A SIMULTANEOUS TASK COMPARISON OF DIFFERENTIATED AND UNDIFFERENTIATEDHEMISPHERIC RESOURCE THEORIES

Multiple resource theory and related principles hold that resources ar e differentiated both within and between cerebral hemispheres (C. D. W ickens, 1984, 1991, 1992), An opposing view is that each hemisphere co nstitutes a Fool of undifferentiated resources (A. Friedman, M. C. Pol son, C. G, Dafoe, & S. J. Gaskill, 1982; M. C. Polson & A. Friedman, 1 988). Here the authors compare the theories by using dual-task methodo logy, drawing on tasks emerging from factor analytic studies of latera lized processes. Selective interference occurs when 2 tasks draw on th e same process in the same hemisphere but not otherwise, a conclusion further supported by analyses of difficulty trade-off. Differentiation indeed exists within and between hemispheres, but evidence is found f or resources not envisaged in multiple resource theory. The results su ggest that orthogonal processes represent orthogonal resources, and a full accounting of them is likely to be needed in any complete multipl e resource model.