Visual landmarks and response delay in estimates of reach.

Visual background information may facilitate visually guided and memory guided estimates of reach, as estimates have been linked to the mental representation of action. Right-handed adults were asked to give verbal estimates of distance reachability using motor imagery in conditions with no visual background or with visual background. In each condition, four delays were used: 0, 1, 2, and 4 sec. There were no distinctions between conditions; however, comparisons at each delay were significantly different at 2 and 4 sec. With each delay, participants displayed significantly less error when the visual background was presented. These findings are consistent with the notion that motor simulation approximates motor planning and execution.