Unity and
variety in visual form
Emanuel L. J. Leeuwenberg, Peter A. van der
Helm
Abstract.
Some stimuli are perceived as unitary patterns, and others as dual or
plural patterns. Such 'unity-and-variety' phenomena are explained by
various process approaches of perception, such as the global precedence
hypothesis, the preattentive orientation detection assumption, and the
recognition-by-components model. However, these three approaches, which
will be discussed in this paper, each explain a different subset of
these phenomena. It will be argued that not only these three subsets
but also other unity-and-variety phenomena can be explained from just
one point of view by adopting the descriptive minimum principle. This
principle states that the preferred interpretation of a
pattern is reflected by the simplest of all possible representations of
that pattern. The highest hierarchical level in the simplest
pattern-representation
will be called the 'superstructure' of the pattern. The superstructure
of
a pattern neither refers necessarily to the largest or global pattern
component,
nor is assessed nesessarily in a primary stage in the perception
process.
Yet, it will be argued that the superstructure is decisive in
determining
whether a shape is perceived either as unitary or as dual.
Peter
A. van der Helm 