Do emotional stimuli enhance or impede recall relative to neutral stimuli? An investigation of two "false memory" tasks

Effects of emotional ambiguity and emotional intensity on true and false memory

Whereas the effects of emotional intensity (the perceived strength of an item's valence or arousal) have long been studied in true- and false-memory research, emotional ambiguity (the uncertainty that attaches to perceived emotional intensity) has only been studied recently. Available evidence suggests that emotional ambiguity has reliable effects on true memory that are distinct from those of emotional intensity. However, those findings are mostly restricted to recall, and the effects of emotional ambiguity on false memory remain unexplored. The current study addressed both limitations by measuring the effects of emotional ambiguity and emotional intensity on true and false recognition. In two experiments, we manipulated valence ambiguity and valence intensity (Experiment 1) and arousal ambiguity and arousal intensity (Experiment 2) of Deese/Roediger/McDermott lists. Multiple linear regression analyses were conducted for Experiment 1, Experiment 2, and the combined data of the experiments to separate the effects of emotional ambiguity and emotional intensity. Our results showed that both valence ambiguity and arousal ambiguity improved true recognition, and the effects of valence ambiguity remained robust even when controlling for valence intensity, arousal intensity, and arousal ambiguity. More importantly, for both valence and arousal, there was an interaction between ambiguity and intensity in false memory. Specifically, we found that valence ambiguity increased false recognition with positive valence, while arousal ambiguity amplified the effect of arousal intensity on false recognition. Our results are discussed in the context of the emotional ambiguity hypothesis and fuzzy-trace theory.

A systematic review of the relationship between emotion and susceptibility to misinformation

Inaccurate memory reports can have serious consequences within forensic and clinical settings, where emotion and misinformation are two common sources of memory distortion. Many studies have investigated how these factors are related; does emotion protect memory or leave it more vulnerable to the distorting effects of misinformation? The findings remain diffused. Thus, the present review aimed to clarify the relationship between emotion and susceptibility to misinformation. 39 eligible studies were reviewed. Results varied according to the type and dimension of emotion measured. Level of arousal may be unrelated to susceptibility to misinformation when retrieval occurs without delay; studies including delayed retrieval were limited. Stimuli valence may be associated with increased susceptibility to peripheral misinformation but unrelated to other misinformation. The following results were reported by limited studies: short-term distress and moderate levels of stress may decrease susceptibility, while anger and greater cortisol response to stress may increase susceptibility to misinformation. Source memory may also be unaffected by emotion. The results have important potential implications for forensic and clinical practice, for example by highlighting the value of enquiring witnesses' source memory. Methodological recommendations for future studies are made.

Adult memory for instances of emotionally stressful and non-stressful repeated events

Repeated offences, such as domestic violence, are often distressing for victims. When victims of such offences make an allegation of abuse, they are usually required to report details about specific incidents. Therefore, this pre-registered study examined whether memory for an emotionally stressful versus non-stressful repeated event would differ depending on the instance being recalled. Eighty female participants (M_age = 22.3, SD = 7.4) imagined being involved in four abusive (emotionally stressful repeated event) or non-abusive relationship instances (non-stressful repeated event) over a four-week period. One-week after the last instance, participants completed recall and source memory questions about each instance. We found no evidence that memory for stressful versus non-stressful repeated events differed depending on the instance being recalled. Instead, we found that memory was more accurate for the last instance relative to the other instances (i.e., recency effect), regardless of event stressfulness. We also found that memory accuracy was better across all instances in the stressful than the non-stressful group. The findings suggest that victim-survivors of abuse might find the last instance of abuse particularly memorable when the delay between the offence and report is one-week or less, and the stressfulness of the instance might help them recall more details.

Linking creativity and false memory: Common consequences of a flexible memory system

Episodic retrieval plays a functional-adaptive role in supporting divergent thinking, the ability to creatively combine different pieces of information. However, the same constructive memory process that provides a functional-adaptive benefit can also leave memory prone to error. In two experiments, we employed an individual differences approach to examine the relationship between different forms of creative thinking (divergent and convergent thinking) and false memory generation in the Deese-Roediger-McDermott paradigm. In Experiment 1, and replicating prior findings, false recognition was significantly predicted by convergent thinking performance. Critically, we also observed a novel predictive relationship between false recognition and quantitative metrics of divergent thinking performance. In Experiment 2, these findings were replicated and we further showed that false recall was predicted by quantitative metrics of divergent thinking. Our findings suggest that constructive memory processes link creative thinking with the production of memory errors.

The Impact of Emotion and Sex on Fabrication and False Memory Formation

The aim of the present study was to examine how negative emotion and sex affect self-generated errors as in fabrication set-up and later false recognition of those errors. In total, 120 university students volunteered to take part in the study. Participants were assigned at random into two equal sized groups (N = 60) depending on the type of event they received (negative emotional or neutral). We expected that fabrication and false recognition would be enhanced for the emotional event compared to the neutral one. We further hypothesized that both the willingness to fabricate and later false recognition would be enhanced for women compared with men. The results partly confirmed the hypotheses. The results showed that emotional valence (negative) affects both the willingness to fabricate about events that never took place, and the recognition of the fabrication as true at a later point. Women and men were equally likely to fabricate but women were more likely to recognize their fabrication, particularly for the emotional event. The results are discussed in the context of prior work.

