Time course of burn to repeated applications of capsaicin

Human subjects rated the burn of 100 ppm capsaicin applied to the tongue vi a filter paper and replaced every minute. Capsaicin was presented at a cons tant concentration for 10 min, followed by 10 min of blank stimuli; this se quence was then repeated once. Both sensitization and desensitization were seen. A dynamic model composed of a level detector and change detector pred icted the results and also previous data. Thus, the model provides a parsim onious description of responses to constant and intermittent capsaicin stim ulation. (C) 1999 Elsevier Science Inc.