Last posts on mental practice

Facilitation of motor imagery through movement-related cueing

2009-05-03T21:15:41+02:00

Facilitation of motor imagery through movement-related cueing.

Brain Res. 2009 Apr 27;

Authors: Heremans E, Helsen WF, De Poel HJ, Alaerts K, Meyns P, Feys P

In the past few years, the use of motor imagery as an adjunct to other forms of training has been studied extensively. However, very little attention has been paid to how imagery could be used to greatest effect. It is well known that the provision of external cues has a beneficial effect on motor skill acquisition and performance during physical practice. Since physical execution and mental imagery share several common mechanisms, we hypothesized that motor imagery might be affected by external cues in a similar way. To examine this, we compared the motor imagery performance of three groups of 15 healthy participants who either physically performed or imagined performing a goal-directed cyclical wrist movement in the presence or the absence of visual and/or auditory external cues. As outcome measures, the participants' imagery vividness scores and eye movements were measured during all conditions. We found that visual movement-related cues improved the spatial accuracy of the participants' eye movements during imagery, while auditory cues specifically enhanced their temporal accuracy. Furthermore, both types of cues significantly improved the participants' imagery vividness. These findings indicate that subjects may imagine a movement in a better way when provided with external movement-related stimuli, which may possibly be useful with regard to the efficiency of mental practice in (clinical) training protocols.

Development of hierarchical structures for actions and motor imagery

2009-04-16T02:26:54+02:00

Development of hierarchical structures for actions and motor imagery: a constructivist view from synthetic neuro-robotics study.

Psychol Res. 2009 Apr 8;

Authors: Nishimoto R, Tani J

The current paper shows a neuro-robotics experiment on developmental learning of goal-directed actions. The robot was trained to predict visuo-proprioceptive flow of achieving a set of goal-directed behaviors through iterative tutor training processes. The learning was conducted by employing a dynamic neural network model which is characterized by their multiple time-scale dynamics. The experimental results showed that functional hierarchical structures emerge through stages of developments where behavior primitives are generated in earlier stages and their sequences of achieving goals appear in later stages. It was also observed that motor imagery is generated in earlier stages compared to actual behaviors. Our claim that manipulatable inner representation should emerge through the sensory-motor interactions is corresponded to Piaget's constructivist view.

Effects of mental imagery styles on shoulder and hip rotations during preparation of pirouettes

2008-07-18T13:06:14+02:00

Effects of mental imagery styles on shoulder and hip rotations during preparation of pirouettes.

J Mot Behav. 2008 Jul;40(4):281-90

Authors: Golomer E, Bouillette A, Mertz C, Keller J

To analyze individual behavior in spatial navigation especially for pirouette preparations (complete whole-body rotations), the authors studied horizontal shoulder-hip interactions under 2 constraints: postural (right and left supporting legs [SL]) and spatial (clockwise [CW] and counterclockwise [CCW]). They performed kinematic analysis at the start and end of the shoulder-hip horizontal rotations (run-up) with regard to imagery of motor actions. On the basis of the Vividness of Movement Imagery Questionnaire, they classified 8 female expert ballet dancers and 7 untrained female participants according to their movement imagery style (kinesthetic and visual). At the run-up's end, the shoulders initiated the turn independently of SL but differently depending on training: CW for dancers and CCW for untrained participants (their commonly used direction). Kinesthetic and mixed imagery styles prevailed in dancers, whereas simply a mixed style appeared among untrained participants. Thus, dance training enhances the imagery of kinesthetic sensation and influences the choice of spatial direction, facilitating the body-space interaction.

Using mental practice in stroke rehabilitation: a framework

2008-07-09T00:43:34+02:00

Using mental practice in stroke rehabilitation: a framework.

Clin Rehabil. 2008 Jul;22(7):579-91

Authors: Braun S, Kleynen M, Schols J, Schack T, Beurskens A, Wade D

Introduction: Motor imagery and mental practice are getting increased attention in neurological rehabilitation. Several different mental practice intervention protocols have been used in studies on its effect on recovery in stroke rehabilitation. The content of the intervention protocols itself is rarely discussed or questioned.Objective: To give a practical framework of how mental practice could be integrated into therapy, drawing on available evidence and theory. The aim of the treatment programme described is to enhance both the patient's physical performance and their empowerment and self-determination.The framework: Based on evidence from sports rehabilitation and our own experiences the framework will eventually be evaluated in a randomized controlled trial. Five steps are described to teach and upgrade the patient's imagery technique: (1) assess mental capacity to learn imagery technique; (2) establish the nature of mental practice; (3) teach imagery technique; (4) embed and monitor imagery technique; (5) develop self-generated treatments. The description is not, however, a recipe that should be followed precisely. It leaves enough room to tailor the mental practice intervention to the specific individual possibilities, skills and needs of the patient in accordance with evidence-based practice.Discussion: Different aspects of the described protocol are discussed and compared with experiences from sports and evidence available in rehabilitation.

Neural activation in cognitive motor processes

2008-04-23T16:46:44+02:00

Neural activation in cognitive motor processes: comparing motor imagery and observation of gymnastic movements.

Exp Brain Res. 2008 Apr 19;

Authors: Munzert J, Zentgraf K, Stark R, Vaitl D

The simulation concept suggested by Jeannerod (Neuroimage 14:S103-S109, 2001) defines the S-states of action observation and mental simulation of action as action-related mental states lacking overt execution. Within this framework, similarities and neural overlap between S-states and overt execution are interpreted as providing the common basis for the motor representations implemented within the motor system. The present brain imaging study compared activation overlap and differential activation during mental simulation (motor imagery) with that while observing gymnastic movements. The fMRI conjunction analysis revealed overlapping activation for both S-states in primary motor cortex, premotor cortex, and the supplementary motor area as well as in the intraparietal sulcus, cerebellar hemispheres, and parts of the basal ganglia. A direct contrast between the motor imagery and observation conditions revealed stronger activation for imagery in the posterior insula and the anterior cingulate gyrus. The hippocampus, the superior parietal lobe, and the cerebellar areas were differentially activated in the observation condition. In general, these data corroborate the concept of action-related S-states because of the high overlap in core motor as well as in motor-related areas. We argue that differential activity between S-states relates to task-specific and modal information processing.

Kinesthetic Imagery and Tool-Specific Modulation of Corticospinal Representations in Expert Tennis Players

2008-03-10T13:32:53+01:00

Kinesthetic Imagery and Tool-Specific Modulation of Corticospinal Representations in Expert Tennis Players.

Cereb Cortex. 2008 Feb 21;

Authors: Fourkas AD, Bonavolontà V, Avenanti A, Aglioti SM

Specific physical or mental practice may induce short- and long-term neuroplastic changes in the motor system and cause tools to become part of one's own body representation. Athletes who use tools as part of their practice may be an excellent model for assessing the neural correlates of possible bodily representation changes that are specific to extensive practice. We used single-pulse transcranial magnetic stimulation to measure corticospinal excitability in forearm and hand muscles of expert tennis players and novices although they mentally practiced a tennis forehand, table tennis forehand, and a golf drive. The muscles of expert tennis players showed increased corticospinal facilitation during motor imagery of tennis but not golf or table tennis. Novices, although athletes, were not modulated across sports. Subjective reports indicated that only in the tennis imagery condition did experts differ from novices in the ability to form proprioceptive images and to consider the tool as an extension of the hand. Neurophysiological and subjective data converge to suggest a key role of long-term experience in modulating sensorimotor body representations during mental simulation of sports.

Clinical Assessment of Motor Imagery After Stroke

2008-03-10T13:31:55+01:00

Clinical Assessment of Motor Imagery After Stroke.

Neurorehabil Neural Repair. 2008 Mar 6;

Authors: Malouin F, Richards C, Durand A, Doyon J

OBJECTIVE: The aim of this study was to investigate: (1) the effects of a stroke on motor imagery vividness as measured by the Kinesthetic and Visual Imagery Questionnaire (KVIQ-20); (2) the influence of the lesion side; and (3) the symmetry of motor imagery. METHODS: Thirty-two persons who had sustained a stroke, in the right (n = 19) or left (n = 13) cerebral hemisphere, and 32 age-matched healthy persons participated. The KVIQ-20 assesses on a 5-point ordinal scale the clarity of the image (visual scale) and the intensity of the sensations (kinesthetic scale) that the subjects are able to imagine from the first-person perspective. RESULTS: In both groups, the visual scores were higher (P = .0001) than the kinesthetic scores and there was no group difference. Likewise, visual scores remained higher than kinesthetic scores irrespective of the lesion side. The visual scores poststroke were higher (P = .001) when imagining upper limb movements on the unaffected side than those on the affected side. When focusing on the lower limb only, however, the kinesthetic scores were higher (P = .001) when imagining movements of the unaffected compared to those on the affected side. CONCLUSIONS: The vividness of motor imagery poststroke remains similar to that of age-matched healthy persons and is not affected by the side of the lesion. However, after stroke motor imagery is not symmetrical and motor imagery vividness is better when imagining movements on the unaffected than on the affected side, indicating an overestimation possibly related to a hemispheric imbalance or a recalibration of motor imagery perception.

