Multiple roles of motor imagery during action observation

Over the last 20 years, the topics of action observation (AO) and motor imagery (MI) have been largely studied in isolation from each other, despite the early integrative account by Jeannerod (1994, 2001). Recent neuroimaging studies demonstrate enhanced cortical activity when AO and MI are performed concurrently (“AO+MI”), compared to either AO or MI performed in isolation. These results indicate the potentially beneficial effects of AO+MI, and they also demonstrate that the underlying neurocognitive processes are partly shared. We separately review the evidence for MI and AO as forms of motor simulation, and present two quantitative literature analyses that indeed indicate rather little overlap between the two bodies of research. We then propose a spectrum of concurrent AO+MI states, from congruent AO+MI where the contents of AO and MI widely overlap, over coordinative AO+MI, where observed and imagined action are different but can be coordinated with each other, to cases of conflicting AO+MI. We believe that an integrative account of AO and MI is theoretically attractive, that it should generate novel experimental approaches, and that it can also stimulate a wide range of applications in sport, occupational therapy, and neurorehabilitation

Experts bodies, experts minds: How physical and mental training shape the brain

Skill learning is the improvement in perceptual, cognitive, or motor performance following practice. Expert performance levels can be achieved with well-organized knowledge, using sophisticated and specific mental representations and cognitive processing, applying automatic sequences quickly and efficiently, being able to deal with large amounts of information, and many other challenging task demands and situations that otherwise paralyze the performance of novices. The neural reorganizations that occur with expertise reflect the optimization of the neurocognitive resources to deal with the complex computational load needed to achieve peak performance. As such, capitalizing on neuronal plasticity, brain modifications take place over time-practice and during the consolidation process. One major challenge is to investigate the neural substrates and cognitive mechanisms engaged in expertise, and to define “expertise” from its neural and cognitive underpinnings. Recent insights showed that many brain structures are recruited during task performance, but only activity in regions related to domain-specific knowledge distinguishes experts from novices. The present review focuses on three expertise domains placed across a motor to mental gradient of skill learning: sequential motor skill, mental simulation of the movement (motor imagery), and meditation as a paradigmatic example of “pure” mental training. We first describe results on each specific domain from the initial skill acquisition to expert performance, including recent results on the corresponding underlying neural mechanisms. We then discuss differences and similarities between these domains with the aim to identify the highlights of the neurocognitive processes underpinning expertise, and conclude with suggestions for future research

Effects of Age and Task Load on Drivers’ Response Accuracy and Reaction Time When Responding to Traffic Lights

International audienceDue to population aging, elderly drivers represent an increasing proportion of car drivers. Yet, how aging alters sensorimotor functions and impacts driving safety remains poorly understood. This paper aimed at assessing to which extent elderly drivers are sensitive to various task loads and how this affects the reaction time (RT) in a driving context. Old and middle-aged people completed RT tasks which reproduced cognitive demands encountered while driving. Participants had to detect and respond to traffic lights or traffic light arrows as quickly as possible, under three experimental conditions of incremental difficulty. In both groups, we hypothesized that decision-making would be impacted by the number of cues to be processed. The first test was a simple measure of RT. The second and third tests were choice RT tasks requiring the processing of 3 and 5 cues, respectively. Responses were collected within a 2 s time-window. Otherwise, the trial was considered a no-response. In both groups, the data revealed that RT, error rate (incorrect answers), and no-response rate increased along with task difficulty. However, the middle-aged group outperformed the elderly group. The RT difference between the two groups increased drastically along with task difficulty. In the third test, the rate of no-response suggested that elderly drivers needed more than 2 s to process complex information and respond accurately. Both prolonged RT and increased no-response rate, especially for difficult tasks, might attest an impairment of cognitive abilities in relation to aging. Accordingly, casual driving conditions for young drivers may be particularly complex and stressful for elderly people who should thus be informed about the effects of normal aging upon driving

Effects of Action Observation and Action Observation Combined with Motor Imagery on Maximal Isometric Strength

Action observation (AO) alone or combined with motor imagery (AO + MI) has been shown to engage the motor system. While recent findings support the potential relevance of both techniques to enhance muscle function, this issue has received limited scientific scrutiny. In the present study, we implemented a counterbalanced conditions design where 21 participants performed 10 maximal isometric contractions (12-s duration) of elbow flexor muscles against a force platform. During the inter-trial rest periods, participants completed i) AO of the same task performed by an expert athlete, ii) AO + MI, i.e. observation of an expert athlete while concurrently imagining oneself performing the same task, and iii) watching passively a video documentary about basketball shooting (Control). During force trials, we recorded the total force and integrated electromyograms from the biceps brachii and anterior deltoideus. We also measured skin conductance from two finger electrodes as an index of sympathetic nervous system activity. Both AO and AO + MI outperformed the Control condition in terms of total force (2.79–3.68%, p < 0.001). For all conditions, we recorded a positive relationship between the biceps brachii activation and the total force developed during the task. However, only during AO was a positive relationship observed between the activation of the anterior deltoideus and the total force. We interpreted the results with reference to the statements of the psycho-neuromuscular theory of mental practice. Present findings extend current knowledge regarding the priming effects of AO and AO + MI on muscle function, and may contribute to the optimization of training programs in sports and rehabilitation

