The effects of encoding instruction and opportunity on the recollection of behaviourally relevant events.

How does attending to a brief, behaviourally relevant stimulus affect episodic memory encoding? In the attentional boost effect, increasing attention to a brief target in a detection task boosts memory for items that are presented at the same time (relative to distractor-paired items). Although the memory advantage for target-paired items is well established, the effects of attending to targets on other aspects of episodic memory encoding are unclear. This study examined the effects of target detection and goal-directed attention on memory for task-irrelevant information from a single event, focusing on the contributions of recollection and familiarity during recognition. In Experiment 1, participants viewed a series of briefly presented faces as they performed a detection task on unrelated squares, pressing the space bar only when the square was a target colour (e.g., blue) rather than a distractor colour (e.g., orange). Half of the participants were told to memorise the faces, and half were told to ignore them. Results indicated that both recollection and familiarity were greater for target-paired faces than for distractor-paired faces, regardless of whether the faces were intentionally encoded. Experiment 2 examined whether these effects are present for single events, replicating the recollection benefit when encoding time is sufficient. Attending to behaviourally relevant targets appears to facilitate both intentional and incidental memory for the background item and the context in which it occurred, boosting subsequent recollection as well as familiarity.