Sex differences on a mental rotation task: Variations in electroencephalogram hemispheric activation between children and college students

The area of cognitive research that has produced the most consistent sex di fferences is spatial ability. In particular, men usually perform better on mental rotation tasks than women. Performance on mental rotation tasks has been associated with right parietal activation levels, both during task per formance and prior to performance during bass line recordings. This study e xamined the relations among sex, age, electroencephalogram (EEG) hemispheri c activation (at the 10.5 Hz to 13.5 Hz frequency band), and 2-D mental rot ation task ability. Nineteen 8-year-olds (10 boys) and 20 college students (10 men) had EEG recorded at baseline and while performing a mental rotatio n task. Men had a faster reaction time on the mental rotation task than wom en, whereas there were no differences between boys and girls. After covaryi ng for baseline EEG power values, men exhibited more activation (lower EEG power values) than women in the parietal and posterior temporal regions, wh ereas boys' and girls' power values did not differ in the parietal or poste rior temporal regions. Furthermore, during the baseline condition, men gene rally exhibited more activation (lower EEG power values) throughout all reg ions of the scalp. Results support the hypothesis that a change that affect s both brain activation and performance on mental rotation tasks occurs som etime between childhood and adulthood.