Do women see things differently than men do?

The aim of the study was to investigate the influence of gender on brain activity. Thirty male and 30 female respondents solved simple auditory and visual tasks while their electroencephalogram (EEG) was recorded. Also recorded was the percentage of oxygen saturation of hemoglobin (%StO(2)) in the respondents' frontal brain areas with near-infrared spectroscopy (NIRS). The attended task condition was based on the oddball paradigm. Respondents had to mentally count infrequent target stimuli - tones or shapes. In the unattended condition they just listened to tones or viewed different shapes. Gender related differences in EEG activity were only observed in the amplitudes of the early evoked gamma response and the P3 component. Women displayed higher amplitudes than men. A second finding was that these differences were more pronounced for the visual than for the auditory stimuli. No gender related differences were observed in the ERP latencies, as well as in the amplitudes of the P1-N1 complex, and the induced gamma response. The NIRS data showed that males in their frontal brain areas displayed a higher percentage of StO(2) than did females; and males also showed a higher increase in %StO(2) during task performance as compared with the resting condition. Taken all together the results suggest that the females' visual event-categorization process is more efficient than in males. The data are discussed in the theoretical framework of the evolutionary theory of human spatial sex differences.