Unconscious Inference and Judgment In Perception

Abstract

The notion of unconscious inference and the suggestion that it has a part to play in perception is, I suppose, mainly associated with the name of Helmholtz. He used it to explain those cases where the way in which we perceive things deviates from what would be expected on the basis of the pattern of stimulation alone — in connection, for example, with the phenomena of colour contrast, or size perception. Though I put it in this way — in terms of the pattern of stimulation — this is in fact not quite correct. For, why should not the phenomena of colour contrast, for example, be explained entirely in terms of the pattern of stimulation on the retina, or if not there in the cortex, as long as interaction between areas of excitation is allowed? Why should it not be the case that a grey patch looks different when set alongside or in the context of an area of red from what it does when set in a neutral context? And what prevents our explaining this, at any rate partially, by reference to the effects that the stimulation of one area of the retina has on the effects in another area produced by accompanying or parallel stimulation, wherever in the nervous system the final integrating mechanism is to be found? (I make this last qualification for reasons that will appear directly.)