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Primary motor cortex underlies multi-joint integration for fast feedback control.
- Source :
-
Nature [Nature] 2011 Sep 28; Vol. 478 (7369), pp. 387-90. Date of Electronic Publication: 2011 Sep 28. - Publication Year :
- 2011
-
Abstract
- A basic difficulty for the nervous system is integrating locally ambiguous sensory information to form accurate perceptions about the outside world. This local-to-global problem is also fundamental to motor control of the arm, because complex mechanical interactions between shoulder and elbow allow a particular amount of motion at one joint to arise from an infinite combination of shoulder and elbow torques. Here we show, in humans and rhesus monkeys, that a transcortical pathway through primary motor cortex (M1) resolves this ambiguity during fast feedback control. We demonstrate that single M1 neurons of behaving monkeys can integrate shoulder and elbow motion information into motor commands that appropriately counter the underlying torque within about 50 milliseconds of a mechanical perturbation. Moreover, we reveal a causal link between M1 processing and multi-joint integration in humans by showing that shoulder muscle responses occurring ∼50 milliseconds after pure elbow displacement can be potentiated by transcranial magnetic stimulation. Taken together, our results show that transcortical processing through M1 permits feedback responses to express a level of sophistication that rivals voluntary control; this provides neurophysiological support for influential theories positing that voluntary movement is generated by the intelligent manipulation of sensory feedback.
- Subjects :
- Adult
Animals
Biomechanical Phenomena physiology
Evoked Potentials, Motor physiology
Female
Humans
Macaca mulatta
Male
Motor Neurons physiology
Muscle, Skeletal physiology
Time Factors
Elbow physiology
Feedback, Sensory physiology
Motor Cortex cytology
Motor Cortex physiology
Shoulder physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1476-4687
- Volume :
- 478
- Issue :
- 7369
- Database :
- MEDLINE
- Journal :
- Nature
- Publication Type :
- Academic Journal
- Accession number :
- 21964335
- Full Text :
- https://doi.org/10.1038/nature10436