Effect of mental imagery on the development of skilled motor actions

2008-02-11T22:36:45+01:00

Effect of mental imagery on the development of skilled motor actions.

Percept Mot Skills. 2007 Dec;105(3 Pt 1):803-26

Authors: Fontani G, Migliorini S, Benocci R, Facchini A, Casini M, Corradeschi F

To test the effect of imagery in the training of skilled movements, an experiment was designed in which athletes learned a new motor action and trained themselves for a month either by overt action or by mental imagery of the action. The experiment was carried out with 30 male karateka (M age = 35 yr., SD = 8.7; M years of practice = 6, SD = 3) instructed to perform an action (Ura-Shuto-Uchi) that they had not previously learned. The athletes were divided into three groups: Untrained (10 subjects who did not perform any training), Action Trained (10 subjects who performed Ura-Shuto-Uchi training daily for 16 minutes), and Mental Imagery (10 subjects who performed mental imagery training of Ura-Shuto-Uchi daily for 16 minutes). The subjects were tested five times, once every 7 days. During each test, they performed a series of 60 motor action trials. In Tests 1, 3, and 5, they also performed a series of 60 mental imagery trials. During the trials, an electroencephalogram (EEG), electromyography (EMG), muscle strength and power, and other physiological parameters were recorded. The results differed by group. Untrained subjects did not show significant effects. In the Action Trained group, training had an effect on reactivity and movement speed, with a reduction of EMG activation and reaction times. Moreover, muscle strength, power, and work increased significantly. The Mental Imagery group showed the same effects on muscle strength, power, and work, but changes in reactivity were not observed. In the Mental Imagery group, the study of Movement Related Brain Macropotentials indicated a progressive modification of the profile of the waves from Test 1 to Test 5 during imagery, showing significant variations of the amplitude of the waves related to the premotor and motor execution periods. Results show that motor imagery can influence muscular abilities such as strength and power and can modify Movement Related Brain Macropotentials, the profile of which potentially could be used to verify the effectiveness of motor imagery training.

Effect of mental imagery on the development of skilled motor actions

2008-02-11T22:35:49+01:00

Effect of mental imagery on the development of skilled motor actions.

Percept Mot Skills. 2007 Dec;105(3 Pt 1):803-26

Authors: Fontani G, Migliorini S, Benocci R, Facchini A, Casini M, Corradeschi F

The suppressive influence of SMA on M1 in motor imagery

2008-02-11T22:34:34+01:00

The suppressive influence of SMA on M1 in motor imagery revealed by fMRI and dynamic causal modeling.

Neuroimage. 2007 Dec 8;

Authors: Kasess CH, Windischberger C, Cunnington R, Lanzenberger R, Pezawas L, Moser E

Although motor imagery is widely used for motor learning in rehabilitation and sports training, the underlying mechanisms are still poorly understood. Based on fMRI data sets acquired with very high temporal resolution (300 ms) under motor execution and imagery conditions, we utilized Dynamic Causal Modeling (DCM) to determine effective connectivity measures between supplementary motor area (SMA) and primary motor cortex (M1). A set of 28 models was tested in a Bayesian framework and the by-far best-performing model revealed a strong suppressive influence of the motor imagery condition on the forward connection between SMA and M1. Our results clearly indicate that the lack of activation in M1 during motor imagery is caused by suppression from the SMA. These results highlight the importance of the SMA not only for the preparation and execution of intended movements, but also for suppressing movements that are represented in the motor system but not to be performed.

Mental rotation of congenitally absent hands

2007-12-16T14:05:47+01:00

Mental rotation of congenitally absent hands.

J Int Neuropsychol Soc. 2008 Jan;14(1):81-9

Authors: Funk M, Brugger P

We compared motor imagery performance of normally limbed individuals with that of individuals with one or both hands missing since birth (i.e., hand amelia). To this aim, 14 unilaterally and 2 bilaterally amelic participants performed a task requiring the classification of hands depicted in different degrees of rotation as either a left or a right hand. On the same task, 24 normally limbed participants recapitulated previously reported effects; that is, that the hand motor dominance and, more generally, a lifelong use of hands are important determinants of left-right decisions. Unilaterally amelic participants responded slower to hands corresponding to their absent, compared with their existing, hand. Moreover, left and right hand amelic participants showed prolonged reaction times to hands (whether left or right) depicted in unnatural orientations compared with natural orientations. Among the bilateral amelics, the individual with phantom sensations, but not the one without, showed similar differentiation. These findings demonstrate that the visual recognition of a hand never physically developed is prolonged, but still modulated by different rotation angles. They are further compatible with the view that phantom limbs in hand amelia may constrain motor imagery as much as do amputation phantoms.

The emergence of motor imagery in children

2007-12-08T18:13:24+01:00

The emergence of motor imagery in children.

J Exp Child Psychol. 2007 Nov 28;

Authors: Molina M, Tijus C, Jouen F

A total of 80 children (40 5-year-olds and 40 7-year-olds) took part in an experiment to evaluate their capacity to mentally evoke a motor image of their own displacement. Using a chronometry paradigm, movement duration was compared in a task where children were asked to move in order to take a puppet back to its home (actual) and to think about themselves executing the same action (virtual). Movement durations for actual and virtual displacements were obtained in two conditions, where either no information was provided about the weight of the puppet to be displaced (standard situation) or the puppet was described as being heavy (informed situation). A significant correlation between actual and virtual walking durations was observed for 7-year-olds in the informed condition. This result provides evidence for a motor imagery process emerging in 7-year-olds when children are required to think about themselves in action.

Quasi-movements: A novel motor-cognitive phenomenon

2007-11-25T23:42:01+01:00

Quasi-movements: A novel motor-cognitive phenomenon.

Neuropsychologia. 2007 Oct 22;

Authors: Nikulin VV, Hohlefeld FU, Jacobs AM, Curio G

We introduce quasi-movements and define them as volitional movements which are minimized by the subject to such an extent that finally they become undetectable by objective measures. They are intended as overt movements, but the absence of the measurable motor responses and the subjective experience make quasi-movements similar to motor imagery. We used the amplitude dynamics of electroencephalographic alpha oscillations as a marker of the regional involvement of cortical areas in three experimental tasks: movement execution, kinesthetic motor imagery, and quasi-movements. All three conditions were associated with a significant suppression of alpha oscillations over the sensorimotor hand area of the contralateral hemisphere. This suppression was strongest for executed movements, and stronger for quasi-movements than for motor imagery. The topography of alpha suppression was similar in all three conditions. Proprioceptive sensations related to quasi-movements contribute to the assumption that the "sense of movement" can originate from central efferent processes. Quasi-movements are also congruent with the postulated continuity between motor imagery and movement preparation/execution. We also show that in healthy subjects quasi-movements can be effectively used in brain-computer interface research leading to a significantly smaller classification error ( approximately 47% of relative decrease) in comparison to the errors obtained with conventionally used motor imagery strategies.

High loads induce differences between actual and imagined movement duration

2007-11-04T12:39:06+01:00

High loads induce differences between actual and imagined movement duration.

