Argon laser induced single cortical responses: a new method to quantify pre-pain and pain perceptions.

The shape (amplitude and latency) of single cortical responses to argon laser stimulation was found to match six perceptual classes: three pre-pain and three pain. The amplitude of the pain related single cortical responses correlated with the perceived feeling of pain. Easy detectable responses were obtained because habituation to the stimuli was reduced and a high degree of attention was given to each stimulus. Single cortical responses to argon laser stimuli are suggested as a new quantitative technique with application in the assessment of function in the thermal and nociceptive pathways.