Individual Differences in Disqualifying Monitoring Underlie False Recognition of Associative and Conjunction Lures

The current study leveraged experimental and individual differences methodology to examine whether false memories across different list-learning tasks arise from a common cause. Participants completed multiple false memory (associative and conjunction lure), working memory (operation and reading span), and source monitoring (verbal and picture) tasks. Memory discriminability in the associative and conjunction tasks loaded onto a single (general) factor and were unaffected by warnings provided at encoding. Consistent with previous research, source-monitoring ability fully mediated the relation between working memory and false memories. Moreover, individuals with higher source monitoring-ability were better able to recall contextual information from encoding to correctly reject lures. These results suggest that there are stable individual differences in false remembering across tasks. The commonality across tasks may be due, at least in part, to the ability to effectively use disqualifying monitoring processes.

Dissociation and false memory: the moderating role of trauma and cognitive ability

The term dissociation is often used to refer to a diverse range of psychological symptoms, including perceptual impairments, emotional detachment, and memory fragmentation. In the present study, we examined whether there was a relation between participants' self-reports of dissociative experiences and their memory performance in the Deese-Roediger-McDermott (DRM) paradigm-a laboratory-based procedure that is frequently used to investigate false memory. University students (N = 298) completed the Dissociative Experiences Scale (DES) and the Traumatic Life Events Questionnaire (TLEQ). Participants were also administered a standardised intelligence test (Shipley-2), and they were tested in the DRM paradigm. Overall, experiencing trauma and dissociation, as well as lower levels of cognitive ability, were associated with higher false memory. These findings are discussed in the context of the activation monitoring theory of DRM false memory.

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

In general, memory of highly negative and even traumatic events can distort. However, the effect of misinformation exposure on such memories requires further investigation given the inconsistent past findings. With two experiments, we investigated: (1) whether misinformation distorts memory for highly negative analogue events, (2) whether memory distortion is increased for more emotional and potentially traumatic details compared to unemotional details, and (3) whether repeated misinformation exposure further increases memory distortion for highly negative events compared to single exposure, a possibility that has not been investigated to our knowledge. In both experiments, participants viewed a trauma analogue film with some scenes removed. Twenty-four hours later, they were given three "eyewitness" reports describing the film's events. To manipulate misinformation repetition, either zero, one, or all three of the reports described removed scenes. To determine whether memory distortion is increased for emotional details, half of the removed scenes were more traumatic than the other half. Participants exposed to misinformation falsely remembered more removed scenes compared to participants who were not exposed to misinformation. Further, memory distortion was increased for emotional (vs. unemotional) aspects of the film. Repeated misinformation exposure, however, did not lead to significantly higher error rates compared to single exposure. The lack of perceptual overlap between our written misinformation and film test items may have limited false memories even with repeated misinformation. Alternatively, the repeated vs. single misinformation effect may exist but be very small, as suggested by our raw means and effect sizes.

Investigating the Relations Among Different Measures of False Memory

Researchers have used the term false memory to describe various memory errors, including the incorporation of erroneous information into a memory, misremembering a word presented as a picture, and the construction of a detailed memory of an event that did not occur. Whether such diverse manifestations of false memory are assessing the same construct has not been evaluated. The purpose of this study is to examine the relations among a set of variables that have been used in the literature to measure false memory. The sample consisted of 112 college students who completed four false memory measures, including the commonly used Deese-Roediger-McDermott (DRM) and the misinformation tasks. Zero-order correlations indicated that there are little to no associations between false memories in the DRM and the misinformation tasks, as well as the other false memory tasks. A confirmatory factor analysis of the DRM and misinformation variables further suggested that the false memory variables share little variance in common and may not be represented by a unitary factor. Thus, the results of the current study suggest that tasks intended to measure false memory may be measuring different types of memory errors. 

Who is susceptible in three false memory tasks?

Decades of research show that people are susceptible to developing false memories. But if they do so in one task, are they likely to do so in a different one? The answer: "No". In the current research, a large number of participants took part in three well-established false memory paradigms (a misinformation task, the Deese-Roediger-McDermott [DRM] list learning paradigm, and an imagination inflation exercise) as well as completed several individual difference measures. Results indicate that many correlations between false memory variables in all three inter-paradigm comparisons are null, though some small, positive, significant correlations emerged. Moreover, very few individual difference variables significantly correlated with false memories, and any significant correlations were rather small. It seems likely, therefore, that there is no false memory "trait". In other words, no one type of person seems especially prone, or especially resilient, to the ubiquity of memory distortion.