Motor imagery

About: Motor imagery is a research topic. Over the lifetime, 4158 publications have been published within this topic receiving 126962 citations.

Mapping motor representations with positron emission tomography

Abstract: Brain activity was mapped in normal subjects during passive observation of the movements of an 'alien' hand and while imagining grasping objects with their own hand. None of the tasks required actual movement. Shifting from one mental task to the other greatly changed the pattern of brain activation. During observation of hand movements, activation was mainly found in visual cortical areas, but also in subcortical areas involved in motor behaviour, such as the basal ganglia and the cerebellum. During motor imagery, cortical and subcortical areas related to motor preparation and programming were strongly activated. These data support the notion that motor learning during observation of movements and mental practice involves rehearsal of neural pathways related to cognitive stages of motor control.

The emulation theory of representation: Motor control, imagery, and perception - eScholarship

Abstract: The emulation theory of representation is developed and explored as a framework that can revealingly synthesize a wide variety of representational functions of the brain. The framework is based on constructs from control theory (forward models) and signal processing (Kalman filters). The idea is that in addition to simply engaging with the body and environment, the brain constructs neural circuits that act as models of the body and environment. During overt sensorimotor engagement, these models are driven by efference copies in parallel with the body and environment, in order to provide expectations of the sensory feedback, and to enhance and process sensory information. These models can also be run off-line in order to produce imagery, estimate outcomes of different actions, and evaluate and develop motor plans. The framework is initially developed within the context of motor control, where it has been shown that inner models running in parallel with the body can reduce the effects of feedback delay problems. The same mechanisms can account for motor imagery as the off-line driving of the emulator via efference copies. The framework is extended to account for visual imagery as the off-line driving of air emulator of the motor-visual loop. I also show how such systems can provide for amodal spatial imagery. Perception, including visual perception, results from such models being used to form expectations of, and to interpret, sensory input. I close by briefly outlining other cognitive functions that might also be synthesized within this framework, including reasoning, theory of mind phenomena, and language.

The cognitive neuroscience of action

Abstract: Part I: General Introduction:1.1. Action as a Coordination Problem.1.2. Internal Models and the Purpose of Actions.1.3. Motor Engrams.1.4. Outline.Part II: Neural Substrates for Object Orientated Actions:2.1. Visuomotor Coordination as a Dissociable Visual Function.2.1.1. The Two-Visual-Systems Hypothesis.2.1.2. Two Cortical Visual Systems.2.1.3. Visuomotor Channels.2.2 Neural Coding in the Visuomotor (dorsal) Pathway: Reaching Movements.2.2.1. Reaching Neurons in the Parietal Cortex.2.2.2. The Role of Motor and Premotor Cortex.2.3 Neural Coding in the Visuomotor (dorsal) Pathway: Grasping Movements.2.3.1. The Pattern of Grip Formation.2.3.2. Neural Mechanisms Involved in the Control of Visually Guided Grasping.2.3.2.1. Motor Cortex.2.3.2.2. Parietal Cortical Areas.2.3.2.3. Premotor Cortex Neurons.2.4. Predetermined Motor Patterns: The Schema Approach.Part III: Task-Dependent Representations for Action:3.1. Relevance of Neural Systems to Task-Dependent Representations of Action.3.1.1. Effects of Posterior Parietal Lesions on Object-Orientated Actions.3.1.2. Testing Object-Oriented Behavior.3.1.3. Two Illustrative Clinical Cases.3.2. Object-Oriented Behaviour in Lesions of the Ventral System.3.3. Brain Activity Mapping During Object-Oriented Actions.3.4. The Representation of Object-Oriented Actions.3.4.1. Classifying Object Attributes.3.4.2. The Frame of Reference Problem.3.5. Task Dependent Dissociations of Visumotor and Perceptual Responses.3.5.1. Motor Vs Perceptual Responses.3.5.2. Time-Based Dissociations.3.5.3. Implicit Functioning of Pragmatic Representations.3.5.4. The Semantic Penetration of Pragmatic Representations.3.6. A Note on Apraxia.Part IV: The Contribution of Mental Imagery to Understanding Motor Representations:4.1. Motor Imagery, A "First Person" Process.4.2. What is Represented in Motor Images.4.2.1. The Problem of the Representation of Time.4.2.2. The Representation of Motor Rules.4.2.3. Representation of Motor Constraints and Potentialities.4.3. Physiological Correlates of Mental Simulation of Movement.4.3.1. Muscular Activity.4.3.2. Autonomic Nervous System.4.3.3. Brain Activity.4.4. The Effects of Mental Training.4.5. Motor Imagery in Clinical Disorders of Movement and Action.Part V: Action Planning:5.1. A Cognitive Approach to Action Planning.5.1.1. Mental Chronometry Paradigms.5.2. A Neuropsychological Approach to Action Planning.5.2.1. Anatomical Connections of the Frontal Granular Cortex.5.2.2. Frontal Lobe Lesions in Mokeys.5.2.3. Paradigms for Studying Neuronal Activity in Prefrontal Areas.5.2.4. Planning Deficits Following Frontal Lesion in Man.5.3. Study of Human Brain Activity during Motor Preparation and Action Planning.5.4. The Role of Basal Ganglia in Action Planning.5.5. A Synthetic Conclusion on Action Planning.Part VI: Design for a Motor Representation:6.1. Requirements for Representing Neurons.6.2. The Internal Structure of Motor Representations.6.2.1. The Corollary Discharge Concept.6.2.2. Comparator Models.6.3. Testing the Validity of Comparator Models.6.3.1. Perturbation Experiments.6.3.2. The Role of Reafference.6.4. Monitoring Intentions.6.4.1. Sensations of Innervation.6.4.2. The Problem of Awareness of Intentions.6.4.3. Understanding Intentions of Others.6.4.4. Imitation and Observational Learning.

