CUED Publications database

Grip force when reaching with target uncertainty provides evidence for motor optimization over averaging

Nashed, JY and Diamond, JS and Gallivan, JP and Wolpert, DM and Flanagan, JR (2017) Grip force when reaching with target uncertainty provides evidence for motor optimization over averaging. Scientific Reports, 7. 11703-.

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When presented with competing potential reach targets and required to launch a movement before knowing which one will be cued as the target, people initially reach in the average target direction. Although this spatial averaging could arise from executing a weighted average of motor plans for the potential targets, it could also arise from planning a single, optimal movement. To test between these alternatives we used a task in which participants were required to reach to either a single target or towards two potential targets while grasping an object. A robotic device applied a lateral elastic load to the object requiring large grip forces for reaches to targets either side of midline and a minimal grip force for midline movements. As expected, in trials with two targets located either side of midline, participants initially reached straight ahead. Critically, on these trials the initial grip force was minimal, appropriate for the midline movement, and not the average of the large grip forces required for movements to the individual targets. These results indicate that under conditions of target uncertainty, people do not execute an average of planned actions but rather a single movement that optimizes motor costs.

Item Type: Article
Uncontrolled Keywords: Adult Decision Making Female Hand Strength Humans Male Motor Activity Movement Psychomotor Performance Reflex Uncertainty Young Adult
Divisions: Div F > Computational and Biological Learning
Depositing User: Cron Job
Date Deposited: 28 Sep 2017 01:28
Last Modified: 16 Apr 2021 20:27
DOI: 10.1038/s41598-017-10996-6