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The Olympic brain. Does corticospinal plasticity play a role in acquisition of skills required for high-performance sports?

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Abstract

Non-invasive electrophysiological and imaging techniques have recently made investigation of the intact behaving human brain possible. One of the most intriguing new research areas that have developed through these new technical advances is an improved understanding of the plastic adaptive changes in neuronal circuitries underlying improved performance in relation to skill training. Expansion of the cortical representation or modulation of corticomotor excitability of specific muscles engaged in task performance is required for the acquisition of the skill. These changes at cortical level appear to be paralleled by changes in transmission in spinal neuronal circuitries, which regulate the contribution of sensory feedback mechanisms to the execution of the task. Such adaptive changes also appear to be essential for the consolidation of a memory of performance of motor tasks and thus for the lasting ability of performing highly skilled movements such as those required for Olympic sports.

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... Accessing such information is of great interest for applied fields such as rehabilitation, exercise training and applied physiology. In both rehabilitation and exercise training, the objective is often to induce long-lasting changes in motor behavior, either to restore correct motor patterns or to increase motor performance (Falla et al. 2007;Nielsen and Cohen 2008;Zehr 2006). Thus, an adequate exercise intervention requires an understanding of how and to which extent the neuromuscular system can be changed in response to repeated exposure to motor training (Farina et al. 2004c;Zehr 2006). ...
... Knowledge on the neuromuscular adaptation to training is of great interest for both rehabilitation and exercise training fields (Zehr 2006). Both fields aim to induce long-lasting changes in motor behavior, either to restore correct motor patterns or to increase motor performance (Falla et al. 2007;Nielsen and Cohen 2008;Zehr 2006). ...
... The specific neural adaptations evoked by specific training experiences certainly contribute for the optimization of the motor performance, however such association has been difficult to clearly demonstrate (Nielsen and Cohen 2008). Understanding the extent to which the nervous system can adapt to specific motor training programs is of extreme importance, not only in the exercise field, but also in the rehabilitation field (Zehr 2006 Depending on the type of information intended to extract, different methods can be applied. ...
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Over the last decades, it has been shown that the human neuromuscular system is highly adaptive and can be modified in response to different motor training programs. Depending on the demands of the motor training, the adaptations seem to involve distinct structural and functional changes across the motor cortex, spinal cord and skeletal muscle. The technological development observed in the last years, increased the use of electrophysiological techniques to assess the neuromuscular adaptations to motor training. Nonetheless, the current evidences on the neuromuscular adaptations to different motor training are inconsistent and incomplete, in particular regarding endurance and strength training. This is mainly due to lack of studies based on a rigorous consideration of the limitations of the available techniques. Therefore, the main goal of this dissertation is to give new insights on the adaptations of the neuromuscular system by systematically investigating the changes in its central and peripheral properties, in response to endurance and strength training. For this purpose, recent developed techniques for recording and processing electromiographycal (EMG) signals were applied. The first study (STUDY I) investigated if 6 weeks of either endurance or strength training alters the motor unit behavior and if such changes were accompanied by alterations in muscle fiber properties. Intramuscular and multichannel surface EMG recordings were used to investigate the motor unit discharge rates and motor unit conduction velocity (MUCV) of the vastus medialis obliquus and vastus lateralis during submaximal isometric contractions. The results demonstrated that endurance training increased endurance capacity and was accompanied by a decrease of the motor unit discharge rates. In contrast, strength training enhanced maximum force output and was accompanied by an increase of the motor unit discharge rates. By the end of 6 weeks of training, both training programs elicited increases in the motor unit conduction velocity, revealing electrophysiological adaptations of the muscle fiber membrane properties in similar directions. However, in the first 3 weeks of training, when changes in motor unit discharge rates were most marked, changes in MUCV were not observed. These findings reveal different time courses of some of the neural and peripheral adaptations in response to different motor training programs. The observed changes may contribute for distinct neuromuscular fatigue profiles among endurance and strength-trained athletes. Therefore, the aim of the second study (STUDY II) was to investigate the effects of 6 weeks of endurance and a strength training program on acute responses of the muscle fiber membrane properties and discharge rates of low threshold motor units of the vastus medialis obliquus and vastus lateralis muscles, during prolonged submaximal isometric contractions. The conduction velocity of the individual motor units was estimated from the averaged multichannel EMG surface potentials by a spike triggered average technique. It was shown that the motor unit discharge rate declines over the duration of the sustained contraction and this trend was not significantly affected by training. Conversely, the rate of decline of motor unit conduction velocity during sustained contractions was reduced after six weeks of both endurance and strength training. However, a greater reduction is observed following endurance training. These alterations likely contribute to longer times to task failure following endurance training. The third study (STUDY III) intended to clarify the mechanisms involved in the opposite adjustments of the motor unit discharge rate observed in study I. The results revealed that following 3 weeks of endurance training, the excitability in the H-reflex pathway increased but the V-wave amplitude remained unchanged. In contrast, following strength training, the V-wave amplitude increased whereas subtle changes were observed in the H-reflex pathway. These results suggest that the elements of the H-reflex pathway are strongly involved in chronic adjustments in response to endurance training, contributing to enhance resistance to fatigue. Conversely, following strength training, it is more likely that increased descending neural drive during MVC and/or modulation, in afferents other than Ia afferents, contributed to increased motoneuron excitability and maximal voluntary contraction. This work revealed for the first time that endurance and strength training induces opposite adjustments in the motor unit behavior. Moreover, the distinct adjustments in the spinal cord output seem to result from changes in different neural mechanisms located at supraspinal and/or spinal level. The neural adjustments following endurance training seem to result from changes at spinal level whereas the adjustments following strength training are likely due to changes at supraspinal level. These adaptations occurred following a short period of training, while no changes in the contractile and electrophysiological properties of the muscle fibers were detectable. Changes at peripheral level occurred only following a longer period of training.
... Heavily involved in voluntary movements, the M1 shows a high degree of plasticity and adaptation, due to motor learning and practice [2,3], which determine modifications in the number of synapses, synaptic strength, and topography of stimulation-evoked movement representations [4]. In particular, training induces persistent encoded behaviors within the adult nervous system [5,6] to allow the precise execution of difficult motor tasks [7,8]. ...
... As a non-invasive technique, transcranial magnetic stimulation (TMS) and neuroimaging techniques have been largely used to investigate adaptive changes in human motor cortex [18,19], contributing to understand how networks in the brain build and optimize the motor programs responsible for coordination of muscle activity involved in complex motor learning [5]. Due to the measurable characteristics of the motor evoked potential (MEP) from peripheral muscles, motor cortex excitability has become a relevant topic in TMS studies [3]. ...
... In particular, the lower rMT, shorter MEP latency and higher MEP amplitude observed in karate athletes support the hypothesis that training determines specific brain organizations to meet specific sport challenges. According to literature [5], in this study karate athletes showed different M1 excitability compared to controls, substantiating the role of acquisition and maintenance of specific motor skills on plastic changes in the controlling neural system. Similarly, a decrease in rMT was shown in subjects trained to produce skilled digit movements on a piano, accompanied by an increase in the corresponding area of digit representation [19]. ...
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Objectives: To investigate the involvement of the primary motor cortex (M1) in the coordination performance of karate athletes through transcranial magnetic stimulation (TMS). Methods: Thirteen right-handed male karate athletes (25.0±5.0 years) and 13 matched non-athlete controls (26.7±6.2 years) were enrolled. A single-pulse TMS was applied using a figure-eight coil stimulator. Resting motor threshold (rMT) was determined. Surface electromyography was recorded from the first dorsal interosseous muscle. Motor evoked potential (MEP) latencies and amplitudes at rMT, 110%, and 120% of rMT were considered. Functional assessment of the coordination performance was assessed by in-phase (IP) and anti-phase (AP) homolateral hand and foot coordination tasks performed at 80, 120, and 180 bpm. Results: Compared to controls, athletes showed lower rMT (p<0.01), shorter MEP latency (p<0.01) and higher MEP amplitude (p<0.01), with a significant correlation (r = 0.50, p<0.01) between rMT and MEP latency. Coordination decreased with increasing velocity, and better IP performances emerged compared to AP ones (p<0.001). In general, a high correlation between rMT and coordination tasks was found for both IP and AP conditions. Conclusion: With respect to controls, karate athletes present a higher corticospinal excitability indicating the presence of an activity-dependent alteration in the balance and interactions between inhibitory and facilitatory circuits determining the final output from the M1. Furthermore, the high correlation between corticospinal excitability and coordination performance could support sport-specific neurophysiological arrangements.
... Motor skill learning has become an important issue, due to the increasing involvement of human movement behaviors in neuroscience, psychology, and physical education [1][2][3][4][5] . However, until now, motor learning has puzzled contemporary science, and its mechanisms and contributing factors remaining unclear. ...
... For RA, there was no significant difference in the between-group comparison (F (1,28) =0.146, p=0.706) nor in the interaction of group × three tests (F (2,28) =2.085, p=0.160). However, there was a significant main effect of the withingroup comparison of the three tests (F (2,28) =38.917, p=0.000). ...
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[Purpose] The purpose of the current study was to compare the effectiveness of motor sequential learning according to two different types of practice schedules, distributed practice schedule (two 12-hour inter-trial intervals) and massed practice schedule (two 10-minute inter-trial intervals) using a serial reaction time (SRT) task. [Subjects and Methods] Thirty healthy subjects were recruited and then randomly and evenly assigned to either the distributed practice group or the massed practice group. All subjects performed three consecutive sessions of the SRT task following one of the two different types of practice schedules. Distributed practice was scheduled for two 12-hour inter-session intervals including sleeping time, whereas massed practice was administered for two 10-minute inter-session intervals. Response time (RT) and response accuracy (RA) were measured in at pre-test, mid-test, and post-test. [Results] For RT, univariate analysis demonstrated significant main effects in the within-group comparison of the three tests as well as the interaction effect of two groups × three tests, whereas the between-group comparison showed no significant effect. The results for RA showed no significant differences in neither the between-group comparison nor the interaction effect of two groups × three tests, whereas the within-group comparison of the three tests showed a significant main effect. [Conclusion] Distributed practice led to enhancement of motor skill acquisition at the first inter-session interval as well as at the second inter-interval the following day, compared to massed practice. Consequentially, the results of this study suggest that a distributed practice schedule can enhance the effectiveness of motor sequential learning in 1-day learning as well as for two days learning formats compared to massed practice.
... Namely, it would be justified to enhance cognitive function (from a biolibertarian perspective) or not (from a bioconservative perspective). Indeed, the development of tDCS uses within competitive environments relies on meritocratic arguments, comparable to arguments about sports doping (Nielsen and Cohen, 2008). Questions concerning enhancement legitimacy do not spare the use of tDCS for memory enhancement (Nielsen and Cohen, 2008;Hamilton et al., 2011;Pustovrh, 2014). ...
... Indeed, the development of tDCS uses within competitive environments relies on meritocratic arguments, comparable to arguments about sports doping (Nielsen and Cohen, 2008). Questions concerning enhancement legitimacy do not spare the use of tDCS for memory enhancement (Nielsen and Cohen, 2008;Hamilton et al., 2011;Pustovrh, 2014). These concerns are real in environments where it could be considered that if these improvements are neither authentic nor deserved, then they are not morally commendable (Caplan, 2004;Hamilton et al., 2011). ...
Article
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Transcranial direct current stimulation (tDCS) is a promising technology to enhance cognitive and physical performance. One of the major areas of interest is the enhancement of memory function in healthy individuals. The early arrival of tDCS on the market for lifestyle uses and cognitive enhancement purposes lead to the voicing of some important ethical concerns, especially because, to date, there are no official guidelines or evaluation procedures to tackle these issues. The aim of this article is to review ethical issues related to uses of tDCS for memory enhancement found in the ethics and neuroscience literature and to evaluate how realistic and scientifically well-founded these concerns are? In order to evaluate how plausible or speculative each issue is, we applied the methodological framework described by Racine et al. (2014) for “informed and reflective” speculation in bioethics. This framework could be succinctly presented as requiring: (1) the explicit acknowledgment of factual assumptions and identification of the value attributed to them; (2) the validation of these assumptions with interdisciplinary literature; and (3) the adoption of a broad perspective to support more comprehensive reflection on normative issues. We identified four major considerations associated with the development of tDCS for memory enhancement: safety, autonomy, justice and authenticity. In order to assess the seriousness and likelihood of harm related to each of these concerns, we analyzed the assumptions underlying the ethical issues, and the level of evidence for each of them. We identified seven distinct assumptions: prevalence, social acceptance, efficacy, ideological stance (bioconservative vs. libertarian), potential for misuse, long term side effects, and the delivery of complete and clear information. We conclude that ethical discussion about memory enhancement via tDCS sometimes involves undue speculation, and closer attention to scientific and social facts would bring a more nuanced analysis. At this time, the most realistic concerns are related to safety and violation of users’ autonomy by a breach of informed consent, as potential immediate and long-term health risks to private users remain unknown or not well defined. Clear and complete information about these risks must be provided to research participants and consumers of tDCS products or related services. Broader public education initiatives and warnings would also be worthwhile to reach those who are constructing their own tDCS devices.
