Conflict Dynamics Within and Across Trials: The Effect of Distractor-Target Stimulus Onset Asynchrony

Abstract Understanding how conflict dynamics work in conflict tasks is crucial for unraveling why we can effectively focus on target information while ignoring distractor information. One way to examine conflict dynamics between distractor and target information is to manipulate distractor-target stimulus onset asynchronies (SOAs), which influence the allocation of attention and subsequent adaptations to conflict in the next trial. Both the spatial Stroop and flanker paradigms have been used to investigate the effects of SOA manipulations, revealing distinct conflict dynamics across different SOA conditions. However, it remains unclear whether the underlying cognitive mechanisms responsible for these differing patterns of effects can be explained within a common attention shift framework. To investigate this research question, we integrated an experimental manipulation of the spatial Stroop and flanker tasks with a model-based approach using the revised diffusion model for conflict tasks Lee and Sewell (2024). Our examination of the spatial Stroop and flanker tasks revealed a shared mechanism for within-trial conflict adjustment, where evidence is extracted from the target faster when the target is preceded by a distractor. Furthermore, the results suggest that when distractor information appears first, both tasks share common attributes of conflict dynamics, including reduced urgency in attentional shifts during congruent trials. Based on the behavioral and model-based evidence, an increasing sequential modulation across SOAs was only observed in the spatial Stroop task but not in the flanker task. Notably, our modeling results suggest that a larger sequential effect when distracting information precedes target information for a longer duration is likely due to stronger attentional control following an incongruent trial. This further implies that conflict adaptation is proactive and selective with respect to the congruency of the previous trial.