The role of executive functions in the effects of lying on memory

Recent studies have demonstrated that lying can affect memory and that such memory effects are based on the cognitive load required in performing the lie. The present study aimed to verify whether the impact of two deceptive strategies (i.e., false denials and fabrication) depends on individuals' cognitive resources in terms of Executive Functions (i.e., EF: Shifting, Inhibition, and Updating). A sample of 147 participants watched a video of a robbery and then were instructed to either fabricate (i.e., fabrication condition), deny (i.e. false denial condition), or tell the truth (i.e., truth-telling condition) to some questions about the crime. Two days later, all participants had to provide an honest account on a final memory test where they indicated their memory for having discussed details (i.e., fabricated, denied, or told the truth) and their memory for the video. Finally, their EF resources were also assessed. Our findings demonstrated that individual differences in EFs played a role in how the event was recalled and on the effects of lying on memory. That is, memory for the event after having lied depended especially on individuals' Shifting resources. We also found that the two deceptive strategies differentially affected individuals' memory for the interview and for the event: Denying affected memory for the interview while fabricating affected memory for the event. Our findings can inform legal professionals on the possibility to assess individuals' EF as an indicator of witnesses' credibility.