Multisensory interactions between nociception and vision through the looking glass

Kuzminova, Avgustina [UCL] Legrain, Valéry [UCL] Filbrich, Lieve [UCL] et al.

It has been demonstrated that nociceptive stimuli influence the perception of visual stimuli especially when those visual stimuli occurred near the body, i.e. in the peripersonal space, a multisensory representation of the body integrating the external space immediately surrounding it. In the present study, we examined whether nociceptive stimuli influence the perception of visual stimuli when those are indirectly seen as occurring near the stimulated body parts. To this aim, we used a visual temporal order judgment task (TOJ) in which pairs of visual stimuli were presented, one to each side of space. Those visual stimuli were preceded by a nociceptive stimulus applied only on one of the hands to attract attention in one side of visual space. Visual stimuli were presented either at a far distance from the participants’ hands or at a similar distance but indirectly seen near the hands through a mirror. It was expected that visual judgments would be biased to the advantage of the visual stimulus presented in the same side of space as the stimulated hand. Moreover, it was hypothesized that the visual bias induced by the nociceptive stimulus will be stronger in the mirror condition than in far condition, i.e. the condition without the mirror, even though stimuli are projected at a similar retinal distance in both conditions. Results showed that indeed, nociceptive stimuli facilitated more significantly the perception of visual stimuli in the mirror condition. Multisensory interaction between nociception and vision seems driven by a mental representation of the peripersonal space.