Citation

Selen LP, Shadlen MN, Wolpert DM. J. Neurosci. 2012; 32(7): 2276-2286.

Affiliation

Computational and Biological Learning Laboratory, Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, United Kingdom, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, 6500HB Nijmegen, The Netherlands, and Howard Hughes Medical Institute, National Primate Research Center, and Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195.

Copyright

(Copyright © 2012, Society for Neuroscience)

DOI

10.1523/JNEUROSCI.5273-11.2012

PMID

22396403

PMCID

PMC3299561

Abstract

Both decision making and sensorimotor control require real-time processing of noisy information streams. Historically these processes were thought to operate sequentially: cognitive processing leads to a decision, and the outcome is passed to the motor system to be converted into action. Recently, it has been suggested that the decision process may provide a continuous flow of information to the motor system, allowing it to prepare in a graded fashion for the probable outcome. Such continuous flow is supported by electrophysiology in nonhuman primates. Here we provide direct evidence for the continuous flow of an evolving decision variable to the motor system in humans. Subjects viewed a dynamic random dot display and were asked to indicate their decision about direction by moving a handle to one of two targets. We probed the state of the motor system by perturbing the arm at random times during decision formation. Reflex gains were modulated by the strength and duration of motion, reflecting the accumulated evidence in support of the evolving decision. The magnitude and variance of these gains tracked a decision variable that explained the subject's decision accuracy. The findings support a continuous process linking the evolving computations associated with decision making and sensorimotor control.

Language: en