Mismatch responses evoked by nociceptive stimuli
We studied whether nociceptive mismatch negativity (nMMN) could be obtained as result of nociceptive fibers stimulation. The purported nMMN revealed a topography similar to the somatosensory MMN (sMMN), which was observed at the bilateral temporal regions of the scalp. Importantly, only early negativities (100–250 ms) located at these regions revealed a selective modulation associated to the processing of deviancy regardless of the attentional focus. The amplitude modulation of the sMMN had an earlier onset than the nMMN (110 ms vs. 182 ms) as well as a larger difference of latency between the contralateral and the ipsilateral onset of the activity (52 ms vs. 4 ms). Altogether, these observations provide evidence that (a) a nMMN can be elicited by nociceptive stimuli, and (b) the nMMN is topographically similar to the sMMN while differing in latency and possibly in functional organization of their generators.