Retroactive Facilitation and Change Awareness Across Lags and Retention Intervals

Memory for an earlier event can be impaired by a later event (retroactive interference). However, when later events cue retrieval of earlier events, memory for the earlier event can be enhanced (retroactive facilitation). Two experiments using continuous A-B, A-C paired-associate tasks examined these retroactive memory effects across lags and retention intervals. Associations between change awareness and first-response recall were used as indices of study-phase retrieval and related encoding processes. Participants studied A-B, A-C, and retention-interval-matched A-B pairs and indicated when they detected response changes. The lag between A-B and A-C and the retention interval between A-C and test trials varied across 4, 16, and 48 intervening items. Cued-recall test formats differed: Experiment 1 prompted retrieval of first responses, with participants reporting recollected changes. Experiment 2 used modified-modified free recall in which participants reported responses as they came to mind and indicated whether each response was first, second, or only; the first two decisions indexed recollection of changes. Retroactive facilitation increased across retention intervals. Experiment 1 showed a negatively curvilinear, non-monotonic lag pattern for A-B, A-C recall at the longest retention interval, but this pattern was not supported in Experiment 2. Facilitation occurred on trials in which change awareness persisted from study to test. These findings suggest that retroactive facilitation reflects instances in which study-phase retrieval supports detection and recollection of change, consistent with accounts in which integrative encoding preserves ordered memories. The variation in lag patterns tentatively implicates a contribution from contextual variability, but this awaits confirmation.