Neurons in Primary Motor Cortex Encode Hand Orientation in a Reach-to-Grasp Task

Chaolin Ma*, Xuan Ma, Jing Fan, Jiping He

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


It is disputed whether those neurons in the primary motor cortex (M1) that encode hand orientation constitute an independent channel for orientation control in reach-to-grasp behaviors. Here, we trained two monkeys to reach forward and grasp objects positioned in the frontal plane at different orientation angles, and simultaneously recorded the activity of M1 neurons. Among the 2235 neurons recorded in M1, we found that 18.7% had a high correlation exclusively with hand orientation, 15.9% with movement direction, and 29.5% with both movement direction and hand orientation. The distributions of neurons encoding hand orientation and those encoding movement direction were not uniform but coexisted in the same region. The trajectory of hand rotation was reproduced by the firing patterns of the orientation-related neurons independent of the hand reaching direction. These results suggest that hand orientation is an independent component for the control of reaching and grasping activity.

Original languageEnglish (US)
Pages (from-to)383-395
Number of pages13
JournalNeuroscience Bulletin
Issue number4
StatePublished - Aug 1 2017
Externally publishedYes


  • Hand orientation
  • Non-human primate
  • Primary motor cortex
  • Single neuron recording

ASJC Scopus subject areas

  • General Neuroscience
  • Physiology


Dive into the research topics of 'Neurons in Primary Motor Cortex Encode Hand Orientation in a Reach-to-Grasp Task'. Together they form a unique fingerprint.

Cite this