Activation and suppression in conflict tasks: empirical clarification through distributional analyses

Abstract

Abstract Abstract. The purpose of the present study was to explore and clarify the role of inhibitory processes in correspondence effects in con2ict tasks (and in the Simon task in particular), in which responses are typically slowed when an irrelevant stimulus feature is associated with the incorrect response. An activation-suppression hypothesis, describing a pattern of direct activation followed by the selective suppression of that activation, was developed and applied to the Simon task. Distributional analyses (in particular, delta plots for both response speed and accuracy) were argued to reveal the dynamics of these inhibitory processes. Three different empirical approaches provided evidence for differential patterns of selective suppression in Simon tasks. First, the results of an experimental manipulation, designed explicitly to vary the need to suppress (the context in which the Simon task appeared either emphasized or opposed the need to suppress the task-irrelevant location of the stimulus), provided independent evidence that differential patterns of suppression of location-driven direct activation showed up in diverging delta plot patterns.