Spatial Error Detection in Rapid Unimanual and Bimanual Aiming Movements

Abstract

According to closed-loop accounts of motor control, movement errors are detected by comparing sensory feedback to an acquired reference state. Differences between the reference state and the movement-produced feedback results in an error signal which serves as a basis for a correction. The current study assessed whether error detection is less accurate when feedback from both hands must be analyzed compared to one hand and if error detection is more accurate in longer movements compared to shorter movements. 36 college-age participants (26 women and 10 men) performed a rapid aiming movement of varying distances with one hand or both hands simultaneously. Participants verbally estimated the distance moved on all trials before knowledge of results was given. Error detection was measured by the correlation and the mean absolute difference between the actual and estimated distance. Error detection was not more accurate for the longer movements, and participants underestimated errors in all conditions. Strong positive correlations were shown for both unimanual and bimanual aiming tasks, suggesting that two streams of sensory information can be processed concurrently.