Finger movement tracking control in 8- and 9-year-old males and females in stimulus-response compatible and non-compatible hand positions

This study examined whether differences exist between 8-9 year-old males and females in two finger movement tracking tasks with different degrees of stimulus-reponse (S-R) compatibility. Sixteen males and 20 females performed finger extension and flexion movements to track a computer screen cursor along a sine wave target in two different hand positions. Subjects had control of cursor movement only in the vertical plane as the cursor moved automatically from left to right across the target. In the compatible position, the hand was pronated so that finger motion occurred in the vertical plane. In the non-compatible position, the hand was neutral between pronation and supination so that finger motion occurred in the horizontal plane. The results showed that males tracked significantly more accurately than females in both the compatible and non-compatible positions. Also, an S-R compatibility effect was found in females but not in males. These results are consistent with other reports of higher information processing performance in adult males compared to females during visual-spatial tasks. The results are discussed as a possible manifestation of hormonally induced brain organization differences between males and females.