Exp Brain Res. 2007 Nov 1;

Authors: Slifkin AB

Actual and imagined action may be governed by common information and neural processes. This hypothesis has found strong support from a range of chronometric studies showing that it takes the same amount of time to actually move and to imagine moving. However, exceptions have been observed when actual and imagined movements were made under conditions of inertial loading: sometimes the equivalency of actual and imagined movement durations (MDs) has been preserved, and other times it has been disrupted. The purpose of the current study was to test the hypothesis that the appearance and magnitude of actual-imagined MD differences in those studies was dependent on the level of load relative to the maximum loading capacity of the involved effector system [the maximum voluntary load (MVL)]. The experiment required 12 young, healthy humans to actually produce, and to imagine producing, single degree of freedom index finger movements under a range of loads (0, 5, 10, 20, 40, and 80% MVL). As predicted, statistically significant actual-imagined MD differences were absent at lower loads (0-20% MVL), but differences appeared and increased in magnitude with further increases in %MVL (40 and 80% MVL). That pattern of results may relate to the common, everyday experience individuals have in interacting with loads. Participants are likely to have extensive experience interacting with very low loads, but not high loads. It follows that the control of low inertial loads should be governed by complete central representations of action, while representations should be less complete for high loads. A consequence may be increases in the uncertainty of predicting motor output with increases in load. Compensation for the increased uncertainty may appear as increases in the MD values selected during both the preparation and imagery of action-according to a speed-uncertainty trade-off. Then, during actual action, MD may be reduced if movement-related feedback indicates that a faster movement would succeed.

Using movement imagery and electromyography-triggered feedback in stroke rehabilitation

2007-11-04T12:35:54+01:00

Effects of movement imagery and electromyography-triggered feedback on arm hand function in stroke patients in the subacute phase.

Clin Rehabil. 2007 Jul;21(7):587-94

Authors: Hemmen B, Seelen HA

OBJECTIVE: To investigate the effects of movement imagery-assisted electromyography (EMG)-triggered feedback (focused on paretic wrist dorsiflexors) on the arm-hand function of stroke patients. DESIGN: Single-blinded, longitudinal, multicentre randomized controlled trial. Measurements were performed (on average) 54 days post stroke (baseline), three months later (post training) and at 12 months post baseline. SETTING: Two rehabilitation centres. SUBJECTS: Twenty-seven patients with a first-ever, ischaemic, subacute stroke. INTERVENTIONS: A reference group received conventional electrostimulation, while the experimental group received arm-hand function training based on EMG-triggered feedback combined with movement imagery. Both groups were trained for three months, 5 days/week, 30 minutes/day, in addition to their therapy as usual. MAIN MEASURES: Arm-hand function was evaluated using the upper extremity-related part of the Brunnstrom Fugl-Meyer test and the Action Research Arm test. RESULTS: During training, Brunnstrom Fugl-Meyer scores improved 8.7 points and Action Research Arm scores by 19.4 points (P < 0.0001) in both groups relative to baseline results, rising to 13.3 and 28.4 points respectively at one year follow-up (P < 0.0001). No between-group differences were found at any time. CONCLUSIONS: EMG-triggered feedback stimulation did not lead to more arm-hand function improvement relative to conventional electrostimulation. However, in contrast to many clinical reports, a significant improvement was still observed in both groups nine months after treatment ceased.

Movement imagery increases pain in people with neuropathic pain following complete thoracic spinal cord injury

2007-10-24T16:50:00+02:00

Movement imagery increases pain in people with neuropathic pain following complete thoracic spinal cord injury.

Pain. 2007 Oct 15;

Authors: Gustin SM, Wrigley PJ, Gandevia SC, Middleton JW, Henderson LA, Siddall PJ

Spinal cord injury (SCI) results in deafferentation and the onset of neuropathic pain in a substantial proportion of people. Based on evidence suggesting motor cortex activation results in attenuation of neuropathic pain, we sought to determine whether neuropathic SCI pain could be modified by imagined movements of the foot. Fifteen subjects with a complete thoracic SCI (7 with below-level neuropathic pain and 8 without pain) were instructed in the use of movement imagery. Movement imagery was practiced three times daily for 7days. On the eighth day, subjects performed the movement imagery in the laboratory and recorded pain ratings during the period of imagined movement. Six out of 7 subjects with neuropathic pain reported an increase in pain during imagined movements from 2.9+/-0.7 during baseline to 5.0+/-1.0 during movement imagery (p<0.01). In SCI subjects without neuropathic pain, movement imagery evoked an increase in non-painful sensation intensity from a baseline of 1.9+/-0.7 to 4.8+/-1.3 during the movement imagery (p<0.01). Two subjects without a history of pain or non-painful phantom sensations had onset of dysesthesia while performing imagined movements. This study reports exacerbation of pain in response to imagined movements and it contrasts with reports of reduction pain in people with peripheral neuropathic pain. The potential mechanisms underlying this sensory enhancement with movement imagery are discussed.

Preservation of motor programs in paraplegics

2007-10-09T23:20:00+02:00

Preservation of motor programs in paraplegics as demonstrated by attempted and imagined foot movements.

Neuroimage. 2007 Aug 23;

Authors: Hotz-Boendermaker S, Funk M, Summers P, Brugger P, Hepp-Reymond MC, Curt A, Kollias SS

Execution and imagination of movement activate distinct neural circuits, partially overlapping in premotor and parietal areas, basal ganglia and cerebellum. Can long-term deafferented/deefferented patients still differentiate attempted from imagined movements? The attempted execution and motor imagery network of foot movements have been investigated in nine chronic complete spinal cord-injured (SCI) patients using fMRI. Thorough behavioral assessment showed that these patients were able to differentiate between attempted execution and motor imagery. Supporting the outcome of the behavioral assessment, fMRI disclosed specific patterns of activation for movement attempt and for motor imagery. Compared with motor execution data of healthy controls, movement attempt in SCI patients revealed reduced primary motor cortex activation at the group level, although activation was found in all single subjects with a high variability. Further comparisons with healthy subjects revealed that during attempt and motor imagery, SCI patients show enhanced activation and recruitment of additional regions in the parietal lobe and cerebellum that are important in sensorimotor integration. These findings reflect central plastic changes due to altered input and output and suggest that SCI patients may require additional cognitive resources to perform these tasks that may be one and the same phenomenon, or two versions of the same phenomenon, with quantitative differences between the two. Nevertheless, the retained integrity of movement attempt and motor imagery networks in SCI patients demonstrates that chronic paraplegics can still dispose of the full motor programs for foot movements and that therefore, attempted and imagined movements should be integrated in rehabilitative strategies.

Visuo-motor learning with combination of different rates of motor imagery and physical practice

2007-09-13T22:13:24+02:00

Visuo-motor learning with combination of different rates of motor imagery and physical practice.

Exp Brain Res. 2007 Sep 12;

Authors: Allami N, Paulignan Y, Brovelli A, Boussaoud D

Sports psychology suggests that mental rehearsal facilitates physical practice in athletes and clinical rehabilitation attempts to use mental rehearsal to restore motor function in hemiplegic patients. Our aim was to examine whether mental rehearsal is equivalent to physical learning, and to determine the optimal proportions of real execution and rehearsal. Subjects were asked to grasp an object and insert it into an adapted slot. One group (G0) practiced the task only by physical execution (240 trials); three groups imagined performing the task in different rates of trials (25%, G25; 50%, G50; 75%, G75), and physically executed movements for the remaining trials; a fourth, control group imagined a visual rotation task in 75% of the trials and then performed the same motor task as the others groups. Movement time (MT) was compared for the first and last physical trials, together with other key trials, across groups. All groups learned, suggesting that mental rehearsal is equivalent to physical motor learning. More importantly, when subjects rehearsed the task for large numbers of trials (G50 and G75), the MT of the first executed trial was significantly shorter than the first executed trial in the physical group (G0), indicating that mental practice is better than no practice at all. Comparison of the first executed trial in G25, G50 and G75 with the corresponding trials in G0 (61, 121 and 181 trials), showed equivalence between mental and physical practice. At the end of training, the performance was much better with high rates of mental practice (G50/G75) compared to physical practice alone (G0), especially when the task was difficult. These findings confirm that mental rehearsal can be beneficial for motor learning and suggest that imagery might be used to supplement or partly replace physical practice in clinical rehabilitation.

Relationship between visual and motor imagery

2007-09-05T12:45:51+02:00

Relationship between visual and motor imagery.

Percept Mot Skills. 2007 Jun;104(3 Pt 1):823-43

Authors: McAvinue LP, Robertson IH

The relationship between visual and motor imagery was investigated by administering a battery of visual and motor imagery measures to a sample of 101 men (n=49) and women (n=52), who ranged in age from 18 to 59 (M=34.5, SD= 12.6). A principal components analysis applied to the correlation matrix indicated four underlying components, which explained 62.9% of the variance. The components were named Implicit Visual Imagery Ability, Self-report of Visual and Motor Imagery, Implicit Motor Imagery Ability, and Explicit Motor Imagery Ability. These results suggested a dissociation between visual and motor imagery although visual and motor imagery were associated as self-reports and there were correlations among particular measures.

