Involuntary orienting of attention to nociceptive events: neural and behavioral signatures.
Pain can involuntarily capture attention and disrupt pain-unrelated cognitive activities. The brain mechanisms of these effects were explored by laser- and visual-evoked potentials. Consecutive nociceptive laser stimuli and visual stimuli were delivered in pairs. Subjects were instructed to ignore nociceptive stimuli while performing a task on visual targets. Because involuntary attention is particularly sensitive to novelty, in some trials (17%), unexpected laser stimuli were delivered on a different hand area (location-deviant) relative to the more frequent standard laser stimuli. Compared with frequent standard laser stimuli, deviant stimuli enhanced all nociceptive-evoked brain potentials (laser N1, N2, P2a, P2b). Deviant laser stimuli also decreased the amplitude of late latency-evoked responses (visual N2-P3) to the subsequent visual targets and delayed reaction times to them. The data confirm that nociceptive processing competes with pain-unrelated cognitive activities for attentional resources and that concomitant nociceptive events affect behavior by depressing attention allocation to ongoing cognitive processing. The laser-evoked potential magnitude reflected the engagement of attention to the novel nociceptive stimuli. We conclude that the laser-evoked potentials index the activity of a neural system involved in the detection of novel salient stimuli in order to focus attention and prioritize action to potentially damaging dangers.
Legrain
Valéry
V
Unité de Réadaptation et de Médecine physique (READ), Université catholique de Louvain, Louvain-la-Neuve and Brussels, Belgium. valery.legrain@uclouvain.be
Perchet
Caroline
C
García-Larrea
Luis
L
D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D001921:Brain / Q000503:physiopathology*; D003071:Cognition / Q000502:physiology; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D006225:Hand; D006801:Humans; D007834:Lasers; D008297:Male; D009483:Neuropsychological Tests; D010146:Pain / Q000503:physiopathology*; D011930:Reaction Time; D013997:Time Factors