Questioning the functional significance of the pain matrix
Neuroimaging and neurophysiological studies have shown that transient nociceptive stimuli elicit responses in an extensive cortical network including somatosensory, insular and cingulate areas, as well as frontal and parietal areas. A long-standing view in the field of pain research has been that this network, often referred to as the “pain matrix”, represents the neural activity through which pain emerges as a percept. Recently, we have performed a number of studies challenging this interpretation. First, we conducted a number of experiments showing that pain intensity can be entirely dissociated from the magnitude of the responses in the so-called “pain matrix”, and that the magnitude of the elicited brain responses are strongly influenced by the context within which the stimulus appears, in particular, stimulus novelty. Second, using EEG and fMRI, we showed that non-nociceptive stimuli as well as stimuli not perceived as painful can elicit cortical responses having a spatial distribution that is indistinguishable from that of the “pain matrix”. For these different reasons, we proposed an alternative view of the functional significance of the “pain matrix”, in which it would reflect a system involved in detecting, orientation attention towards, and reacting to the occurrence of salient and/or behaviorally-relevant sensory events. Furthermore, we postulate that this cortical network might represent a basic mechanism through which significant events for the body’s integrity are detected, regardless of the sensory channel through which these events are conveyed.
Researchers involved
Publications
2009
Are there nociceptive-specific brain potentials?
Journal of Neurophysiology
Mouraux A, Plaghki L, Iannetti GD.
102(5):3075-3076
2008
Combining EEG and fMRI in pain research
EEG-fMRI
Iannetti GD, Mouraux A.
L Lemieux, C Mulert, editors. New York: Springer-Verlag
2006
Are the processes reflected by late and ultra-late laser evoked potentials specific of nociception?
Clinical Neurophysiology
Mouraux A, Plaghki L.
59:197-204
2004
Refractoriness cannot explain why C-fiber laser-evoked brain potentials are recorded only if concomitant Adelta-fiber activation is avoided
Pain
Mouraux A, Guerit JM, Plaghki L.
112(1-2):16-26