Internal and external imagery perspective measurement and use in imagining open and closed sports skills

2007-08-02T19:05:17+02:00

Internal and external imagery perspective measurement and use in imagining open and closed sports skills: an exploratory study.

Percept Mot Skills. 2007 Apr;104(2):387-404

Authors: Spittle M, Morris T

This study explored the measurement and use of internal and external imagery perspectives during imagery of open and closed sports skills. Participants (N=41; male=23; female=18), ages 14 to 28 (M = 19.4 yr.; SD = 3.1), who were recruited from undergraduate classes in human movement and physical education, and local sporting teams, completed the Imagery Use Questionnaire and then imagined performing eight common sports skills, four open skills and four closed skills, in a random order. Participants provided concurrent verbalisation during their imagery. Immediately after imagining each skill, participants completed a rating scale and retrospective verbalisation of imagery perspective use. Analysis indicated that the questionnaire gave a general imagery perspective preference but was not a strong predictor of imagery used on specific occasions. The three measures of imagery perspective were equivalent in imagining performing particular skills. Participants experienced more internal imagery than external imagery while imagining the eight sports skills, but there was no significant difference between perspective use on the open and closed skills.

Influence of mirror therapy on human motor cortex

2007-07-08T00:42:14+02:00

Influence of mirror therapy on human motor cortex.

Int J Neurosci. 2007 Jul;117(7):1039-48

Authors: Fukumura K, Sugawara K, Tanabe S, Ushiba J, Tomita Y

This article investigates whether or not mirror therapy alters the neural mechanisms in human motor cortex. Six healthy volunteers participated. The study investigated the effects of three main factors of mirror therapy (observation of hand movements in a mirror, motor imagery of an assumed affected hand, and assistance in exercising the assumed affected hand) on excitability changes in the human motor cortex to clarify the contribution of each factor. The increase in motor-evoked potential (MEP) amplitudes during motor imagery tended to be larger with a mirror than without one. Moreover, MEP amplitudes increased greatly when movements were assisted. Watching the movement of one hand in a mirror makes it easier to move the other hand in the same way. Moreover, the increase in MEP amplitudes is related to the synergic effects of afferent information and motor imagery.

Cerebellar activity evoked by common tool-use execution and imagery tasks

2007-06-29T17:52:51+02:00

Cerebellar activity evoked by common tool-use execution and imagery tasks: an fMRI study.

Cortex. 2007 Apr;43(3):350-8

Authors: Higuchi S, Imamizu H, Kawato M

The purpose of this study is to identify the functional brain networks activated in relation to actual tool-use in humans. Although previous studies have identified brain activity related to tool-use gestures (Moll et al., 2000), they did not investigate the brain activity involved in such tool-use. We investigated brain activity using functional magnetic resonance imaging (fMRI) while human subjects mentally imagined using sixteen common tools and while they actually used them. Brain activity for both actual and imagined tool-use was found in the posterior part of the parietal cortex, in the supplementary motor area, and in the cerebellum. Under imagined tool-use conditions, we found brain activity in the premotor and right pars opercularis. Under actual tool-use conditions, we found it in the primary motor area, in the thalamus, and in the left pars opercularis. Our precise analysis in the cerebellum indicated that activity evoked by imagery was located significantly more lateral to that evoked by actual use. We found a relationship between activity in the tool imagery and execution conditions by comparing their t-value-weighted centroid of activation coordinates. Moreover, for half of the subjects the spatial distribution pattern for each tool was similar, suggesting that neural mechanisms contributing to skillful tool-use are modularly organized in the cerebellum.

Cognitive tools for rehabilitation

2007-06-29T17:50:13+02:00

Motor imagery and action observation: cognitive tools for rehabilitation.

J Neural Transm. 2007 Jun 20;

Authors: Mulder T

Rehabilitation, for a large part may be seen as a learning process where old skills have to be re-acquired and new ones have to be learned on the basis of practice. Active exercising creates a flow of sensory (afferent) information. It is known that motor recovery and motor learning have many aspects in common. Both are largely based on response-produced sensory information. In the present article it is asked whether active physical exercise is always necessary for creating this sensory flow. Numerous studies have indicated that motor imagery may result in the same plastic changes in the motor system as actual physical practice. Motor imagery is the mental execution of a movement without any overt movement or without any peripheral (muscle) activation. It has been shown that motor imagery leads to the activation of the same brain areas as actual movement. The present article discusses the role that motor imagery may play in neurological rehabilitation. Furthermore, it will be discussed to what extent the observation of a movement performed by another subject may play a similar role in learning. It is concluded that, although the clinical evidence is still meager, the use of motor imagery in neurological rehabilitation may be defended on theoretical grounds and on the basis of the results of experimental studies with healthy subjects.

Overt and imagined singing of an Italian aria

2007-05-07T21:49:11+02:00

Overt and imagined singing of an Italian aria.

Neuroimage. 2007 Mar 24;

Authors: Kleber B, Birbaumer N, Veit R, Trevorrow T, Lotze M

Activation maps of 16 professional classical singers were evaluated during overt singing and imagined singing of an Italian aria utilizing a sparse sampling functional magnetic imaging (fMRI) technique. Overt singing involved bilateral primary and secondary sensorimotor and auditory cortices but also areas associated with speech and language production. Activation magnitude within the gyri of Heschl (A1) was comparable in both hemispheres. Subcortical motor areas (cerebellum, thalamus, medulla and basal ganglia) were active too. Areas associated with emotional processing showed slight (anterior cingulate cortex, anterior insula) activation. Cerebral activation sites during imagined singing were centered on fronto-parietal areas and involved primary and secondary sensorimotor areas in both hemispheres. Areas processing emotions showed intense activation (ACC and bilateral insula, hippocampus and anterior temporal poles, bilateral amygdala). Imagery showed no significant activation in A1. Overt minus imagined singing revealed increased activation in cortical (bilateral primary motor; M1) and subcortical (right cerebellar hemisphere, medulla) motor as well as in sensory areas (primary somatosensory cortex, bilateral A1). Imagined minus overt singing showed enhanced activity in the medial Brodmann's area 6, the ventrolateral and medial prefrontal cortex (PFC), the anterior cingulate cortex and the inferior parietal lobe. Additionally, Wernicke's area and Brocca's area and their homologues were increasingly active during imagery. We conclude that imagined and overt singing involves partly different brain systems in professional singers with more prefrontal and limbic activation and a larger network of higher order associative functions during imagery.

Mirror therapy enhances lower-extremity motor recovery and motor functioning after stroke

2007-05-02T23:35:20+02:00

Mirror therapy enhances lower-extremity motor recovery and motor functioning after stroke: a randomized controlled trial.

Arch Phys Med Rehabil. 2007 May;88(5):555-9

Authors: Sütbeyaz S, Yavuzer G, Sezer N, Koseoglu BF

OBJECTIVE: To evaluate the effects of mirror therapy, using motor imagery training, on lower-extremity motor recovery and motor functioning of patients with subacute stroke. DESIGN: Randomized, controlled, assessor-blinded, 4-week trial, with follow-up at 6 months. SETTING: Rehabilitation education and research hospital. PARTICIPANTS: A total of 40 inpatients with stroke (mean age, 63.5y), all within 12 months poststroke and without volitional ankle dorsiflexion. INTERVENTIONS: Thirty minutes per day of the mirror therapy program, consisting of nonparetic ankle dorsiflexion movements or sham therapy, in addition to a conventional stroke rehabilitation program, 5 days a week, 2 to 5 hours a day, for 4 weeks. MAIN OUTCOME MEASURES: The Brunnstrom stages of motor recovery, spasticity assessed by the Modified Ashworth Scale (MAS), walking ability (Functional Ambulation Categories [FAC]), and motor functioning (motor items of the FIM instrument). RESULTS: The mean change score and 95% confidence interval (CI) of the Brunnstrom stages (mean, 1.7; 95% CI, 1.2-2.1; vs mean, 0.8; 95% CI, 0.5-1.2; P=.002), as well as the FIM motor score (mean, 21.4; 95% CI, 18.2-24.7; vs mean, 12.5; 95% CI, 9.6-14.8; P=.001) showed significantly more improvement at follow-up in the mirror group compared with the control group. Neither MAS (mean, 0.8; 95% CI, 0.4-1.2; vs mean, 0.3; 95% CI, 0.1-0.7; P=.102) nor FAC (mean, 1.7; 95% CI, 1.2-2.1; vs mean, 1.5; 95% CI, 1.1-1.9; P=.610) showed a significant difference between the groups. CONCLUSIONS: Mirror therapy combined with a conventional stroke rehabilitation program enhances lower-extremity motor recovery and motor functioning in subacute stroke patients.

