Goal-equivalent joint coordination in pointing: affect of vision and arm dominance.

摘要: This study used the uncontrolled manifold (UCM) approach to joint coordination underlying control of task-related variables important for success at reaching and pointing targets. More combinations motions are available system achieve task than strictly necessary. How this abundance motor solutions is managed by nervous whether how availability visual information affects solution was investigated in study. The variability angle partitioned into 2 components with respect either hand's path or arm's center mass (CM). goal-equivalent (GEV) component represents trial-to-trial fluctuations configuration consistent a stable value hand CM path. other component, non-goal-equivalent (NGEV), led deviations away from desired We hypothesized style which NGEV selectively restricted while allowing range be stability paths. Twelve healthy right-handed subjects reached across their body circular target both right left arms eyes open closed on different trials. When repeating same arm under identical conditions, configurations entire trajectory motion, as well terminal position pointer-tip. Overall consistently larger middle movement, near time peak velocity. qualitatively similar regardless point condition. Quantitative differences structure were present non-dominant arm, however, when absence vision target. results suggest that uses strategy provides goal-equivalent, rather unique, stabilize values variables, restricting change these values. possible advantage discussed. Absence during affected only quantitatively less skilled suggesting role may greater organizing arm.