An irrelevant speech effect on incidental memory

In most irrelevant speech experiments, the key dependent variable is intentional memory (i.e. participants encode items with the clear instruction to remember them later). Here, we investigated the irrelevant speech effect on incidental memory (i.e. participants encoded items without any expectation of a later recall). We used the survival processing paradigm. Participants rated words according to their fitness relevance or pleasantness, followed by a surprise memory test. In Experiment 1, we found the typical survival processing memory advantage in quiet, but not when irrelevant speech was played during encoding, retention and recall. In Experiments 2 and 3, irrelevant speech was played only during the rating task (encoding), but not during the intermediate task (retention) or the surprise memory test (recall). The survival processing effect persisted, suggesting that incidental memory is rather robust against irrelevant speech when played during encoding, but not during the retention and retrieval of information.