Mental practice in chronic stroke: results of a randomized, placebo-controlled trial

2007-05-02T23:34:12+02:00

Mental practice in chronic stroke: results of a randomized, placebo-controlled trial.

Stroke. 2007 Apr;38(4):1293-7

Authors: Page SJ, Levine P, Leonard A

BACKGROUND AND PURPOSE: Mental practice (MP) of a particular motor skill has repeatedly been shown to activate the same musculature and neural areas as physical practice of the skill. Pilot study results suggest that a rehabilitation program incorporating MP of valued motor skills in chronic stroke patients provides sufficient repetitive practice to increase affected arm use and function. This Phase 2 study compared efficacy of a rehabilitation program incorporating MP of specific arm movements to a placebo condition using randomized controlled methods and an appropriate sample size. Method- Thirty-two chronic stroke patients (mean=3.6 years) with moderate motor deficits received 30-minute therapy sessions occurring 2 days/week for 6 weeks, and emphasizing activities of daily living. Subjects randomly assigned to the experimental condition also received 30-minute MP sessions provided directly after therapy requiring daily MP of the activities of daily living; subjects assigned to the control group received the same amount of therapist interaction as the experimental group, and a sham intervention directly after therapy, consisting of relaxation. Outcomes were evaluated by a blinded rater using the Action Research Arm test and the upper extremity section of the Fugl-Meyer Assessment. RESULTS: No pre-existing group differences were found on any demographic variable or movement scale. Subjects receiving MP showed significant reductions in affected arm impairment and significant increases in daily arm function (both at the P<0.0001 level). Only patients in the group receiving MP exhibited new ability to perform valued activities. CONCLUSIONS: The results support the efficacy of programs incorporating mental practice for rehabilitating affected arm motor function in patients with chronic stroke. These changes are clinically significant.

Motor imagery for pathologic pain

2007-01-22T21:48:04+01:00

Graded motor imagery for pathologic pain: a randomized controlled trial.

Neurology. 2006 Dec 26;67(12):2129-34

Authors: Moseley GL

BACKGROUND: Phantom limb and complex regional pain syndrome type 1 (CRPS1) are characterized by changes in cortical processing and organization, perceptual disturbances, and poor response to conventional treatments. Graded motor imagery is effective for a small subset of patients with CRPS1. OBJECTIVE: To investigate whether graded motor imagery would reduce pain and disability for a more general CRPS1 population and for people with phantom limb pain. METHODS: Fifty-one patients with phantom limb pain or CRPS1 were randomly allocated to motor imagery, consisting of 2 weeks each of limb laterality recognition, imagined movements, and mirror movements, or to physical therapy and ongoing medical care. RESULTS: There was a main statistical effect of treatment group, but not diagnostic group, on pain and function. The mean (95% CI) decrease in pain between pre- and post-treatment (100 mm visual analogue scale) was 23.4 mm (16.2 to 30.4 mm) for the motor imagery group and 10.5 mm (1.9 to 19.2 mm) for the control group. Improvement in function was similar and gains were maintained at 6-month follow-up. CONCLUSION: Motor imagery reduced pain and disability in these patients with complex regional pain syndrome type I or phantom limb pain, but the mechanism, or mechanisms, of the effect are not clear.

Motor imagery and stroke rehabilitation

2007-01-21T23:42:07+01:00

Motor imagery and stroke rehabilitation: a critical discussion.

J Rehabil Med. 2007 Jan;39(1):5-13

Authors: de Vries S, Mulder T

Motor disorders are a frequent consequence of stroke and much effort is invested in the re-acquisition of motor control. Although patients often regain some of their lost function after therapy, most remain chronically disabled. Functional recovery is achieved largely through reorganization processes in the damaged brain. Neural reorganization depends on the information provided by sensorimotor efferent-afferent feedback loops. It has, however, been shown that the motor system can also be activated "offline" by imagining (motor imagery) or observing movements. The discovery of mirror neurones, which fire not only when an action is executed, but also when one observes another person performing the same action, also show that our action system can be used "online" as well as offline. It is an intriguing question as to whether the information provided by motor imagery or motor observation can lead to functional recovery and plastic changes in patients after stroke. This article reviews the evidence for motor imagery or observation as novel methods in stroke rehabilitation

The neural basis of narrative imagery

2007-01-21T23:40:00+01:00

The neural basis of narrative imagery: emotion and action.

Prog Brain Res. 2006;156:93-103

Authors: Sabatinelli D, Lang PJ, Bradley MM, Flaisch T

It has been proposed that narrative emotional imagery activates an associative network of stimulus, semantic, and response (procedural) information. In previous research, predicted response components have been demonstrated through psychophysiological methods in peripheral nervous system. Here we investigate central nervous system concomitants of pleasant, neutral, and unpleasant narrative imagery with functional magnetic resonance imaging. Subjects were presented with brief narrative scripts over headphones, and then imagined themselves engaged in the described events. During script perception, auditory association cortex showed enhanced activation during affectively arousing (pleasant and unpleasant), relative to neutral imagery. Structures involved in language processing (left middle frontal gyrus) and spatial navigation (retrosplenium) were also active during script presentation. At the onset of narrative imagery, supplementary motor area, lateral cerebellum, and left inferior frontal gyrus were initiated, showing enhanced signal change during affectively arousing (pleasant and unpleasant), relative to neutral scripts. These data are consistent with a bioinformational model of emotion that considers response mobilization as the measurable output of narrative imagery.

Motor imagery of gait: a quantitative approach

2007-01-15T22:52:25+01:00

Motor imagery of gait: a quantitative approach.

Exp Brain Res. 2007 Jan 9;

Authors: Bakker M, de Lange FP, Stevens JA, Toni I, Bloem BR

Motor imagery (MI) is widely used to study cognitive aspects of the neural control of action. Prior studies were mostly centred on hand and arm movements. Recently a few studies have used imagery tasks to explore the neurophysiology of human gait, but it remains unclear how to ascertain whether subjects actually perform imagery of gait as requested. Here we describe a new experimental protocol to quantify imagery of gait, by behaviourally distinguishing it from visual imagery (VI) processes and by showing its temporal correspondence with actual gait. Fourteen young healthy subjects performed two imagery tasks and an actual walking (AW) task. During both imagery tasks subjects were sitting on a chair and faced a computer screen that presented photographs of walking trajectories. During one task (MI), subjects had to imagine walking along the walking trajectory. During the other task (VI), subjects had to imagine seeing a disc moving along the walking trajectory. During the AW task, subjects had to physically walk along the same walking trajectory as presented on the photographs during the imagery tasks. We manipulated movement distance by changing the length of the walking trajectory, and movement difficulty by changing the width of the walking trajectory. Subjects reported onset and offset of both actual and imagined movements with a button press. The time between the two button presses was taken as the imagined or actual movement time (MT). MT increased with increasing path length and decreasing path width in all three tasks. Crucially, the effect of path width on MT was significantly stronger during MI and AW than during VI. The results demonstrate a high temporal correspondence between imagined and AW, suggesting that MI taps into similar cerebral resources as those used during actual gait. These results open the possibility of using this protocol for exploring neurophysiological correlates of gait control in humans.

Pushing the limits of imagination: mental practice for learning sequences

2007-01-06T14:54:12+01:00

Pushing the limits of imagination: mental practice for learning sequences.

J Exp Psychol Learn Mem Cogn. 2007 Jan;33(1):254-61

Authors: Wohldmann EL, Healy AF, Bourne LE

In 2 experiments, the efficacy of motor imagery for learning to type number sequences was examined. Adults practiced typing 4-digit numbers. Then, during subsequent training, they either typed in the same or a different location, imagined typing, merely looked at each number, or performed an irrelevant task. Repetition priming (faster responses for old relative to new numbers) was observed on an immediate test and after a 3-month delay for participants who imagined typing. Improvement across the delay in typing old and new numbers was found for the imagined and actual typing conditions but not for the other conditions. The findings suggest that imagery can be used to acquire and retain representations of sequences and to improve general typing skill. ((c) 2007 APA, all rights reserved).

Intentional motor phantom limb syndrome

2006-12-28T19:37:37+01:00

Intentional motor phantom limb syndrome.

