Binding von Objekt- und Lokalisationsinformationen im Arbeitsgedächtnis

Abstract

Simultaneous memorizing of objects and their locations requires both correct storing of these two single dimensions of information and their associations. Thus, this specific memory performance poses high demands on working memory. This view is supported by the results of studies yielding a lower memory capacity for this so-called binding information than for the single dimensions location or identity. Although to date numerous studies investigate the relationship between working memory performance and other cognitive abilities, there seems to be little research on the question how memory capacity for binding information is associated with executive functions, working memory capacity and processing speed.In the present study (N = 96) a memory task was employed in which geometrical shapes were presented in a matrix. The task comprised three conditions, each requiring different memory performances. In the so-called localization condition only the positions of the geometrical figures had to be stored. Likewise, in the identity condition only the figures should be memorized. In contrast, in the binding condition these two dimensions of information had to be maintained simultaneously. Furthermore, several tasks assessed the performance on various cognitive abilities such as, executive functions, the short-term and the working memory capacities for both visual and spatial information as well as the processing speed. In subsequent analyses the functional relationships between the performances on these tasks and the memory capacities in the three conditions (location, identity and binding) were examined.In the line with recent findings, the present study yielded a lower memory capacity for the binding information than for the two single dimensions of information. While the memory capacity for the shapes was not affected by the demand to memorize the position of the identified object, the memory performance for the locations was significantly reduced in the binding condition. Obviously, the additional effort of connecting the shapes to their positions leads to deficits in the recall of the locations. This apparent asymmetry between visual and spatial short-term memory might be explained by a specific effect of spatial attention. Spatial attention represents a cognitive mechanism that is supposed to be responsible for both the storage of the locations and the specific associations between the objects and their positions.With regard to possible effects of other cognitive functions on the binding process, the findings of the present study did not provide evidence for an involvement of the central executive in the storage of the binding information. Nevertheless, the results support the view that memory capacity for the binding information is clearly influenced by the individual's working memory capacity. This finding suggests that controlled attention is essential for maintaining both information dimensions in the binding condition. Furthermore, processing speed was shown to be relevant to memory performance in the binding condition. Eventually, it is discussed to what extent the results could be integrated into the working memory model of Baddeley (2000).