Muscular co-contraction covaries with task load to control the flow of motion in fine motor tasks [An article from: Biological Psychology]

This digital document is a journal article from Biological Psychology, published by Elsevier in 2005. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
This study focuses on the relationship between movement-time fluctuations in fine motor tasks and changing levels of muscular co-contraction. Based on a recent neuromotor noise theory, we expected that increased task stress would increase muscular co-contraction and prolong movement times. Ten right-handed adults performed a graphic task, which elicited local movement-time prolongations. In half the trials, a distracting sound was presented as an external stressor. Besides pen-tip kinematics, two estimates of muscular co-contraction were obtained from the surface EMG measurements of eight arm and hand muscles. The results confirm the presumed co-variation of movement time and co-contraction. We conclude that muscular co-contraction forms a strategic means to adapt the flow of motion to central information processing demands.