The spatial logic of fear

Peripersonal space (PPS) is the multimodal sensorimotor representation of the space surrounding the body. This thesis investigates how PPS is modulated by emotional faces, which represent particularly salient cue in our environment. Study 1 shows that looming neutral, joyful, and angry faces gradually facilitate motor responses to tactile stimuli. Conversely, looming fearful faces show no such effect. Also, at the closest position in PPS, multisensory response facilitation is lower for fearful than neutral faces. Study 2a addresses the hypothesis that fearful faces promote a redirection of attention towards the peripheral space. In line with this, it shows that motor responses to tactile stimuli are facilitated when a looming fearful face is associated with the appearance of a visual element presented in the periphery, rather than close to the face. Also, this effect is found in near space and not in far space. This result suggests that a near looming fearful face elicits a redirection of attention to the peripheral space. Such effect is not found for neutral, joyful, or angry faces (Study 2b). Study 3 shows that the redirection of attention in PPS by fearful faces is accompanied by a modulation of the electrophysiological signal associated with face processing (N170). Finally, Study 4 shows that the skin conductance response to looming fearful, but not joyful or neutral faces, is modulated by the distance of the face from participants’ body, being maximal in the near space. Together these studies show that, at variance with other emotions, fearful faces shift attention to other portions of space - than that of the face - where the threat may be located. It is argued that this fear-evoked redirection of attention may enhance the defensive function of PPS, when most needed, i.e., when the source of threat is nearby, but its location remains unknown.