Shifting attention between the space of the body and external space. Electrophysiological correlates of visual-nociceptive crossmodal spatial attention

Filbrich, Lieve [UCL] Favril, Louis [UGent] Mouraux, André [UCL] Sambo, Chiara [UCL - London] Legrain, Valéry [UCL]

Question: The study tested whether nociceptive stimuli applied to a body limb can orient spatial attention in external space toward visual stimuli delivered close to that limb. Methods: Nociceptive stimuli were applied to either the left or the right hand. 800 ms later, task-relevant visual stimuli were delivered at the location adjacent to the stimulated hand (70% valid trials) or adjacent to the other hand (30% invalid trials). Participants were instructed to respond as fast as possible to the infrequent occurrence of a target visual stimulus. Results: Visual stimuli were discriminated with shorter reaction times and elicited ERPs of greater magnitude in the valid as compared to the invalid trials. This enhancement affected the N1 component, suggesting that the location of the nociceptive cue modifies visual processing through a modulation of neural activity in the visual cortex. Conclusions: We hypothesize the existence of a common frame of reference able to coordinate the mapping of physical threats both on the space of the body and in external space.