... To investigate adaptive changes in human motor cortex TMS and neuroimaging techniques were largely used (Pascual-Leone et al., 1995;Missitzi et al., 2011;Chieffi et al., 2014;Viggiano et al., 2016), contributing to the understanding of how brain networks organize the optimal motor programs which coordinate muscle activity involved in several tasks of motor learning (Nielsen and Cohen, 2008). In TMS studies, motor cortex excitability has become fundamental for the assessment of the MEP of peripheral muscles (Lee et al., 2010). ...
... According to literature FIGURE 2 | ROC curve of the resting motor threshold considering the whole of population, **p < 0.001. (Nielsen and Cohen, 2008), different M1 excitability reflects the neural plasticity substrate responsible for the acquisition and maintenance of specific motor skills. Similarly, decrease in rMT was seen in subjects trained to produce skilled finger movements (piano playing). ...
Article
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Purpose: The mechanisms involved in the coordination of muscle activity are not completely known: to investigate adaptive changes in human motor cortex Transcranial magnetic stimulation (TMS) was often used. The sport models are frequently used to study how the training may affect the corticospinal system excitability: Karate represents a valuable sport model for this kind of investigations for its high levels of coordination required to athletes. This study was aimed at examining possible changes in the resting motor threshold (rMT) and in the corticospinal response in karate athletes, and at determining whether athletes are characterized by a specific value of rMT. Methods: We recruited 25 right-handed young karate athletes and 25 matched non-athletes. TMS was applied to primary motor cortex (M1). Motor evoked potential (MEP) were recorded by two electrodes placed above the first dorsal interosseous (FDI) muscle. We considered MEP latencies and amplitudes at rMT, 110% of rMT, and 120% of rMT. Results: The two groups were similar for age (p > 0.05), height (p > 0.05) and body mass (p > 0.05). The TMS had a 70-mm figure-of-eight coil and a maximum output of 2.2 T, placed over the left motor cortex. During the stimulation, a mechanical arm kept the coil tangential to the scalp, with the handle at 45° respect to the midline. The SofTaxic navigator system (E.M.S. Italy, www.emsmedical.net) was used in order to correctly identifying and repeating the stimulation for every subject. Compared to non-athletes, athletes showed a lower resting motor threshold (p < 0.001). Furthermore, athletes had a lower MEP latency (p < 0.001) and a higher MEP amplitude (p < 0.001) compared to non-athletes. Moreover, a ROC curve for rMT was found significant (area: 0.907; sensitivity 84%, specificity 76%). Conclusions: As the main finding, the present study showed significant differences in cortical excitability between athletes and non-athletes. The training can improve cortical excitability inducing athletes' modifications, as demonstrated in rMT and MEP values. These finding support the hypothesis that the sport practice determines specific brain organizations in relationship with the sport challenges.
... Heavily involved in voluntary contraction of skeletal muscles, the M1 shows a high degree of plasticity and adaptation due to motor learning and practice [5,6], which produces modifications in the number of synapses, synaptic strength, and topography of stimulus-evoked movement representations [7]. In particular, training induces persistent-encoded behaviors within the adult nervous system [8,9] to allow the precise execution of difficult motor tasks [10]. By requiring a high level of coordination for the precise execution of technical skills in static and dynamic conditions, karate could represent a valuable model to investigate the effects of chronic training on the corticospinal system excitability of athletes. ...
... In fact, authors consider RT as a key strategy in competitive sports which require fast reactions, such as karate and sprint events of athletics [15]. As non-invasive techniques, transcranial magnetic stimulation (TMS) and neuroimaging techniques have been largely used to investigate adaptive changes in human motor cortex [16,17], contributing to understand how networks in the brain build and to optimize the motor programs responsible for coordination of muscle activity involved in complex motor learning [8]. Due to the measurable characteristics of the MEP from peripheral muscles, motor cortex excitability has become the most common topic in TMS studies [18]. ...
Article
Full-text available
The aim of this study was to verify the hypothesis that transcranial magnetic stimulation (TMS) parameters over the hand region of the motor cortex, such as resting motor threshold (rMT) and motor evoked potential (MEP) latency, predict the behavioural performance of karate athletes in the response time (RT) test. Twenty-five male karate athletes (24.9 ± 4.9 years) and 25 matched non-athletes (26.2 ± 4.5 years) were recruited. Using TMS, we investigated cortico-spinal system excitability. Compared with controls, the athletes showed faster RT (p < 0.001), lower rMT (p < 0.01), shorter MEP latency (p < 0.01), and higher MEP amplitude (p < 0.01); moreover, there was a significant positive linear correlation between RT and rMT (p < 0.001), between RT and MEP latency (p < 0.0001), and a negative correlation between RT and MEP amplitude (p < 0.001). The practice of competitive sports affects both the central and peripheral nervous system. Subjects that showed higher cortical excitability showed also higher velocity, at which the neural signal is propagated from the motor cortex to the muscle and consequently better RT. The lower rMT and the shorter MEP latency observed in athletes support the effects of training in determining specific brain organizations to meet specific sport challenges.
... The underlying mirror mechanisms result in comparable activation of motor or motor-related cortical networks when individuals are observing or conducting the identical action (Mattar and Gribble, 2005;Loporto et al., 2011). This neural system activation by observation enhances motor skill acquisition of the observer (Heyes and Foster, 2002;Nielsen and Cohen, 2008). The likely mechanism of this skill-enhancing effect of action observation might be long-term potentiation (LTP)-like plasticity of the respective regions, which is suggested to be promoted by task-related motor cortex activity and excitability enhancements (Celnik et al., 2006;Loporto et al., 2011). ...
Article
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Pathways of the human mirror neuron system are activated during both, action observation and action execution, including lateralized activation of respective areas, as shown by observed right-or left-hand actions. Here, we investigated whether execution-dependent motor cortex excitability is affected by prior interaction between transcranial random noise stimulation (tRNS) and action observation. Sham or real tRNS (1 mA) was applied for 10-min over the left primary motor cortex during action observation. In the main experiments, participants received sham or real tRNS while they watched a video showing repeated tapping tasks, involving either the right-hand (Experiment 1, congruent action observation), or a mirror-reversed video showing the same performance (Experiment 2), followed by action execution of the right-hand. In control Experiments 1–3, participants received real tRNS while observing a perceptual sequence, watching a landscape picture, or observing the left-hand performing the action (the sequence was identical to Experiment 1), followed by action execution of the right-hand. In control Experiment 4, participants received real tRNS during congruent action observation, and then took 6-min rest. Motor-evoked potentials (MEP) were recorded before action observation, a perceptual sequence or a landscape picture, immediately after, and after action execution, or an interval of 6-min, dependent on the respective experimental condition. MEPs in the right first dorsal interosseous muscle increased significantly after real tRNS combined with congruent action observation, and after action execution compared to the sham session in Experiment 1 and control experiments. We conclude that prior interaction between real tRNS and action observation of mirror-matched movements modulates subsequent execution-dependent motor cortex excitability.
... Skill acquisition is accompanied by numerous changes in the neuromuscular system (Wolpaw 2007;Nielsen and Cohen 2008). One well-known change involves recruitment properties of motor unit activity (Semmler and Nordstrom 1998;Kornatz et al. 2005;Onushko et al. 2013). ...
Article
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The study aimed to compare the ability of dance and non-dance subjects to perform fine control of a simple heel-raising/lowering movement, and to determine if there are any differences in motor unit activity in the primary plantar flexor muscles during the movement. Subjects were instructed to accurately track a sinusoidal trace with a heel-raising and lowering movement at four controlled frequencies (1, 0.5, 0.25, and 0.125 Hz). The ankle joint angle was used to characterize movement errors from the target. Surface electromyography was recorded from the soleus and medial gastrocnemius muscles. One trial including five sinusoidal traces was divided into two phases: an up phase and a down phase. To characterize motor unit activity of the plantar flexor muscles, a wavelet transform was applied to electromyographic signals recorded in each phase. For both phases, errors in movement accuracy were lower in dancers than in controls (8.7 ± 4.6 vs. 11.5 ± 6.8%, P < 0.05) regardless of the frequency of the sinusoidal wave traced. During the down phase, peak power of soleus electromyographic signals at ~ 10 Hz was statistically larger in control subjects than in dancers (10.4 ± 0.7 vs. 6.3 ± 0.4% total power, P < 0.05). These results indicate that dancers have a higher degree of motor skill in a heel raise tracking task and exhibit adaptations in the motor unit activity during skilled dynamic movements.
... Sport Expertise and Movement Disorders 4 control of perceptual-motor skills (e.g., Latash & Anson, 1996;Nielsen & Cohen, 2008; 75 Pazzaglia & Galli, 2015). However, previous reviews using an expert athlete to disabled 76 patient framework have either been too narrowly focused on one point of the skill continuum 77 or have not been comprehensive enough to include both behavioural and neuroscience 78 evidence. ...
Article
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A framework is presented of how theoretical predictions can be tested across the expert athlete to disabled patient skill continuum. Common-coding theory is used as the exemplar to discuss sensory and motor system contributions to perceptual-motor behavior. Behavioral and neural studies investigating expert athletes and patients recovering from cerebral stroke are reviewed. They provide evidence of bi-directional contributions of visual and motor systems to perceptual-motor behavior. Majority of this research is focused on perceptual-motor performance or learning, with less on transfer. The field is ripe for research designed to test theoretical predictions across the expert athlete to disabled patient skill continuum. Our view has implications for theory and practice in sports science, physical education, and rehabilitation.
... This has been interpreted as a shift in postural control from the low-level to high-level control centers and serves as a feedforward mechanism of postural control (23,49). This task-related modulation of both spinal and supraspinal control appears to be essential for developing highly skilled athletic performance (40). Badminton players exhibited reduced spinal excitability during receive stance while football juggling experts displayed enhanced supraspinal excitability, both of which represent better postural control (18,34). ...
... They must precisely control their direction of movement, their speed of execution, and monitor their spatial location relative to objects in the surrounding environment (Huang et al. 2015;Wang et al. 2013aWang et al. , 2016. Gymnastics relies on the ability of the nervous system to activate the correct muscles to the proper extent at the right time and in the right sequence (Nielsen and Cohen 2008). Gymnastics also requires integration of inputs from multiple sensory modalities (Calvert and Thesen 2004;Stein and Stanford 2008). ...
Article
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Long-term intensive gymnastic training can induce brain structural and functional reorganization. Previous studies have identified structural and functional network differences between world class gymnasts (WCGs) and non-athletes at the whole-brain level. However, it is still unclear how interactions within and between functional networks are affected by long-term intensive gymnastic training. We examined both intra- and inter-network functional connectivity of gymnasts relative to non-athletes using resting-state fMRI (R-fMRI). R-fMRI data were acquired from 13 WCGs and 14 non-athlete controls. Group-independent component analysis (ICA) was adopted to decompose the R-fMRI data into spatial independent components and associated time courses. An automatic component identification method was used to identify components of interest associated with resting-state networks (RSNs). We identified nine RSNs, the basal ganglia network (BG), sensorimotor network (SMN), cerebellum (CB), anterior and posterior default mode networks (aDMN/pDMN), left and right fronto-parietal networks (lFPN/rFPN), primary visual network (PVN), and extrastriate visual network (EVN). Statistical analyses revealed that the intra-network functional connectivity was significantly decreased within the BG, aDMN, lFPN, and rFPN, but increased within the EVN in the WCGs compared to the controls. In addition, the WCGs showed uniformly decreased inter-network functional connectivity between SMN and BG, CB, and PVN, BG and PVN, and pDMN and rFPN compared to the controls. We interpret this generally weaker intra- and inter-network functional connectivity in WCGs during the resting state as a result of greater efficiency in the WCGs’ brain associated with long-term motor skill training.
... We make use of this ability when acquiring new motor skills and when adapting our movements to account for predictable changes to our environment. Motor learning plays a critical role in acquiring the motor actions necessary for high-performance sports (Nielsen and Cohen, 2008) and for motor recovery after brain lesions (Kitago and Krakauer, 2013). Applying weak direct current through the scalp induces polarity-specific changes in the excitability of cortical neurons Brunoni et al., 2012). ...
