Adaptive memory: Temporal, semantic, and rating-based clustering following survival processing

Processing items for their survival relevance often produces a robust memory advantage. The current experiments assessed possible proximate mechanisms responsible for this advantage by assessing output strategies during free recall. Previous research has shown that item clustering during recall can provide diagnostic information about the structure of representations in episodic memory, particularly the encoding of temporal, semantic, and source information. Following survival processing and moving or pleasantness controls, measures of temporal and semantic clustering were generated. A robust recall advantage was found for survival processing, but no evidence for temporal clustering was detected. Above-chance levels of semantic clustering were obtained, but there were no differences between the survival and control conditions. An additional clustering measure based on scenario-based relevance ratings also failed to explain recall differences, as did absolute and relative measures of remembered temporal position. Our results indicate that neither enhanced temporal coding nor increased semantic processing among the items on the study list can easily explain the oft-replicated survival processing advantage. Our results also suggest that the ubiquitous temporal clustering patterns seen in free recall studies may be a product, in part, of using intentional learning and multiple study trials. 2016 Elsevier Inc. All rights reserved.