Signal-dependent noise determines motor planning

Christopher M. Harris and Daniel M. Wolpert
Additional contact information
Christopher M. Harris: Great Ormond Street Hospital for Children NHS Trust, and Institute of Child Health, University College London
Daniel M. Wolpert: Institute of Neurology, Queen Square, University College London

Nature, 1998, vol. 394, issue 6695, 780-784

Abstract: Abstract When we make saccadic eye movements or goal-directed arm movements, there is an infinite number of possible trajectories that the eye or arm could take to reach the target1,2. However, humans show highly stereotyped trajectories in which velocity profiles of both the eye and hand are smooth and symmetric for brief movements3,4. Here we present a unifying theory of eye and arm movements based on the single physiological assumption that the neural control signals are corrupted by noise whose variance increases with the size of the control signal. We propose that in the presence of such signal-dependent noise, the shape of a trajectory is selected to minimize the variance of the final eye or arm position. This minimum-variance theory accurately predicts the trajectories of both saccades and arm movements and the speed–accuracy trade-off described by Fitt's law5. These profiles are robust to changes in the dynamics of the eye or arm, as found empirically6,7. Moreover, the relation between path curvature and hand velocity during drawing movements reproduces the empirical ‘two-thirds power law’8,9. This theory provides a simple and powerful unifying perspective for both eye and arm movement control.

Date: 1998
References: Add references at CitEc
Citations: View citations in EconPapers (51)

Downloads: (external link)
https://www.nature.com/articles/29528 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:394:y:1998:i:6695:d:10.1038_29528

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/29528

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().