Trauma films, information processing, and intrusive memory development

Three experiments indexed the effect of various concurrent tasks, while watching a traumatic film, on intrusive memory development. Hypotheses were based on the dual-representation theory of posttraumatic stress disorder (C. R. Brewin, T. Dalgleish, & S. Joseph, 1996). Nonclinical participants viewed a trauma film under various encoding conditions and recorded any spontaneous intrusive memories of the film over the following week in a diary. Changes in state dissociation, heart rate, and mood were also measured. As predicted, performing a visuospatial pattern tapping task at encoding significantly reduced the frequency of later intrusions, whereas a verbal distraction task increased them. Intrusive memories were largely unrelated to recall and recognition measures. Increases in dissociation and decreases in heart rate during the film were also associated with later intrusions.     

Reducing the vividness and emotional impact of distressing autobiographical memories: the importance of modality-specific interference

Experimental analogues of post-traumatic stress disorder suggest that loading the visuospatial sketchpad of working memory with a concurrent task reduces the vividness and associated distress of predominantly visual images. The present experiments explicitly tested the hypothesis that interfering with the phonological loop could analogously reduce the vividness and emotional impact of auditory images. In Experiment 1, 30 undergraduates formed non-specific images of emotive autobiographical memories while performing a concurrent task designed to load either the visuospatial sketchpad (eye movements) or phonological loop (articulatory suppression). Participants reported their images to be primarily visual, corresponding to the greater dual-task disruption observed for eye movements. Experiment 2 instructed participants to form specifically visual or auditory images. As predicted, concurrent articulation reduced vividness and emotional intensity ratings of auditory images to a greater extent than did eye movements, whereas concurrent eye movements reduced ratings of visual images much more than did articulatory suppression. Such modality-specific dual-task interference could usefully contribute to the treatment and management of intrusive distressing images in both clinical and non-clinical settings.     

Visuospatial over verbal demands in predicting Tower of London planning tasks

The role of verbal and visuospatial information processing in Tower of London (TOL) tasks was investigated. The first part of the investigation examined the verbal and visuospatial abilities and preferred cognitive style (visualizer vs. verbalizer) of 79 participants, in an inter-individual differences approach. Visuospatial abilities significantly predicted TOL performance, but the impact of cognitive style was negligible. The second part applied a dual-task manipulation of concurrent interference of TOL planning tasks on verbal and visuospatial memory, using the same participants. Concurrent processing of the TOL tasks diminished visuospatial memory performance considerably but had no effect on verbal memory, and there was no interaction between cognitive style and memory. These findings clearly underscore the role of visuospatial information processing in TOL tasks and indicate little bearing of verbal or visual cognitive style on TOL problem solving. These results have important implications for TOL and cognitive style in clinical application and cognitive neuroimaging research.     

Count out your intrusions: Effects of verbal encoding on intrusive memories

Peri-traumatic information processing is thought to affect the development of intrusive trauma memories. This study aimed to replicate and improve the study by Holmes, Brewin, and Hennessy (2004, Exp. 3) on the role of peri-traumatic verbal processing in analogue traumatic intrusion development. Participants viewed an aversive film under one of three conditions: counting backwards in 3s (“verbal interference”), verbalising emotions and thoughts (“verbal enhancement”), or without an extra task. A dual-process account of PTSD would predict that verbal interference would increase intrusion frequency compared to no task, whereas verbal enhancement would lead to a decrease. In contrast, mainstream memory theory predicts a decrease in intrusion frequency from any concurrent task that diverts attention away from the trauma film. The main finding was that the verbal interference task led to a decrease in intrusive memories of the film compared to the other two conditions. This finding does not support a dual-process account of PTSD, but is in line with general theories of memory and attention.     

