ReviewContribution from neurophysiological and psychological methods to the study of motor imagery
Introduction
Motor Imagery (MI) is defined as a mental representation of movement without any body movement. MI may involve the whole body or be limited to part of the body, thus requiring body representation as the generator of acting forces and not only of the effects of these forces on the external world [70]. MI is known to improve motor task performance, combination of mental and physical practice being more efficient than, or at least equal to physical execution, when there is no decrease in total physical performance time [37], [41]. However, athletes have to respect several rules of mental work to improve its efficiency. For example, Roure et al. [112] provided evidence that the characteristics of mental training should be close to those related to execution. In a volleyball task, they observed that MI led to improved performance, but that the benefit of mental training was not transferred, even in a close (but different) motor skill. Several types of imagery may be used, according to each sensory modality. Visual and kinesthetic imagery are often performed by athletes to simulate motor performance. Visual imagery requires self-visualization of movement, whereas kinesthetic imagery requires to “feel” the movement, i.e., to mentally perceive muscle contractions, the latter being however beneficial only with an adequate degree of expertise [60]. MI may be studied through several techniques. Behavioral and psychological tools are very useful in field studies and lead to the evaluation of individual ability to either imagine an event accurately or preserve temporal characteristics of movement during MI. However, psychological tests include an important part of subjectivity and mental chronometry gives no information about MI accuracy, but only the characteristic of time preservation. As it is now well known that common neural substrate underlie motor performance and MI [92], understanding the neural correlates of goal-directed action, whether executed or imagined, has been an important aim of cognitive brain research since the advent of functional imaging studies using for example positron emission tomography and functional magnetic resonance imaging. Such brain mapping techniques have therefore provided converging evidence that imagined and executed movements share the same neural substrate [84], [92]. Results suggest overlapping of neural networks in motor and premotor cortices, including supplementary motor area, were activated during MI and motor performance [29], [30], [96], [105], [111], although the primary motor cortex was not always found to be activated [30]. These studies also emphasized the involvement of several parietal areas [95], [116], [130] and subcortical structures such as the cerebellum and the basal ganglia [26], [82], [96]. Neuroimaging data have also provided evidence that cerebral plasticity occurring during incremental acquisition of a motor task was reflected in the same brain regions during MI [80], and that specific cerebral structures were activated while distinguishing MI in a first-person process from MI of another person acting with an object [114]. Such results may be of interest to better understand agency disorders in both neurological and psychopathological patients and to investigate the potential therapeutic effects of MI. Indeed, the use of MI for the rehabilitation of patients with cerebral motor impairments to facilitate the future execution of specific movements is currently one of the most actual growing topics of MI research [35], [36], [69], [72], [83], [85], [86], [100], [103], [124], [135]. However, such neuroimaging techniques cannot be used in the field as they are non-ambulatory methods, and the type and amplitude of movements are limited. Autonomic nervous system (ANS) effectors are activated by MI, and their activities can be measured continuously by non-invasive sensors associated with portable instrumentation. Although the relationships between physiological responses and central mental processes are inferred, data brought by peripheral recordings paralleled those obtained by central nervous system investigation and thus appear to be well-adapted to study MI. Therefore, both central and peripheral methods may be useful to evaluate MI quality, in reference to both direct and indirect data.
Section snippets
Recording of autonomic nervous system activity during motor imagery
Higher brain functions may be studied through ANS effector activity at a peripheral level [63]. Central operations (planning and programming) are paralleled by ANS responses which anticipate and accompany behavior, thus representing non-conscious physiological mechanisms of central mental processes [14], [104], [117]. According to Jeannerod [70], monitoring vegetative functions during motor preparation and MI is an interesting way to compare the two situations: as ANS escapes voluntary control
Changes in muscular activity during motor imagery
The psychoneuromuscular theory is one of the first that attempted to explain the effects of MI in motor performance. Since the early works by Jacobson [66], [67], Shaw [118], [119] and McGuigan [90], it has been presumed that a subliminal activity of the same muscles occurs during MI and during overt movement execution. The Golgi tendon organs are thought to be stimulated and thereby generate neuromuscular feedback [115]. Motor performance enhancement may result from such neuromuscular effects
Behavioral and psychological techniques
MI effects on forthcoming performance have been extensively studied in experimental and cognitive psychology. Several techniques are used to analyze the effects on motor performance, motor learning, evaluation of MI accuracy and vividness, and to understand why, where and when MI is performed. Among the various validated questionnaires, the most frequently used are the Vividness of Visual Imagery Questionnaire [87], the Movement Imagery Questionnaire [55] or its revised version [54], the
Conclusion
At this time, EMG activity during MI cannot bring reliable information to evaluate MI accuracy, and experimental investigation on postural control when mentally simulating a movement remains also necessary. By contrast, ANS activity recording has been shown to match MI in real time and to evaluate qualitatively MI accuracy and individual ability to form mental images. Moreover, a good correlation was obtained in good imagers between four autonomic indices and performance improvement [113]: (i)
References (136)
- et al.
