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Updated: Jun 2, 2026
12:33
Corticospinal Excitability Modulation During Action Observation
Published on: December 31, 2013
Grip-dependent cortico-spinal excitability during grasping imagination and execution
Paola Cesari1, Fabio Pizzolato, Mirta Fiorio
1Department of Neurological, Neuropsychological, Morphological and Movement Sciences, University of Verona, Italy. paola.cesari@univr.it
Neuropsychologia
|May 5, 2011
Summary
Motor imagery of actions shows muscle-specific control, similar to real execution. However, force production during actual actions is more finely tuned than during imagined actions.
Area of Science:
- Neuroscience
- Motor Control
- Cognitive Neuroscience
Background:
- Action observation and execution share neural mechanisms.
- Transcranial magnetic stimulation (TMS) studies show muscle specificity in action observation.
- The specificity of muscle activation during action imagination remains unclear.
Purpose of the Study:
- To investigate muscle-specific corticospinal excitability during imagined grasping actions.
- To compare motor control during imagination versus execution of grasping.
- To determine if grip configuration is selected during motor imagery.
Main Methods:
- Applied TMS to the primary motor cortex to measure corticospinal excitability (MEP).
- Measured MEP in FDI, ADM, and FDS muscles during imagined grasping of objects with varying sizes and materials.
- Compared imagined grasping activation with electromyography (EMG) during actual grasping.
Main Results:
- Muscle activation patterns during imagined grasping mirrored those during actual execution.
- FDI was more active for small objects, ADM/FDS for large objects, and all muscles equally for medium objects during imagination.
- Actual action execution showed finer tuning to object dimensions for force production than imagination.
Conclusions:
- The corticospinal system is modulated in a muscle- and grip-specific manner during action imagination.
- Motor imagery prepares the motor system similarly to actual action execution.
- Force control during real actions involves a more refined mechanism than during imagination.
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