.

Conclusion

Response inhibition could be enhanced via training, and it was most effective when motor imagery and physical training were combined. We demonstrate that motor imagery training significantly improves response inhibition and should be accompanied by physical training when performing SST.

Mental practice modulates functional connectivity between the cerebellum and the primary motor cortex

Our brain has the extraordinary capacity to improve motor skills through mental practice. Conceptually, this ability is attributed to internal forward models, which are cerebellar neural networks that can predict the sensory consequences of motor commands. In our study, we employed single and dual-coil transcranial magnetic stimulations to probe the level of corticospinal excitability and cerebellar-brain inhibition, respectively, before and after a mental practice session or a control session. Motor skill (i.e., accuracy and speed) was measured using a sequential finger tapping-task. We found that mental practice enhanced both speed and accuracy. In parallel, the functional connectivity between the cerebellum and the primary motor cortex changed, with less inhibition from the first to the second. These findings reveal the existence of neuroplastic changes within the cerebellum, supporting the involvement of internal models after mental practice.

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The update of internal forward models involves cerebellar neural adaptations

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Mental practice is assumed to engage internal forward models

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Cerebellar-brain Inhibition was probed by TMS before and after mental practice

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Mental practice reduces Cerebellar-brain Inhibition and may update internal models

Simulating Extreme Environmental Conditions via Mental Imagery: The Case of Microgravity and Weight Estimation

Mental imagery can be used for recreating an extreme environment experience. Here we assessed whether microgravity effects over cognition, that typically occur during a space mission, may be reproduced via mental imagery. Participants were randomly assigned to one of two conditions in which they were guided to imagine to be (1) in outer space or (2) in a nature scenario and subsequently estimate the weight of common objects. We found that only for those who engaged in a space scenario imagery, there was a decrease in object weight estimation compared with a prior rating. This finding is the first to indicate that the effects of weightlessness on cognition can be simulated via an imagery-based technique and add to the ongoing debate about the importance of trying to disentangle the effect of microgravity alone on human performance. Moreover, our findings ultimately suggest that imagery can be used as a less expensive simulated scenario for studying the impact of extreme environmental conditions over astronauts' cognition and behavior.

Online training module for micro suturing incorporating motor imagery and mental practice: a design and development research study

INTRODUCTION

There have been reduced opportunities for surgical skill acquisition due to the COVID-19 pandemic and the regulated training hours. Despite these challenges, self-regulated learning allows trainees to learn continuously, and one form of this is through mental practice and motor imagery. The study aimed to design and develop an online basic micro suturing training module for skill acquisition for self-regulated learning using a low-fidelity rubber glove model.

METHODS

This study utilized a design and developmental research framework and Mayer's multimedia theory guidelines. The primary author created an online instructional module on micro suturing based on the ADDIE instructional design model. This module was then evaluated in a pilot study comparing the new training model to traditional methods of learning using an experimental design.

RESULTS

This study describes the use of Design and Development Research to create a new model for surgical skill training and a tool for producing instructional materials and learning products for online learning. The product was evaluated using an experimental design and showed a significant effect on the quality of motor skill outcome and the richness of motor imagery using the resource developed in the research.

CONCLUSION

This study describes the methodological approach of a design and developmental framework to create an online training module for micro suturing which has significant utility in hand surgery.

Influence of combined action observation and motor imagery of walking on lower limb reflex modulation in patients after stroke-preliminary results

Objective

The combined use of action observation and motor imagery (AOMI) is a promising technique in neurorehabilitation that can be usefully applied in addition to conventional forms of therapy. Previous studies with healthy participants showed that the mere passive observation of walking results in a phase-dependent reflex modulation in the tibialis anterior muscle that resembles the pattern occurring when walking. In patients after stroke, a similar reflex modulation was found in several lower limb muscles during the real execution of walking, but responses were blunted. To clarify whether and how lower limb reflex responses are also modulated in such patients during the combined synchronous observation and imagery of walking, medium-latency cutaneous reflexes from the tibialis anterior muscle were measured. We compared the reflex responses of seven patients after stroke during the AOMI of walking from two different conditions: (a) elicited during the end stance phase and (b) during the end swing phase, both normalized to a baseline condition.

Results

So far, using the identical methodological set-up as in our study with healthy individuals, we could not find any noteworthy reflex response modulation. The study was registered with the German Clinical Trials Register (DRKS00028255).

Trial registration : The study was registered with the German Clinical Trials Register: DRKS00028255.

Does mental practice or mirror therapy help prevent functional loss after distal radius fracture? A randomized controlled trial

STUDY DESIGN

A randomized, single-blinded controlled trial.

INTRODUCTION

Therapy results after distal radius fractures (DRF) especially with older patients are often suboptimal. One possible approach for counteracting the problems are motor-cognitive training interventions such as Mental Practice (MP) or Mirror Therapy (MT), which may be applied in early rehabilitation without stressing the injured wrist.