Neurology. 2006 Dec 26;67(12):2140-6

Authors: Staub F, Bogousslavsky J, Maeder P, Maeder-Ingvar M, Fornari E, Ghika J, Vingerhoets F, Assal G

OBJECTIVE: To investigate the clinical and anatomic correlates of a previously unreported form of chronic supernumerary phantom limb, which developed only in association with motor intent directed at a hemiplegic-anesthetic upper limb. METHODS: We explored the phenomenology of the phantom illusion in the light of motor control models. Hemodynamic correlates of supernumerary phantom limb were studied with an fMRI sensorimotor paradigm consisting of finger-thumb opposition movements. RESULTS: The kinesthetic-proprioceptive illusion of a third arm was triggered by any attempt to move the paretic limb, by bimanual actions, and by motor imagery involving the nonfunctional limb. The responsible lesion destroyed the posterior part of the posterior limb of the internal capsule on the opposite side, damaging corticospinal and thalamocortical tracts. Comparison between fMRI signals performed during virtual movement of the phantom hand vs imaginary movement of the paretic hand showed increased activation in thalamus and caudate nucleus in the first condition. CONCLUSIONS: A preserved sense of agency provided by intact premotor processes translating intention into action may lead to the vivid feeling of movement in a paralyzed limb, similar to kinesthetic illusions in amputees. The interruption of thalamic afferences may explain the persistence and stability of the phantom by preventing any correction of the mismatch between expected and effective movement. The increased blood oxygen level-dependent (BOLD) signal in the basal ganglia-thalamus-cortex pathway during movement of the supernumerary hand may reflect an abnormal closed-loop functioning of the thalamocortical system underlying the phantom phenomenon.

Integration of motor imagery and physical practice in PD patients

2006-12-20T21:37:39+01:00

Integration of motor imagery and physical practice in group treatment applied to subjects with Parkinson's disease.

Neurorehabil Neural Repair. 2007 Mar;21(1):68-75

Authors: Tamir R, Dickstein R, Huberman M

BACKGROUND: and PURPOSE: The application of motor imagery practice in the treatment of Parkinson's disease (PD) is a novel treatment approach for improving motor function. The purpose of this study was to compare group treatment using a combination of physical and motor imagery practice with group treatment using only physical practice in subjects with PD. METHODS: . Of 23 patients with idiopathic PD, 12 received combined therapy, whereas 11 received physical therapy alone. Exercises for both groups were applied during 1-h sessions held twice a week for 12 weeks. Comparable motor tasks provided to both groups included callisthenic exercises, functional tasks, and relaxation exercises. However, the experimental group was treated with both imagery and real practice, whereas the control group received only physical exercises. Outcome measures included the time required to complete sequences of movements, the performance of balance tasks, impairment and functional scores on the Unified Parkinson's Disease Rating Scale (UPDRS), and specific cognitive abilities (Stroop and clock drawing tests). RESULTS: . Following the intervention, the combined treatment group exhibited significantly faster performance of movement sequences than the control group. In addition, the experimental subjects demonstrated higher gains in the mental and motor subsets of the UPDRS and in the cognitive tests. Both groups improved on the activities of daily living scale. CONCLUSIONS: . The combination of motor imagery and real practice may be effective in the treatment of PD, especially for reducing bradykinesia. The implementation of this treatment regimen allows for the extension of practice time with negligible risk and low cost.

Motor imagery of complex everyday movements

2006-11-28T23:50:54+01:00

Motor imagery of complex everyday movements. An fMRI study.

Neuroimage. 2006 Nov 15;

Authors: Szameitat AJ, Shen S, Sterr A

The present study aimed to investigate the functional neuroanatomical correlates of motor imagery (MI) of complex everyday movements (also called everyday tasks or functional tasks). 15 participants imagined two different types of everyday movements, movements confined to the upper extremities (UE; e.g., eating a meal) and movements involving the whole body (WB; e.g., swimming), during fMRI scanning. Results showed that both movement types activated the lateral and medial premotor cortices bilaterally, the left parietal cortex, and the right basal ganglia. Direct comparison of WB and UE movements further revealed a homuncular organization in the primary sensorimotor cortices (SMC), with UE movements represented in inferior parts of the SMC and WB movements in superior and medial parts. These results demonstrate that MI of everyday movements drives a cortical network comparable to the one described for more simple movements such as finger opposition. The findings further are in accordance with the suggestion that motor imagery-based mental practice is effective because it activates a comparable cortical network as overt training. Since most people are familiar with everyday movements and therefore a practice of the movement prior to scanning is not necessarily required, the current paradigm seems particularly appealing for clinical research and application focusing on patients with low or no residual motor abilities.

Motor imagery and EEG-based control of spelling devices and neuroprostheses

2006-11-22T09:29:27+01:00

Motor imagery and EEG-based control of spelling devices and neuroprostheses.

Prog Brain Res. 2006;159:393-409

Authors: Neuper C, Müller-Putz GR, Scherer R, Pfurtscheller G

A brain-computer interface (BCI) transforms signals originating from the human brain into commands that can control devices or applications. With this, a BCI provides a new non-muscular communication channel, which can be used to assist patients who have highly compromised motor functions. The Graz-BCI uses motor imagery and associated oscillatory EEG signals from the sensorimotor cortex for device control. As a result of research in the past 15 years, the classification of ERD/ERS patterns in single EEG trials during motor execution and motor imagery forms the basis of this sensorimotor-rhythm controlled BCI. The major frequency bands of cortical oscillations considered here are the 8-13 and 15-30Hz bands. This chapter describes the basic methods used in Graz-BCI research and outlines possible clinical applications.

Motor imagery practice in gait rehabilitation of chronic post-stroke hemiparesis

2006-11-22T09:28:07+01:00

Motor imagery practice in gait rehabilitation of chronic post-stroke hemiparesis: four case studies.

Int J Rehabil Res. 2006 Dec;29(4):351-356

Authors: Dunsky A, Dickstein R, Ariav C, Deutsch J, Marcovitz E

The aim of this series of pilot case studies was to examine the feasibility of enhancing the walking of individuals with post-stroke hemiparesis through the imagery practice of gait activities at home. Four persons with chronic hemiparesis received imagery gait practice, 3 days a week for 6 weeks. The intervention addressed gait impairments of the affected lower limb and task-specific gait training. Pre-intervention, mid-term, post-intervention and follow-up evaluations were performed. At 6 weeks from the beginning of treatment, the participants increased walking speed, stride length, cadence and single-support time on the affected lower limb, while decreasing double-support time. The findings appear to justify the institution of a larger-scale study in order to better delineate the contribution of motor imagery practice to gait performance in individuals with post-stroke hemiparesis.

A strategy for computer-assisted mental practice in stroke rehabilitation

2006-11-05T22:29:08+01:00

A strategy for computer-assisted mental practice in stroke rehabilitation.

Neurorehabil Neural Repair. 2006 Dec;20(4):503-7

Authors: Gaggioli A, Meneghini A, Morganti F, Alcaniz M, Riva G

OBJECTIVE: To investigate the technical and clinical viability of using computer-facilitated mental practice in the rehabilitation of upper-limb hemiparesis following stroke. DESIGN: A single-case study. SETTING: Academic-affiliated rehabilitation center.Participant. A 46-year-old man with stable motor deficit of the upper right limb following subcortical ischemic stroke.Intervention. Three computer-enhanced mental practice sessions per week at the rehabilitation center, in addition to usual physical therapy. A custom-made virtual reality system equipped with arm-tracking sensors was used to guide mental practice. The system was designed to superimpose over the (unseen) paretic arm a virtual reconstruction of the movement registered from the nonparetic arm. The laboratory intervention was followed by a 1-month home-rehabilitation program, making use of a portable display device. MAIN OUTCOME MEASURES: Pretreatment and posttreatment clinical assessment measures were the upper-extremity scale of the Fugl-Meyer Assessment of Sensorimotor Impairment and the Action Research Arm Test. Performance of the affected arm was evaluated using the healthy arm as the control condition. RESULTS: The patient's paretic limb improved after the first phase of intervention, with modest increases after home rehabilitation, as indicated by functional assessment scores and sensors data. CONCLUSION: Results suggest that technology-supported mental training is a feasible and potentially effective approach for improving motor skills after stroke.

Recovery of hand function through mental practice: A study protocol.

2006-10-28T18:40:28+02:00

Recovery of hand function through mental practice: A study protocol.

