Understanding the structure of autobiographical memories: A study of trauma memories from the 1994 Rwandan genocide.

How do we remember traumatic events, and are these memories different in individuals who experience post-traumatic stress? Some evidence suggests that traumatic events are mnemonically enhanced, or include more episodic detail, relative to other types of memories. Simultaneously, individuals with post-traumatic stress disorder (PTSD) have more non-episodic details in all of their memories, a pattern hypothesized to result from impairment in executive function. Here, we explore these questions in a unique population that experienced severely traumatic events more than 20 years ago - individuals who lived through the 1994 genocide in Rwanda. Participants recalled events from the genocide, negative events unrelated to the genocide, neutral events, and positive events. We used the Autobiographical Interview method to label memory details as episodic or non-episodic. We found that memories from the genocide showed robust mnemonic enhancement, with more episodic than non-episodic details, and contained more details overall than any other memory type. This pattern was not impacted by post-traumatic stress. Overall, this study provides evidence that traumatic events create vivid long-lasting episodic memories, in this case even more than 20 years later.

Hearing fearful prosody impairs visual working memory maintenance.

Interference by distractors has been associated multiple times with diminished visual and auditory working memory (WM) performance. Negative emotional distractors in particular lead to detrimental effects on WM. However, these associations have only been seen when distractors and items to maintain in WM are from the same sensory modality. In this study, we investigate cross-modal interference on WM. We invited 20 participants to complete a visual change-detection task, assessing visual WM (VWM), while hearing emotional (fearful) and neutral auditory distractors. Electrophysiological activity was recorded to measure contralateral delay activity (CDA) and auditory P2 event-related potentials (ERP), indexing WM maintenance and distractor salience respectively. At the behavioral level, fearful prosody didn't decrease significantly working memory accuracy, compared to neutral prosody. Regarding ERPs, fearful distractors evoked a greater P2 amplitude than neutral distractors. Correlations between the two ERP potentials indicated that P2 amplitude difference between the two types of prosody was associated with the difference in CDA amplitude for fearful and neutral trials. This association suggests that cognitive resources required to process fearful prosody detrimentally impact VWM maintenance. That result provides a piece of additional evidence that negative emotional stimuli produce greater interference than neutral stimuli and that the cognitive resources used to process stimuli from different modalities come from a common pool.

An investigation of the mechanisms underlying the link between abstract reasoning and intrusive memories: A trauma analogue study.

Potentially traumatic events elicit intrusive memories to which some individuals are more vulnerable than others. Lower abstract reasoning capacity has been related to more intrusive memories. A more perceptual processing style when encoding the event may mediate this link. Another potential mechanism is lower attentional control, resulting in greater attentional bias toward trauma-related content. We examined both of these possibilities using a trauma-analogue paradigm. One hundred and twenty participants completed abstract reasoning tasks. Then, 90 participants watched a negative video, and 30 participants watched a neutral video. The level of perceptual processing (P1) and attentional bias (RT) towards trauma-related stimuli were measured with a pictorial Stroop task while recording EEG. Intrusive memories were recorded for 5 days. Abstract reasoning was not associated with intrusive memories. However, lower abstract reasoning tended to be associated with more perceptual processing (greater P1 amplitude) following the negative video. More perceptual processing also tended to be related to more intrusive memories for younger participants. A more pronounced attentional bias was related to more intrusive memories, but only for women. Unexpectedly, also for women, better verbal reasoning was linked to a more pronounced attentional bias. Results are compared to existing studies and future implications are discussed.

Intergenerational transmission of trauma and its association with attitudes toward reconciliation.

OBJECTIVE: We aimed to investigate the link between mothers' posttraumatic stress disorder (PTSD) symptoms and their adult offspring's attitudes toward reconciliation and psychopathology among survivors of the 1994 genocide perpetrated against the Tutsi in Rwanda. We also sought to examine whether parenting styles mediate the relationship between mothers' PTSD symptoms and their adult offspring's psychopathology, if any. METHOD: Mother-child dyads (N = 181) were recruited in Rwanda and completed measures of trauma exposure, PTSD, depression, attitudes toward reconciliation, and parenting styles. RESULTS: Adult offspring of mothers who suffered from more severe PTSD symptoms had less favorable attitudes toward reconciliation, even after controlling for their own PTSD symptoms. Mothers' PTSD symptoms were not associated with their adult offspring's PTSD or depression symptoms. In addition, mothers' PTSD symptoms did not predict their parenting styles. CONCLUSIONS: These results suggest that the mental health of survivors of mass violence has repercussions on the intergroup attitudes of the following generation. This study has practical implications for sustainable peacebuilding in postconflict societies. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Affective States During the First Wave of the COVID-19 Pandemic: Progression of Intensity and Relation With Public Health Compliance Behavior.

