Characteristics of visual short-term memory

Abstract

It is clear that human beings have the capacity to retain visual information over brief intervals, and that the representation may take the form of active visualisation. However, the characteristics of the cognitive mechanism(s) or system(s) involved in visualisation and temporary storage of visual information are as yet unclear. Of particular interest are the limitations on the operation of such a system. One suggestion is that the system has a capacity of a single pattern (Phillips, 1983). Other studies have suggested that several patterns may be retained. More recent work has suggested a limitation in terms of pattern complexity or the similarity of pattern elements. Studies of verbal short-term memory have benefited from the exploration of the effects on retention of phonological similarity or word length. Both of these effects constitute limitations on the effective function of verbal “working memory”. This paper will review contrasting views and data on the characteristics of visual short-term memory, in order to assess whether an understanding of this function might benefit from an approach analogous to that used in the theoretical development of verbal short-term memory. It is argued that there are a number of different limitations on visual short-term storage, and that these limitations may be interpreted within the context of a specialised mechanism for short-term visual storage as a component of a working memory system.