Sex, Lies and fMRI—Gender Differences in Neural Basis of Deception

Abstract

Deception has always been a part of human communication as it helps to promote self-presentation. Although both men and women are equally prone to try to manage their appearance, their strategies, motivation and eagerness may be different. Here, we asked if lying could be influenced by gender on both the behavioral and neural levels. To test whether the hypothesized gender differences in brain activity related to deceptive responses were caused by differential socialization in men and women, we administered the Gender Identity Inventory probing the participants’ subjective social sex role. In an fMRI session, participants were instructed either to lie or to tell the truth while answering a questionnaire focusing on general and personal information. Only for personal information, we found differences in neural responses during instructed deception in men and women. The women vs. men direct contrast revealed no significant differences in areas of activation, but men showed higher BOLD signal compared to women in the left middle frontal gyrus (MFG). Moreover, this effect remained unchanged when self-reported psychological gender was controlled for. Thus, our study showed that gender differences in the neural processes engaged during falsifying personal information might be independent from socialization.

Using functional near-infrared spectroscopy (fNIRS) to detect the prefrontal cortical responses to deception under different motivations

“…Our findings indicated that, the lying trials both in deceiving for obtaining rewards and deceiving for avoiding punishments conditions led to significantly larger increase in HbO in the PFC than truth-telling trials in the control condition, which was similar to previous brain imaging studies [12,20]. Numerous studies have revealed the important role of the PFC in deception [10][11][12][13], which mainly reflected various executive functions of the brain [12,19].…”

“…In this study, we mainly focused on the inhibition function of the brain during deception [12,18], and thus we selected one channel in the right IFG and one channel in left MFG as two regions of interest (ROIs) respectively according to topographic images.…”

“…Numerous studies have revealed the important role of the PFC in deception [10][11][12][13], which mainly reflected various executive functions of the brain [12,19]. Specially, both motivations would activate the right IFG during deception.…”

“…Recent efforts have focused on finding some brain signatures that would allow for reliable detection of deception with various brain-imaging techniques [9]. As a result, some fMRI and fNIRS studies have consistently reported that the prefrontal cortex was involved in deceiving [10][11][12][13]. During the process of deception, the prefrontal cortex plays a significant role in executive functions, including planning, application of strategies, and suppressing the truth [14][15][16].…”

“…Thus the prefrontal cortex is recognized as the primary activated brain area during deception [17]. Among the regions of the prefrontal cortex, the right inferior frontal gyrus (IFG) and the left middle frontal gyrus (MFG) were recognized as two important regions for deception [12,18]. Both regions were associated with inhibition, which is the fundamental function of deceiving [19].…”