The role of right and left posterior parietal cortex in the modulation of spatial attentional biases by self and non-self face stimuli

In the present research we investigated whether the direction of the attentional bias in line bisection judgment displayed by healthy subjects is influenced by the evaluation of the social distance between self and other. We used inhibitory repetitive transcranial magnetic stimulation (rTMS) trains over the right and left parietal cortex to investigate the role of these regions in the task. Following right parietal rTMS, the self face is perceived as closer when it is located at the right line endpoint; following left parietal rTMS, the self face is perceived as closer when it is located at the left line endpoint. In both cases, the side of space ipsilateral to the rTMS is underestimated from an attentional point of view, while it is overestimated from a social point of view. These results are a projection of how an individual perceives himself in the social relational space.