The effects of movement direction on movement time and accuracy during manual control tasks


The two frames of reference used to position the body in space are termed egocentric, where location and orientation are determined with respect to the individual, and allocentric, where location and orientation are based on the environment (Dassonville, Schlag & Schlag-Rey, 1995). Egocentric movements are used most often within peripersonal space, such as reaching. Kelly & Weaton (2013) showed that tool manipulation is completed more successfully in egocentric space than allocentric space, regardless of hand preference. The current study investigated whether handedness and movement direction influence accuracy and movement time on a manual task without tools. Forty-two young adults (29 right-handers, 13 left-handers) completed the Waterloo Handedness Questionnaire and a tablet-tracing task. An ACER Aspire Switch tablet was placed on a table in front of the participant, who then traced a track slightly larger than finger-width either going toward (egocentric) or away from (allocentric) the body. Results showed that movement time was significantly faster for egocentric trials, and the preferred hand performed significantly faster than the non-preferred hand, regardless of the task. Additionally, a 3-way interaction was found between direction, hand preference, and the hand used, where the preferred hand of right-handers was significantly faster making movements toward the body than the non-preferred hand. Interesting, left-handers showed no difference between the preferred and non-preferred hands. No effect of accuracy was found for movement type or hand preference, suggesting that participants sacrificed speed for accuracy. These results will be discussed in light of current theories regarding hand preference.