Abstract
Rollman [13,14] has clearly raised important questions about the application of signal detection (TSD) procedures to the study of the perceived painfulness of stimuli. Researchers have often failed to realize that the discriminability of two usually painful stimuli need not be related to their reported painfulness. Thus indices of discrimination accuracy derived form TSD are logically (though not necessarily empirically) independent of the analgesic properties of any treatment. However, Rollman misleadingly gives the impression that he is questioning the general validity of the application of TSD to answering questions in pain research. This is not the case. Procedures derived from TSD may play an important part in answering questions of interest to pain researchers especially as Rollman has exaggerated the practical difficulties associated with TSD experiments. It must be emphasized that there is no one TSD model as Rollman often seems to imply but a variety of models [5,9]. The usefulness of any model in any situation is a matter for experiment. Rollman has certainly criticized effectively one dubious analogy to TSD procedures which pain researchers have used. That is not the same as questioning the general usefulness of TSD models.