0000000000161773
AUTHOR
Florent Lebon
Effect of mental fatigue on speed–accuracy trade-off
International audience; The aim of this study was to investigate the effects of mental fatigue on the duration of actual and imagined goal-directed arm movements involving speed-accuracy trade-off. Ten participants performed actual and imagined point-to-point arm movements as accurately and as fast as possible, before and after a 90-min sustained cognitive task inducing mental fatigue, and before and after viewing a neutral control task (documentary movie) that did not induce mental fatigue. Target width and center-to-center target distance were varied, resulting in five different indexes of difficulty. Prior to mental fatigue, actual and imagined movement duration increased with the diffic…
Motor imagery and cortico-spinal excitability: A review
International audience; Motor imagery (MI) has received a lot of interest during the last decades as its chronic or acute use has demonstrated several effects on improving sport performances or skills. The development of neuroimagery techniques also helped further our understanding of the neural correlates underlying MI. While some authors showed that MI, motor execution and action observation activated similar motor cortical regions, transcranial magnetic stimulation (TMS) studies brought great insights on the role of the primary motor cortex and on the activation of the cortico-spinal pathway during MI. After defining MI and describing the TMS technique, a short report of MI activities on…
Motor imagery training: Kinesthetic imagery strategy and inferior parietal fMRI activation
Motor imagery (MI) is the mental simulation of action frequently used by professionals in different fields. However, with respect to performance, well‐controlled functional imaging studies on MI training are sparse. We investigated changes in fMRI representation going along with performance changes of a finger sequence (error and velocity) after MI training in 48 healthy young volunteers. Before training, we tested the vividness of kinesthetic and visual imagery. During tests, participants were instructed to move or to imagine moving the fingers of the right hand in a specific order. During MI training, participants repeatedly imagined the sequence for 15 min. Imaging analysis was performed…
Spinal plasticity with motor imagery practice.
KEY POINTS: While a consensus has now been reached on the effect of motor imagery (MI) – the mental simulation of an action – on motor cortical areas, less is known about its impact on spinal structures. The current study, using H‐reflex conditioning paradigms, examined the effect of a 20 min MI practice on several spinal mechanisms of the plantar flexor muscles. We observed modulations of spinal presynaptic circuitry while imagining, which was even more pronounced following an acute session of MI practice. We suggested that the small cortical output generated during MI may reach specific spinal circuits and that repeating MI may increase the sensitivity of the spinal cord to its effects. T…
Modèles internes et imagerie motrice
L’imagerie motrice (IM) est la representation mentale d’une action, sans production concomitante de mouvement. Les techniques d’enregistrement et de stimulation du systeme nerveux central ont montre au cours de ces trois dernieres decennies que l’IM partageait des sites d’activation corticale et sous-corticale avec l’action reellement executee. Cette similitude, sans pour autant etre parfaitement identique, se retrouve aussi dans les activations peripheriques nerveuses et vegetatives. De plus, le travail mental est un element facilitateur de l’apprentissage, favorisant l’amelioration de la performance. Certains courants de pensee attribuent les mecanismes sous-jacents de l’IM et les benefic…
Does a Mental Training Session Induce Neuromuscular Fatigue?
ROZAND, V., F. LEBON, C. PAPAXANTHIS, and R. LEPERS. Does a Mental Training Session Induce Neuromuscular Fatigue? Med. Sci. Sports Exerc., Vol. 46, No. 10, pp. 1981–1989, 2014. Mental training, as physical training, enhances muscle strength. Whereas the repetition of maximal voluntary contractions (MVC) induces neuromuscular fatigue, the effect of maximal imagined contractions (MIC) on neuromuscular fatigue remains unknown. Here, we investigated neuromuscular alterations after a mental training session including MIC, a physical training session including MVC, and a combined training session including both MIC and MVC of the elbow flexor muscles. Methods: Ten participants performed 80 MIC (d…
Perception, Observation et Action
L’observation d’actions est une caracteristique preponderante de l’Homme et de l’animal et participe grandement au developpement des habiletes motrices. Le fait de voir une tierce personne realiser un mouvement active le reseau des neurones miroirs, reconnus comme la base neurophysiologique de la comprehension des actions d’autrui. Dans cette revue, nous discutons, dans un premier temps, des reponses centrales et comportementales sous-jacentes a l’observation. Ensuite, nous decrivons les benefices et les limites d’un (re)apprentissage par observation. Enfin, nous presentons de nouvelles approches de la simulation d’actions combinant l’observation a d’autres operations mentales d’origine int…
Influence of Delay Period Duration on Inhibitory Processes for Response Preparation.
In this study, we examined the dynamics of inhibitory preparatory processes, using a delayed response task in which a cue signaled a left or right index finger (Experiment 1) or hand (Experiment 2) movement in advance of an imperative signal. In Experiment 1, we varied the duration of the delay period (200, 500, and 900 ms). When transcranial magnetic stimulation (TMS) was applied 100 ms before the imperative, motor evoked potentials (MEPs) elicited in the first dorsal interosseous were strongly inhibited. For delays of 500 ms or longer, this inhibition was greater when the targeted muscle was selected compared with when it was not selected. In contrast, the magnitude of inhibition just aft…
Stimulation magnétique transcrânienne et imagerie motrice : corrélats neurophysiologiques de l’action mentalement simulée
La stimulation magnetique transcrânienne (SMT) est devenue en a peine trois decennies un outil scientifique experimental majeur dans l’etude du systeme nerveux chez l’homme. Dotee de nombreux atouts methodologiques (technique non-invasive et a haute resolution temporelle), la SMT est complementaire des outils d’exploration fonctionnelle du cerveau et elle a permis d’accumuler un nombre considerable de donnees dans le domaine des neurosciences cognitives et comportementales. Cet article de synthese presente les recentes avancees en cognition motrice et plus particulierement en imagerie motrice, un champ de recherche dans lequel la SMT a ete grandement utilisee pour explorer l’implication des…
Motor imagery and action observation following immobilization-induced hypoactivity: A narrative review.
Abstract Background In sports, the risk of pathology or event that leads to an injury, a cessation of practice or even to an immobilization is high. The subsequent reduction of physical activity, or hypoactivity, induces neural and muscular changes that adversely affect motor skills and functional motor rehabilitation. Because the implementation of physical practice is difficult, if not impossible, during and immediately following injury or immobilization, complementary techniques have been proposed to minimize the deleterious impact of hypoactivity on neuromuscular function. Objective The current narrative review aimed to discuss the contributions of motor imagery and action observation, w…
Generic Inhibition of the Selected Movement and Constrained Inhibition of Nonselected Movements during Response Preparation
Abstract Previous studies have identified two inhibitory mechanisms that operate during action selection and preparation. One mechanism, competition resolution, is manifest in the inhibition of the nonselected response and attributed to competition between candidate actions. The second mechanism, impulse control, is manifest in the inhibition of the selected response and is presumably invoked to prevent premature response. To identify constraints on the operation of these two inhibitory mechanisms, we manipulated the effectors used for the response alternatives, measuring changes in corticospinal excitability with motor-evoked potentials to TMS. Inhibition of the selected response (impulse …