PURPOSE OF THE STUDY

The aim of the study is to investigate the effects of MP and MT on wrist function after DRF. The pilot study should furthermore provide information about the feasibility of these methods.

METHODS

Thirty-one women were assigned either to one of the two experimental groups (MP, MT) or to a control group (relaxation intervention). The participants completed a training for six weeks, administered at their homes. Measurements were taken at four times (weeks 0, 3, 6 and 12) to document the progression in subjective function (PRWE, QuickDASH) and objective constraints of the wrist (ROM, grip strength) as well as in health-related quality of life (EQ-5D).

RESULTS

The results indicated that both experimental groups showed higher improvements across the intervention period compared to the control group; e.g. PRWE: MT 74.0%, MP 66.2%, CG 56.9%. While improvements in grip strength were higher for the MP group, the MT group performed better in all other measures. However, time by group interactions approached significance at best; e.g. ROM: P = .076; η_p² = .141.

CONCLUSION

The superiority of MP as well as MT supports the simulation theory. Motor-cognitive intervention programs are feasible and promising therapy supplements, which may be applied in early rehabilitation to counteract the consequences of immobilization without stressing the injured wrist.

Imagined paralysis reduces motor cortex excitability

Mental imagery is a powerful capability that engages similar neurophysiological processes that underlie real sensory and motor experiences. Previous studies show that motor cortical excitability can increase during mental imagery of actions. In this study, we focused on possible inhibitory effects of mental imagery on motor functions. We assessed whether imagined arm paralysis modulates motor cortical excitability in healthy participants, as measured by motor evoked potentials (MEPs) of the hand induced by near-threshold transcranial magnetic stimulation (TMS) over the primary motor cortex hand area. We found lower MEP amplitudes during imagined arm paralysis when compared to imagined leg paralysis or baseline stimulation without paralysis imagery. These results show that purely imagined bodily constraints can selectively inhibit basic motor corticospinal functions. The results are discussed in the context of motoric embodiment/disembodiment.

Using Motor Imagery to Access Alternative Attentional Strategies When Navigating Environmental Boundaries to Prevent Freezing of Gait – A Perspective

Freezing of gait can cause reduced independence and quality of life for many with Parkinson’s disease. Episodes frequently occur at points of transition such as navigating a doorway. Therapeutic interventions, i.e., drugs and exercise, do not always successfully mitigate episodes. There are several different, but not exclusive causes for freezing of gait. People with freezing of gait are able to navigate dynamic situations like stairways by utilizing a different attentional strategy to over-ground walking, but may freeze when passing through a doorway. The question is, is it possible to employ a special attentional strategy to prevent freezing at this point? Motor imagery allows for learning motor skills in absolute safety and has been widely employed in a variety of populations, including other neuro-compromised groups. Motor imagery is not studied in a homologous manner in people with Parkinson’s Disease, leading to conflicting results, but may have the potential to establish a different attentional strategy which allows a subject to mitigate freezing of gait episodes. This paper will identify and discuss the questions that still need to be answered in order to consider this approach i.e., can this population access motor imagery, can motor imagery alter the attentional strategy employed when moving through doorways, what is the best motor imagery approach for people with Parkinson’s Disease and freezing of gait, and what dosage is most effective, while briefly outlining future research considerations.

Effects of actual and imagined music-cued gait training on motor functioning and brain activity in people with multiple sclerosis: protocol of a randomised parallel multicentre trial

INTRODUCTION

Motor imagery (MI) refers to the mental rehearsal of a physical action without muscular activity. Our previous studies showed that MI combined with rhythmic-auditory cues improved walking, fatigue and quality of life (QoL) in people with multiple sclerosis (pwMS). Largest improvements were seen after music and verbally cued MI. It is unclear whether actual cued gait training achieves similar effects on walking as cued MI in pwMS. Furthermore, in pwMS it is unknown whether any of these interventions leads to changes in brain activation. The purpose of this study is therefore to compare the effects of imagined and actual cued gait training and a combination thereof on walking, brain activation patterns, fatigue, cognitive and emotional functioning in pwMS.

METHODS AND ANALYSIS

A prospective double-blind randomised parallel multicentre trial will be conducted in 132 pwMS with mild to moderate disability. Randomised into three groups, participants will receive music, metronome and verbal cueing, plus MI of walking (1), MI combined with actual gait training (2) or actual gait training (3) for 30 min, 4× per week for 4 weeks. Supported by weekly phone calls, participants will practise at home, guided by recorded instructions. Primary endpoints will be walking speed (Timed 25-Foot Walk) and distance (2 min Walk Test). Secondary endpoints will be brain activation patterns, fatigue, QoL, MI ability, anxiety, depression, cognitive functioning, music-induced motivation-to-move, pleasure, arousal and self-efficacy. Data will be collected at baseline, postintervention and 3-month follow-up. MRI reference values will be generated using 15 matched healthy controls.