Activation of Cortical and Cerebellar Motor Areas during Executed and Imagined Hand Movements: An fMRI Study

Abstract: Brain activation during executed (EM) and imagined movements (IM) of the right and left hand was studied in 10 healthy right-handed subjects using functional magnetic resonance imagining (fMRI). Low electromyographic (EMG) activity of the musculi flexor digitorum superficialis and high vividness of the imagined movements were trained prior to image acquisition. Regional cerebral activation was measured by fMRI during EM and IM and compared to resting conditions. Anatomically selected regions of interest (ROIs) were marked interactively over the entire brain. In each ROI activated pixels above a t value of 2.45 (p < 0.01) were counted and analyzed. In all subjects the supplementary motor area (SMA), the premotor cortex (PMC), and the primary motor cortex (M1) showed significant activation during both EM and IM; the somatosen sory cortex (S1) was significantly activated only during EM. Ipsilateral cerebellar activation was decreased during IM compared to EM. In the cerebellum, IM and EM differed in their foci of maximal activation: Highest ipsilateral activation of the cerebellum was observed in the anterior lobe (Larsell lobule H IV) during EM, whereas a lower maximum was found about 2-cm dorsolateral (Larsell lobule H VII) during IM. The prefrontal and parietal regions revealed no significant changes during both conditions. The results of cortical activity support the hypothesis that motor imagery and motor performance possess similar neural substrates. The differential activation in the cerebellum during EM and IM is in accordance with the assumption that the posterior cerebellum is involved in the inhibition of movement execution during imagination.

Mu and beta rhythm topographies during motor imagery and actual movements.

Abstract: People can learn to control the 8-12 Hz mu rhythm and/or the 18-25 Hz beta rhythm in the EEG recorded over sensorimotor cortex and use it to control a cursor on a video screen. Subjects often report using motor imagery to control cursor movement, particularly early in training. We compared in untrained subjects the EEG topographies associated with actual hand movement to those associated with imagined hand movement. Sixty-four EEG channels were recorded while each of 33 adults moved left- or right-hand or imagined doing so. Frequency-specific differences between movement or imagery and rest, and between right- and left-hand movement or imagery, were evaluated by scalp topographies of voltage and r spectra, and principal component analysis. Both movement and imagery were associated with mu and beta rhythm desynchronization. The mu topographies showed bilateral foci of desynchronization over sensorimotor cortices, while the beta topographies showed peak desynchronization over the vertex. Both mu and beta rhythm left/right differences showed bilateral central foci that were stronger on the right side. The independence of mu and beta rhythms was demonstrated by differences for movement and imagery for the subjects as a group and by principal components analysis. The results indicated that the effects of imagery were not simply an attenuated version of the effects of movement. They supply evidence that motor imagery could play an important role in EEG-based communication, and suggest that mu and beta rhythms might provide independent control signals.