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Motor learning consists of the ability to improve motor actions through practice playing a major role in the acquisition of skills required for high-performance sports or motor function recovery after brain lesions. During the last decades, it has been reported that transcranial direct-current stimulation (tDCS), consisting in applying weak direct current through the scalp, is able of inducing polarity-specific changes in the excitability of cortical neurons. This low-cost, painless and well-tolerated portable technique has found a wide-spread use in the motor learning domain where it has been successfully applied to enhance motor learning in healthy individuals and for motor recovery after brain lesion as well as in pathological states associated to motor deficits. The main objective of this mini-review is to offer an integrative view about the potential use of tDCS for human motor learning modulation. Furthermore, we introduce the basic mechanisms underlying immediate and long-term effects associated to tDCS along with important considerations about its limitations and progression in recent years.
... The last decades of the twentieth century witnessed an important shift in the paradigm of talent detection (Durand-Bush & Salmela, 2001;Lidor, et al., 2009) and scientists progressively produced evidence that more than a genetic construct, talent and expertise result from a dynamic process of development and interaction between genetic and environmental constraints (Davids & Baker, 2007;Phillips, Davids, Renshaw, & Portus, 2010;Simonton, 1999). Such constraints might be training and psychosocial factors (Araújo, et al., 2010;Barreiros, Côté, & Fonseca, 2013;Côté & Vierimaa, 2014;) which are subtended by profound neural adaptations (e.g., Abreu, Macaluso, Azevedo, Cesari, Urgesi, & Aglioti, 2012;Abreu & Duarte, 2015;Aglioti et al., 2008;Draganski, et al., 2004;Nielsen & Cohen, 2008;Yarrow, Brown, & Krakauer, 2009). ...
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For long, people have wondered about the reasons for the superior performance of elite athletes. As it seems, researchers have been divided between reasons that pertain to nature and those that pertain to nurture. More recently, more complex interactionist theories have come to light. These theories posit that both genes and environment contribute to the development of motor expertise in a non-linear way. It is possible that this discussion might never be resolved. Here, we propose that instead of concentrating on the reasons " why " , we concentrate on the " how " , i.e., brain function associated to motor expertise. There is much support for specific neural activation associated to expertise in sports. Here we discuss some of the main findings in this area and propose that by understanding the motor expert brain, we might optimize training and, ultimately, performance. Crucially, we suggest that neurofeedback techniques might constitute an important tool to achieve this.
... Animals who display with high degrees of precision and fine motor control might show similar levels of skill in organismal functions more directly related to survival such as foraging and predator evasion (Byers et al. 2010). Skill in the blue-black grassquit leap display could presumably also be achieved and improved through the repeated performance of this motor task, similarly to what has been shown for high-achievement athletes (Nielsen and Cohen 2008). ...
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Animal social behaviors are often mediated by signals that provide information about signaler attributes. Although some signals are structurally simple, others are temporally dynamic and multifaceted. In such cases, exaggeration of some display components is likely to curtail the expression of others. We quantified features of the acrobatic, multimodal “leap display” of blue-black grassquits (Volatinia jacarina), which appears to entail moderate-to-high performance levels in terms of vigor and skill. We video recorded and quantified leap parameters (height, duration, rotation angle, launch velocity, and number of wing beats) and assessed how these parameters covaried with each other and with vocal parameters, display rates, and body mass index. Our analyses revealed correlations among multiple performance variables: leap height, duration, launch velocity, and number of wing beats. Leap height also correlated positively with song duration. By contrast, no leap parameters covaried with rotation angle. Our analyses also revealed a trade-off in vigor and skill-based leap attributes: birds with a lower body mass index showed a negative relationship between leap heights and the proportion of displays that included leaps (vs. perched vocalizations only). Our results identify directions of display evolution subject to mechanical or timing constraints and provide evidence that display attributes that emphasize vigor and skill may limit one another. Our results also support a key expectation of handicap models of display evolution, which is that costs of display execution should be borne disproportionately by signalers of lower quality.
... Being noninvasive techniques, transcranial magnetic stimulation (TMS) and neuroimaging techniques have been largely used to investigate adaptive changes in human motor cortex (Pascual-Leone et al. 1995;Missitzi et al. 2011), contributing to understanding how networks in the brain build and optimize the motor programs responsible for motor performance (Nielsen and Cohen 2008;Viggiano et al. 2014). ...
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Objectives: In taekwondo competitions, fatigue has a large influence on performance. Recent studies have reported that the excitability in the primary hand motor cortex, investigated with transcranial magnetic stimulation (TMS), is enhanced at the end of a maximal exercise and that this improvement correlates with blood lactate. The aim of the present study was to investigate the relationship between blood lactate and cortical excitability in taekwondo athletes and non-athletes. Methods: The excitability of the primary motor cortex was measured before and after fatiguing hand-grip exercise by TMS. Capillary blood lactate was measured at rest (pre-test), at the end (0 min), and at 3 and 10 min after the exercise by using a "Lactate Pro" portable lactate analyzer. Results: Significant differences in cortical excitability between the two groups were found after the exercise (p < 0.05). Furthermore, we found a significant relationship between cortical excitability and blood lactate (p < 0.01). Conclusion: The present findings showed changes in the excitability in the athletes group and also in the non-athletes group. However, blood lactate seems to have the greater effect in trained subjects compared to untrained subjects. In fact, it appears that, during extremely intensive exercise in taekwondo athletes, lactate may delay the onset of fatigue not only by maintaining the excitability of muscle, but also by increasing the excitability of the primary motor cortex more than in non-athletes.
... psychopedagogika twórczości (Szmidt, Modrzejewska-Śmigulska, 2005;Wiechnik, 1996), koncepcja rozkwitu (Seligman, 2012), paradygmat ekspercki (Nielsen, Cohen, 2008) oraz uważność. ...
Conference Paper
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The nature of the education system is changing throughout the time and space. The view that education is a tool to produce the well-prepared conformists and workforces is being eclipsed by the movement in thought where a child is recognised as an individual. Mainstream schools around the world (USA, Australia, Great Britain, Israel, Hong-Kong) are contemporary actively implementing new programs based on results of empirical research in psychology (person-centered approach-Carl Rogers and humanistic psychology; orienting to creativity – Allport and Maslow; model of flourishing – Seligman; expert paradigm – Nilsen, Cohen; mindfulness conceptualization) and pedagogy (dialogic education and mindfulness-based interventions). These programs are cited that nurturing a child's emotional, mental and spiritual well-being are essential in decreasing stress in the school system, effectiveness of education and stimulating of wellness both students and teachers. Especially mindfulness interventions programs can be shown as effective exemplification of the person-oriented strategy (burgeoning literature on mindfulness meditation with youth, big empirical evidence, meta-analysis confirmations, longtime experiences, positive effectiveness for pupils and parents, for teachers and school stuff and low cost). These new strategies that are being used with increased frequency and receiving mainstream acceptance around the world. And now it's time for Poland.
... Indeed, it is generally accepted that athletes are faster, stronger, more accurate, more efficient, more consistent, and more automatic in the performance of their particular sport, and able to jump higher than non-athletes. For example, the beauty of any gymnastic move or the overwhelming power of a javelin throw relies on the ability of the nervous system to ensure that the correct muscles are activated to the proper extent at the right time and in the right sequence (Nielsen and Cohen, 2008). These notions suggest that the neuronal activities in athletes' brains are flexibly modulated through many years of deliberate practice activities (Ericsson and Lehmann, 1996). ...
Article
While novices who are unfamiliar to a new motor skill typically show variable and unstable movements, highly skilled experts show a stable and accurate performance. These distinct differences in motor control between experts and novices have led researchers to hypothesize that neuromotor noise is reduced in the process of motor skill acquisition. On the other hand, it should be noted that novices' movements have other characteristics; they are habituated and stereotyped. In this review, we discuss the principles governing spatiotemporal organization of movements in novices and experts while solving specific motor problems under varied conditions, by introducing experimental and theoretical studies that use neurophysiological techniques such as electromyography, functional magnetic resonance imaging, and transcranial magnetic stimulation, and mathematical models such as stochastic and dynamical models. On the basis of the findings from a variety of perceptual-motor skills (e.g., ballthrowing, badminton smash, long-distance running, piano and drum performance, street dance, a popular hand game of rock-paper-scissors, and temporal order judgement task), we argue that the novices' characteristic movement patterns were organized under specific constraints and typical strategy, without which the variability would increase even more, while experts' movements were organized with functional and compensatory variability that can drive out erroneous noise variability. We also showed that in a particular type of interlimb coordination, skilled and unskilled movement patterns could be seamlessly described as the time evolution of nonlinear and self-organized dynamical systems, suggesting that the dynamical systems approach is a major candidate for understanding the principle underlying organization of experts' and novices' movements.
... Typically, the notion of a motor program relates to a set of muscle commands, although this definition is subject to disagreement (Summers & Anson, 2009). Certainly, at least some evidence points to strengthening of activity in certain areas of the brain as motor skills are learned (Nielsen & Cohen, 2007), but this evidence falls short of elucidating "programs" that store representations of the movement. Furthermore, the acquisition of these programs has not been explained adequately. ...
Chapter
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At the end of this chapter, you should be able to: • Explain the processes by which motor skills are acquired • Describe the major tenets of diff erent theoretical approaches to the coordination and control of motor skills • Understand which factors infl uence the processes of skill acquisition and adaptations in coordination during the execution of motor skills • Identify organismic, environmental, and task constraints that infl uence the emergence of the coordination and control of movements during the execution of specifi c motor skills • Explain how organismic, environmental, and task constraints infl uence the acquisition of motor skills • Explain how the variables of practice structure and attentional focus infl uence the acquisition of motor skills • Identify the ways in which the variables of practice structure and attentional focus can be manipulated by a coach to ensure the eff ective acquisition of motor skills
... psychopedagogika twórczości (Szmidt, Modrzejewska-Śmigulska, 2005;Wiechnik, 1996), koncepcja rozkwitu (Seligman, 2012), paradygmat ekspercki (Nielsen, Cohen, 2008) oraz uważność. ...
Conference Paper
Full-text available
The nature of the education system is changing throughout the time and space. The view that education is a tool to produce the well-prepared conformists and workforces is being eclipsed by the movement in thought where a child is recognised as an individual. Mainstream schools around the world (USA, Australia, Great Britain, Israel, Hong-Kong) are contemporary actively implementing new programs based on results of empirical research in psychology (person-centered approach-Carl Rogers and humanistic psychology; orienting to creativity – Allport and Maslow; model of flourishing – Seligman; expert paradigm – Nilsen, Cohen; mindfulness conceptualization) and pedagogy (dialogic education and mindfulness-based interventions). These programs are cited that nurturing a child's emotional, mental and spiritual well-being are essential in decreasing stress in the school system, effectiveness of education and stimulating of wellness both students and teachers. Especially mindfulness interventions programs can be shown as effective exemplification of the person-oriented strategy (burgeoning literature on mindfulness meditation with youth, big empirical evidence, meta-analysis confirmations, longtime experiences, positive effectiveness for pupils and parents, for teachers and school stuff and low cost). These new strategies that are being used with increased frequency and receiving mainstream acceptance around the world. And now it's time for Poland.
... 1. Constrangimentos genéticos e ambientais (Davids & Baker, 2007;Phillips, Davids, Renshaw & Portus, 2010;Simonton, 1999); 2. Fatores inerentes ao contexto de treino e fatores psicossociais (Barreiros, Côté & Fonseca, 2013;Côté & Vierimaa, 2014;Araújo, et al., 2010); 3. As intensas adaptações ao nível da atividade cerebral (Abreu & Duarte, 2015;Coyle, 2009, Draganski, et al., 2004Fields, 2008;Nielsen & Cohen;Yarrow, Brown & Krakauer, 2009). ...
... This can include perception, decision-making, motor preparation, and execution of movements. For instance, in order to perform a skilled movement, the nervous system needs to activate required motor unit(s) in a proper manner at the right time and in the correct sequence [34]. This statement suggests that neural activities in the athletes' brains are modified with the participation of long-term training activities [35]. ...
Article
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Background It has been stated that long-term participation in sport training can influence the motor asymmetry of the arms with a decreased interlimb difference. However, whether this pattern is observable in different sports and with different variables, like perceptual performance, still needs to be tested. Therefore, we investigated if long-term sports participation might modify the motor and perceptual performance asymmetries of arms in water polo players. It was hypothesized that water polo players would perform with less interlimb asymmetry in comparison to nonathletes. Methods Right-handed water polo players and nonathletes were tested on motor performance for both arms during a reaching task. Thirteen water polo players and thirteen nonathletes performed reaching movements under two experimental conditions: (a) right arm and (b) left arm. Velocity, accuracy, hand path deviation from linearity, and reaction time were calculated for each trial and for both arms. The potential interlimb differences in movement performance could be assessed by testing. Results Consistent with the hypothesis, our findings showed that water polo players displayed substantially less asymmetry in the performance of accuracy and reaction time. Conclusions These findings suggest that performance asymmetries of arms can be altered via intense long-term practice.