ETHICS AND DISSEMINATION

This study follows the Standard Protocol Items: Recommendations for Interventional Trials-PRO Extension. Ethical approval was received from the Ethics Committees of the Medical Universities of Innsbruck (1347/2020) and Graz (33-056 ex 20/21), Austria. Results will be disseminated via national and international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

DRKS00023978.

EEG as a marker of brain plasticity in clinical applications

Neural networks are dynamic, and the brain has the capacity to reorganize itself. This capacity is named neuroplasticity and is fundamental for many processes ranging from learning and adaptation to new environments to the response to brain injuries. Measures of brain plasticity involve several techniques, including neuroimaging and neurophysiology. Electroencephalography, often used together with other techniques, is a common tool for prognostic and diagnostic purposes, and cortical reorganization is reflected by EEG measurements. Changes of power bands in different cortical areas occur with fatigue and in response to training stimuli leading to learning processes. Sleep has a fundamental role in brain plasticity, restoring EEG bands alterations and promoting consolidation of learning. Exercise and physical inactivity have been extensively studied as both strongly impact brain plasticity. Indeed, EEG studies showed the importance of the physical activity to promote learning and the effects of inactivity or microgravity on cortical reorganization to cope with absent or altered sensorimotor stimuli. Finally, this chapter will describe some of the EEG changes as markers of neural plasticity in neurologic conditions, focusing on cerebrovascular and neurodegenerative diseases. In conclusion, neuroplasticity is the fundamental mechanism necessary to ensure adaptation to new stimuli and situations, as part of the dynamicity of life.

A 1D CNN for high accuracy classification and transfer learning in motor imagery EEG-based brain-computer interface

OBJECTIVE

Brain-computer interface (BCI) aims to establish communication paths between the brain processes and external devices. Different methods have been used to extract human intentions from electroencephalography (EEG) recordings. Those based on motor imagery (MI) seem to have a great potential for future applications. These approaches rely on the extraction of EEG distinctive patterns during imagined movements. Techniques able to extract patterns from raw signals represent an important target for BCI as they do not need labor-intensive data pre-processing.

APPROACH

We propose a new approach based on a 10-layer one-dimensional convolution neural network (1D-CNN) to classify five brain states (four MI classes plus a 'baseline' class) using a data augmentation algorithm and a limited number of EEG channels. In addition, we present a transfer learning method used to extract critical features from the EEG group dataset and then to customize the model to the single individual by training its outer layers with only 12-minute individual-related data.

MAIN RESULTS

The model tested with the 'EEG Motor Movement/Imagery Dataset' outperforms the current state-of-the-art models by achieving a 99.38% accuracy at the group level. In addition, the transfer learning approach we present achieves an average accuracy of 99.46%.

SIGNIFICANCE

The proposed methods could foster future BCI applications relying on few-channel portable recording devices and individual-based training.

Arthrogenic Muscle Inhibition: Best Evidence, Mechanisms, and Theory for Treating the Unseen in Clinical Rehabilitation

CONTEXT

Arthrogenic muscle inhibition (AMI) impedes the recovery of muscle function following joint injury, and in a broader sense, acts as a limiting factor in rehabilitation if left untreated. Despite a call to treat the underlying pathophysiology of muscle dysfunction more than three decades ago, the continued widespread observations of post-traumatic muscular impairments are concerning, and suggest that interventions for AMI are not being successfully integrated into clinical practice.

OBJECTIVES

To highlight the clinical relevance of AMI, provide updated evidence for the use of clinically accessible therapeutic adjuncts to treat AMI, and discuss the known or theoretical mechanisms for these interventions.

EVIDENCE ACQUISITION

PubMed and Web of Science electronic databases were searched for articles that investigated the effectiveness or efficacy of interventions to treat outcomes relevant to AMI.

EVIDENCE SYNTHESIS

122 articles that investigated an intervention used to treat AMI among individuals with pathology or simulated pathology were retrieved from 1986 to 2021. Additional articles among uninjured individuals were considered when discussing mechanisms of effect.

CONCLUSION

AMI contributes to the characteristic muscular impairments observed in patients recovering from joint injuries. If left unresolved, AMI impedes short-term recovery and threatens patients' long-term joint health and well-being. Growing evidence supports the use of neuromodulatory strategies to facilitate muscle recovery over the course of rehabilitation. Interventions should be individualized to meet the needs of the patient through shared clinician-patient decision-making. At a minimum, we propose to keep the treatment approach simple by attempting to resolve inflammation, pain, and effusion early following injury.