How response inhibition modulates nociceptive and non-nociceptive somatosensory brain-evoked potentials.
OBJECTIVE
To examine and compare the modulation of nociceptive somatosensory laser-evoked potentials (LEPs) and non-nociceptive somatosensory electrically-evoked potentials (SEPs) by brain processes related to response inhibition.


METHODS
A warning auditory tone was followed by either an electrical or a laser stimulus. Subjects performed a Go/Nogo task in which they were instructed to respond to the laser stimulus and refrain from responding to the electrical stimulus in half of the runs. In the other half, they performed the opposite. The paradigm allowed a direct, within-subject comparison of the electrophysiological correlates of brain processes related to the Go/Nogo task in both somatosensory submodalities.


RESULTS
In the Nogo-condition, SEPs displayed an enhanced N120 (early Nogo-response), a reduced vertex P240 and enhanced frontal P3 (late Nogo-responses). In contrast, LEPs only displayed late Nogo-related responses (reduced vertex P350 and enhanced frontal P3).


CONCLUSIONS
The early Nogo-related enhancement of SEPs may reflect brain processes specific to the processing of non-nociceptive somatosensory stimuli. Later components of the Nogo-response may reflect cortical activity common to the processing of both nociceptive and non-nociceptive somatosensory stimuli.


CONCLUSIONS
Response inhibition significantly modulates both LEPs and SEPs. Part of these activities may be specific of the eliciting stimulus modality.
Hatem
S M
SM
Unité de Réadaptation et de Médecine Physique, Université Catholique de Louvain, Belgium. samar.hatem@read.ucl.ac.be
Plaghki
L
L
Mouraux
A
A
D000328:Adult; D003627:Data Interpretation, Statistical; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006358:Hot Temperature; D006801:Humans; D007834:Lasers; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000502:physiology; D036421:Nerve Fibers, Unmyelinated / Q000502:physiology; D010146:Pain / Q000503:physiopathology*; D010147:Pain Measurement; D011930:Reaction Time / Q000502:physiology