Do reminders of the crime reverse the memory-undermining effect of simulating amnesia?

Abstract

Research shows that simulating amnesia impairs actual memory for a mock crime. Lack of rehearsal has been suggested as the most likely explanation for this finding because feigning amnesia is linked to reduced thinking about the offence. We investigated whether reminders about the crime could reverse the memory-undermining effect of simulation. In two studies, participants watched a video of a violent crime. After, they were asked to either simulate amnesia or confess the crime. During the week between the first and second memory test phase, participants were provided with reminders of the crime in two different modalities. In Study 1 (pilot), participants received frames of the mock crime video via WhatsApp. Findings showed that such reminders did not enhance ex-simulators’ memory. In Study 2, participants were asked to put sequences of the mock crime in the right order. This latter modality led to enhanced memory for the offence in simulating participants. Theoretical and practical implications of our findings for the legal field are discussed.Electronic supplementary materialThe online version of this article (10.3758/s13421-019-00939-z) contains supplementary material, which is available to authorized users.

An experimental investigation of the misinformation effect in crime‐related amnesia claims

“…In the current experiment, we combined two different paradigms (i.e., simulated amnesia and misinformation) to experimentally investigate the effects of misleading post‐event information on individuals who were asked to feign memory loss for a mock crime. Our findings reflect, and to some degree extend, those found in the literature with respect to both the simulating amnesia for a mock crime paradigm (e.g., Bylin & Christianson, 2002; Mangiulli, Van Oorsouw, et al, 2018; Mangiulli, Lanciano, et al, 2019, Mangiulli, Van Oorsouw, et al, 2019; Van Oorsouw & Merckelbach, 2006) and misinformation studies (e.g., Loftus et al, 1978; McCloskey & Zaragoza, 1985; Takarangi et al, 2006).…”

“…To begin with, we observed the standard memory‐undermining effect of simulating amnesia (Mangiulli, Van Oorsouw, et al, 2018; Mangiulli, Lanciano, et al, 2019; Van Oorsouw & Merckelbach, 2004, 2006). Participants who were previously asked to simulate memory loss reported fewer correct details than those who were instructed to confess to the mock crime.…”

“…However, our data restrict us from fully attributing the simulating amnesia effect to such explanation, mainly because we did not include a control group (i.e., participants who are assessed only during the second memory phase). In this regard, recent studies show that simulators report more correct information than controls because they actually remember some aspects of the event (Mangiulli, Van Oorsouw, et al, 2018, Mangiulli, Lanciano, et al, 2019; McWilliams et al, 2014). As a matter of fact, drawing on the cognitive load theory, when lying, individuals should be able to think of their truthful actions and have a good memory for it (DePaulo et al, 2003; Vrij, Fisher, Mann, & Leal, 2008; Vrij, Mann, Leal, & Granhag, 2010).…”

“…That is, because simulating amnesia can be exerted in at least two ways—by solely omitting information versus by simultaneously omitting, distorting and introducing new information (Bylin & Christianson, 2002; Mangiulli, Van Oorsouw, et al, 2018; Mangiulli, Lanciano, Van Oorsouw, Jelicic, & Curci, 2019; Otgaar & Baker, 2018)—this deceptive strategy can impair memory for the crime in terms of forgetting, but it might also lead to distortions and/or commission errors over time (e.g., Mangiulli, Van Oorsouw, et al, 2018; Mangiulli, Van Oorsouw, Curci, & Jelicic, 2019; Van Oorsouw & Giesbrecht, 2008). An increasing wave of studies has investigated the effects of simulated crime‐related amnesia claims on genuine memory for such events (e.g., Christianson & Bylin, 1999; Mangiulli, Van Oorsouw, et al, 2018; Mangiulli, Lanciano, et al, 2019; Mangiulli, Van Oorsouw, et al, 2019; Romeo, Otgaar, Smeets, Landström, & Jelicic, 2018; Van Oorsouw & Merckelbach, 2004, 2006). For instance, using the classic simulated amnesia for a mock crime procedure, Mangiulli, Van Oorsouw, et al, (2018) exposed participants to a mock crime during a first memory test phase and subsequently asked them to either simulate memory loss or confess to that crime.…”

“…Investigating this issue is relevant to examine whether such factors have an independent impact on memory or whether they might interact with each other, thereby differentially affecting individuals' memory performance. That is, on the one hand, because some research has shown that simulators might still continue to remember crucial aspects of an experienced event (e.g., Mangiulli, Van Oorsouw, et al, 2018; Mangiulli, Lanciano, et al, 2019; McWilliams et al, 2014), simulators and confessors might evince a similar misinformation effect. However, on the other hand, it could also be the case that because simulators sometimes have a weak memory trace of an event due to lack of rehearsal or RIF (Bylin & Christianson, 2002; Mangiulli, Van Oorsouw, et al, 2019; Van Oorsouw & Merckelbach, 2004), they are unable to detect discrepancies between the original event and post‐event information, which would make them more susceptible to misinformation than confessors.…”