Neural Correlates of Human Body Perception

Abstract

The objective of this study was to investigate potential sex differences in the neural response to human bodies using fMRI carried out in healthy young adults. We presented human bodies in a block-design experiment to identify body-responsive regions of the brain, namely, extrastriate body area (EBA) and fusiform body area (FBA). In a separate event-related "adaptation" experiment, carried out in the same group of subjects, we presented sets of four human bodies of varying body size and shape. Varying levels of body morphing were introduced to assess the degree of morphing required for adaptation release. Analysis of BOLD signal in the block-design experiment revealed significant Sex x Hemisphere interactions in the EBA and the FBA responses to human bodies. Only women showed greater BOLD response to bodies in the right hemisphere compared with the left hemisphere for both EBA and FBA. The BOLD response in right EBA was higher in women compared with men. In the adaptation experiment, greater right versus left hemisphere response for EBA and FBA was also identified among women but not men. These findings are particularly novel in that they address potential sex differences in the lateralization of EBA and FBA responses to human body images. Although previous studies have found some degree of right hemisphere dominance in body perception, our results suggest that such a functional lateralization may differ between men and women.

Gender differences in the neural underpinning of perceiving and appreciating the beauty of the body

“…Recent evidence suggests that the gender of the observer may influence the lateralization of EBA response to human body images. Aleong and Paus (2010) showed that healthy women exhibited greater response to human bodies in the right vs. left EBA and greater right EBA response compared with men. The right and left hemispheres may have complimentary roles in visual body representation and their relative involvement may be different in women and men.…”

“…Furthermore, since higher BMI values are observed in men than women, considering this confounding variable is crucial when testing gender differences in body perception. Aleong and Paus (2010) reported that men and women with higher BMI showed reduced hemispheric asymmetry in the response of EBA.…”

“…According to Aleong and Paus (2010), we anticipated a greater right hemisphere dominance of EBA involvement in both perceptual and esthetic judgments of human bodies among women than among men. Furthermore, we controlled for the relationship between the hemispheric lateralization of EBA and variations of participants' body mass index (BMI).…”

Different contributions of visual and motor brain areas during liking judgments of same- and different-gender bodies

“…It is worth noting that exactly the same stimuli were used for both tasks, thus suggesting that the different roles of extrastriate and premotor areas in processing body forms and body actions arise from the implicit task demands (i.e., whether the stimuli can be differentiated by form or action 13 cues) rather than from the stimulus features per se (i.e., whether the posture implies more or less motion). Furthermore, EBA activity is sensitive to subtle variation of human body size and shape in healthy individuals (Aleong & Paus, 2010) and its structural and neurofunctional alteration is associated with body image disturbance, such us body size overestimation and negative body evaluation in patients with EDs (Uher et al, 2005).…”

“…Furthermore, the design of our study had not enough power to analyze and detect gender differences in the pattern of results, but it is possible that the relative contribution of left and right hemisphere areas in the aesthetic appreciation of same and different-gender bodies may vary also according to the gender of the observer (Cazzato et al, 2014;Aleong & Paus, 2010).…”