IntroductionPeople are more likely to believe repeated information—this is known as the Illusory Truth Effect (ITE). Recent research on the ITE has shown that semantic processing of statements plays a key role. In our day to day experience, we are often multi-tasking which can impact our ongoing processing of information around us. In three experiments, we investigate how asking participants to engage in an ongoing secondary task in the ITE paradigm influences the magnitude of the effect of repetition on belief.MethodsUsing an adapted ITE paradigm, we embedded a secondary task into each trial of the encoding and/or test phase (e.g., having participants count the number of vowels in a target word of each trivia claim) and calculated the overall accuracy on the task.ResultsWe found that the overall ITE was larger when participants had no ongoing secondary task during the experiment. Further, we predicted and found that higher accuracy on the secondary task was associated with a larger ITE.DiscussionThese findings provide initial evidence that engaging in an ongoing secondary task may reduce the impact of repetition. Our findings suggest that exploring the impact of secondary tasks on the ITE is a fruitful area for further research.

The Transfer-appropriate Processing (TAP) framework has demonstrated enhanced recognition memory when processing operations engaged at encoding and at test match. Our research applied TAP to study the illusory truth effect (ITE). We investigated whether the match/mismatch of evaluative goals at encoding and at test affects the ITE. At encoding, participants saw target words (Experiments 1-3; or full trivia claims Experiments 4-5) and completed an evaluative goal: imagery task or vowel-counting. At test, participants saw target words embedded in trivia claims that were old or new and completed the same (matching) or different (mismatching) evaluative goal that they completed at encoding, before making truth or memory ratings. We found a typical TAP effect for memory judgements when people saw words at encoding, but no TAP effect when people saw claims at encoding. We also found an ITE when people saw claims at encoding, but no ITE when people saw words at encoding (no evidence of TAP moderating truth judgments). Together these results extend both the TAP and ITE literatures, suggesting boundary conditions for TAP and the conditions under which the ITE emerges.

•Truthiness and the Illusory Truth Effects replicated across studies.•There was little evidence that Need for Cognition moderated Truthiness.•There was some evidence that (without warnings) NFC moderated Illusory Truth.•Experimental context may be important in considering individual differences in truth biases.