Reducing depressive intrusions via a computerized cognitive bias modification of appraisals task: Developing a cognitive vaccine

A feature of depression is the distressing experience of intrusive, negative memories. The maladaptive appraisals of such intrusions have been associated with symptom persistence. This study aimed to experimentally manipulate appraisals about depressive intrusions via a novel computerized cognitive bias modification (CBM) of appraisals paradigm, and to test the impact on depressive intrusion frequency for a standardized event (a depressive film). Forty-eight participants were randomly assigned to either a session of positive or negative CBM. Participants then watched a depressing film (including scenes of bereavement and bullying) and subsequently monitored the occurrence of depressive intrusions related to the film in a diary for one week. At one-week follow-up, participants completed additional measures of intrusions – the Impact of Event Scale (IES) and an intrusion provocation task. As predicted, compared to the negative condition, participants who underwent positive CBM showed a more positive appraisal bias. Further, one week later, positive CBM participants reported fewer intrusions of the film and had lower IES scores. Our findings demonstrate that it is possible to manipulate maladaptive appraisals about depressive intrusions via a computerized CBM task. Further, this effect transfers to reducing intrusive symptomatology related to a standardized event (a depressive film) over one week, suggesting novel clinical implications.     

执行控制资源损耗对自传体记忆生动性和情绪的影响

旨在探究健康个体执行控制资源损耗对自传体记忆生动性及情绪的影响。实验一采用Stroop任务探讨了一般执行控制资源损耗的影响,结果发现损耗组自传体记忆生动性和情绪强度显著低于控制组。实验二进一步探讨不同的执行控制资源损耗的影响,结果显示中央执行的资源损耗对生动性和情绪强度影响最大,而视空间模板与语音环之间没有显著差异。实验结果支持了自传体记忆的执行控制资源受损理论和资源有限理论,并对临床治疗具有实际应用价值。     

Inducing and modulating intrusive emotional memories: a review of the trauma film paradigm

Highly affect-laden memory intrusions are a feature of several psychological disorders with intrusive images of trauma especially associated with post-traumatic stress disorder (PTSD). The trauma film paradigm provides a prospective experimental tool for investigating analogue peri-traumatic cognitive mechanisms underlying intrusion development. We review several historical papers and some more recent key studies that have used the trauma film paradigm. A heuristic diagram is presented, designed to simplify predictions about analogue peri-traumatic processing and intrusion development, which can also be related to the processing elements of recent cognitive models of PTSD. Results show intrusions can be induced in the laboratory and their frequency amplified/attenuated in line with predictions. Successful manipulations include competing task type (visuospatial vs. verbal) and use of a cognitive coping strategy. Studies show that spontaneous peri-traumatic dissociation also affects intrusion frequency although attempts to manipulate dissociation have failed. It is hoped that further use of this paradigm may lead to prophylactic training for at risk groups and an improved understanding of intrusions across psychopathologies.     

Planning sentences while doing other things at the same time: effects of concurrent verbal and visuospatial working memory load

This study investigated to what extent advance planning during sentence production is affected by a concurrent cognitive load. In two picture–word interference experiments in which participants produced subject–verb–object sentences while ignoring auditory distractor words, we assessed advance planning at a phonological (lexeme) and at an abstract–lexical (lemma) level under visuospatial or verbal working memory (WM) load. At the phonological level, subject and object nouns were found to be activated before speech onset with concurrent visuospatial WM load, but only subject nouns were found to be activated with concurrent verbal WM load, indicating a reduced planning scope as a function of type of WM load (Experiment 1). By contrast, at the abstract–lexical level, subject and object nouns were found to be activated regardless of type of concurrent load (Experiment 2). In both experiments, sentence planning had a more detrimental effect on concurrent verbal WM task performance than on concurrent visuospatial WM task performance. Overall, our results suggest that advance planning at the phonological level is more affected by a concurrently performed verbal WM task than advance planning at the abstract–lexical level. Also, they indicate an overlap of resources allocated to phonological planning in speech production and verbal WM.     

Contextual cueing under working memory load: Selective interference of visuospatial load with expression of learning

In a series of experiments, we investigated the dependence of contextual cueing on working memory resources. A visual search task with 50 % repeated displays was run in order to elicit the implicit learning of contextual cues. The search task was combined with a concurrent visual working memory task either during an initial learning phase or a later test phase. The visual working memory load was either spatial or nonspatial. Articulatory suppression was used to prevent verbalization. We found that nonspatial working memory load had no effect, independent of presentation in the learning or test phase. In contrast, visuospatial load diminished search facilitation in the test phase, but not during learning. We concluded that visuospatial working memory resources are needed for the expression of previously learned spatial contexts, whereas the learning of contextual cues does not depend on visuospatial working memory.     