... The M1 shows a high degree of plasticity and adaptation in response to motor learning and practice (Jensen et al., 2005;Lee et al., 2010). Specifically, motor skill training is known to induce persistent encoded neural activations within the cortex that cascade through M1 to facilitate the precise execution of difficult motor tasks (Adkins et al., 2006;Nielsen & Cohen, 2008). As such, M1 appears to be an ideal target for tDCS insofar as the stimulation can easily facilitate the neural cascade that travels through motor cortical neurons during movement tasks, leading to accelerated plasticity of the associated neural circuitry. ...
Article
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Recently, increased attention has been directed to the brain to better understand how motor skill expertise develops. One promising technique purported to accelerate motor skill improvement is transcranial direct current stimulation (tDCS). While simple fine motor tasks involving the hands and fingers are most frequently used to investigate the role of tDCS on motor skill learning, less work has examined the role of tDCS on complex sensori-motor tasks applicable to occupational, sport, and daily living activities. Esports require a high degree of sensori-motor control and have become one of the most popular forms of digital entertainment worldwide. Currently, no research has quantified the development of motor skill expertise in esports or whether tDCS can enhance skill improvement. The current study aimed to first differentiate the sensorimotor performance of a key gameplay skill among esports players of different skill levels. Secondly, we quantified the training effect on performance. Finally, we investigated the effect of tDCS on performance improvements. We hypothesised that esport players would perform superiorly compared to novice gamers, that all groups would be able to improve their performance through training, and that tDCS would enhance training induced performance improvements. We found that performance on a single fundamental esport skill can differentiate expertise among novice and skilled players, that training can significantly improve performance among all expertise levels and that tDCS preferentially accelerates the performance improvements of novice players. The implications of this work, specifically regarding the temporal application of tDCS during complex motor skill learning and rehabilitation, are discussed.
... Despite the physical impairments that these individuals have, they engage in daily physical training to improve their performance and increase their chances of winning. It is well known that the intense motor practices that elite athletes, musicians, or ballet dancers engage in induce both functional and structural plastic changes in their brains (1)(2)(3). The underlying property of these plastic changes is called experience-or use-dependent neural plasticity, which refers to fundamental neural properties leading to sustained functional and anatomical remodeling of different areas in the central nervous system. ...
Article
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Use-dependent and impairment-specific brain plasticity are hypothesized to interact and enhance neural reorganization in the central nervous system (CNS) of athletes with physical impairments. Paralympic brain studies are helpful in achieving a fundamental understanding of the underlying neural mechanism related to CNS reorganization after physical therapy or athletic training. Information learned from these individuals also provides new insights into sports- and rehabilitation-related neuroscience.
... One novel finding of this study is that individuals with greater lower limb (VL) CSE (HIGH) performed better throughout SMOS and that differences in CSE were directly related to physical activity levels. A plethora of work has detailed the use-dependent properties of the human motor cortex (55-60), whereby use (or disuse) is accompanied by task-specific changes in cortical representations (61), gray matter volume (62), and corticomotor excitability (63). Accordingly and in contrast to our observation of a weak positive relationship between CSE and physical activity, recent work suggests that individuals with lower physical activity habits display greater corticospinal excitability (30,31). ...
Article
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Simulated military operational stress (SMOS) provides a useful model to better understand resilience in humans as the stress associated with caloric restriction, sleep deficits, and fatiguing exertion degrades physical and cognitive performance. Habitual physical activity may confer resilience against these stressors by promoting favorable use-dependent neuroplasticity, but it is unclear how physical activity, resilience, and corticospinal excitability (CSE) relate during SMOS. Purpose: To examine associations between corticospinal excitability, physical activity, and physical performance during SMOS. Methods: Fifty-three service members (age: 26±5yrs, 13 women) completed a five day and night intervention composed of familiarization, baseline, SMOS (two nights/days), and recovery days. During SMOS, participants performed rigorous physical and cognitive activities while receiving half of normal sleep (two 2h blocks) and caloric requirements. Lower and upper limb CSE were determined with transcranial magnetic stimulation (TMS) stimulus-response curves. Self-reported resilience, physical activity, military-specific physical performance (TMT) and endocrine factors were compared in individuals with high (HIGH) and low CSE based on a median split of lower limb CSE at baseline. Results: HIGH had greater physical activity and better TMT performance throughout SMOS. Both groups maintained physical performance despite substantial psychophysiological stress. Physical activity, resilience, and TMT performance were directly associated with lower limb CSE. Conclusion: Individual differences in physical activity coincide with lower (but not upper) limb CSE. Such use-dependent corticospinal excitability directly relates to resilience and physical performance during SMOS. Future studies may use non-invasive neuromodulation to clarify the interplay among CSE, physical activity, and resilience and improve physical and cognitive performance.
... In line with this, decreased SMN-DMN connection in the CS group was to ensure functional optimization of the SMN. The SMN dominates complex motor processes by integrating various sensory inputs [34,35]. In this context, negative correlations of SMN-VIN and SMN-AUN may prevent visual, auditory, and motor functional systems from interfering with each other, to flexibly estimate motor direction, executive speed, and spatial location during the combat process. ...
Article
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Purpose To explore the effects of combat sports on functional network connectivity (FNC) in healthy adolescents. Methods Resting-state fMRI data were acquired from the combat sports (CS) group (n = 32) and non-athlete healthy control (HC) group (n = 29). Resting-state networks (RSNs) were obtained based on independent component analysis (ICA), and FNC analysis was performed. Then, the intra-network and inter-network connections were compared between the two groups. Results Compared with the HC group, the CS group demonstrated increased intra-network FC within the sensorimotor network (SMN), visual network (VIN), and cerebellum network (P < 0.01, FDR correction). Besides, decreased inter-network FC was found in the SMN-VIN, SMN-auditory network, SMN-default mode network, attention network (AN)-VIN, and AN-executive control network connections (P < 0.01, FDR correction). Conclusion This study showed a complex relationship between combat sports and FNC in adolescents. The observed FNC patterns in the CS group may reflect training-related brain network optimization, early signs of subclinical brain damage, or preexisting differences. The extensive effects of combat sports on FNC in adolescents could expand our understanding of neuromodulatory mechanisms.
... Therefore, developing a practical intensive training or rehabilitation program requires consideration of time and intensity (12,13). Some studies have demonstrated that traditional center-based CP rehabilitation programs (e.g., hospitals, gyms, sports centers) positively affect children with CP with 30-45 min sessions per day, which seems to be necessary for neuroplasticity (14)(15)(16)(17). Traditional center-based approaches in physical therapy, such as group therapy and therapist-assisted therapy, target children with certain types of CP in a face-toface manner and can enhance communication between children with CP and their parents (18). ...
Article
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Virtual Reality (VR) therapy is popular in treating children with Cerebral Palsy (CP) as a new technology for rehabilitation. Nevertheless, no substantial evidence supporting VR therapy promotion has been developed to date. This study aimed to investigate the effects of VR therapy on balance in children with CP. We conducted a systematic search in PubMed and Web of Science (updated to December 30, 2021). The systematic review and meta-analysis included all randomized controlled trials that included children with CP. A total of 18 RCT studies were eligible for inclusion in the systematic review, and meta-analysis was performed on 16 of them. Results showed that the VR intervention was beneficial for balance (SMD 0.47 [95% CI, SD 0.28, 0.66]). We concluded that VR therapy interventions for children with CP have positive effects. However, cautious implementation is needed in clinical applications.
... To perform optimally, rugby players train vigorously to improve skills such as catching, passing and kicking in pressure situations (Meir, 2005). Research suggests that chronic training produces modifications in the number of synapses, synaptic strength, and topography of stimulus-evoked movement representation, and induces persistent-encoded behaviours within the nervous system (Monfils et al., 2005;Nielsen and Cohen, 2008). This causes athletes to improve exponentially in relation to decision making tasks that occur within their sporting environment, which in turn causes enhanced performance when compared to non-athletes. ...
Article
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The present study aimed to compare the visual expertise of non-athletes (n ¼ 40; 19-35 years old; age: 22.13 AE 2.37 years) to amateur, non-professional South-African Rugby Union (SARU) first-division club rugby players (n ¼ 40; 19-35 years old; age: 23.88 AE 4.36 years; training age mean: 9.0 AE 1.5 years). Research suggests that athletes have enhanced visio-spatial expertise in comparison to non-athletes. However, conflicting research suggests that this is not always the case as non-athletes possess similar visio-spatial expertise in certain visual skills. Participants underwent an optometric assessment after which the following 6 visio-spatial intelligence (VSI) components were measured; accommodation facility, saccadic eye movement, speed of recognition, peripheral awareness, visual memory and hand-eye coordination using the following tests; hart near far rock, saccadic eye movement, evasion, accumulator, flash memory and ball wall toss tests. Results indicated that first-division rugby players performed significantly better (p 0.05) in five of the six tests performed, except for visual memory (p ¼ 0.893). While this study substantiates the notion that athletes, in this case first-division rugby players, performs significantly better in most VSI components, this is not the case for all, as with visual memory in this study. To more accurately distinguish between athletes and non-athletes, research should move away from tests that focus on basic visual function and develop sport specific testing methods that can be used by a variety of sports.
... By means of NAT 2.0, we examined three groups of subjects with completely different age, clinical conditions, cognitive abilities, and motor skills inviting them to walk with closed eyes along a sequence of numbered or colored cubes after visual memorization of the path: [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. They were all asymptomatic and presented normal LSC-VOR at VHIT. ...
Article
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Aim of the study: in humans, spatial orientation consists of the ability to move around the environment through memorized and pre-programmed movements, according to the afferent sensory information of the body and environmental analysis of the Central Nervous System (CNS). The purpose of this study is to analyze the abilities of professional athletes, such as footballers, to use mental navigation systems, cognitive maps, and memorized motor patterns in order to obtain better physical performance and to obtain useful information for training both non-sports subjects and vestibular patients for rehabilitation purposes. Materials and methods: all the motor performances of sportsmen, healthy non-sporting subjects, or vestibular patients are based on the acquisition of visual-spatial and training information. In this study, we analyzed the visual-spatial performance of 60 trained sportsmen (professional footballers), 60 healthy non-sports subjects, and 48 patients affected by chronic unilateral vestibular loss by means of the Navigation Ability Test 2.0. A score based on the number of targets correctly reached in the various tests quantifies the degree of performance of the subjects. Results: NAT 2.0 scores progressively improve from vestibular subjects to healthy non-sporting subjects to footballers. NAT 2.0 scores improve in all three subject groups as the number of tasks performed in all patient groups increases, regardless of gender and age. Conclusions: the analysis of performance data through NAT 2.0 in athletes (footballers) opens new perspectives for rehabilitation purposes, regardless of age, sex, and training conditions, both in healthy non-sporting subjects to improve their sporting potential and in patients affected by chronic vestibular dysfunction, in order to optimize their motor skills and prevent falls.
... In humans, neuroplasticity is commonly investigated indirectly e.g. using brain stimulation and neuroimaging techniques (see 1 for review of early, seminal papers). The corticospinal tract plays a key role in motor control 2 , and plastic changes in the corticospinal pathway are important mechanisms for the acquisition of skilled movement 3 . In humans, the early phase of motor skill acquisition is accompanied by a transient increase in corticospinal excitability (CSE). ...
Article
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Motor skill acquisition depends on central nervous plasticity. However, behavioural determinants leading to long lasting corticospinal plasticity and motor expertise remain unexplored. Here we investigate behavioural and electrophysiological effects of individually tailored progressive practice during long-term motor skill training. Two groups of participants practiced a visuomotor task requiring precise control of the right digiti minimi for 6 weeks. One group trained with constant task difficulty, while the other group trained with progressively increasing task difficulty, i.e. continuously adjusted to their individual skill level. Compared to constant practice, progressive practice resulted in a two-fold greater performance at an advanced task level and associated increases in corticospinal excitability. Differences were maintained 8 days later, whereas both groups demonstrated equal retention 14 months later. We demonstrate that progressive practice enhances motor skill learning and promotes corticospinal plasticity. These findings underline the importance of continuously challenging patients and athletes to promote neural plasticity, skilled performance, and recovery.
... position of an opposing player. Although athletes often make this process appear simple, the cognition required to perform a skill is complex (Nielsen & Cohen, 2008). Consequently, the brain holds a key role in technical performance, ranging from, for example, the accuracy of passing between team-mates or closeness of foot position to the front of the long jump take-off board. ...
