The effects of age and sex on mental rotation performance, verbal performance, and brain electrical activity.

This study examined the effects of age and sex on mental rotation performance, verbal performance, and brain-wave activity. Thirty-two 8-year-olds (16 boys) and 32 college students (16 men) had EEG recorded at baseline and while performing four computerized tasks: a two-dimensional (2D) gingerbread man mental rotation, a 2D alphanumeric mental rotation, of three-dimensional (3D) basketball player mental rotation, and lexical decision making. Additionally, participants completed a paper- and pencil water level task and an oral verbal fluency task. On the 2D alphanumeric and 3D basketball player mental rotation tasks, men performed better than boys, but the performance of women and girls did not differ. On the water level task, men performed better than women whereas there was no difference between boys and girls. No sex differences were found on the 2D gingerbread man mental rotation, lexical decision-making, and verbal fluency tasks. EEG analyses indicated that men exhibited left posterior temporal activation during the 2D alphanumeric task and that men and boys both exhibited greater left parietal activation than women and girls during the 2D gingerbread man task. On the 3D basketball player mental rotation task, all participants exhibited greater activation of the right parietal area than the left parietal area. These data give insight into the brain activity and cognitive development changes that occur between childhood and adulthood.