The COVID-19 pandemic was expected to cause intense affective reactions. This situation provided a unique opportunity to examine the characteristics and correlates of emotions in a real-world context with great significance. Our study aimed to describe the progression of positive and negative affective states during the pandemic, and to investigate which affective states predicted compliance with public health measures. We undertook a survey of affective states in the province of Quebec at the beginning, the peak, and the aftermath of the first wave of the COVID-19 pandemic. We recruited 530 responders; 154 responded to all three surveys. We used self-report scales to measure affective states and compliance with public health measures. We then computed separate linear regressions for the three phases of our study, with compliance with health measures as the dependent variable. Affective states were generally most intense at the beginning of the pandemic. Fear-related pandemic-related affective states reliably predicted compliance with public health measures in the three phases of our study. Positively valenced affective states related to the societal response also contributed predictive value, but only at the peak of the first wave.

DLPFC controls the rapid neural response to visual threat: An ERP and rTMS study.

Individuals are faster at detecting threatening stimuli than neutral stimuli. While generally considered a rapid bottom-up response, this threat superiority effect is also modulated by top-down mechanisms known to rely on the dorsolateral prefrontal cortex (DLPFC). What remains unclear is whether the response is modulated only at later stages of processing, or whether rapid attention to threat itself is controlled in a top-down manner. To test this, we used repetitive transcranial magnetic stimulation (rTMS) to inhibit activity in the DLPFC, and measured EEG to index the immediate neural response to threat. Twenty participants attended two sessions where they performed a visual search task with threatening or neutral targets. Prior to this, they received 15 min of 1 Hz inhibitory or sham rTMS targeting the right DLPFC. We measured the impact of rTMS on the P1, a rapid visually-evoked potential that is modulated by attention. We found that threatening targets increased the amplitude of the P1 in the sham condition, but inhibition of the DLPFC abolished this increase. These results suggest that the neural signature of rapid attentional detection of threat, even at its earliest stage, is influenced in a top-down fashion by the right DLPFC.

Stressful Life Events Are Related to More Negative Interpretations, but Not Under Acute Stress.

Studies have identified deleterious effects of stress on multiple cognitive processes such as memory and attention. Little is known about the impact of stress on interpretation. We investigated how an induced acute stress and more long-term stress related to life events were associated with interpretations of ambiguous stimuli. Fifty participants answered a questionnaire indexing the number of stressful life events. A median split was used to compare those reporting few or more events. Half of participants performed an arithmetic task that induced acute stress; they were compared to a control group performing a less stressful task. We measured the interpretation of ambiguous visual stimuli, which participants had to judge as "negative" or "positive". We found a significant interaction between the number of stressful life events and the induced acute stress on the proportion of positive interpretations. In the control group, participants reporting more stressful events produced less positive interpretations than those reporting few events. In the induced stress condition, no significant difference was found. Life events tend to influence interpretation in the absence of an acute stressor, which seems to be more influent in the short term.

Disruption of working memory and contralateral delay activity by nociceptive stimuli is modulated by task demands.

ABSTRACT: Top-down processes allow the selection and prioritization of information by limiting attentional capture by distractors, and these mechanisms depend on task demands such as working memory (WM) load. However, bottom-up processes give salient stimuli a stronger neuronal representation and provoke attentional capture. The aim of this study was to examine the effect of salient nociceptive stimuli on WM while manipulating task demands. Twenty-one healthy participants performed a change detection task during which they had to determine whether 2 successive visual arrays were different or the same. Task demands were modulated by manipulating the WM load (set size included 2 or 4 objects to recall) and by the correspondence between the 2 successive visual arrays (change vs no change). Innocuous stimuli (control) or nociceptive stimuli (distractors) were delivered during the delay period between the 2 visual arrays. Contralateral delay activity and laser-evoked potentials were recorded to examine neural markers of visual WM and nociceptive processes. Nociceptive stimuli decreased WM performance depending on task demands (all P < 0.05). Moreover, compared with control stimuli, nociceptive stimuli abolished the increase in contralateral delay activity amplitude for set size 4 vs set size 2 (P = 0.04). Consistent with these results, laser-evoked potential amplitude was not decreased when task demands were high (P = 0.5). These findings indicate that WM may shield cognition from nociceptive stimuli, but nociceptive stimuli disrupt WM and alter task performance when cognitive resources become insufficient to process all task-relevant information.

