Signal detection theory measurement of pain: a review and critique.

Pain is a subjective experience. Therefore, attempts to measure its extent face the same difficulties which have long plagued experimenters hoping to scale other human sensations, but they are compounded further by complex emotional reactions and cognitive interpretations [ 411. Nonetheless, the need for improved methods of pain control mandates continued research on pain and its possible modulation by chemical, surgical, physiologic(al, or psychological procedures. Laboratory studies with normal rather than clinical subjecks allow parametric variations in the level of an experimentally induced pain, rather than reliance upon some unknown endogenous one. It is possible, as well, that some of the emotional variability associated with a pain of internti origin is thus eliminated, leading to more stable estimates of the magnitude of the pain sensation itself. The ability to vary the level of a potentially nociceptive stimulus has raised the hope that psychophysical procedures 1393, well-developed for studies of vision, audition, and the other senses, might also increase our understanding of human suffering. Although some notable advances have been made in the scaling of intense discomfort [1,26,34,51], many pain investigations have concentrated on the traditional “‘threshold” as the dependent variable, sometimes attempting to distinguish sep te thresholds for sensation, mild pain, strong pain, and maximal tolerance. The threshold appears, at first, to be easy to measure an easy to in”%3 pret. Its value can be obtained by noting the level of some uncomfor stimulus such as radiant heat or electric shock ntecessary to elicit a report of pain. In those instances where no manipulation is involved, thresholds hw been compared across groups (e.g. the variables of age, sex, race, or &l-ok group). In other instances, where the nature of a adecluate control is still