Preliminary statement of the theory: Autochthonous versus Behavioral determinants; “Formal” vs “Functional” criticism

Bruner and postman divide the determinants of perception into two sharply constrasted categories, the “autochthonous” or “structural” on the one hand, and behavioral or motivational on the other. Corresponding to these, they outline two contrasting program of experiment and theory, the formal and the functional. Autochthonous determinants include the stimulus, the effects of stimulation upon the receptors, the afferent neurons and the sensory cortical areas. They represent the innate and relatively unchangeable endowment of the individual for the activity of perceiving. The so-called stimulus binding of sensory dimensions and the facts of psychophysics are based upon autochthonous factors, as are also the laws of perceptual organization of the gestaltists. Theories based upon such conditions are said to be formal. The behavioral determinants on the other hand, are related to the control of the “higher-level” processes. Such factors are involved whether they are elicited by the momentary stimulus and context or represent a stable part of the individual personality. Taken together they from a central directive state; and a theory that takes them into account is said to be a functional theory. The older, formal theories are alleged to have neglected these behavioral determinants. The experimenter tried his best to control them, that is, to hold them constant so that they would not enter into the experiment and distort the effect of the purely autochonouus determinants.  They maintain that their task is to very also the behavioral determinants, treating them nor merely as something to be controlled but as independent variables.