Is Visuospatial Attention Controlled by a Unitary Process Or Separate Processes?

Abstract

Visuospatial attention facilitates search. Search facilitation is not instantaneous, but develops over time. Furthermore, the time necessary for the first occurrence of search facilitation varies with different processes. One line of research concerned with the orienting of visuospatial attention indicates that an involuntary process facilitates search faster when compared to a voluntary process. Another line of research concerned with the distribution of visuospatial attention has shown that a constricted focus facilitates search faster than an enlarged focus. The differences in search facilitation between these processes, however, have not been directly compared in the same study. Thus, it is unclear whether visuospatial attention is governed by a unitary process or separate processes. The results of this experiment support the separate process view, specifically an involuntary and voluntary process that is independent of the component process of the distribution of visuospatial attention.