Some points about human vision and visual neglect

Abstract

Before making my points, it is necessary to comment on the nature of visual representation. The expression “visual representation” is taken to have specific meaning that concerns the manner in which visual information is held within the information processing stream. A visual representation is a store that holds a set of information, derived visually, and which makes certain properties of that set of information explicit. For example, whilst the information that is necessary to gauge the identity of a person is available in the optic array entering the eye, it cannot be used in that form for the purpose of identifying the person. The information has to be converted into a form that is useful for distinguishing between people's faces. Those cues to the identity of the person are implicitly available in the optic array, but need to be made explicit as visual descriptions of (say) how long the person's nose is. In this sense, a visual representation is a store within which the results of computations can be held, perhaps briefly or perhaps indefinitely.