The impending demise of the icon: A critique of the concept of iconic storage in visual information processing

TLDR

Evidence shows that brief displays can be accessed for a fraction of a second and that visual stimuli persist after termination, yet the author argues this evidence does not support the usefulness of an iconic storage in perception. The paper aims to show that a storage of excitation cannot serve as a useful device for storing visual information. It reviews experimental evidence on temporal integration, saccadic suppression, masking, and the photoreceptor basis of visual persistence to support this claim. The author concludes that abandoning the icon concept would require little change to existing theories of visual perception.

Abstract

Abstract Without disputing the experimental evidence that subjects have available most of the content of brief displays for a fraction of a second, or that visual stimuli Persist after their physical termination for a similar time, I argue that this evidence is irrelevant to perception. Specifically, the notion of an icon as a brief storage of information persisting after stimulus termination cannot possibly be useful in any typical visual information-processing task except reading in a lightning storm. Since the visual world that provides the stimuli for perception is continuous and not chopped up by tachistoscopes, and since our eyes and heads are rarely motionless, no realistic circumstances exist in which having a frozen iconic storage of information could be helpful. Rather, the presence of such an icon interferes with perception. This paper examines instances of normal perception, and then reviews experimental evidence on temporal integration, saccadic suppression, masking, and the photoreceptor basis of visual persistence, to further demonstrate that a storage of excitation cannot be a useful device for storing information. Finally, I note that little would have to be changed in our theories of visual perception or information processing if we simply forgot all about the icon and iconic memory as an early stage of processing.