Behavioral measurement of thermal pain sensitivity in humans: effects of stimulus intensity and instructions.
This study validated a human behavioral model of thermal nociception analogous to the rodent tail-flick assay. Effects of instructions and stimulus intensity on behavior (i.e., finger withdrawal latency) were evaluated. Using a repeated measures randomized crossover design, the authors exposed 10 volunteers to varying radiant heat intensities (from 42.2 to 52.2 degrees C) during each of four sessions. In the different sessions, participants were told to remove their finger when they felt heat, felt unpleasant, felt pain, or could no longer tolerate pain. Withdrawal latencies significantly decreased as stimulus intensity increased and significantly increased for sensory, affective, pain, and intolerance instructions. Instruction set differences were significantly larger at higher stimulus intensities. This technique may be useful in human psychopharmacological research.
Greenwald
M K
MK
Department of Psychiatry and Behavioral Neurosciences, Wayne  State University School of Medicine, Detriot, Michigan 48207, USA. mgreen@med.wayne.edu.
Johanson
C E
CE
D000293:Adolescent; D000328:Adult; D001519:Behavior / Q000502:physiology*; D018592:Cross-Over Studies; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008875:Middle Aged; D009619:Nociceptors / Q000187:drug effects; D010146:Pain / Q000523:psychology*; D010147:Pain Measurement / Q000379:methods*; D011930:Reaction Time