• Distinct contributions of extrastriate body area and temporoparietal junction in perceiving one's own and others' body

      Cazzato, Valentina; Mian, E.; Serino, A.; Mele, S.; Urgesi, C. (2015-03)
      The right temporoparietal cortex plays a critical role in body representation. Here, we applied repetitive transcranial magnetic stimulation (rTMS) over right extrastriate body area (EBA) and temporoparietal junction (TPJ) to investigate their causative roles in perceptual representations of one's own and others' body. Healthy women adjusted size-distorted pictures of their own body or of the body of another person according to how they perceived the body (subjective task) or how others perceived it (intersubjective task). In keeping with previous reports, at baseline, we found an overall underestimation of body size. Crucially, EBA-rTMS increased the underestimation bias when participants adjusted the images according to how others perceived their own or the other woman's body, suggesting a specific role of EBA in allocentric body representations. Conversely, TPJ-rTMS increased the underestimation bias when participants adjusted the body of another person, either a familiar other or a close friend, in both subjective and intersubjective tasks, suggesting an involvement of TPJ in representing others' bodies. These effects were body-specific, since no TMS-induced modulation was observed when participants judged a familiar object. The results suggest that right EBA and TPJ play active and complementary roles in the complex interaction between the perceptions of one's own and other people's body.
    • Gender differences in the neural underpinning of perceiving and appreciating the beauty of the body

      Cazzato, Valentina; Mele, S.; Urgesi, C. (2014-05-01)
      Although previous studies have suggested a certain degree of right hemisphere dominance for the response of extrastriate body area (EBA) during body perception, recent evidence suggests that this functional lateralization may differ between men and women. It is unknown, however, whether and how gender differences in body perception affect appreciating the beauty of the body of conspecifics. Here, we applied five 10-Hz repetitive transcranial magnetic stimulation (rTMS) pulses over left and right EBA and over the vertex to investigate the contribution of visual body representations in the two hemispheres on esthetic body perception. Female and male healthy volunteers were requested to judge how much they liked opposite- and same-gender virtual model bodies or to judge their weight, thus allowing us to compare the effects of right- and left-EBA rTMS on esthetic (liking) and perceptual (weight) judgments of human bodies. The analysis of the esthetic judgments provided by women revealed that right-EBA rTMS increased the liking judgments of opposite- but not same-gender models, as compared to both vertex and left EBA stimulation. Conversely, in men the liking judgments of opposite-gender models decreased after virtual disruption of both right and left EBA as compared to vertex stimulation. Crucially, no significant effect was found for the perceptual task, showing that left- and right-EBA rTMS did not affect weight perception. Our results provide evidence of gender difference in the hemispheric asymmetry of EBA in the esthetic processing of human bodies, with women showing stronger right hemisphere dominance in comparison with men.