Gender differences in neural activity associated with recognition of happy and sad faces by human subjects: An functional magnetic resonance imaging study

摘要

Do men and women process emotional stimuli differently?This question has been addressed in some prior studies. For example,Kesler/West et al. [1] used functional magnetic resonanceimaging (fMRI) to investigate explicit processing of facial emotions,including happiness and sadness. They observed that menshowed greater left hemispheric activation when observing sadfaces than when observing happy faces. This study explored howthe gender of the subjects and of the stimuli affects neural activityassociated with emotion recognition of happy or sad expressionsusing a functional magnetic resonance imaging. The experimentalstimuli were 12 photographs of Japanese adults selectedfrom Matsumoto and Ekman’s Pictures of Facial Affect.Using a blocked-design paradigm, the neural activity of the 24volunteers, 12 men and 12 women, was monitored on a 1.5 T MagnetomVision MRI scanner (Siemens, Erlangen, Germany) at theChang Gung Memorial Hospital while they were viewing photosof men or women portraying happy or sad emotions shownthrough a goggle display system (Resonance Technology Inc., Calif.,USA). Our findings support previous reports of gender differencesin the neural correlates of emotion recognition, whichseems to relate to both the gender of the subjects and the genderof the models portraying the target facial emotions. Our observationof a stronger activation associated with facial emotion recognitionin our male subjects, particularly when viewing sad facialemotions, is consistent with our previous finding [2]that genderdifferences in facial emotion recognition are more noticeablewhen processing faces portraying sad emotions than when processingfaces portraying happy emotions. Relative differenceswere observed between the male and female subjects in the volumeof activation and the lateralization pattern associated withprocessing emotion recognition when looking at male or femalefaces. Regarding regions and volumes of activation, both our maleand female subjects, when viewing happy emotions portrayed bymodels of the same gender as themselves, displayed a stronger anda more extensive network of activation. In terms of the lateralizationpattern, we observed a general trend of their becoming lessleft lateralized when our male or female subjects were viewingphotos of women portraying either happy or sad emotions thanwhen they were viewing photos of men. Our findings suggest thatthe laterality of facial emotion processing could be gender, subjectsand stimuli, and emotion specific. This observation may further explain the contradictory findings of laterality models ofemotion processing reported in the literature. Our findings suggestfundamental gender differences in neural activity associatedwith processing emotion in male or female faces. Thus, the generalizationof the findings in regard to neural activity associatedwith facial emotion recognition should take gender of the subjectsas well as the stimuli into the consideration. References 1 Kesler-West M, et al: Cogn Brain Res 2001; 11: 213–226. 2 Lee TMC, et al: Neurosci Lett 2002; 333: 13–16.