Effect of cognitive load on postural control
Brain Res. Bull.
(2002) - et al.
Dynamics of central nervous activation during motor imagination
Int. J. Psychophysiol.
(1990) - et al.
Mental simulation of an action modulates the excitability of spinal reflex pathways in man
Cogn. Brain Res.
(1997) - et al.
Biomechanical study if the programming of anticipatory postural adjustments associated with voluntary movement
J. Biomech.
(1987) - et al.
The effect of an external load on the force and timing components of mentally represented actions
Behav. Brain Res.
(2000) - et al.
Programming or inhibiting action: autonomic nervous system control of anticipation
Int. J. Psychophysiol.
(1999) - et al.
Neurophysiological correlates of mental processes through non-invasive micro-sensors recording in the field
Sci. Sports
(2003) - et al.
Chronometric studies of the rotation of mental images
- et al.
Influence of a visuo-spatial, verbal and central executive working memory task on postural control
Gait Posture
(2001) - et al.
Does articulation contribute to modifications of postural control during dual-task paradigms?
Cogn. Brain Res.
(2003)
Do imagined and executed actions share the same neural substrate?
Cogn. Brain Res.
Comparative analysis of actual and mental movement times in two graphic tasks
Brain Cogn.
The timing of mentally represented actions
Behav. Brain Res.
The cerebellum participates in mental activity: tomographic measurements of regional cerebral blood flow
Brain Res.
Vegetative response during imagined movement is proportional to mental effort
Behav. Brain Res.
Cerebral processes related to visuomotor imagery and generation of simple finger movements studied with positron emission tomography
NeuroImage
Relationship between mental imagery and sporting performance
Behav. Brain Res.
Autonomic nervous system response patterns correlate with mental imagery
Physiol. Behav.
Real-time independent component analysis of fMRI time-series
NeuroImage
Cognitive influences on human autonomic nervous system function
Curr. Opin. Neurobiol.
Postural control: visual and cognitive manipulations
Gait Posture
Functional cerebral reorganization following motor sequence learning through mental practice with motor imagery
NeuroImage
Stimulation through simulation? Motor imagery and functional reorganization in hemiplegic stroke patients
Brain Cogn.
Motor learning produces parallel dynamic functional changes during the execution and imagination of sequential foot movements
NeuroImage
Mental imagery for promoting relearning for people after stroke: a randomized controlled trial
Arch. Phys. Med. Rehabil.
The voluntary control of motor imagery. Imagined movements in individuals with feigned impairment and conversion disorder
Neuropsychologia
Movement, posture and equilibrium: interaction and coordination
Prog. Neurobiol.
Reopening the mental imagery debate: lessons from functional anatomy
NeuroImage
Cortical and cerebellar activity of the human brain during imagined and executed unimanual and bimanual action sequences: a functional MRI study
Cogn. Brain Res.
Amplitude reduction of H-reflex during mental movement simulation in elite athletes
Behav. Brain Res.
Changes in muscular activity while imaging weight-lifting using stimulus or response propositions
J. Sport Exerc. Psychol.
EMG quantification of mental rehearsal
Percept. Mot. Skills
Autonomic nervous system activity during actual and mentally simulated preparation for movement
Appl. Psychophysiol. Biofeedback
Action-based Imagery: On The Nature of Mentally Imagined Motor Actions
Cardioventilatory changes induced by mentally imaged rowing
Eur. J. Appl. Physiol.
Exp. Brain Res.
Duration of physical and mental execution of gymnastic routines
Sport Psychol.
A model of sporting performance constructed from autonomic nervous system responses
Eur. J. Appl. Physiol.
Athletes' use of imagery in the off-season
Sport Psychol.
Movement-related potentials associated with movement preparation and motor imagery
Exp. Brain Res.
Mentally simulated movements in virtual reality: does Fitts's law hold in motor imagery?
Behav. Brain Res.
Central activation of autonomic effectors during mental simulation of motor actions in man
J. Physiol.
Mapping motor representations with positron emission tomography
Nature
Scanning visual mental images: a window o the mind
Curr. Psychol. Cogn.
Visual imagery and the use of mental practice in the development o motor skills
Can. J. Appl. Sport Sci.
Motor imagery for gait rehabilitation in post-stroke hemiparesis
Phys. Ther.
Does motor imagery training improve hand function in chronic stroke patients? A pilot study
Clin. Rehabil.
Does mental practice enhance performance?
J. Appl. Psychol.
Visual spatial abilities of pilots
J. Appl. Psychol.
Cited by (188)
Is there a continuum of agentive awareness across physical and mental actions? The case of quasi-movements
2023, Consciousness and CognitionFactors and strategies affecting motor imagery ability in people with multiple sclerosis: a systematic review
2023, Physiotherapy (United Kingdom)Innovations in Neuropsychology: Future Applications in Neurosurgical Patient Care
2023, World NeurosurgeryMotor imagery and the muscle system
2022, International Journal of PsychophysiologyPlaying under pressure: EEG monitoring of activation in professional tennis players
2022, Physiology and Behavior