Figure 1

Cortical Evoked Potential Evoked by 60 ms High Intensity Diode Infrared Laser Pulses. Each trace represents grand average of EEG response of 10 subjects subjected to 15 pulses of each of 4 intensities (3 painful intensities, 1 sub pain threshold). Traces show distinct earlier negative (up) phase and positive (down) phases the amplitude of which are directly correlated to the numeric pain rating evoked for that stimulus.