In studying sensory experience, a primary goal is to describe explicitly how sensations relate to the underlying physical stimuli. Although both physical stimuli and a person's behavioral responses are relatively easy to observe, a preeminent problem is to gain a handle on the unobservable intervening sensation. For example, if a patient judges a pain to be 4 on a 10-point scale, is that twice as much pain as a 2? Or, if two people judge a pain to be 4, how can we compare their experiences? For more than a century, these general issues have been studied intensely. Despite that long history and considerable progress, the problems are still far from completely solved, in part, because much past research has not been expressed in the form of testable foundational assumptions, formulated as explicit mathematical laws. The elaboration and testing of such is pivotal to progress in many areas of psychological science.
With support of the National Science Foundation, Drs. Duncan Luce, Louis Narens, and Ragnar Steingrimsson will continue their work in establishing a general, empirically-based, mathematically-expressed foundation of psychological measurement. In particular, the investigators will apply their general approach to the study of sensations. Experiments in both the auditory and visual domains will be used to evaluate the adequacy of behavioral axioms and, thus, of the numerical representations derived from them. The research extends their theoretical and empirical work to several topics including the effects of temporal or spatial order of stimulus presentation, sequential effects, and evaluating how observations obtained using different methodologies are related. An important aspect is the adequacy with which representations can accommodate individual differences without any statistical fitting of unspecified functions and free parameters. Successful progress on this program promises much unification of now separate theories, notably those involving intensity, frequency, and presentation order, and theories that treat those in a domain-specific fashion, and the relations between and evaluation of different methodologies.
