Conflict-Monitoring Theory in Overtime: Is Temporal Learning a Viable Explanation for the Congruency Sequence Effect?

In interference tasks (e.g., Stroop, 1935), congruency effects are larger following a congruent versus an incongruent trial. This “congruency sequence effect” has been traditionally explained in terms of a conflict-monitoring mechanism that focuses attention toward relevant information when conflict has recently been experienced. More recently, it has been suggested that effects of this sort result from differences in the temporal expectancies formed following congruent trials (fast responding) versus incongruent trials (slow responding). Evidence supporting this “temporal-learning” account was recently reported for a similar effect, the finding that congruency effects are larger in a mostly congruent list than in a mostly incongruent list. That is, consistent with the idea that this “proportion-congruent effect” is based on different temporal expectancies following congruent versus incongruent trials in interference tasks, the proportion-congruent effect was eliminated on normal (i.e., immediate-response) trials when temporal expectancies were equated by requiring a delayed response on the prior trial. In two experiments, we examined whether this delayed-response procedure would have a similar impact on the congruency sequence effect. Consistent with the temporal-learning account (but not inconsistent with conflict-monitoring accounts), the congruency sequence effect on immediate-response trials was eliminated when the previous trial required a delayed response. However, no evidence supporting the temporal-learning account emerged from reanalyses of experiments requiring only immediate responses in which the response latency in the previous trial functioned as the temporal-expectancy index. Overall, the present results and analyses do not provide much evidence favoring the temporal-learning account over conflict-monitoring accounts of the congruency sequence effect.