La Problématique D’intégration Des Migrants Ressortissants Du Rwanda Et Du Burundi En République Démocratique Du Congo

This article critically diagnoses the integration difficulties encountered by Rwandan and Burundian immigrants in the Democratic Republic of Congo since 1960. Main treatments, xenophobic, and discriminatory practices used against the nationals of these two countries by indigenous Congolese people were analyzed in terms of obstacles to integration. The article also scrutinizes the derogatory, hegemonic, and disdainful behavior and attitudes of these immigrants towards the host society. The problems that these immigrants have to face from the authorities of the host country in the application of national migration policies were analyzed. Also, the way they were led into a clandestine life into the host country was also studied. The article, however, aims to reveal socio-cultural, political, and legal challenges which plague the daily life of Rwandan and Burundian nationals who have chosen the DRC as their second homeland

Measuring motor imagery using psychometric, behavioural, and psychophysiological tools

Measuring motor imagery using psychometric, behavioral, and psychophysiological tools. Exerc. Sport Sci. Rev., Vol. 39, No. 2, pp. 85Y92, 2011. This review examines the measurement of motor imagery (MI) processes. First, self-report measures of MI are evaluated. Next, mental chronometry measures are considered. Then, we explain how physiological indices of the autonomic nervous system can measure MI. Finally, we show how these indices may be combined to produce a measure of MI quality called the Motor Imagery Index. Key Words: motor imagery, mental imagery, psychometric measures, mental chronometry, autonomic nervous system, electrodermal and cardiac activities. MOTOR IMAGERY Motor imagery (MI), or the mental simulation of motor movement, is the cognitive rehearsal of an action without actually executing it (9,26). As the mental representation of a movement without the concomitant production of the muscle activity necessary for its implementation, MI has attracted increasing interest from researchers in sport science, psychology, and cognitive neuroscience During the past 15 years or so, we have conducted a number of studies on theoretical, practical, and rehabilitation issues involving MI. First, we have investigated the brain mechanisms underlying motor skill rehearsal and movement planning (11). Second, we have shown with others that the MI technique of mental practice (''seeing'' and ''feeling'' a movement in one's imagination before executing it) can increase physical strength performance (30) and enhance skill learning (3) and technical performance in athletes (4,32). Finally, we confirmed that MI training can facilitate rehabilitation from physical injury or neurological damage ((5) see (22) for a review). Elsewhere, we have provided a detailed account of research findings on MI (12). Considering that MI is a multidimensional construct (see model developed by Guillot and Collet (10)), we have measured its underlying processes using a combination of psychometric tests (18), qualitative procedures (19,25), chronometric methods in which MI processes are investigated by comparing the duration required to execute real and imagined actions (8), and psychophysiological techniques (1). Although these approaches have each yielded some interesting results (12), they have not yet been combined adequately to provide an aggregate index of MI quality. Therefore, the purpose of this review is to propose a rationale for our novel hypothesis that it is possible to calculate an index of MI quality by quantitatively combining psychometric, qualitative, chronometric, and psychophysiological measures. Our proposed Motor Imagery Index (MII) has significant implications for researchers and practitioners because it can be used to understand individual differences in MI and to assess the efficacy of MI interventions. PSYCHOMETRIC APPROACH For more than a century, researchers have used standardized self-report questionnaires to measure individual differences in imagery dimensions such as vividness (i.e., the clarity or sensory richness of an image) and controllability (i.e., the ease and accuracy with which an image can be manipulated mentally, see (24)). We have investigated both of these dimensions of imagery in sport settings. For example, we found that elite canoe-slalom competitors reported significantly greater use of MI than did less proficient counterparts when preparing for races (17). We investigated the effects of MI on the learning (through both physical and mental practice) of volleyball technique among intermediate performers of this sport (32). We found that a combination of MI and physical practice produced the most efficien

Task-Dependent Interaction between Parietal and Contralateral Primary Motor Cortex during Explicit versus Implicit Motor Imagery

Both mental rotation (MR) and motor imagery (MI) involve an internalization of movement within motor and parietal cortex. Transcranial magnetic stimulation (TMS) techniques allow for a task-dependent investigation of the interhemispheric interaction between these areas. We used image-guided dual-coil TMS to investigate interactions between right inferior parietal lobe (rIPL) and left primary motor cortex (M1) in 11 healthy participants. They performed MI (right index-thumb pinching in time with a 1 Hz metronome) or hand MR tasks, while motor evoked potentials (MEPs) were recorded from right first dorsal interosseous. At rest, rIPL conditioning 6 ms prior to M1 stimulation facilitated MEPs in all participants, whereas this facilitation was abolished during MR. While rIPL conditioning 12 ms prior to M1 stimulation had no effect on MEPs at rest, it suppressed corticomotor excitability during MI. These results support the idea that rIPL forms part of a distinct inhibitory network that may prevent unwanted movement during imagery tasks

Motor imagery effectiveness in enhancing motor performance and recovery : muscular strength and motor imagery

