Differences in visuomotor control between the upper and lower visual fields.

Danckert and Goodale [Exp Brain Res 137:303-308 (2001)] have shown that increases in movement time as target size decreased were greater when movements were performed in the lower compared with upper visual field. On this basis, they suggested that visual feedback processing was more effective in the lower visual field. However, despite the greater influence of target size on movement time for the lower compared to upper visual field, there were no differences in accuracy between visual fields for movements to the smallest targets. In the present study, we investigated whether superior performance would be observed in the lower visual field when movement times were constrained. Analysis of the variability in distance travelled at key kinematic markers (e.g. peak acceleration, peak velocity, and peak negative acceleration) revealed that limb trajectories were more consistent in the lower compared to upper visual field at the late stages of the movement. Also, squared correlation coefficients between the distance travelled at peak velocity and the distance at the end of the movement were smaller for movements performed in the lower visual field. These results imply that superior performance in the lower visual field was due to better utilization of visual feedback during movement execution.