A behavioral and fNIRS comparative study of gender and task differences in mental rotation among primary students

Purpose: This study investigated the sex and task effects in mental rotation (MR) among Chinese primary school students, employing behavioral assessments and functional near-infrared spectroscopy (fNIRS) for a comprehensive analysis. 

Method: The sample consisted of 62 Grade 4 and 5 students aged between 9.58 and 11.33 (M_age = 10.604, SD = 0.35). Participants completed two MR tasks: MR1, which required the rotation of 24 figures, and MR2, which involved the rotation of 16 English letters. fNIRS was employed to measure neural activation in specific brain areas, and behavioral performance was assessed alongside brain activity. 

Findings: Behavioral data revealed no significant effects of sex or task type on the performance of MR1 or MR2. However, the fNIRS results demonstrated notable sex and task effects. Specifically, boys exhibited significantly higher brain activation in Brodmann Areas (BAs) 6, 9, and 46 than girls. In contrast, girls showed significantly more activation in BA 46 during the MR1 figure rotation task. This suggests that while behavioral tasks showed no differences, neuroimaging revealed underlying neural disparities. 

Conclusion: The discrepancy between behavioral and fNIRS findings reveals a tendency in behavioral studies to accept a false negative, resulting in Type II errors. While neuroimaging data indicate substantial differences not reflected in behavioral measures, this challenges the reliability of null results typically associated with traditional behavioral paradigms. This study highlights the critical need to integrate neuroimaging techniques to understand cognitive processes better. Furthermore, it emphasizes the importance of reevaluating conventional interpretations of behavioral data to ensure a more comprehensive view of mental function. Copyright © 2025 The Author(s).