Teaching with virtual 2D and 3D figures from computer techniques is a trend since visualized teaching materials can effectively deliver curriculum contents to students. However, few studies were directed to explore the influences caused by the visualized teaching materials onto the cognitive process. Via ERPs, this study aims at investigating gender's behaviors and cerebral cortex activation types when people engage in 2D and 3D object recognition. Research result suggested that the correct rate of 2D tasks was higher than the 3D's; also, the response time for 2D tasks was shorter. No significant differences were found respectively from both student groups' (male and female) correct rates and response time. Through brainwave analysis, we found that both groups' P300 amplitudes at parietal lobe PZ electrode reached a significant level, and females' were greater. This result revealed that the ways of mental resource allocation were different when both genders of students underwent 2D and 3D tasks; it also explained why the visualization courses from both groups were different.