Recalling a Witnessed Event Increases Eyewitness Suggestibility

Abstract

People's later memory of an event can be altered by exposure to misinformation about that event. The typical misinformation paradigm, however, does not include a recall test prior to the introduction of misinformation, contrary to what real-life eyewitnesses encounter when they report to a 911 operator or crime-scene officer. Because retrieval is a powerful memory enhancer (the testing effect), recalling a witnessed event prior to receiving misinformation about it should reduce eyewitness suggestibility. We show, however, that immediate cued recall actually exacerbates the later misinformation effect for both younger and older adults. The reversed testing effect we observed was based on two mechanisms: First, immediate cued recall enhanced learning of the misinformation; second, the initially recalled details became particularly susceptible to interference from later misinformation, a finding suggesting that even human episodic memory may undergo a reconsolidation process. These results show that real-life eyewitness memory may be even more susceptible to misinformation than is currently envisioned.

Retrieval does not always enhance suggestibility: Testing can improve witness identification performance.

“…Interestingly, this pattern seems to contradict those reported by Chan et al (2009) Loftus and Greene (1980), in which participants were told that the narrative was written by a professor after he/she watched the video. This suggested that the narrative was based on the professor's memory of the video event.…”

Retrieval enhances eyewitness suggestibility to misinformation in free and cued recall.

“…If retrieval practice enhances memory of a witnessed event, then this enhancement would seem likely to reduce misinformation suggestibility. However, contrary to this possibility, retrieval practice can sometimes increase the negative influence of misleading suggestions on eyewitness memory performance -a finding termed retrieval-enhanced suggestibility (RES, Chan, Thomas, & Bulevich, 2009). Due to the frequency that witnesses engage in repeated retrieval, it is prudent to examine the conditions under which recalling details of a witnessed event might, or might not, produce RES.…”

“…We do not dwell on the reconsolidation hypothesis in this paper because these experiments were not designed to address this possibility. account ascribes RES to preferential encoding of the misinformation following initial testing (Chan et al, 2009;Thomas, Bulevich, & Chan, 2010). For explication purposes, we refer to this notion as the attention allocation hypothesis (Chan, Wilford, & Hughes, 2012;Thomas et al, 2010).…”

The Impact of Testing on the Formation of Children's and Adults' False Memories

“…Researchers argue that taking a test strengthens the memory trace for a specific event, which in turn reduces the impact of forgetting and external misinformation (e.g., Chan, Thomas, & Bulevich, 2009). In support of the protective value of testing, studies have frequently found an inoculation effect against misinformation (e.g., Pansky & Tenenboim, 2011; Wang, Paterson, & Kemp, 2014).…”

“…That is, recent studies have demonstrated elevated false memory rates after taking a test (e.g., Chan & Langley, 2011; Chan & LaPaglia, 2011; Gordon & Thomas, 2014; Wilford, Chan, & Tuhn, 2014). This effect, labeled retrieval‐enhanced suggestibility (Chan et al, 2009), may be related to two underlying mechanisms: a focus on the misinformed items or the overwriting of the original memory trace because of testing. The former mechanism represents a preference for the newly stored (erroneous) information, while the latter causes the previously stored (correct) information to become inaccessible.…”