Ambiguity

Abstract

Human communication thrives on ambiguity. It is built into our languages and it is a fundamental feature of pictures . Most of the words we use have more than one meaning and ambiguities are usually resolved by the context in which they occur. We play upon linguistic ambiguities to convey subtle distinctions that would be difficult to define precisely. Perceptual ambiguity refers to the alternation over time between differing interpretations of a pattern. Ambiguities often involve fluctuations in apparent depth that occur when insufficient evidence of true depth is available, either in pictures or when viewing distant objects. In contemporary vision research, ambiguities are studied almost entirely in the province of pictures; they feed from the flat surface. Visual ambiguities offer alternative interpretations of the depth in drawings or alternative descriptions of objects defined by equivalent contours. The alternatives appear successively rather than simultaneously and their perception is referred to as multistable. Ambiguities seldom arise when relatively near solid objects are viewed, and so there is the danger of basing their investigation on artificial stimuli that do not reflect the characteristics of everyday perception – viewing solid objects with two eyes. We associate ambiguous stimuli with relatively recent research in perception but pictorial ambiguities have been produced for many centuries. We have seen that Roman mosaics display not only the Gestalt laws of grouping , but they also produced subtle mosaic ambiguities . Spatial ambiguity is grist to the artist’s mill and many examples are shown.