Cortical neurons multiplex reward-related signals along with sensory and motor information

Arjun Ramakrishnana, Yoon Woo Byunb, Kyle Rand, Christian E. Pedersen, Mikhail A. Lebedev, Miguel A.L. Nicolelis

Research output: Contribution to journalArticlepeer-review

29 Citations (Scopus)

Abstract

Rewards are known to influence neural activity associated with both motor preparation and execution. This influence can be exerted directly upon the primary motor (M1) and somatosensory (S1) cortical areas via the projections from reward-sensitive dopaminergic neurons of the midbrain ventral tegmental areas. However, the neurophysiological manifestation of reward-related signals in M1 and S1 are not well understood. Particularly, it is unclear how the neurons in these cortical areas multiplex their traditional functions related to the control of spatial and temporal characteristics of movements with the representation of rewards. To clarify this issue, we trained rhesus monkeys to perform a center-out task in which arm movement direction, reward timing, and magnitude were manipulated independently. Activity of several hundred cortical neurons was simultaneously recorded using chronically implanted microelectrode arrays. Many neurons (9-27%) in both M1 and S1 exhibited activity related to reward anticipation. Additionally, neurons in these areas responded to a mismatch between the reward amount given to the monkeys and the amount they expected: A lower-than-expected reward caused a transient increase in firing rate in 60-80% of the total neuronal sample, whereas a larger-than-expected reward resulted in a decreased firing rate in 20-35% of the neurons. Moreover, responses of M1 and S1 neurons to reward omission depended on the direction of movements that led to those rewards. These observations suggest that sensorimotor cortical neurons corepresent rewards and movement-related activity, presumably to enable reward-based learning.

Original languageEnglish
Pages (from-to)E4841-E4850
JournalProceedings of the National Academy of Sciences of the United States of America
Volume114
Issue number24
DOIs
Publication statusPublished - 13 Jun 2017
Externally publishedYes

Keywords

  • Motor cortex
  • Multichannel recording
  • Prediction error
  • Primate
  • Reward

Fingerprint

Dive into the research topics of 'Cortical neurons multiplex reward-related signals along with sensory and motor information'. Together they form a unique fingerprint.

Cite this