The motor cortex and the coding of force

Apostolos P Georgopoulos, James Ashe, Nikolaos Smyrnis, Masato Taira

Research output: Contribution to journalArticlepeer-review

303 Scopus citations


The relation of cellular activity in the motor cortex to the direction of two-dimensional isometric force was investigated under dynamic conditions in monkeys. A task was designed so that three force variables were dissociated: the force exerted by the subject, the net force, and the change in force. Recordings of neuronal activity in the motor cortex revealed that the activity of single cells was directionally tuned and that this tuning was invariant across different directions of a bias force. Cell activity was not related to the direction of force exerted by the subject, which changed drastically as the bias force changed. In contrast, the direction of net force, the direction of force change, and the visually instructed direction all remained quite invariant and congruent and could be the directional variables, alone or in combination, to which cell activity might relate.

Original languageEnglish (US)
Pages (from-to)1692-1695
Number of pages4
Issue number5064
StatePublished - 1992


Dive into the research topics of 'The motor cortex and the coding of force'. Together they form a unique fingerprint.

Cite this