CONDITIONAL AND UNCONDITIONAL AUTOMATICITY - A DUAL-PROCESS MODEL OF EFFECTS OF SPATIAL STIMULUS - RESPONSE CORRESPONDENCE

Distributional analyses and event-related brain potentials were used t o show that effects of irrelevant spatial stimulus-response correspond ence consist of 2 qualitatively different automatic components that ca n be distinguished on the basis of their dependencies on relative resp onse speed and on computational requirements of the primary task. One component reflects priming of the spatially corresponding response by an abrupt stimulus onset that does not depend on the nature of the pri mary task. This unconditional component exhibits a biphasic pattern, w ith initial facilitation later turning into inhibition, analogous to t hat found for spatial cuing in visual detection tasks. The 2nd compone nt reflects automatic generalization of task-defined transformations o f relevant stimulus information to spatial codes; this conditional com ponent does not depend on relative response speed. Possible connection ist implementations of the conditional mechanism are discussed.