BMC Neurol. 2006 Oct 26;6(1):39

Authors: Ietswaart M, Johnston M, Dijkerman HC, Scott CL, Joice SA, Hamilton S, Macwalter RS

BACKGROUND: The study aims to assess the therapeutic benefits of motor imagery training in stroke patients with persistent motor weakness. There is evidence to suggest that mental rehearsal of movement can produce effects normally attributed to practising the actual movements. Imagining hand movements could stimulate the redistribution of brain activity, which accompanies recovery of hand function, thus resulting in a reduced motor deficit. Methods/ Design A multi-centre randomised controlled trial recruiting individuals between one and six months post-stroke ( n = 135). Patients are assessed before and after a four-week evaluation period. In this trial, 45 patients daily mentally rehearse movements with their affected arm under close supervision. Their recovery is compared to 45 patients who perform closely supervised non-motor mental rehearsal, and 45 patients who are not engaged in a training program. Motor imagery training effectiveness is evaluated using outcome measures of motor function, psychological processes, and level of disability. DISCUSSION: The idea of enhancing motor recovery through the use of motor imagery rehabilitation techniques is important with potential implications for clinical practice. The techniques evaluated as part of this randomised controlled trial are informed by the current understanding in cognitive neuroscience and the trial is both of scientific and applied interest. Trial Registration; Clinical Trial Registration; current clinical trial protocol registration NCT00355836.

EEG-based brain-computer interface

2006-10-11T21:49:03+02:00

Electro-encephalogram based brain-computer interface: improved performance by mental practice and concentration skills.

Med Biol Eng Comput. 2006 Oct 7;

Authors: Mahmoudi B, Erfanian A

Mental imagination is the essential part of the most EEG-based communication systems. Thus, the quality of mental rehearsal, the degree of imagined effort, and mind controllability should have a major effect on the performance of electro-encephalogram (EEG) based brain-computer interface (BCI). It is now well established that mental practice using motor imagery improves motor skills. The effects of mental practice on motor skill learning are the result of practice on central motor programming. According to this view, it seems logical that mental practice should modify the neuronal activity in the primary sensorimotor areas and consequently change the performance of EEG-based BCI. For developing a practical BCI system, recognizing the resting state with eyes opened and the imagined voluntary movement is important. For this purpose, the mind should be able to focus on a single goal for a period of time, without deviation to another context. In this work, we are going to examine the role of mental practice and concentration skills on the EEG control during imaginative hand movements. The results show that the mental practice and concentration can generally improve the classification accuracy of the EEG patterns. It is found that mental training has a significant effect on the classification accuracy over the primary motor cortex and frontal area.

Song and speech

2006-10-07T17:18:47+02:00

Song and speech: brain regions involved with perception and covert production.

Neuroimage. 2006 Jul 1;31(3):1327-42

Authors: Callan DE, Tsytsarev V, Hanakawa T, Callan AM, Katsuhara M, Fukuyama H, Turner R

This 3-T fMRI study investigates brain regions similarly and differentially involved with listening and covert production of singing relative to speech. Given the greater use of auditory-motor self-monitoring and imagery with respect to consonance in singing, brain regions involved with these processes are predicted to be differentially active for singing more than for speech. The stimuli consisted of six Japanese songs. A block design was employed in which the tasks for the subject were to listen passively to singing of the song lyrics, passively listen to speaking of the song lyrics, covertly sing the song lyrics visually presented, covertly speak the song lyrics visually presented, and to rest. The conjunction of passive listening and covert production tasks used in this study allow for general neural processes underlying both perception and production to be discerned that are not exclusively a result of stimulus induced auditory processing nor to low level articulatory motor control. Brain regions involved with both perception and production for singing as well as speech were found to include the left planum temporale/superior temporal parietal region, as well as left and right premotor cortex, lateral aspect of the VI lobule of posterior cerebellum, anterior superior temporal gyrus, and planum polare. Greater activity for the singing over the speech condition for both the listening and covert production tasks was found in the right planum temporale. Greater activity in brain regions involved with consonance, orbitofrontal cortex (listening task), subcallosal cingulate (covert production task) were also present for singing over speech. The results are consistent with the PT mediating representational transformation across auditory and motor domains in response to consonance for singing over that of speech. Hemispheric laterality was assessed by paired t tests between active voxels in the contrast of interest relative to the left-right flipped contrast of interest calculated from images normalized to the left-right reflected template. Consistent with some hypotheses regarding hemispheric specialization, a pattern of differential laterality for speech over singing (both covert production and listening tasks) occurs in the left temporal lobe, whereas, singing over speech (listening task only) occurs in right temporal lobe.

The neural basis of narrative imagery

2006-10-04T22:43:08+02:00

The neural basis of narrative imagery: emotion and action.

Prog Brain Res. 2006;156:93-103

Authors: Sabatinelli D, Lang PJ, Bradley MM, Flaisch T

Effects of motor imagery training after spinal cord injury

2006-09-06T20:45:33+02:00

Effects of motor imagery training after chronic, complete spinal cord injury.

Exp Brain Res. 2006 Aug 31;

Authors: Cramer SC, Orr EL, Cohen MJ, Lacourse MG

Abnormalities in brain motor system function are present following spinal cord injury (SCI) and could reduce effectiveness of restorative interventions. Motor imagery training, which can improve motor behavior and modulate brain function, might address this concern but has not been examined in subjects with SCI. Ten subjects with SCI and complete tetra-/paraplegia plus ten healthy controls underwent assessment before and after 7 days of motor imagery training to tongue and to foot. Motor imagery training significantly improved the behavioral outcome measure, speed of movement, in non-paralyzed muscles. Training was also associated with increased fMRI activation in left putamen, an area associated with motor learning, during attempted right foot movement in both groups, despite foot movements being present in controls and absent in subjects with SCI. This fMRI change was absent in a second healthy control group serially imaged without training. In subjects with SCI, training exaggerated, rather than normalized, baseline derangement of left globus pallidus activation. The current study found that motor imagery training improves motor performance and alters brain function in subjects with complete SCI despite lack of voluntary motor control and peripheral feedback. These effects of motor imagery training on brain function have not been previously described in a neurologically impaired population, and were similar to those found in healthy controls. Motor imagery might be of value as one component of a restorative intervention.

Mapping implied body actions in the human motor system

2006-07-31T16:45:56+02:00

Mapping implied body actions in the human motor system.

J Neurosci. 2006 Jul 26;26(30):7942-9

Authors: Urgesi C, Moro V, Candidi M, Aglioti SM

The human visual system is highly tuned to perceive actual motion as well as to extrapolate dynamic information from static pictures of objects or creatures captured in the middle of motion. Processing of implied motion activates higher-order visual areas that are also involved in processing biological motion. Imagery and observation of actual movements performed by others engenders selective activation of motor and premotor areas that are part of a mirror-neuron system matching action observation and execution. By using single-pulse transcranial magnetic stimulation, we found that the mere observation of static snapshots of hands suggesting a pincer grip action induced an increase in corticospinal excitability as compared with observation of resting, relaxed hands, or hands suggesting a completed action. This facilitatory effect was specific for the muscle that would be activated during actual execution of the observed action. We found no changes in responsiveness of the tested muscles during observation of nonbiological entities with (e.g., waterfalls) or without (e.g., icefalls) implied motion. Thus, extrapolation of motion information concerning human actions induced a selective activation of the motor system. This indicates that overlapping motor regions are engaged in the visual analysis of physical and implied body actions. The absence of motor evoked potential modulation during observation of end posture stimuli may indicate that the observation-execution matching system is preferentially activated by implied, ongoing but not yet completed actions.

Motor Imagery. A Backdoor to the Motor System After Stroke?

2006-06-04T22:05:37+02:00

Stroke. 2006 Jun 1;

Authors: Sharma N, Pomeroy VM, Baron JC

BACKGROUND AND PURPOSE: Understanding brain plasticity after stroke is important in developing rehabilitation strategies. Active movement therapies show considerable promise but depend on motor performance, excluding many otherwise eligible patients. Motor imagery is widely used in sport to improve performance, which raises the possibility of applying it both as a rehabilitation method and to access the motor network independently of recovery. Specifically, whether the primary motor cortex (M1), considered a prime target of poststroke rehabilitation, is involved in motor imagery is unresolved. Summary of Review--We review methodological considerations when applying motor imagery to healthy subjects and in patients with stroke, which may disrupt the motor imagery network. We then review firstly the motor imagery training literature focusing on upper-limb recovery, and secondly the functional imaging literature in healthy subjects and in patients with stroke. CONCLUSIONS: The review highlights the difficulty in addressing cognitive screening and compliance in motor imagery studies, particularly with regards to patients with stroke. Despite this, the literature suggests the encouraging effect of motor imagery training on motor recovery after stroke. Based on the available literature in healthy volunteers, robust activation of the nonprimary motor structures, but only weak and inconsistent activation of M1, occurs during motor imagery. In patients with stroke, the cortical activation patterns are essentially unexplored as is the underlying mechanism of motor imagery training. Provided appropriate methodology is implemented, motor imagery may provide a valuable tool to access the motor network and improve outcome after stroke.

