Unringing the bell: Successful debriefing following a rich false memory study.

In rich false memory studies, familial informants often provide information to support researchers in planting vivid memories of events that never occurred. The goal of the current study was to assess how effectively we can retract these false memories via debriefing - i.e., to what extent can we put participants back the way we found them? We aimed to establish (1) what proportion of participants would retain a false memory or false belief following debriefing, and (2) whether richer, more detailed memories would be more difficult to retract. Participants (N = 123) completed a false memory implantation protocol as part of a replication of the "Lost in the Mall" study (Loftus & Pickrell, Psychiatric Annals, 25, 720-725, 1995). By the end of the protocol, 14% of participants self-reported a memory for the fabricated event, and a further 52% believed it had happened. Participants were then fully debriefed, and memory and belief for the false event were assessed again. In a follow-up assessment 3 days post-debriefing, the false memory rate had dropped to 6% and false belief rates also fell precipitously to 7%. Moreover, virtually all persistent false memories were found to be nonbelieved memories, where participants no longer accepted that the fabricated event had occurred. Richer, more detailed memories were more resistant to correction, but were still mostly retracted. This study provides evidence that participants can be "dehoaxed", and even very convincing false memories can be retracted.

Do cognitive abilities reduce eyewitness susceptibility to the misinformation effect? A systematic review.

The fact that memories can be distorted by post-event misinformation has cast considerable doubt over the dependability of eyewitness evidence in legal contexts. However, despite its adverse practical implications, the misinformation effect is likely an unavoidable distortion stemming from the reconstructive nature of episodic memory. Certain cognitive abilities have been reported to offer protection against misinformation, suggesting that mechanisms aside from episodic memory may also be underpinning this type of memory distortion. The purpose of this review was to collate findings of associations between eyewitness misinformation susceptibility and individual differences in cognitive ability in adults aged 18 and over. Nine studies met the eligibility criteria for this review, including 23 distinct associations. Using a narrative synthesis, three categories of cognitive ability were identified as influencing susceptibility to misinformation: general intelligence and reasoning, perceptual abilities, and memory abilities. Across almost all categories, higher levels of ability were associated with reduced susceptibility to misinformation. While there is no indication that any one trait provides total immunity to the misinformation effect, there is a reasonable amount of evidence to suggest that several cognitive abilities create variance in individual levels of susceptibility. Future research should investigate not only if but how these cognitive abilities protect against misinformation distortions, for example, by contributing to more detailed encoding of the memory, enhancing discrepancy detection in the face of post-event misinformation, or improving source-monitoring during an eyewitness memory test.

Can we enhance working memory? Bias and effectiveness in cognitive training studies.

Meta-analyses have found that working memory (WM) can be improved with cognitive training; however, some authors have suggested that these improvements are mostly driven by biases in the measurement of WM, especially the use of similar tasks for assessment and training. In the present meta-analysis, we investigated whether WM, fluid intelligence, executive functions, and short-term memory can be improved by cognitive training and evaluated the impact of possible sources of bias. We performed a risk of bias assessment of the included studies and took special care in controlling for practice effects. Data from 52 independent comparisons were analyzed, including cognitive training aimed at different cognitive functions. Our results show small improvements in WM after training (SMD = 0.18). Much larger effects were observed when the analysis was restricted to assessment tasks similar to those used for training (SMD = 1.15). Fluid intelligence was not found to improve as a result of training, and improvements in WM were not related to changes in fluid intelligence. Our analyses did however indicate that cognitive training can improve specific executive functions. Contrary to expectations, a set of meta-regressions indicated that characteristics of the training programme, such as dosage and type of training, do not have an impact on the effectiveness of training. The risk of bias assessment revealed some concerns in the randomization process and possible selective reporting among studies. Overall, our results identified various potential sources of bias, with the most significant being the choice of assessment tasks.