Visual exploration in adults: Habituation, mere exposure, or optimal level of arousal?

Exploration is one of the most powerful behaviours that drive learning from infancy to adulthood. The aim of the current study was to examine the role of novelty and subjective preference in visual exploration. To do this, we combined a visual exploration task with a subjective evaluation task, presenting novel and familiar pictures. The first goal was to ascertain whether, as demonstrated in babies, short habituation favors visual exploration of familiarity, whereas longer habituation leads to an exploration of novelty. The second goal was to evaluate the influence of familiarization on participants' subjective evaluation of the stimuli. When presented with novel and very familiar stimuli, participants explored the novel stimuli more. In line with the optimal-level of arousal model, participants showed more positive evaluations of the semi-familiar stimuli compared with very familiar or very novel ones.

Alteration of early attentional processing after analogue trauma exposure: evidence from event-related potentials.

The present study aimed to determine whether exposure to an analogue traumatic event affects attentional processing of emotional information. Two groups of non-clinical participants matched on anxiety level, depression symptoms and stressful life events viewed either a trauma or a neutral film. They then performed an emotional Stroop task during which both continuous electroencephalographic activity was recorded and intrusive memories were measured. Results revealed that the valence effect (measured by the difference between emotional and neutral conditions) for the P1 amplitude was significantly greater in participants who viewed the trauma film than in participants who viewed the neutral film. This interaction was specific to words semantically related to the analogue trauma event and did not extend to all negative words. Further analyses revealed a relationship between intrusions frequency, P1 amplitude and emotional Stroop interference, indicating a link between attention and intrusive memories. Our findings suggest that exposure to potentially traumatic events has an important impact on neurocognitive function, even in the absence of psychopathology, and that this impact occurs at an early, possibly automatic stage of processing.

Perceptual processing of stimuli related to an analogue traumatic event: An ERP study.

Previous research has suggested that exposure to potentially traumatic events can lead to increased perceptual processing specific to trauma-related stimuli. Moreover, conceptual processing strategies during encoding may reduce the effect of trauma exposure on perceptual processing. The current study investigated the effect of a trauma film on perceptual processing with visual evoked potentials. Participants were primed with perceptual or conceptual processing strategies, then viewed a trauma film and a control film. Participants then looked at emotionally negative and neutral images that were related or unrelated to the films. The amplitude of the P1 evoked potential was measured during image presentation. P1 amplitude was more positive specifically for negative film-related stimuli. Moreover, this effect was stronger in participants primed with perceptual processing. These results suggest that potentially traumatic events increase perceptual processing specifically for trauma-related stimuli, and that conceptual encoding strategies attenuate the effect of exposure to potentially traumatic events on perception.

Exploring the mechanisms responsible for the modulating role of frowning in emotional reasoning: An ERP study.

Studies show that emotions impact reasoning, and that emotions are embodied. A recent study revealed that emotions embodied in facial expressions can modulate the impact of emotional content on reasoning accuracy. In the current study, we aimed to explore the mechanisms responsible for the impact of frowning on emotional reasoning using electrophysiology. We examined two reasoning-related ERPs: the N400 related to inference process and the N2 related to conflict detection. We also measured the LPP, associated with sustained attention to emotional stimuli. Twenty-six participants completed a reasoning task with emotional content while we recorded their brain activity with electroencephalography. In one block, they were instructed to solve syllogisms while voluntarily frowning. In another block, they were asked to solve syllogisms while contracting a non-facial muscle. Results revealed that frowning influenced sustained attention towards emotional stimuli, as measured through LPP. Frowning also showed a trend for a deleterious effect on the inference process measured through the N400. In line with the dual process models, this suggests that frowning impacts sustained attention, but surprisingly it might also impact Type 2 processes. This study provides useful insight regarding the link between reasoning and emotions in the body.

Reduction of Pain and Spinal Nociceptive Transmission by Working Memory is Load Dependant.

