Protective effects of testing across misinformation formats in the household scene paradigm.

Many studies have demonstrated retrieval-enhanced suggestibility (RES), in which taking an initial recall test after witnessing an event increases suggestibility to subsequent misinformation introduced via a narrative. Recently, however, initial testing has been found to have a protective effect against misinformation introduced via cued-recall questions. We examined whether misinformation format (narrative vs. cued-recall questions) yields a similar dissociation in a paradigm that, to date, has consistently yielded a protective effect of testing (PET). After studying photos of household scenes (e.g., kitchen), some participants took an initial recall test. After a 48-hr delay, items not presented in the scenes (e.g., knives/plates) were suggested either via narrative or questions. Regardless of the misinformation format, we found a PET on both initial-test-conditionalised free recall and source-monitoring tests. However, initial testing also yielded memory costs, such that suggested items reported on the initial test were likely to persist on a final recall test. Thus, initial testing can protect against suggestibility, but can also precipitate memory errors when intrusions emerge on an initial test.