Does emotional or repeated misinformation increase memory distortion for a trauma analogue event?

Experimental and meta-analytic evidence that source variability of misinformation does not increase eyewitness suggestibility independently of repetition of misinformation

Considerable evidence has shown that repeating the same misinformation increases its influence (i.e., repetition effects). However, very little research has examined whether having multiple witnesses present misinformation relative to one witness (i.e., source variability) increases the influence of misinformation. In two experiments, we orthogonally manipulated repetition and source variability. Experiment 1 used written interview transcripts to deliver misinformation and showed that repetition increased eyewitness suggestibility, but source variability did not. In Experiment 2, we increased source saliency by delivering the misinformation to participants via videos instead of written interviews, such that each witness was visibly and audibly distinct. Despite this stronger manipulation, there was no effect of source variability in Experiment 2. In addition, we reported a meta-analysis (k = 19) for the repeated misinformation effect and a small-scale meta-analysis (k = 8) for the source variability effect. Results from these meta-analyses were consistent with the results of our individual experiments. Altogether, our results suggest that participants respond based on retrieval fluency rather than source-specifying information.

Associations between the misinformation effect, trauma exposure and symptoms of posttraumatic stress disorder and depression

This research aimed to conduct an initial investigation into the relationships between the "misinformation effect" and trauma exposure, posttraumatic stress disorder (PTSD) and depression. Study 1 was a pilot study developing an online misinformation paradigm that could assess the influence of emotion and arousal on memory distortions. Participants (n = 162, M_age = 39.90; SD = 10.90) were recruited through TurkPrime. In Study 2 community members (n = 116, M_age = 28.96; SD = 10.33) completed this misinformation paradigm and measures of trauma exposure, PTSD, and depression. Study 1 found memory for central details was better for high-arousal than low-arousal and neutral-arousal images. Peripheral memory appeared worse for negative and neutral images than positive images. Study 2 found that, when controlling for age and gender, PTSD symptoms significantly predicted proportion of correct responses on control items. However, there was no evidence to indicate that trauma exposure, PTSD symptoms nor depression symptoms, were associated with proportion of correct responses on misled items. Valence and arousal did not influence these associations. These findings have important implications in clinical and legal contexts where individuals with a history of trauma, or who are experiencing symptoms of PTSD or depression, are often required to recall emotionally-laden events. There is a surprising dearth of research into the misinformation effect in clinical populations and further research is required.

False denials increase false memories for trauma-related discussions

False denials are sometimes used to cope with traumatic experiences. We examined whether false denials can affect true and false memory production for a traumatic event and conversations surrounding the trauma. One hundred and twenty-six participants watched a trauma analogue video of a car crash before being randomly asked in a discussion with the experimenter to (1) respond honestly or (2) falsely deny that certain details happened in the video. After one week, all participants received misinformation about the discussion with the experimenter and the car crash. Finally, all participants were instructed to respond truthfully in a source memory task. Participants who falsely denied information during the first session were statistically significantly more prone than honest participants to omit details they denied and to report misinformation about what was discussed in the first session. Our work suggests that false denials of a traumatic experience might lead to both forgetting and increased false memory levels for earlier conversations about the event.

Misinformation effects in an online sample: results of an experimental study with a five day retention interval

Traditional face-to-face laboratory studies have contributed greatly to our understanding of how misinformation effects develop. However, an area of emerging concern that has been relatively under-researched is the impact of misinformation following exposure to traumatic events that are viewed online. Here we describe a novel method for investigating misinformation effects in an online context. Participants (N = 99) completed the study online. They first watched a 10-min video of a fictional school shooting. Between 5 and 10 days later, they were randomly assigned to receive misinformation or no misinformation about the video before completing a recognition test. Misinformed participants were less accurate at discriminating between misinformation and true statements than control participants. This effect was most strongly supported by ROC analyses (Cohen's d = 0.59, BF10 = 8.34). Misinformation effects can be established in an online experiment using candid violent viral-style video stimuli.