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Updated: Dec 17, 2025
05:05
Assessing Corticospinal Excitability During Goal-Directed Reaching Behavior
Published on: December 2, 2022
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A bang-bang control model predicts the triphasic muscles activity during hand reaching
Raz Leib1,2, Marta Russo3, Andrea d'Avella4,5
1Department of Biomedical Engineering, Ben-Gurion University of the Negev, Be'er Sheva, Israel.
Journal of Neurophysiology
|June 25, 2020
Summary
The brain may not control muscles smoothly, but rather uses sparse, on-off commands. This "bang-bang control" model explains muscle bursts during reaching and can improve neuroprosthetics.
Area of Science:
- Neuroscience
- Motor Control
- Robotics
Background:
- Reaching movements appear smooth, but muscle activity shows distinct bursts and silent periods.
- This challenges the traditional view of continuous motor control signals from the brain.
Purpose of the Study:
- To propose and validate a new model of motor control based on piecewise-constant control signals.
- To explain the observed muscle activity patterns during reaching movements.
Main Methods:
- Developed a computational model using bang-bang control principles.
- Employed Markov chain Monte Carlo (MCMC) methods to analyze muscle state transitions.
- Fitted the bang-bang model to movement kinematics.
Main Results:
- The bang-bang control model successfully predicts transitions in muscle states.
- This model links abrupt muscle activity changes to smooth reaching trajectories.
- Muscle control appears to be sparse, not continuous.
Conclusions:
- The brain likely uses a bang-bang control strategy for ballistic movements, simplifying control.
- This finding has implications for designing more efficient neuroprostheses and human-robot interaction systems.
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