L’analyse de l’activité électromyographique (EMG) corrélative de l’imagerie motrice (IM) et l’effet de l’entraînement mental sur l’amélioration et le recouvrement de la force musculaire permettent de mieux comprendre les mécanismes nerveux de l’IM et l’importance du contenu de l’image mentale. Une activité EMG subliminale a en effet été enregistrée lors de l’IM, validant l’hypothèse d’une inhibition incomplète de la commande motrice. Elle était modulée selon l’intensité de l’effort mental et le régime de contraction, comme lors d’une contraction physique. Ces données renforcent l’équivalence physiologique entre IM et exécution réelle. Les programmes d’entraînement et de réhabilitation intégrant l’IM s’appuient sur ces données théoriques. L’amélioration de la force musculaire était significativement plus importante suite à un entraînement combinant répétitions physiques et mentales, comparativement à une pratique physique seule, même si l’effet ne concernait que certains groupes musculaires. Ce travail démontre également l’efficacité d’un entraînement par IM, lorsqu’il est associé à des soins de kinésithérapie, après rupture du ligament croisé antérieur ou brûlure de la main. L’IM jouerait un rôle prépondérant dans l’activation des programmes moteurs et faciliterait la récupération fonctionnelle. L’IM peut donc être considérée comme un complément bénéfique aux programmes d’entraînement et de réhabilitation dans le développement et le recouvrement des fonctions motricesAnalyzing the electromyographic (EMG) activity accompanying motor imagery (MI) as well as the imagery‐related effects on strength enhancement contributes to a better understanding of the neural mechanisms of MI. Accordingly, the subliminal EMG activity recorded during MI supports the hypothesis of an incomplete inhibition of the motor command during mental rehearsal. Interestingly, the pattern of EMG response was modulated by the mental effort and the imagined contraction type, in the same way as during physical movement. Furthermore, the data provided evidence that MI contributed both to increase muscle strength, though strength gains were not observed in all muscles. Finally, MI was found to facilitate motor recovery following anterior cruciate ligament tear as well as in burned patients. These results confirm that MI should be considered a reliable and costeffective technique to improve motor recovery and motor performance

Efficience du travail mental sur le développement et le recouvrement des capacités motrices : force musculaire et imagerie motrice

Analyzing the electromyographic (EMG) activity accompanying motor imagery (MI) as well as the imagery‐related effects on strength enhancement contributes to a better understanding of the neural mechanisms of MI. Accordingly, the subliminal EMG activity recorded during MI supports the hypothesis of an incomplete inhibition of the motor command during mental rehearsal. Interestingly, the pattern of EMG response was modulated by the mental effort and the imagined contraction type, in the same way as during physical movement. Furthermore, the data provided evidence that MI contributed both to increase muscle strength, though strength gains were not observed in all muscles. Finally, MI was found to facilitate motor recovery following anterior cruciate ligament tear as well as in burned patients. These results confirm that MI should be considered a reliable and costeffective technique to improve motor recovery and motor performance.L’analyse de l’activité électromyographique (EMG) corrélative de l’imagerie motrice (IM) et l’effet de l’entraînement mental sur l’amélioration et le recouvrement de la force musculaire permettent de mieux comprendre les mécanismes nerveux de l’IM et l’importance du contenu de l’image mentale. Une activité EMG subliminale a en effet été enregistrée lors de l’IM, validant l’hypothèse d’une inhibition incomplète de la commande motrice. Elle était modulée selon l’intensité de l’effort mental et le régime de contraction, comme lors d’une contraction physique. Ces données renforcent l’équivalence physiologique entre IM et exécution réelle. Les programmes d’entraînement et de réhabilitation intégrant l’IM s’appuient sur ces données théoriques. L’amélioration de la force musculaire était significativement plus importante suite à un entraînement combinant répétitions physiques et mentales, comparativement à une pratique physique seule, même si l’effet ne concernait que certains groupes musculaires. Ce travail démontre également l’efficacité d’un entraînement par IM, lorsqu’il est associé à des soins de kinésithérapie, après rupture du ligament croisé antérieur ou brûlure de la main. L’IM jouerait un rôle prépondérant dans l’activation des programmes moteurs et faciliterait la récupération fonctionnelle. L’IM peut donc être considérée comme un complément bénéfique aux programmes d’entraînement et de réhabilitation dans le développement et le recouvrement des fonctions motrice

The recruitment of indirect waves within primary motor cortex during motor imagery: A directional transcranial magnetic stimulation study

International audienceMotor imagery (MI) refers to the mental simulation of an action without overt movement. While numerous transcranial magnetic stimulation (TMS) studies provided evidence for a modulation of corticospinal excitability and intracortical inhibition during MI, the neural signature within the primary motor cortex is not clearly established. In the current study, we used directional TMS to probe the modulation of the excitability of early and late indirect waves (I-waves) generating pathways during MI. Corticospinal responses evoked by TMS with posterior–anterior (PA) and anterior–posterior (AP) current flow within the primary motor cortex evoke preferentially early and late I-waves, respectively. Seventeen participants were instructed to stay at rest or to imagine maximal isometric contractions of the right flexor carpi radialis. We demonstrated that the increase of corticospinal excitability during MI is greater with PA than AP orientation. By using paired-pulse stimulations, we confirmed that short-interval intracortical inhibition (SICI) increased during MI in comparison to rest with PA orientation, whereas we found that it decreased with AP orientation. Overall, these results indicate that the pathways recruited by PA and AP orientations that generate early and late I-waves are differentially modulated by MI

Stimulation magnétique transcrânienne et imagerie motrice : corrélats neurophysiologiques de l’action mentalement simulée

La stimulation magnétique transcrânienne (SMT) est devenue en à peine trois décennies un outil scientifique expérimental majeur dans l’étude du système nerveux chez l’homme. Dotée de nombreux atouts méthodologiques (technique non-invasive et à haute résolution temporelle), la SMT est complémentaire des outils d’exploration fonctionnelle du cerveau et elle a permis d’accumuler un nombre considérable de données dans le domaine des neurosciences cognitives et comportementales. Cet article de synthèse présente les récentes avancées en cognition motrice et plus particulièrement en imagerie motrice, un champ de recherche dans lequel la SMT a été grandement utilisée pour explorer l’implication des structures centrales et périphériques sous-jacentes. Après avoir défini les principes neurophysiologiques et méthodologiques de la SMT, nous montrerons que l’imagerie motrice est une activité cognitive à part entière, le cortex moteur et la voie corticomotrice étant spécifiquement impliqués selon le contenu de l’image mentale