Plasticité cérébrale et corrélats neurofonctionnels de l'imagerie motrice après lésion médullaire : étude magnétoencéphalographique et applications en rééducation

Neuroplasticity can promote motor recovery after neurologic injuries. Neuroplasticity after complete spinal cord injury triggers adaptive reorganization of cerebral regions recruited during motor imagery (i.e., the mental representation of a movement without actually executing it). The neural processes underlying motor command inhibition, required to prevent physical execution of the imagined action, would no longer be relevant and may be weakened. Motor imagery may thus be an efficient approach to brain motor networks stimulation. Prehension is severely disturbed after C6-C7 quadriplegia. Upper limb motor functions spared by the neurologic injury afford motor learning of a compensatory prehension during rehabilitation. Due to its effects on neuroplasticity, our data suggest that motor imagery training enabled motor learning of new prehensile motor programsLa plasticité neuronale permet le recouvrement de fonctions motrices à la suite d’atteintes neurologiques. La plasticité consécutive à une lésion complète de la moelle épinière entraîne la réorganisation de régions cérébrales recrutées au cours de l’imagerie motrice (i.e., la représentation mentale d’un mouvement sans son exécution réelle). Les processus responsables de l’inhibition de la commande motrice, prévenant l’exécution du mouvement imaginé, n’auraient plus de rôle fonctionnel et seraient affaiblis. L’imagerie motrice serait une donc méthode efficace de stimulation des réseaux du système moteur. La préhension est très affectée chez les personnes tétraplégiques de niveau C6-C7. Les fonctions du membre supérieur épargnées par l’atteinte neurologique permettent l’acquisition d’une préhension de compensation au cours de la rééducation. Par son effet sur la plasticité cérébrale, nos données indiquent que l’entraînement par imagerie motrice a favorisé l’acquisition de nouveaux programmes moteurs de préhensio

Cerebral plasticity and neurofunctional correlates of motor imagery after spinal cordinjury : a magnetoencephalogaphic study and applications in rehabilitation

La plasticité neuronale permet le recouvrement de fonctions motrices à la suite d’atteintes neurologiques. La plasticité consécutive à une lésion complète de la moelle épinière entraîne la réorganisation de régions cérébrales recrutées au cours de l’imagerie motrice (i.e., la représentation mentale d’un mouvement sans son exécution réelle). Les processus responsables de l’inhibition de la commande motrice, prévenant l’exécution du mouvement imaginé, n’auraient plus de rôle fonctionnel et seraient affaiblis. L’imagerie motrice serait une donc méthode efficace de stimulation des réseaux du système moteur. La préhension est très affectée chez les personnes tétraplégiques de niveau C6-C7. Les fonctions du membre supérieur épargnées par l’atteinte neurologique permettent l’acquisition d’une préhension de compensation au cours de la rééducation. Par son effet sur la plasticité cérébrale, nos données indiquent que l’entraînement par imagerie motrice a favorisé l’acquisition de nouveaux programmes moteurs de préhensionNeuroplasticity can promote motor recovery after neurologic injuries. Neuroplasticity after complete spinal cord injury triggers adaptive reorganization of cerebral regions recruited during motor imagery (i.e., the mental representation of a movement without actually executing it). The neural processes underlying motor command inhibition, required to prevent physical execution of the imagined action, would no longer be relevant and may be weakened. Motor imagery may thus be an efficient approach to brain motor networks stimulation. Prehension is severely disturbed after C6-C7 quadriplegia. Upper limb motor functions spared by the neurologic injury afford motor learning of a compensatory prehension during rehabilitation. Due to its effects on neuroplasticity, our data suggest that motor imagery training enabled motor learning of new prehensile motor program

The therapeutic role of motor imagery on the functional rehabilitation of a stage II shoulder impingement syndrome

International audiencePurpose: Motor imagery (MI) has been used as a complementary therapeutic tool for motor recovery after central nervous system disease and peripheral injuries. However, it has never been used as a preventive tool. We investigated the use of MI in the rehabilitation of stage II shoulder impingement syndrome. For the first time, MI is used before surgery. Method: Sixteen participants were randomly assigned to either a MI or control group. Shoulder functional assessment (Constant score), range of motion and pain were measured before and after intervention. Results: Higher Constant score was observed in the MI than in the control group (p ¼ 0.04). Participants in the MI group further displayed greater movement amplitude (extension (p50.001); flexion (p ¼ 0.025); lateral rotation (p50.001). Finally, the MI group showed greater pain decrease (p ¼ 0.01). Conclusion: MI intervention seems to alleviate pain and enhance mobility, this is probably due to changes in muscle control and consequently in joint amplitude. MI might contribute to postpone or even protect from passing to stage III that may require surgery