What kind of processing is survival processing? Effects of different types of dual-task load on the survival processing effect

Words judged for their relevance in a survival context are remembered better than words processed in non-survival contexts. This phenomenon is known as the survival processing effect. Recently, inconsistent results were reported on whether the size of the survival processing effect is affected by cognitive load. Whereas Kroneisen, Rummel, and Erdfelder (Memory 22: 92-102, 2014) observed that the survival processing effect vanishes under dual-task conditions, Stillman, Coane, Profaci, Howard, and Howard (Memory & Cognition 42: 175-185, 2014, Experiment 1) found that the size of survival processing effect is essentially unaffected by a cognitively demanding secondary task. In three experiments, we investigated the differences between these studies to achieve a better understanding of dual-task effects on the survival-processing advantage. In the first experiment, we replicated Stillman et al.'s results using their dual-task conditions combined with a sample more than twice as large as theirs. In the second experiment, we compared dual-task conditions that differed regarding how strongly the secondary task taxed (a) working memory load (maintenance of one vs. several items) and (b) processing demands (switching vs. time-sharing between tasks). A third experiment focussed on low (i.e., single-item) load under time-sharing processing conditions. Results consistently showed that the survival processing effect persisted under low load but vanished when the number of items held in working memory increased beyond one, irrespective of processing demands. Implications of these findings for explanations of the survival-processing advantage are discussed.