First pain event related potentials to argon laser stimuli: recording and quantification.

Argon laser induced event related responses to pricking pain (first pain) were recorded. The different recording parameters (recording site, filter setting, averaging technique), quantification parameters (amplitude, power) and variability between successive recordings were studied. The single responses were large, and averaging of 16-32 single trials was sufficient to obtain reliable averaged responses. The power (0.5-7.5Hz) of the averaged vertex recorded response was, for the range of intensities considered, the most sensitive parameter to quantify the stimulus and hence the intensity of pain perceived.