The influence of active suppression on stimulus-response binding and retrieval.

Feature integration across perception and action is a crucial aspect of cognitive processing, creating retrievable episodic representations known as stimulus-response episodes or event files. While some studies suggest that attention is unnecessary for stimulus-response binding and retrieval, others argue its importance in these processes. To reconcile this contradiction, the current study proposed an attentional threshold for feature integration in event files and tentatively tested this assumption. Since active suppression has been documented to down-regulate attention allocation toward certain stimuli, the current study set out to test the influence of active suppression on stimulus-response binding and retrieval. More specifically, we employed a modified distractor-response binding (DRB) paradigm with a search-and-identification task. Participants searched for targets defined by either a positive feature (Experiment 1, e.g., red when the target is a red letter) or a negative feature (Experiment 2, e.g., blue when the target is a non-blue letter). Distractors were unattended in Experiment 1 but were actively suppressed in Experiment 2, when they carried negative features. Significant DRB effects were observed in Experiment 1 but not in Experiment 2, suggesting that active suppression may reduce attention allocation toward distractors below a critical threshold for feature integration in event files. The current findings support the notion of an attentional threshold which determines what can be involved in the stimulus-response binding and retrieval processes.