Working memory (WM) engagement produces pain inhibition. However, it remains unclear whether higher WM load increases this effect. The aim of this study was to investigate the interaction between WM load and pain inhibition by WM and examine the contribution of cerebrospinal mechanism. Thirty-eight healthy volunteers were assigned to one of 2 n-back groups for which WM load was different (2-back or 3-back). The experimental protocol comprised 5 counterbalanced conditions (0-back, n-back, pain, 0-back with pain, and n-back with pain). Pain and the nociceptive flexion reflex (NFR) were evoked by transcutaneous electrical stimulation of the sural nerve. Pain was significantly different between conditions, but not between n-back groups. Both the 0-back and n-back tasks reduced pain compared with pain alone, but the n-back task produced stronger pain inhibition compared with the 0-back task. NFR amplitude was significantly different between conditions but not between n-back groups. NFR was inhibited by the 0-back and n-back tasks, with no difference between the 2 tasks. These findings indicate that pain inhibition by WM is increased by WM load, but only to a certain point. NFR inhibition by WM suggests that inhibition of pain by WM depends, at least in part, on cerebrospinal mechanism. PERSPECTIVE: This behavioral and electrophysiological study shows that engaging in a cognitive task reduces pain by decreasing spinal nociceptive transmission, depending on task difficulty. These findings may yield better nonpharmacological pain therapies based on individual differences in working memory performance and capacity as well as several factors that regulate working memory.

Negative emotions influence EEG correlates of inference formation during analogical reasoning.

Previous research indicates that negative emotions influence cognitive resource utilization during analogical reasoning. However, no research has yet demonstrated an influence of negative emotions on inference formation during analogical reasoning. For this reason, we used evoked response potentials to investigate how negatively valenced content affects inference formation during analogical reasoning. Participants generated inferences about the missing term of 256 four-term analogies consisting of a first pair (A is to B), a second incomplete pair (as C is to?), and a probe term (D). We manipulated the affective valence of the terms (negative/neutral) forming the first two pairs and the soundness of the analogies. In Experiment 1, the terms were words and the relations were semantic in nature. We recorded the N400 event-related component time-locked to the probe term. The effect of analogy soundness on N400 amplitude was weaker when both pairs of terms were negative than when one or both pairs were neutral. In Experiment 2, we used analogies with negatively or neutrally conditioned symbols as terms, and visuospatial transformations as relations. We recorded the P3b event-related component time-locked to the final term of the analogy. The effect of analogy soundness on P3b amplitude was weaker when the first pair of terms was negatively conditioned than when they were neutrally conditioned. Results of both experiments suggested that negatively valenced content impairs the formation of inferences during analogical reasoning, as indicated by reduced effects of analogy soundness on N400 and P3b in the presence of negatively valenced content.

Impact of Music on Working Memory in Rwanda.

Previous research shows that listening to pleasant, stimulating and familiar music is likely to improve working memory performance. The benefits of music on cognition have been widely studied in Western populations, but not in other cultures. The purpose of this study was to explore the impact of music on working memory in a non-Western sociocultural context: Rwanda. One hundred and nineteen participants were randomly assigned to a control group (short story) or one of four different musical conditions varying on two dimensions: arousal (relaxing, stimulating) and cultural origin (Western, Rwandan). Working memory was measured using a behavioral task, the n-back paradigm, before and after listening to music (or the short story in the control condition). Unlike in previous studies with Western samples, our results with this Rwandan sample did not show any positive effect of familiar, pleasant and stimulating music on working memory. Performance on the n-back task generally improved from pre to post, in all conditions, but this improvement was less important in participants who listened to familiar Rwandan music compared to those who listened to unfamiliar Western music or to a short story. The study highlights the importance of considering the sociocultural context in research examining the impact of music on cognition. Although different aspects of music are considered universal, there may be cultural differences that limit the generalization of certain effects of music on cognition or that modulate the characteristics that favor its beneficial impact.

The psychological correlates of transitional justice in Rwanda: A long-term assessment.

OBJECTIVE: We tested the psychological correlates of the Gacaca tribunals, a massive program of transitional justice put in place by the Rwandan government following the 1994 genocide perpetrated against the Tutsi. METHOD: The sample consisted of 679 Rwandese participants, among which 373 (55%) were survivors of the genocide. We contrasted three groups of participants: (1) those who had never attended the Gacaca (N = 229), the control group, (2) those who had attended without testifying (N = 275), the attendance group, and (3) those who had attended and testified (N = 120), the testimony group. In the analyses, we controlled for the level of genocide-related negative consequences that participants reported. RESULTS: The attendance group presented lower levels of PTSD and depression symptoms than both the control and testimony groups. Both attendance and testimony groups had more positive opinions of the Gacaca and higher openness to reconciliation than the control group. CONCLUSIONS: contrary to what has been reported in two previous studies, participation in the Gacaca was not, in our data, negatively related to mental health or to social cohesion. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The impact of trauma exposure on explicit and implicit memory.

