Relational psychophysics: Messages from Ebbinghaus' and Wertheimer's work

In past and modern psychophysics there are several unresolved methodological and philosophical problems of human and animal perception, including the outstanding question of the relational basis of whole psychophysics. Here the main issue is discussed: if, and to what extent, there are viable bridges between the traditional “gestalt” oriented approaches and the modern perceptual-cognitive perspectives in psychophysics. Thereby the key concept of psychological “frame of reference” is presented by pointing to Hermann Ebbinghaus' geometric-optical illusions, on the one hand, and Max Wertheimer's treatment of the traditional transposition phenomenon, on the other hand. A much-needed theoretical reorientation of future research may help to overcome the philosophical narrowness of present-day human and comparative psychophysics