... The definition of Olympic Brain refers to the ability of the brain to reorganize itself in response to new environmental challenges. A reserve of cerebral functions is able to favor the recovery and / or compensation in case of damage [80]. Its development may increase cardiac reserve and reduce the burden of disability and related costs. ...
Article
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Introduction: The central nervous system is the generator of the dynamic balance between cholinergic and noradrenergic activity. Different behavioral tendencies are observed in subjects with prevalent parasympatic tone (defense strategy, energy sparing, dissociation) compared to those with sympathic one (relational interaction, high energy expenditure). These responses may influence susceptibility and vulnerability to diseases. The aim of our study was to examine cardiovascular function from the heart to the periphery by 24 hours detection of both heart and pulse rate in cerebrovascular conditions. Materials and Methods: We recruited 113 Acute Ischaemic Syndromes (AIS, age 73,43 sd 12,34), 32 Chronic Cerebro-Vascular Diseases (CCVD, age 75,95 sd 8,06), 30 Other Neurological Diseases (OND, age 50,09 sd 15,05). Cardiovascular reactivity (CR) was defined by beat indices, ratio (R) or difference (D) between higher maximal or minimal heart rate (HR) on higher maximal or minimal pulse rate (PR). A value < 1 or > 1 were considered as negative (NCR) or positive CR (PCR), respectively. Results: Max PR was significantly higher in CCVD and AIS compared to OND. Max CR was lower in CCVD and AIS compared to OND. Increased levels of glycosylated hemoglobin, cardiac biomarkers, abnormal findings at Holter ECG and Echocardiography were particularly observed in case of NCR. Conclusions: NCR may interfere with normal activity of daily living. Higher Hachinski ischaemic scores in these patients point out a higher ischaemic load. Moreover, NCR identified a category of acute patients with worst outcomes, requiring prompt intensive care because of higher risk of complications and mortality. Our observations may be useful for better choosing among therapeutical options, planning rehabilitation and health enhancing physical activity in aging. Moreover, they may reduce the risk of injuries for training overload in athletes.
... It is well established that the human central nervous system has the capability to reorganize after focal lesions like stroke and spinal cord injury, if physical rehabilitation is applied properly according to the types of disabilities [1,2]. While athletic training that Paralympic athletes engage in is not regarded as physical rehabilitation since the goal is to improve their performance and increase their competitive level rather than to improve physical functions for daily living, this athletic training is also known to induce plastic changes in the central nervous system in a use-dependent manner [3][4][5]. This athletic training, therefore, is also expected to induce central nervous system (CNS) reorganization in the Paralympic athletes. ...
Article
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The main aim of the study was to evaluate how the brain of a Paralympic athlete with severe disability due to cerebral palsy has reorganized after continuous training geared to enhance performance. Both corticospinal excitability of upper-limb muscles and electromyographic activity during swimming were investigated for a Paralympic gold medalist in swimming competitions. Transcranial magnetic stimulation (TMS) to the affected and intact hand motor cortical area revealed that the affected side finger muscle cortical representation area shifted towards the temporal side, and cortico-spinal excitability of the target muscle was prominently facilitated, i.e., the maximum motor evoked potential in the affected side, 6.11 ± 0.19 mV was greater than that in the intact side, 4.52 ± 0.39 mV (mean ± standard error). Electromyographic activities during swimming demonstrated well-coordinated patterns as compared with rather spastic activities observed in the affected side during walking on land. These results suggest that the ability of the brain to reorganize through intensive training in Paralympic athletes can teach interesting lessons to the field neurorehabilitation.
... It is reasonable to think that people who have higher levels of fitness could respond differently to acute AE. 21 TMS studies have shown that adherence to exercise in the longer term increases baseline levels of brain excitability, allowing fitter individuals to benefit more robustly from neuroplasticityinducing interventions 22 including acute AE. 23 Likewise, among people with MS, Chaves et al 6 reported an association between lower levels of fitness and increased GABAergicmediated intracortical inhibition measured with a longer cortical silent period (CSP), a TMS biomarker of diminished neuroplasticity. 24,25 Similarly, a longer CSP has been linked to greater neurological impairments in people with stroke, 26,27 Huntington disease, 28 and MS. 29 In general, most people with MS do not engage in regular physical activity; 4,6,30,31 therefore, it is important to understand whether lower fitness levels and sedentarism may be hindering the potential benefits of strategies aimed at improving brain function. ...
Article
Background and purpose: Even a single bout of aerobic exercise (AE) enhances corticospinal excitability (CSE), a biomarker of neuroplasticity. Because neurodegeneration limits capacity for neuroplasticity, it is not clear whether AE would induce CSE changes in people with progressive multiple sclerosis (MS). Methods: People with progressive MS (n = 10) requiring ambulatory assistive devices completed a graded maximal exercise test. Dual-energy x-ray absorptiometry was used to quantify body fat and lean mass. Before and following one 40-minute AE session using body weight-supported (<10% support) treadmill at moderate intensity, CSE was measured using transcranial magnetic stimulation. Variables included resting and active motor thresholds, motor evoked potential (MEP) amplitudes, recruitment curves, and length of the cortical silent period (CSP). Results: Aerobic exercise reduced inhibition (shorter CSP) and increased excitation (increased MEP amplitude) only in the hemisphere corresponding to the stronger hand. Controlling for age, higher fitness and lower body fat significantly predicted exercise-induced reduction in resting motor threshold (ΔR = +0.458, P = 0.046) and CSP (ΔR = +0.568, P = 0.030), respectively. Discussion and conclusions: Despite high levels of disability, capacity for exercise-induced neuroplasticity was retained among people with progressive MS. The hemisphere contralateral to the weaker hand was resistant to exercise-induced CSE changes, suggesting less neuroplastic potential. Lower fitness and higher body fat were associated with diminished exercise-induced CSE benefits, suggesting that therapists should consider interventions aimed at improving fitness and combating sedentarism to ultimately enhance the benefits of exercise on the brain.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A302).
... Again, thanks to research on modern neuroscience, the theory of neural plasticity clearly illustrates the difference between these two situations. Using functional MRI brain mapping, we can notice, for different situations requiring absolute concentration for a given action without any dispersion (no reflection), that complex multiple neuronal connections become extremely simple thanks to plasticity, (see for example, Adkins et al. 2006, Nielsen andCohen 2008). We encounter such situations, for example in sports competitions where we need a very high level of concentration to achieve a precise action. ...
... Handedness defined as side preference and efficiency depends on practice and experience, which improve motor learning (Serrien et al., 2006;Nielsen and Cohen, 2008;Mawase et al., 2018). Long-term preferential use may result in changes in muscle fiber composition and activity (Diederichsen et al., 2007). ...
Article
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Measuring the quality of movement is a need and a challenge for clinicians. Jerk, defined as the quantity of acceleration variation, is a kinematic parameter used to assess the smoothness of movement. We aimed to assess and compare jerk metrics in asymptomatic participants for 3 important movement characteristics that are considered by clinicians during shoulder examination: dominant and non-dominant side, concentric and eccentric contraction mode, and arm elevation plane. In this pilot study, we measured jerk metrics by using Xsens ® inertial measurement units strapped to the wrists for 11 different active arm movements (ascending and lowering phases): 3 bilateral maximal arm elevations in sagittal, scapular and frontal plane; 2 unilateral functional movements (hair combing and low back washing); and 2 unilateral maximal arm elevations in sagittal and scapular plane, performed with both arms alternately, right arm first. Each arm movement was repeated 3 times successively and the whole procedure was performed 3 times on different days. The recorded time series was segmented with semi-supervised algorithms. Comparisons involved the Wilcoxon signed rank test ( p < 0.05) with Bonferroni correction. We included 30 right-handed asymptomatic individuals [17 men, mean (SD) age 31.9 (11.4) years]. Right jerk was significantly less than left jerk for bilateral arm elevations in all planes (all p < 0.05) and for functional movement ( p < 0.05). Jerk was significantly reduced during the concentric (ascending) phase than eccentric (lowering) phase for bilateral and unilateral right and left arm elevations in all planes (all p < 0.05). Jerk during bilateral arm elevation was significantly reduced in the sagittal and scapular planes versus the frontal plane (both p < 0.01) and in the sagittal versus scapular plane ( p < 0.05). Jerk during unilateral left arm elevation was significantly reduced in the sagittal versus scapular plane ( p < 0.05). Jerk metrics did not differ between sagittal and scapular unilateral right arm elevation. Using inertial measurement units, jerk metrics can well describe differences between the dominant and non-dominant arm, concentric and eccentric modes and planes in arm elevation. Jerk metrics were reduced during arm movements performed with the dominant right arm during the concentric phase and in the sagittal plane. Using IMUs, jerk metrics are a promising method to assess the quality of basic shoulder movement.
Conference Paper
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Mindfulness as person-oriented-pedagogy: conceptualization and empirical findings Mindfulness is defined as nonjudgmental awareness which includes softness, acceptance of experience as it is, non-evaluation, kindness, openness, and curiosity. Mainstream schools around the world are now actively implementing new programs based on mindfulness (person-centered approach, orienting to creativity and flourishing, expert paradigm and dialogic education). Mindfulness interventions programs can be shown as effective exemplification of the person-oriented strategy (burgeoning literature on mindfulness meditation with youth, big empirical evidence, meta-analysis confirmations, longtime experiences, positive effectiveness for pupils and parents, for teachers and school stuff and low cost). Crucial mechanism that impede mindfulness in education are: attentional bias, repetitive negative thought, reappraisal, suppression, experiential avoidance, negative affectivity and emotional reactivity.
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Abstract The aim of this review was to analyze the experimental research literature suggesting a beneficial role of aerobical exercise training on brain structure and function throughout the life span in non-pathological populations, through a search of articles published from 2004 to date, in PubMed, Science Direct and Scopus data. Thirty articles were selected to analyze. Studies show that aerobic training at each stage of life has a positive impact on various cognitive processes, executive functions, processing speed, attention and memory, and produce changes in brain structure like prefrontal and temporal cortex.
Article
Resistance training increases volitional force producing capacity, and it is widely accepted that such an increase is partly underpinned by adaptations in the central nervous system, particularly in the early phases of training. Despite this, the neural substrate(s) responsible for mediating adaptation remains largely unknown. Most studies have focused on the corticospinal tract, the main descending pathway controlling movement in humans, with equivocal findings. It is possible that neural adaptation to resistance training is mediated by other structures; one such candidate is the reticulospinal tract. The aim of this narrative mini-review is to articulate the potential of the reticulospinal tract to underpin adaptations in muscle strength. Specifically, we 1) discuss why the structure and function of the reticulospinal tract implicates it as a potential site for adaptation; 2) review the animal and human literature that supports the idea of the reticulospinal tract as an important neural substrate underpinning adaptation to resistance training; and 3) examine the potential methodological options to assess the reticulospinal tract in humans.
Chapter
Mindfulness-based intervention modalities that were initially introduced within clinical psychology for the treatment of a variety of psychological conditions have also been applied in the sport context for the purpose of enhancing athletic performance and the general psychological well-being of athletic clientele. Since we first introduced systematic mindfulness practice into the sport domain in 2001, mindfulness-based interventions utilized in sports have gained increasing empirical support for their efficacy, and relevant mechanisms of action have been identified. Exploring these developments, this chapter highlights differences between Eastern and Western philosophical mindfulness traditions; describes conceptual considerations, theoretical developments, and mechanisms of action of mindfulness; discusses cognitive demands in human performance contexts; explores the use of mindfulness protocols and the empirical research accumulated to date in the sport milieu; and proposes future considerations that can aid in the evolution of mindfulness-based interventions for the enhancement of athletic performance.
Chapter
Induced by the increasing knowledge about the beneficial impact of physical activity on the structure and function of the nervous system scientific studies have tried to elucidate the underlying neurobiological mechanisms. Numerous animal studies confirmed the release of neurotrophic factors, the induction of neuronal plasticity, and increased proliferation of neuronal stem cells due to regular physical activity (e g., jogging). Additionally, modern innovative imaging techniques and sophisticated molecular methods revealed these effects in healthy subjects due to aerobic endurance exercises. Several studies also indicate beneficial neurobiological effects of sportive exercises that may play an important role in neurorehabilitation after acute injury of the central nervous system and in the treatment of neurodegenerative disorders.
