Still seeking for an explanation of the Sequential Compatibility Effect

The modulation of the Compatibility Effect (CE) according to the compatibility of the previous trial (Sequential Compatibility Effect, SCE) in three types of attentional tasks is explored. The flankers and spatial Stroop tasks have different degrees of cognitive complexity. In all three tasks it is analyzed whether the SCE varies when the stimuli in consecutive trials are exactly the same (pure replicas) or not. The data, collected from three independent samples (total N = 1.159), show the CE in the three tasks. However, SCE only shows up in the spatial Stroop task. The effect is smaller albeit still significant when the pure replica trials are removed, a result inconsistent with those of Mayr et al. (2003) and Hommel (1998) but consistent with the Conflict Theory (Botvinick et al., 2001). Furthermore, we also discuss the importance of cognitive complexity in relation to the perspective of Botvinick et al. (2004). From this point of view more complexity should be reflected in a greater presence of cognitive conflict, and therefore a higher SCE.