Operational, analogical and genuine definitions of psychophysiology.

The reason for considering definitional issues is not that of arriving at a universally agreed-to definition, but rather that of illuminating scientific disagreements. From this viewpoint it will be argued that operational and analogical definitions which have been offered by psychophysiology are not useful, because they do not permit the settling of disputes on objective grounds. Those grounds are relevant only for genuine definitions, which can be tested in terms of the counter-example argument in general, and in particular in terms of whether they adequately differentiate psychophysiology from the closely related but different area of physiological psychology. One such genuine but inadequate definition is that offered by Stern (1964), which differentiates the two areas in terms of the dependent and independent variables being, respectively, manipulated and measured. The definition offered here is in terms of the interests of the investigator, and is that psychophysiology is the study of psychological processes in the intact organism as a whole by means of unobtrusively measured physiological processes. I shall argue that this definition more adequately differentiates psychophysiology from physiological psychology than does Stern's definition. In addition, I shall suggest that adopting this definition does not isolate the two areas from one another, but rather brings them into a more scientifically meaningful relationship. Finally, I shall illustrate, with some examples, how (implicitly adopted) definitions that are different from the proposed one here lead to substantive differences in both the conduct and evaluation of research in psychophysiology. Definitional issues, in other words, are not only of relevance for ivory-tower, armchair philosphers. They affect not only the practice of empirical basic research, but also applied practice.