Objectives: The present study aimed to determine whether explicit and implicit memory systems are modulated by the type of content (neutral, emotional trauma-related and generally-emotional) in sexual abuse victims who did not develop PTSD, compared to non-exposed controls.Design: A mixed-factorial design with Content (neutral, trauma-related, generally-emotional) as a within-subject variable and Group (victims, controls) as a between-subject variable was used in two experiments.Methods: In both experiments, participants were required to learn three stories presented orally: a neutral, an emotional trauma-related (sexual abuse) and a generally-emotional story. In Experiment 1, participants' memory was tested with two explicit tasks (free recall and Remember/Know/Guess) and one implicit task (word-fragment completion task). In Experiment 2, a modified version of the word-fragment completion task was presented, followed by an awareness questionnaire to ensure the implicit character of the test.Results: Victims showed lower performances with neutral contents, relative to controls, in explicit and implicit tasks. However, this difference was not observed with trauma-related contents suggesting this information is preferentially processed by trauma-exposed participants (with increased attentional resources).Conclusions: Our results show that trauma exposure may itself be associated with implicit and explicit memory alterations, even for individuals who did not develop PTSD.

The local perceptual bias of a non-remote and educated population.

In 1977, Navon argued that perception is biased towards the processing of global as opposed to local visual information (or the forest before the trees) and implicitly assumed this to be true across places and cultures. Previous work with normally developing participants has supported this assumption except in one extremely remote African population. Here, we explore local-global perceptual bias in normally developing African participants living much less remotely than the African population tested previously. These participants had access to modern artefacts and education but presented with a local bias on a similarity-matching Navon task, contrary to Navon's assumptions. Nevertheless, the urban and more educated amongst these participants showed a weaker local bias than the rural and less educated participants, suggesting an effect of urbanicity and education in driving differences in perceptual bias. Our findings confirm the impact of experience on perceptual bias and suggest that differences in the impact of education and urbanicity on lifestyles around the world can result in profound differences in perceptual style. In addition, they suggest that local bias is more common than previously thought; a global bias might not be universal after all.

Is it dangerous? The role of an emotional visual search strategy and threat-relevant training in the detection of guns and knives.

Counter-terrorism strategies rely on the assumption that it is possible to increase threat detection by providing explicit verbal instructions to orient people's attention to dangerous objects and hostile behaviours in their environment. Nevertheless, whether verbal cues can be used to enhance threat detection performance under laboratory conditions is currently unclear. In Experiment 1, student participants were required to detect a picture of a dangerous or neutral object embedded within a visual search display on the basis of an emotional strategy 'is it dangerous?' or a semantic strategy 'is it an object?'. The results showed a threat superiority effect that was enhanced by the emotional visual search strategy. In Experiment 2, whilst trainee police officers displayed a greater threat superiority effect than student controls, both groups benefitted from performing the task under the emotional than semantic visual search strategy. Manipulating situational threat levels (high vs. low) in the experimental instructions had no effect on visual search performance. The current findings provide new support for the language-as-context hypothesis. They are also consistent with a dual-processing account of threat detection involving a verbally mediated route in working memory and the deployment of a visual template developed as a function of training.

Peritraumatic dissociation and post-traumatic stress disorder in individuals exposed to armed conflict in the Democratic Republic of Congo.

The purpose of this study was to verify the hypothesis that there is an association between peritraumatic dissociation (PD) and post-traumatic stress disorder (PTSD) in individuals exposed to recurrent armed conflict. More specifically, we sought to evaluate whether PD differentially predicts PTSD according to the degree of exposure to the potentially traumatic event (PTE), the level of education, and gender. A total of 120 individuals between 17 and 75 years of age, including 51 women, completed the Traumatic Events List, the Peritraumatic Dissociative Experiences Questionnaire, and the French version of the Posttraumatic Stress Disorder Checklist Scale, as well as a questionnaire providing information regarding sociodemographic details. The group of participants with high scores for PD had significantly more PTSD. PD differentially predicts PTSD depending on the level of education and gender of the individual. Those who had been physically assaulted and raped, as well as the less educated, were more likely to be dissociated during PTE· exposure compared to witnesses and those with a higher level of education. The primary target population for prevention and early management should comprise individuals with high levels of PD, low levels of education, and women.