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Mindfulness is defined as nonjudgmental awareness which includes softness, acceptance of experience as it is, non-evaluation, kindness, openness, and curiosity. Mainstream schools around the world are now actively implementing new programs based on mindfulness (person-centered approach, orienting to creativity and flourishing, expert paradigm and dialogic education). Mindfulness interventions programs can be shown as effective exemplification of the person-oriented strategy (burgeoning literature on mindfulness meditation with youth, big empirical evidence, meta-analysis confirmations, longtime experiences, positive effectiveness for pupils and parents, for teachers and school stuff and low cost). Crucial mechanism that impede mindfulness in education are: attentional bias, repetitive negative thought, reappraisal, suppression, experiential avoidance, negative affectivity and emotional reactivity
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Cognitive tasks may have the potential to improve visuomotor task performance; however, the reason for this is unclear. If this can be clarified, it may be possible to develop clinically valuable outcomes, such as promotion of motor learning though cognitive tasks. The present study aimed to investigate whether changes in prefrontal area excitability induced by cognitive tasks, especially within the dorsolateral prefrontal cortex (DLPFC), influenced the speed of improvement during visuomotor task performance. Twenty young healthy adults were recruited. The serial reaction time task (SRTT) was used to assess visuomotor task performance. Cognitive tasks included an adjusted N-back task, a non-adjusted N-back task, and a control task, which were evaluated on different days. Additionally, we measured cerebral hemodynamic activity using near-infrared spectroscopy while each cognitive task was being performed. We observed that the adjusted N-back task significantly enhanced the speed of improvement during the SRTT performance compared to the control task. However, there was no relationship between the speed of improvement during the SRTT performance and changes in prefrontal area excitability induced by the cognitive tasks. Our findings contribute towards developing an effective method that uses cognitive tasks to promote visuomotor learning.
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Motor learning plays an important role in the acquisition of new motor skills. In this study, we investigated whether repetition of a cognitive task promoted motor learning. Fifty-one young adults were assigned to either the early, late, or control groups. All participants completed a mouse tracking task in which they manipulated a mouse to track a moving target on a screen. The cursor was rotated 165° in the counterclockwise direction from the actual mouse position, requiring participants to learn how to use a new tool. To determine the task performance, we calculated the distance between the cursor and target position. In addition, to assess the effects of a cognitive task on the progress of motor learning, curve fitting of the learning curves was performed for the total distance. Experiments were conducted as per the following schedule: learning day 1 (L1), learning day 2 (L2: the day after learning day 1), retention day 1 (R1: 2 weeks after learning day 1), and retention day 2 (R2: 4 weeks after learning day 1). Participants underwent mouse tracking for 20 min on L1 and L2 and for 3 min on R1 and R2. As a cognitive task, we adopted the N-back task. The early or late group performed the N-back task for 20 min before performing motor tracking task on L1 or L2, respectively. The control group did not perform the N-back task. Based on curve fitting analysis, it was observed that the rate of change for motor learning in the early group was higher than that in the control group. The retention of motor learning did not differ between all groups. Our results indicate that the repetition of a cognitive task enhanced in the early phase of motor learning of the mouse tracking task.
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Skill increase in motor performance can be defined as explicitly measuring task success but also via more implicit measures of movement kinematics. Even though these measures are often related, there is evidence that they represent distinct concepts of learning. In the present study, the effect of multiple tDCS-sessions on both explicit and implicit measures of learning are investigated in a pointing task in 30 young adults (YA) between 27.07 ± 3.8 years and 30 old adults (OA) between 67.97 years ± 5.3 years. We hypothesized, that OA would show slower explicit skill learning indicated by higher movement times/lower accuracy and slower implicit learning indicated by higher spatial variability but profit more from anodal tDCS compared with YA. We found age-related differences in movement time but not in accuracy or spatial variability. TDCS did not skill learning facilitate learning neither in explicit nor implicit parameters. However, contrary to our hypotheses, we found tDCS-associated higher accuracy only in YA but not in spatial variability. Taken together, our data shows limited overlapping of tDCS effects in explicit and implicit skill parameters. Furthermore, it supports the assumption that tDCS is capable of producing a performance-enhancing brain state at least for explicit skill acquisition.
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objetivo de esta revisión es analizar la evidencia existente sobre los beneficios del componente educativo en el manejo y proceso de rehabilitación de los pacientes con EPOC. Materiales y métodos. Se realizó la búsqueda de evidencia en las bases de datos: PubMed, Ebsco, Science Direct y Pedro. Se incluyeron publicaciones de los últimos 6 años, en idioma inglés y español, que reportaran pacientes con EPOC, adultos mayores y educación. Resultados. En la búsqueda se encontraron 17 estudios que describen la aplicación de un programa de educación. Discusión. En la EPOC, la educación juega un papel importante, ya que se ha demostrado que tiene impacto positivo en diferentes aspectos como son el número de exacerbaciones, calidad de vida, costo-efectividad en el manejo de la enfermedad, nivel de actividad física y adherencia al ejercicio. Por otro lado, la evidencia muestra que el reconocimiento de la enfermedad y apropiación de conceptos, ayudan a incrementar la confianza en ellos mismos y a mejorar en sus actividades de la vida diaria, con una vida más plena y controlada. Conclusiones. Los pacientes que reciben educación sobre su enfermedad y cómo manejarla tienen efectos positivos en cuanto a los síntomas, número de exacerbaciones, y hospitalizaciones, calidad de vida y costo efectividad en el manejo de la enfermedad. Palabras clave: EPOC, Programa de Educación, Calidad de vida
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Background: Regular physical activity or aerobic exercise is well known to increase brain plasticity. Recent studies have reported that aerobic exercise enhances neuroplasticity and motor learning. The aim of this study was to investigate if 12 weeks' aerobic training can modify cortical excitability and motor evoked potential (MEP) responses. Methods: Fifteen untrained males were recruited. Cortical excitability was investigated using TMS. VO2max was estimated using Cooper's test. Aerobic intervention lasted 12 weeks. The subjects performed a 6-week supervised aerobic workout, 3 times a week, at 60-75% of their maximum heart rate (HRmax). Over the following 6 weeks,they performed a supervised aerobic workout 3 times a week at 70-75% of FCmax. Results: After 8 weeks of aerobic training there was a significant increase of distance covered during Cooper's test (p<0.001) and a significant increase of VO2max (p<0.001); there was also an improvement in resting motor threshold (rMT decreased from 60.5%±6.6 (T0) to 55.8%±5.9 (T2); p<0.001), motor evoked potential latency decreased (from 25.3ms±0.8 (T0) to 24.1ms±0.8 (T2); p<0.001), and motor evoked potential amplitude increased (from 0.58mV±0.09 (T0) to 0.65mV±0.08 (T2); p<0.001). Furthermore, after 12 weeks' aerobic training there were improvements in all parameters. Conclusions: This study shows that aerobic activity seems to induce changes 34 in cortical excitability if performed for a period longer than 4 weeks, in addition to typical cardiorespiratory benefits in previously untrained males.
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In the martial arts motor activities that allow the development of the physical qualities of various forms; these disciplines handle mechanisms that facilitate learning and improving the martial art through the collection of data and subsequent analysis to generate learning of movement patterns. Objective: analyze the role that sensory integration processes in learning and performing martial artists to the scientific literature Materials and methods. An article of reflection develops, after reviewing the literature found in databases as: scielo, bireme, PubMed, lilacs, and collaboration cochraine focusing on learning processes and execution of martial arts, later supplemented by reading books of sporting gesture and finished with reflective stance of the author. Results: The review shows that sensory integration processes facilitate the uptake of environmental information and that generate changes in motor engrams allowing athletes learning multiple movement patterns that have multiple martial arts Conclusion: improving patterns of movement in martial arts is possible thanks to the mechanisms of information acquisition means by individuals, this analysis will identify aspects of athletic training can be enhanced by improving the learning motor of martial arts through modifications teaching and practice schemes of movement patterns, making a comprehensive approach to individuals who perform these sports.
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Background The strength of connections between motor cortex (MCX) and muscle can be augmented with a variety of stimulation protocols. Augmenting MCX-to-muscle connection strength by neuromodulation may be a way to enhance the intact motor system's capacity for acquiring motor skills and promote function after injury to strengthen spared connections. But this enhancement must be maintained for functional improvements. Objective We determined if brief MCX muscle evoked potential (MEP) enhancement produced by intermittent theta burst stimulation (iTBS) can be converted into a longer and structurally durable form of response enhancement with repeated daily and longer-term application. Methods Electrical iTBS was delivered through an implanted MCX epidural electrode and MEPs were recorded using implanted EMG electrodes in awake naïve rats. MCX activity was modulated further using chemogenetic (DREADDs) excitation and inhibition. Corticospinal tract (CST) axons were traced and immunochemistry used to measure CST synapses. Results A single MCX iTBS block (600 pulses) produced MEP LTP lasting ∼30–45 min. Concatenating five iTBS blocks within a 30-min session produced MEP LTP lasting 24–48 h, which could be strengthened or weakened by bidirectional MCX activity modulation. Effect duration was not changed. Finally, daily induction of this persistent MEP LTP with daily iTBS for 10-days produced MEP enhancement outlasting the stimulation period by at least 10 days, and accompanied by CST axonal outgrowth and structural changes at the CST-spinal interneuron synapse. Conclusion Our findings inform the mechanisms of iTBS and provide a framework for designing neuromodulatory strategies to promote durable enhancement of cortical motor actions.
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Anterior cruciate ligament (ACL) injury risk reduction strategies primarily focus on biomechanical factors related to frontal plane knee motion and loading. Although central nervous system processing has emerged as a contributor to injury risk, brain activity associated with the resultant ACL injury-risk biomechanics is limited. Thus, the purposes of this preliminary study were to determine the relationship between bilateral motor control brain activity and injury risk biomechanics and isolate differences in brain activity for those who demonstrate high versus low ACL injury risk. Thirty-one high school female athletes completed a novel, multi-joint leg press during brain functional magnetic resonance imaging (fMRI) to characterize bilateral motor control brain activity. Athletes also completed an established biomechanical assessment of ACL injury risk biomechanics within a 3D motion analysis laboratory. Knee abduction moments during landing were modelled as a covariate of interest within the fMRI analyses to identify directional relationships with brain activity and an injury-risk group classification analysis, based on established knee abduction moment cut-points. Greater landing knee abduction moments were associated with greater lingual gyrus, intracalcarine cortex, posterior cingulate cortex and precuneus activity when performing the bilateral leg press (all z > 3.1, p < .05; multiple comparison corrected). In the follow-up injury-risk classification analysis, those classified as high ACL injury-risk had greater activity in the lingual gyrus, parietal cortex and bilateral primary and secondary motor cortices relative to those classified as low ACL injury-risk (all z > 3.1, p < .05; multiple comparison corrected). In young female athletes, elevated brain activity for bilateral leg motor control in regions that integrate sensory, spatial, and attentional information were related to ACL injury-risk landing biomechanics. These data implicate crossmodal visual and proprioceptive integration brain activity and knee spatial awareness as potential neurotherapeutic targets to optimize ACL injury-risk reduction strategies.
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Basic principles of magnetic stimulation of biological tissues are reviewed. Noninvasive magnetic stimulation of the brain delivered over sensorimotor areas evokes movements and less commonly paresthesias in contralateral limbs. We have evaluated the maps of motor outputs in patients with (1) congenital mirror movements, which resulted in marked derangement of the map of outputs of distal hand muscles with enlarged and ipsilateral representations; (2) amputations, which resulted in plastic reorganization of motor outputs targeting muscles immediately proximal to the stump; (3) spinal cord injury, which also resulted in enlargement of the map of outputs targeting muscles proximal to the lesion level; and (4) hemispherectomy performed at an early age for intractable seizures, which resulted in the remaining hemisphere controlling ipsilateral arm muscles. These results demonstrate the potential for reorganization in motor systems following lesions in the peripheral as well as in the central nervous system.
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1. We used transcranial magnetic stimulation (TMS) to study the role of plastic changes of the human motor system in the acquisition of new fine motor skills. We mapped the cortical motor areas targeting the contralateral long finger flexor and extensor muscles in subjects learning a one-handed, five-finger exercise on the piano. In a second experiment, we studied the different effects of mental and physical practice of the same five-finger exercise on the modulation of the cortical motor areas targeting muscles involved in the task. 2. Over the course of 5 days, as subjects learned the one-handed, five-finger exercise through daily 2-h manual practice sessions, the cortical motor areas targeting the long finger flexor and extensor muscles enlarged, and their activation threshold decreased. Such changes were limited to the cortical representation of the hand used in the exercise. No changes of cortical motor outputs occurred in control subjects who underwent daily TMS mapping but did not practice on the piano at all (control group 1). 3. We studied the effect of increased hand use without specific skill learning in subjects who played the piano at will for 2 h each day using only the right hand but who were not taught the five-finger exercise (control group 2) and who did not practice any specific task. In these control subjects, the changes in cortical motor outputs were similar but significantly less prominent than in those occurring in the test subjects, who learned the new skill.(ABSTRACT TRUNCATED AT 250 WORDS)
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Magnetic source imaging revealed that the cortical representation of the digits of the left hand of string players was larger than that in controls. The effect was smallest for the left thumb, and no such differences were observed for the representations of the right hand digits. The amount of cortical reorganization in the representation of the fingering digits was correlated with the age at which the person had begun to play. These results suggest that the representation of different parts of the body in the primary somatosensory cortex of humans depends on use and changes to conform to the current needs and experiences of the individual.