Science News: Fitness is good for the brain

2006-02-28T18:05:00+01:00

From the latest article in Science News Online:

New research suggests that physical exercise encourages healthy brains to function at their optimum levels. Fitness prompts nerve cells to multiply, strengthens their connections, and protects them from harm. Benefits seem to extend to brains and nerves that are diseased or damaged. These findings could suggest new treatments for people with Alzheimer's disease, Parkinson's disease, and spinal cord injuries.
[...]
Preliminary studies indicated that when lab animals exercise, their nerve cells release chemicals called neurotrophic factors. These proteins buffer nerve cells against illness or injury, prompt them to grow and multiply, and strengthen each neuron's connection with other nerve cells.
[...]
Furthermore, memory tests given to 1,740 people over 65 during a 6-year project have linked moderate exercise to reduced risk of dementia. These results were published in the Jan. 17 Annals of Internal Medicine by a Seattle research team.

Modulation of beta oscillations in the subthalamic area during motor imagery in Parkinson's disease

2005-12-22T22:50:00+01:00

Brain. 2005 Dec 19;

Authors: Kühn AA, Doyle L, Pogosyan A, Yarrow K, Kupsch A, Schneider GH, Hariz MI, Trottenberg T, Brown P

Activation of the basal ganglia has been shown during the preparation and execution of movement. However, the extent to which the activation during movement is related to efferent processes or feedback-related motor control remains unclear. We used motor imagery (MI), which eliminates peripheral feedback, to further investigate the role of the subthalamic area in the feedforward organization of movement. We recorded local field potential (LPF) activity from the region of the subthalamic nucleus (STN) in eight patients with Parkinson's disease off dopaminergic medication during performance of a warned reaction time task. Patients were instructed to either extend the wrist [motor execution (ME)], to imagine performing the same task without any overt movement (MI), or, in a subgroup, to perform a non-motor visual imagery (VI) task. MI led to event-related desynchronization (ERD) of oscillatory beta activity in the region of the STN in all patients that was similar in frequency, time course and degree to the ERD occurring during ME. The degree of ERD during MI correlated with the ERD in trials of ME and, like ME, was accompanied by a decrease in cortico-STN coherence, so that STN LFP activity during MI was similar to that in ME. The ERD in ME and MI were both significantly larger than the ERD in VI. In contrast, event-related synchronization (ERS) was significantly smaller in trials of MI, and even smaller in trials of VI, than during ME. The data suggest that the activity in the region of the human STN indexed by the ERD during movement is related to the feedforward organization of movement and is relatively independent of peripheral feedback. In contrast, sensorimotor feedback is an important factor in the ERS occurring in the STN area after completion of movement, consistent with a role for this region in trial-to-trial motor learning or the re-establishment of postural set following movements.

Mental imagery combined with physical practice of approach shots for golf beginners

2005-12-17T12:40:00+01:00

Percept Mot Skills. 2005 Aug;101(1):203-11

Authors: Brouziyne M, Molinaro C

Recent research on motor skills of golf have pointed to the usefulness of mental imagery. In golf, such training is rarely used as a teaching technique for beginners on the grounds that only top professionals stand to gain from mental imagery. This study tested whether mental imagery combined with physical practice can improve golf performance for the approach shot. 23 volunteer beginners, 8 women and 15 men, M age 23.4 yr. (SD = 3.7), enrolled in the University Physical and Sporting Activities Department, were divided into three groups, using a combination of physical practice of the approach shot plus mental imagery, physical practice only, and a third group engaging in various sporting activities instead of either mental or physical practice of the chip shot. Analysis showed that the beginners' approach shot performance improved most in the group combining physical practice and mental imagery when compared with the group just physically practising the approach shot. It seems mental training can be used effectively to improve performance even with beginners.

Improvement and generalization of arm motor performance through motor imagery practice

2005-12-15T01:30:00+01:00

Neuroscience. 2005 Dec 7;

Authors: Gentili R, Papaxanthis C, Pozzo T

This study compares the improvement and generalization of arm motor performance after physical or mental training in a motor task requiring a speed-accuracy tradeoff. During the pre- and post-training sessions, 40 subjects pointed with their right arm as accurately and as fast as possible toward targets placed in the frontal plane. Arm movements were performed in two different workspaces called right and left paths. During the training sessions, which included only the right path, subjects were divided into four training groups (n=10): (i) the physical group, subjects overtly performed the task; (ii) the mental group, subjects imagined themselves performing the task; (iii) the active control group, subjects performed eye movements through the targets, (iv) the passive control group, subjects did not receive any specific training. We recorded movement duration, peak acceleration and electromyographic signals from arm muscles. Our findings showed that after both physical and mental training on the right path (training path), hand movement duration and peak acceleration respectively decreased and increased for this path. However, motor performance improvement was greater after physical compared with mental practice. Interestingly, we also observed a partial learning generalization, namely an enhancement of motor performance for the left path (non-training path). The amount of this generalization was roughly similar for the physical and mental groups. Furthermore, while arm muscle activity progressively increased during the training period for the physical group, the activity of the same muscles for the mental group was unchanged and comparable with that of the rest condition. Control groups did not exhibit any improvement. These findings put forward the idea that mental training facilitates motor learning and allows its partial transfer to nearby workspaces. They further suggest that motor prediction, a common process during both actual and imagined movements, is a fundamental operation for both sensorimotor control and learning.

Influence of imagined posture and imagery modality on corticospinal excitability

2005-11-30T23:25:00+01:00

Behav Brain Res. 2005 Nov 25

Authors: Fourkas AD, Ionta S, Aglioti SM

Single pulse transcranial magnetic stimulation (TMS) was used to test the assumption that kinesthetic imagery of action is more 'motor' than visual imagery of action. We assessed corticospinal excitability during motor imagery of a thumb-palm opposition movement by recording potentials evoked by TMS from two hand muscles that would (opponens pollicis, OP, target) or would not (abductor digiti minimi, ADM, control) be activated during actual performance of the very same movement. Participants were asked to imagine the thumb-palm opposition movement while maintaining first person imagery that was either purely visual or predominately kinesthetic. The motor imagery task was performed in two conditions in which the imagined and the actual hand could be either congruent or incongruent. Facilitation of potentials recorded from OP was higher during imagery carried out in mentally congruent than incongruent postures. This effect was largely due to lack of excitability recorded during incongruent kinesthetic imagery, which was indistinguishable from baseline imagery of the static hand. All other conditions differed from static imagery regardless of position. No significant effects were found in a control muscle (ADM) thus indicating that the effect was not related to spatial coding. Subjective reports obtained after the experiment indicate that the results cannot be ascribed to qualitative differences in the imagery experienced. For relatively simple motor tasks requiring no 'expertise' we found no detectable difference in the motor cortex due to imagery modality.

EMG Activity in Selected Target Muscles During Imagery Rising on Tiptoes in Healthy Adults and Poststroke Hemiparetic Pa

2005-11-26T11:55:00+01:00

J Mot Behav. 2005 Nov;37(5):475-83

Authors: Dickstein R, Gazit-Grunwald M, Plax M, Dunsky A, Marcovitz E

The authors sought to gain further knowledge about activation of target muscles during imagery engagement in a motor task. Six hemiparetic patients and 9 healthy participants performed 3 real rises on tiptoes and then, after pausing, 3 imagery rises on tiptoes. Metronome beats guided the rate of rises and descents. Electromyographic (EMG) activity from the medial gastrocnemius and the rectus femoris muscles were monitored bilaterally throughout the performance of both tasks. In 3 healthy participants and 3 individuals with hemiparesis, EMG activity was related to the imagery task in at least 1 of the target muscles. Conversely, in the other participants, motor imagery practice was not accompanied by task-related EMG activity in the monitored muscles. In all cases, the increment in activation level during motor imagery practice was very low in comparison with that of real performance. The findings were not unequivocal; therefore, EMG activity may sometimes, but not always, be recorded during motor imagery practice both in healthy individuals and in poststroke hemiparetic participants. Further research is needed to align motor imagery practice with the objectives of motor rehabilitation.