Jittered single-event pain-audio experiment

The pain stimulus was a thermal noxious stimuli of 3 seconds duration, and was administered to the dorsum of the volunteer's left hand using an electrical resistor to generate heat. This device consists of a 1.5 by 2 cm copper sheet, which delivered a very fast ramping heat stimulus (30-60 $^0 C$ in 0.8 seconds) and simultaneously measured the skin temperature under the device. The auditory stimuli lasted for 3 seconds each. Both stimuli had varying ISI (between $30$ seconds and $50$ seconds).