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Performance of complex motor tasks, such as rapid sequences of finger movements, can be improved in terms of speed and accuracy over several weeks by daily practice sessions. This improvement does not generalize to a matched sequence of identical component movements, nor to the contralateral hand. Here we report a study of the neural changes underlying this learning using functional magnetic resonance imaging (MRI) of local blood oxygenation level-dependent (BOLD) signals evoked in primary motor cortex (M1). Before training, a comparable extent of M1 was activated by both sequences. However, two ordering effects were observed: repeating a sequence within a brief time window initially resulted in a smaller area of activation (habituation), but later in larger area of activation (enhancement), suggesting a switch in M1 processing mode within the first session (fast learning). By week 4 of training, concurrent with asymptotic performance, the extent of cortex activated by the practised sequence enlarged compared with the unpractised sequence, irrespective of order (slow learning). These changes persisted for several months. The results suggest a slowly evolving, long-term, experience-dependent reorganization of the adult M1, which may underlie the acquisition and retention of the motor skill.
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Using functional magnetic resonance imaging (fMRI) we have evaluated the anatomical location of the motor hand area. The segment of the precentral gyrus that most often contained motor hand function was a knob-like structure, that is shaped like an omega or epsilon in the axial plane and like a hook in the sagittal plane. On the cortical surface of cadaver specimens this precentral knob corresponded precisely to the characteristic 'middle knee' of the central sulcus that has been described by various anatomists in the last century. We were then able to show that this knob is a reliable landmark for identifying the precentral gyrus directly. We therefore conclude that neural elements involved in motor hand function are located in a characteristic 'precentral knob' which is a reliable landmark for identifying the precentral gyrus under normal and pathological conditions. It faces and forms the 'middle knee' of the central sulcus, is located just at the cross point between the precentral sulcus and the central sulcus, and is therefore also visible on the cortical surface.
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While it is known that relatively rapid changes in functional representation may occur in the human sensorimotor cortex in short-term motor-learning studies, there have been few studies of changes in organisation of the corticomotor system associated with the long-term acquisition of motor skills. In the present study, we have used transcranial magnetic stimulation (TMS) to investigate the corticomotor projection to the hand in a group of elite racquet players, who have developed and maintained a high level of skill over a period of many years, and have compared the findings with those in a group of social players and a group of non-playing control subjects. Increased motor-evoked-potential (MEP) amplitudes and shifts in the cortical motor maps for the playing hand were found in all of the elite players and cortical motor thresholds were reduced in some players, whereas in the social players all parameters were within the normal range. The findings in the elite players are interpreted as being indications of a process of functional reorganisation with the motor cortex or corticomotor pathway that are associated with the acquisition and retention of complex motor skills.
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Practicing movements results in improvement in performance and in plasticity of the motor cortex. To identify the underlying mechanisms, we studied use-dependent plasticity in human subjects premedicated with drugs that influence synaptic plasticity. Use-dependent plasticity was reduced substantially by dextromethorphan (an N-methyl-d-aspartate receptor blocker) and by lorazepam [a gamma-aminobutyric acid (GABA) type A receptor-positive allosteric modulator]. These results identify N-methyl-d-aspartate receptor activation and GABAergic inhibition as mechanisms operating in use-dependent plasticity in intact human motor cortex and point to similarities in the mechanisms underlying this form of plasticity and long-term potentiation.
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One fundamental function of primary motor cortex (MI) is to control voluntary movements. Recent evidence suggests that this role emerges from distributed networks rather than discrete representations and that in adult mammals these networks are capable of modification. Neuronal recordings and activation patterns revealed with neuroimaging methods have shown considerable plasticity of MI representations and cell properties following pathological or traumatic changes and in relation to everyday experience, including motor-skill learning and cognitive motor actions. The intrinsic horizontal neuronal connections in MI are a strong candidate substrate for map reorganization: They interconnect large regions of MI, they show activity-dependent plasticity, and they modify in association with skill learning. These findings suggest that MI cortex is not simply a static motor control structure. It also contains a dynamic substrate that participates in motor learning and possibly in cognitive events as well.
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The purpose of this study was to investigate whether repetitive electrical stimulation of the common peroneal nerve (CPN) is associated with changes in the motor response of the tibialis anterior (TA) muscle elicited by focal magnetic stimulation of the motor cortex. Motor evoked potentials (MEP) with a stimulation intensity of 125% of the threshold of the relaxed right TA were obtained before, during, and after repetitive electrical stimulation of the CPN (trains of five pulses of 1 ms, at a frequency of 200 Hz, repeated every second with a 30-min duration). The MEP of the TA muscle elicited after repetitive electrical stimulation were increased by 104% (range: 18-263%), and the increase was maintained for up to 110 min (range: 15-110 min) after the end of nerve stimulation. This increase in the MEP of the TA muscle was associated with a decrease in the threshold from the stimulation-response curve. Furthermore, during that period the early component of the TA stretch reflex as well as the latency of the MEP did not significantly change. To further test the origin of the increased MEP, complementary experiments showed that MEP elicited by transcranial electrical stimulation (TES) were also increased, but to a lesser degree (approximately 50%) than MEP elicited by TMS. It can be concluded that short-term nerve repetitive electrical stimulation of the lower extremities in healthy human participants can lead to a long-term increase in the contralateral MEP. As TES is believed to mainly activate the axon and not the soma of the cortical cells, the increased MEP cannot be explained exclusively by changes in the motor cortex cell excitability, but also by changes in subcortical neural structures involved in the excitation of spinal motoneurons. The results of this study allow the speculation that it would be possible to use repetitive electrical stimulation in the rehabilitation of patients with lower limb muscle weakness and spasticity.
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Training of spinal cord circuits using sensorimotor stimulation has been proposed as a strategy to improve movement after spinal injury. How sensory stimulation may lead to long-lasting changes is not well understood. We studied whether sensory stimulation might induce changes in the strength of a specific spinal interneuronal circuit: spinally mediated reciprocal Ia inhibition. In healthy humans, the strength of reciprocal inhibition between ankle flexor and extensor muscles was assessed before and after 30 min of peroneal nerve stimulation at motor threshold intensity. Three stimulation protocols were assessed: patterned nerve stimulation (10 pulses at 100 Hz every 1.5 sec), uniform nerve stimulation (one pulse every 150 msec), and combined stimulation of the peroneal nerve and the motor cortex with transcranial magnetic stimulation. Short-latency reciprocal inhibition from ankle flexor to extensor muscles was measured by conditioning the soleus H-reflex with stimulation of the common peroneal nerve. The strength of the reciprocal inhibition was measured at baseline and for 20 min after each stimulation session. Patterned stimulation, with or without motor cortex stimulation, enhanced reciprocal inhibition for at least 5 min afterward. The uniform pattern of stimulation was ineffective. These results demonstrate the presence of short-term plasticity within spinal inhibitory circuits. We conclude that the pattern of sensory input is a crucial factor for inducing changes in the spinal circuit for reciprocal inhibition in humans. These findings may have implications for the use of repetitive patterned sensory stimulation in rehabilitative efforts to improve walking ability in patients with spinal injury.
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The substrates that mediate recovery of motor function after stroke are incompletely understood. Several primate and human studies proposed the involvement of the premotor cortex of the lesioned hemisphere. Here, we studied four chronic stroke patients with focal subcortical lesions affecting the corticospinal outflow originating in the primary motor cortex (M1) and good motor recovery. We tested the hypothesis that, in these patients, disruption of activity in the premotor cortex of the lesioned hemisphere by transcranial magnetic stimulation (TMS) would result in degraded behaviour in the paretic hand. TMS was applied to the primary motor cortex, dorsal premotor cortex (PMd) and ventral premotor cortex (PMv) of the affected (M1AH, PMdAH, PMvAH) and intact (M1IH, PMdIH, PMvIH) hemispheres of patients and healthy controls in the setting of a simple reaction time (SRT) paradigm performed with the hand contralateral to the stimulated hemisphere. TMS applied to M1 led to substantial contralateral SRT delays in both groups. TMS applied to PMdAH of patients elicited clear delays in contralateral SRT in the paretic hand, whereas TMS applied to PMdIH of patients or healthy volunteers did not. Motor evoked potentials after stimulation of PMdAH were, on average, larger and had, on average, shorter latency than after stimulation of M1AH. These results indicate that PMdAH participates as a substrate mediating functional recovery of executive motor function in patients with focal lesions of corticospinal outflow originating in M1 and good motor recovery. Our results are consistent with the hypothesis that the dorsal premotor cortex of the affected hemisphere can reorganize to control basic parameters of movement usually assigned to M1 function.
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Unilateral hand movements are accompanied by a transient decrease in corticospinal (CS) excitability of muscles in the opposite hand. However, the rules that govern this phenomenon are not completely understood. We measured the amplitude of motor evoked potentials (MEP) in the left first dorsal interosseus (FDI) elicited by transcranial magnetic stimulation (TMS) of the primary motor cortex in order to assess CS excitability changes that preceded eight possible combinations of unilateral and bilateral index finger movements with different right hand positions. Left FDI MEP amplitude (MEP(Left FDI)) increased when this muscle acted as an agonist and tended to decrease when it was an antagonist. Additionally, MEP(Left FDI) decreased substantially before right index finger abduction (a movement mediated by the right FDI) when both hands were lying flat (a movement mirroring left index finger abduction) but not when the right hand was turned at 90 degrees or flat with the palm up. Therefore, CS excitability of the resting FDI was differentially modulated depending on the direction of the opposite index finger movement, regardless of muscles engaged in the task. These results indicate that inhibitory interactions preceding unilateral finger movements are determined by movement kinematics possibly to counteract the default production of mirror motions.
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Training-induced changes in cortical excitability may play an important role in rehabilitation of gait ability in patients with neurological disorders. In this study, we investigated the effect of a 32-min period of motor skill, non-skill and passive training involving the ankle muscles on leg motor cortical excitability in healthy humans. Transcranial magnetic stimulation (TMS) at a range of intensities was applied to obtain a recruitment curve of the motor evoked potentials (MEPs) in the tibialis anterior (TA) muscle before and after training. We also explored the effect of training on inhibitory and facilitatory cortical circuits by using a paired-pulse TMS technique at intervals of 2.5 ms (short-interval intracortical inhibition, SICI) and 8 ms (intracortical facilitation, ICF). During motor skill training, subjects were instructed to make a cursor follow a series of target lines on a computer screen by performing voluntary ankle dorsi- and plantarflexion movements. Non-skill and passive training consisted of repeated voluntary and assisted dorsi- and plantarflexion movements, respectively. Recruitment curves increased significantly after 32 min of motor skill training but not after non-skill and passive training, suggesting that only skill motor training increases motor cortical excitability. Motor skill training was not accompanied by any changes in the recruitment curves of TA MEPs evoked by transcranial electrical stimulation, suggesting that the increased MEPs to TMS was likely caused by changes in excitability at a cortical site. SICI was decreased after 32 min of motor skill training but no changes were observed in ICF. We conclude that similar plastic changes as have previously been reported for the hand motor following motor skill training may also be observed for the leg motor area. The observed plastic changes appeared to be related to the degree of difficulty in the motor task, and may be of relevance for rehabilitation of gait disorders.
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Stroke is the leading cause of long-term disability worldwide and a condition for which there is no universally accepted treatment. The development of new effective therapeutic strategies relies on a better understanding of the mechanisms underlying recovery of function. Noninvasive techniques to study brain function, including functional magnetic resonance imaging, positron emission tomography, transcranial magnetic stimulation, electroencephalography, and magnetoencephalography, led to recent studies that identified some of these operating mechanisms, resulting in the formulation of novel approaches to motor rehabilitation.
