ABSTRACT
In recent years, some theories of visual attention, such as space-based theory (Eriksen and Hoffman, 1973; Posner, Snyder, & Davidson, 1980), object-based theory (e.g., Neisser, 1967) and discrimination-based theory (Allport, 1971), are proposed to explain the mechanism of selective attention. Although these theories emphasize different factors that control the distribution of visual attention, they agree in that attentional systems enhance the efficiency of processing the properties of attended locations or objects. In the above studies one question remains unresolved: Do attentional systems affect the detection of features processed in separate sensory channels differently?
