Evidence for global processing of complex visual displays

'Polar graphic' displays, in which changes in system status are represented by distortions in the form of a geometric figure, were presented to subjects, and reaction time (RT) to discriminate system status was recorded. Of interest was the extent to which reaction time showed evidence of global processing of these displays as the number of nodes and difficulty of discrimination were varied. When discrimination of system status was easy, RT showed no increase with increasing number of nodes, providing evidence of global processing. When discrimination was difficult, systematic differences in RT as a function of the number of nodes suggested the invocation of other (local) processes, although the data were not consistent with a node-by-node search process.