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Stroke is a leading cause of adult motor disability. Despite recent progress, recovery of motor function after stroke is usually incomplete. This double blind, Sham-controlled, crossover study was designed to test the hypothesis that non-invasive stimulation of the motor cortex could improve motor function in the paretic hand of patients with chronic stroke. Hand function was measured using the Jebsen-Taylor Hand Function Test (JTT), a widely used, well validated test for functional motor assessment that reflects activities of daily living. JTT measured in the paretic hand improved significantly with non-invasive transcranial direct current stimulation (tDCS), but not with Sham, an effect that outlasted the stimulation period, was present in every single patient tested and that correlated with an increment in motor cortical excitability within the affected hemisphere, expressed as increased recruitment curves (RC) and reduced short-interval intracortical inhibition. These results document a beneficial effect of non-invasive cortical stimulation on a set of hand functions that mimic activities of daily living in the paretic hand of patients with chronic stroke, and suggest that this interventional strategy in combination with customary rehabilitative treatments may play an adjuvant role in neurorehabilitation.
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Changes in corticospinal excitability induced by 4 wk of heavy strength training or visuomotor skill learning were investigated in 24 healthy human subjects. Measurements of the input-output relation for biceps brachii motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation were obtained at rest and during voluntary contraction in the course of the training. The training paradigms induced specific changes in the motor performance capacity of the subjects. The strength training group increased maximal dynamic and isometric muscle strength by 31% (P < 0.001) and 12.5% (P = 0.045), respectively. The skill learning group improved skill performance significantly (P < 0.001). With one training bout, the only significant change in transcranial magnetic stimulation parameters was an increase in skill learning group maximal MEP level (MEP(max)) at rest (P = 0.02) for subjects performing skill training. With repeated skill training three times per week for 4 wk, MEP(max) increased and the minimal stimulation intensity required to elicit MEPs decreased significantly at rest and during contraction (P < 0.05). In contrast, MEP(max) and the slope of the input-output relation both decreased significantly at rest but not during contraction in the strength-trained subjects (P < or = 0.01). No significant changes were observed in a control group. A significant correlation between changes in neurophysiological parameters and motor performance was observed for skill learning but not strength training. The data show that increased corticospinal excitability may develop over several weeks of skill training and indicate that these changes may be of importance for task acquisition. Because strength training was not accompanied by similar changes, the data suggest that different adaptive changes are involved in neural adaptation to strength training.
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Using functional magnetic resonance imaging (fMRI) we have evaluated the anatomical location of the motor hand area. The segment of the precentral gyrus that most often contained motor hand function was a knob-like structure, that is shaped like an omega or epsilon in the axial plane and like a hook in the sagittal plane. On the cortical surface of cadaver specimens this precentral knob corresponded precisely to the characteristic 'middle knee' of the central sulcus that has been described by various anatomists in the last century. We were then able to show that this knob is a reliable landmark for identifying the precentral gyrus directly. We therefore conclude that neural elements involved in motor hand function are located in a characteristic 'precentral knob' which is a reliable landmark for identifying the precentral gyrus under normal and pathological conditions. It faces and forms the 'middle knee' of the central sulcus, is located just at the cross point between the precentral sulcus and the central sulcus, and is therefore also visible on the cortical surface.
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The ability of the central nervous system to form motor memories, a process contributing to motor learning and skill acquisition, decreases with age. Dopaminergic activity, one of the mechanisms implicated in memory formation, experiences a similar decline with aging. It is possible that restoring dopaminergic function in elderly adults could lead to improved formation of motor memories with training. We studied the influence of a single oral dose of levodopa (100mg) administered preceding training on the ability to encode an elementary motor memory in the primary motor cortex of elderly and young healthy volunteers in a randomized, double-blind, placebo-controlled design. Attention to the task and motor training kinematics were comparable across age groups and sessions. In young subjects, encoding a motor memory under placebo was more prominent than in older subjects, and the encoding process was accelerated by intake of levodopa. In the elderly group, diminished motor memory encoding under placebo was enhanced by intake of levodopa to levels present in younger subjects. Therefore, upregulation of dopaminergic activity accelerated memory formation in young subjects and restored the ability to form a motor memory in elderly subjects; possible mechanisms underlying the beneficial effects of dopaminergic agents on motor learning in neurorehabilitation. Ann Neurol 2005;58:121–130
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Functional magnetic resonance imaging and transcranial magnetic stimulation studies suggest that human cortex shows evidence of neuroplasticity. Preclinical studies in rats and monkeys suggest that motor cortical stimulation can enhance plasticity and improve recovery after stroke. This study assesses the safety and preliminary efficacy of targeted subthreshold epidural cortical stimulation delivered concurrently with intensive rehabilitation therapy while using an investigational device in patients with chronic hemiparetic stroke. This is a prospective, multicenter, and nonblinded trial randomizing patients to rehabilitation with or without cortical stimulation. Patients aged 20 to 75 years who had had an ischemic stroke at least 4 months previously causing persistent moderate weakness of the arm were included. Functional magnetic resonance imaging localized hand motor function before surgery to place an epidural cortical electrode. Both groups then underwent rehabilitation for 3 weeks after which the electrode was removed. Outcome measures were obtained at baseline, during therapy, and at 1, 4, 8, and 12 weeks postprocedure. Ten patients were randomized; six patients to surgery, four to the control group. No patient deaths, neurological deterioration, or seizures occurred. There were two infections from nonprotocol-related causes. Of the eight patients completing the treatment, the stimulation plus rehabilitation group improved significantly better than controls in the Upper Extremity Fugl-Meyer (P = 0.003 overall) and the hand function score of the Stroke Impact Scale (P =0.001 overall). The technique of cortical stimulation to enhance stroke recovery is well tolerated and safe.
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Numerous clinical studies on patients after hemispherectomy (HS) have provided clear evidence that two distinct groups can be recognized on the basis of the quality of their motor functions after operation. One of these consists of cases where HS was performed after normal brain maturation, the other of patients where the removed hemisphere was damaged early in life. The postoperative motor function has been found to be much better in the latter group. In the present paper it is demonstrated that in contrast to normal subjects ipsilateral compound muscle action potentials (CMAPs) induced by magnetic stimulation of the one intact motor cortex are present in patients after HS. The amplitudes of ipsilateral CMAPs in the muscles roughly correlate with their individual residual motor capacities and show a proximo-distal gradient. In patients with early brain damage prior to HS, CMAPs had short latencies and large amplitudes, whereas in patients with later acquired brain damage prior to HS, CMAPs had long latencies and small amplitudes. It is suggested that reinforcement of the ipsilateral corticospinal pathway may be responsible for residual motor functions in patients with early brain damage, whereas in patients with later acquired brain damage cortico-reticulospinal pathways may play a dominant role in ipsilateral motor control.
Article
In order to examine the effects of repetitive stimulation on functional cortical organization, standard intracortical microstimulation (ICMS) techniques were used to generate maps of movement representations in motor cortex of rat. After identification of caudal and rostral forelimb fields and adjacent vibrissae and neck fields, one or more representational borders were defined in greater detail. Then a microelectrode was introduced into one of these representational fields, and ICMS current pulses were delivered at a rate of 1/sec for 1 to 3 hr. Following repetitive ICMS, significant changes in movement representations were observed using current levels that were either suprathreshold or subthreshold for evoking the site-specific movement. Electromyographic activity could be evoked at suprathreshold and near-threshold current levels, but not at the subthreshold current levels used here. Significant border shifts ranged from 210 to 670 microns. In each case in which shifts occurred, there appeared to be expansion of the movement represented at the repetitively stimulated site. The effects were progressive and reversible. These results suggest that at least under these unusual experimental circumstances, large representational changes can be generated very rapidly within motor cortex in the absence of any evident peripheral feedback.
Article
Transcranial magnetic stimulation over the motor cortex was used to construct a map of the effective sites on the scalp from which short-latency electromyogram responses could be evoked in muscles proximal to either an amputation stump (two subjects) or an ischemically anesthetized forearm (two subjects). At rest, the maps were larger and the responses bigger when stimulating contralateral to the amputated arm or after anesthesia than they were in the intact arm or before anesthesia. However, this difference disappeared when the maps were constructed during a small tonic voluntary contraction of the target muscle. We conclude that reorganisation of the corticospinal projection to a muscle at rest may no longer be present during activity. If so, this calls into question the possible functional benefits of such reorganisation in the control of movement after peripheral damage.
Article
The spinal stretch reflex (SSR), or tendon jerk, is the simplest behavior of the vertebrate nervous system. It is mediated primarily by a wholly spinal, two-neuron pathway. Recent studies from several laboratories have shown that primates, human and nonhuman, can gradually increase or decrease the size of the SSR when reward depends on such change. Evidence of this training remains in the spinal cord after all supraspinal influence is removed. Thus, the learning of this simple motor skill changes the spinal cord itself. Comparable spinal plasticity probably plays a role in the acquisition of many complex motor skills. Intracellular physiological and anatomical studies are seeking the location and nature of this spinal cord plasticity. Attention focuses on the most probable sites of change, the group Ia afferent synapse on the alpha motoneuron and the motoneuron itself. Results to date indicate that modifications are present at several places in the spinal cord. Current clinical studies are investigating the use of spinal cord adaptive plasticity as a basis for a new therapeutic approach to spasticity and other forms of abnormal spinal reflex function that result from spinal cord injury, stroke, or other neurological disorders. In the future, understanding of spinal reflex plasticity may lead to development of improved training methods for a variety of motor skills.
Article
1. The size of the soleus, tibialis anterior and medial gastrocnemius H reflexes were measured at different levels of EMG activity in ankle plantar- and dorsiflexors. At similar levels of EMG activity in the agonist muscle, the soleus and tibials anterior H reflexes were found to be smaller during co-contraction than during an isolated agonist contraction. In contrast to this, the medial gastrocnemius H reflex had the same size during co-contraction as during an isolated plantarflexion at comparable EMG levels. 2. Peaks occurred at monosynaptic reflex latency in the post-stimulus time histogram (PSTH) of firing of soleus and tibialis anterior motor units following stimulation of their respective motor nerves. These homonymous Ia peaks were found to be smaller during co-contraction than during isolated agonist contraction, whereas that of medial gastrocnemius motor units was unchanged. As the monosynaptic peak in the PSTH may give an indirect measure of the size of the monosynaptic EPSP in the motoneurone, it is suggested that these findings reflect a differential control of presynaptic inhibition of soleus and tibialis anterior motor units with respect to medial gastrocnemius motor units. 3. The monosynaptic Ia facilitation of the soleus H reflex evoked by a stimulation of the femoral nerve, was also found to be smaller during co-contraction of tibials anterior and soleus than during isolated plantarflexion. This suggests that presynaptic inhibition of heteronymous Ia fibres from the quadriceps muscle projecting to soleus motoneurones is regulated in the same way as presynaptic inhibition of homonymous Ia fibres during co-contraction. 4. The femoral nerve-induced monosynaptic facilitation of the soleus H reflex was found to decrease with increasing tonic levels of both co-contraction and isolated dorsi- and plantarflexion. The amount of facilitation decreased to the same degree with increasing levels of dorsiflexion and co-contraction. For the same level of EMG in the dorsiflexors there was thus no difference in the amount of facilitation whether the dorsiflexors were activated separately or in a co-contraction. 5. Whereas the soleus H reflex increased in size 50 ms prior to the onset of a dynamic plantarflexion, it did not change prior to the onset of a co-contraction. The femoral nerve-induced facilitation increased prior to the plantarflexion, but decreased prior to the co-contraction.(ABSTRACT TRUNCATED AT 400 WORDS)
The size of the maximalH-reflex (H max) was measured at rest and expressed as a percentage of the maximalM-response (M max) in 17 untrained subjects, 27 moderately trained subjects, 19 well-trained subjects and 7 dancers from the Royal Danish Ballet. TheH max/M max was significantly larger in the moderately and well-trained subjects than in the untrained subjects but smaller in the ballet dancers. It is therefore suggested that both the amount and the type of habitual activity may influence the excitability of spinal reflexes.
Article
We used focal transcranial magnetic stimulation to map the motor cortical areas targeting the first dorsal interosseous and the abductor digiti minimi muscles bilaterally in 10 proficient braille readers and 10 blind controls who were matched for age (mean, 50.6 yr) and age at time of blindness (mean, 7.5 yr). The proficient braille readers had learned braille at age 8 to 14 years and used it daily for 5 to 10 hours. Controls had not learned braille until age 17 to 21 years and used it daily for < 1 hour. In the controls, motor representations of the right and left first dorsal interosseous and abductor digiti minimi muscles were not significantly different. However, in the proficient braille readers, the representation of the first dorsal interosseous muscle in the reading hand was significantly larger than that in the nonreading hand or in either hand of the controls. Conversely, the representation of the abductor digiti minimi muscle in the reading hand was significantly smaller than that in the nonreading hand or in either hand of the controls. These differences were not due to differences in motor thresholds. Our results suggest that the cortical representation of the reading finger in proficient braille readers is enlarged at the expense of the representation of other fingers.