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Cloettapreis_2012_Nr_40

20 ter the stroking period and then asking her to walk back to the original position. As predicted, self-location was experienced at a position that was closer to the virtual body, as if subjects were located «in front» of the position where they had been standing during the experiment (or as if they were located «out-of-the-body»)26 . Later work confirmed that self- location towards and self-identification with the virtual body are strong- ly and systematically influenced by different visuo-tactile conflicts and can also be achieved these changes in the supine position25,27 . Moreover, self-identification and self-location are also associated with physiologi- cal (i.e. skin conductance response to a threat directed towards the virtu- al body24 ) and nociceptive changes (i.e. pain thresholds are elevated dur- ing the full body illusion28 ). Multisensory brain mechanisms Concerning self-identification, a comprehensive fMRI study27 of a full- body illusion reported that self-identification with a virtual body is asso- ciated with activity in bilateral ventral premotor cortex, left posterior pa- rietal cortex, and the left putamen (Figure 3A). The activity in these three regions was enhanced by visuo-tactile stimulation.Another fMRI study25 found that self-identification with a virtual body is associated with acti- vation in the right middle-inferior temporal cortex (partially overlapping with the extrastriate body area [EBA]) (Figure 3A), a region that is like premotor and posterior parietal cortex involved in the multisensory processing of human bodies29-32 . These former experimental procedures were able to induce changes in self-identification, but did not report changes in self-location and the first- person perspective that are a crucial aspect of bodily self-consciousness and prominently altered in an out-of-body experience. Using fMRI and robotics (while participants were in a supine position and viewed a vir- tual body that was filmed from an elevated position) a recent fMRI study25 was able to experimentally manipulate also these two aspects. Thus, de- spite identical visuo-tactile stimulation, half of the participants experi- enced looking upward towards the virtual body (Up-group), and half ex- perienced looking down on the virtual body (Down-group) and these perspectival changes were associated with consistent changes in self-lo-

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