Grasping objects by their handles: a necessary interaction between cognition and action

Research has illustrated dissociations between "cognitive" and "action" systems, suggesting that different representations may underlie phenomenal experience and visuomotor behavior. However, these systems also interact. The present studies show a necessary interaction when semantic processing of an object is required for an appropriate action. Experiment 1 demonstrated that a semantic task interfered with grasping objects appropriately by their handles, but a visuospatial task did not. Experiment 2 assessed performance on a visuomotor task that had no semantic component and showed a reversal of the effects of the concurrent tasks. In Experiment 3, variations on concurrent word tasks suggested that retrieval of semantic information was necessary for appropriate grasping. In all, without semantic processing, the visuomotor system can direct the effective grasp of an object, but not in a manner that is appropriate for its use.     

Selective Association Between Tetris Game Play and Visuospatial Working Memory: A Preliminary Investigation

Recent experimental and clinical research has suggested that Tetris game play can disrupt maladaptive forms of mental imagery because Tetris competes for limited cognitive resources within visuospatial working memory (WM) that contribute to imagery. Whether or not Tetris performance is selectively associated with visuospatial WM remains to be tested. In this study, young adults (N = 46) completed six standardized measures indexing verbal and non‐verbal reasoning, verbal and visuospatial short‐term memory, and verbal and visuospatial WM. They also played Tetris. Consistent with the hypothesis that visuospatial WM resources support Tetris game play, there was a significant moderate positive relationship between Tetris scores and visuospatial WM performance but no association with other cognitive ability measures. Findings suggest that Tetris game play involves both storage and processing resources within visuospatial WM. These preliminary results can inform interventions involving computer games to disrupt the development of maladaptive visual imagery, for example, intrusive memories of trauma. © 2017 The Authors. Applied Cognitive Psychology Published by John Wiley & Sons Ltd.     

Working memory and individual differences in the encoding of vertical, horizontal and diagonal symmetry

Previous studies, using a modified version of the sequential Corsi block task to examine the impact of symmetry on visuospatial memory, showed an advantage of vertical symmetry over non-symmetrical sequences, but no effect of horizontal or diagonal symmetry. The present four experiments investigated the mechanisms underlying the encoding of vertical, horizontal and diagonal configurations using simultaneous presentation and a dual-task paradigm. Results indicated that the recall of vertically symmetric arrays was always better than that of all other patterns and was not influenced by any of the concurrent tasks. Performance with horizontally or diagonally symmetrical patterns differed, with high performing participants showing little effect of concurrent tasks, while low performers were disrupted by concurrent visuospatial and executive tasks. A verbal interference had no effect on either group. Implications for processes involved in the encoding of symmetry are discussed, together with the crucial importance of individual differences.     

Asymmetric interference between domains: evidence from the stimulus order effect in complex span tasks

The stimulus order effect refers to the finding that recall in complex span tasks is better when span lists begin with a longer processing task and end with a shorter task than when these processing tasks are presented in the reverse order. This study independently manipulated processing time and processing difficulty between Long-final and Short-final lists. The processing task required participants to solve arithmetic problems with either verbal (Experiment 1) or visuospatial (Experiment 2) materials. The memory items used in the storage task were either digits (verbal material) or dots-in-matrices (visuospatial materials). Storage of both verbal and visuospatial materials was sensitive to the change in processing difficulty, but not processing time. Furthermore, this study provides further evidence for the asymmetry of domain interference in working memory. The similarities and differences between verbal and visuospatial storage in working memory are discussed.     

The role of working memory in the association between number magnitude and space

In two experiments, participants performed a magnitude comparison task in single and dual-task conditions. In the dual conditions, the comparison task was accomplished while phonological or visuospatial information had to be maintained for a later recall test. The results showed that the requirement of maintaining visuospatial information produced the lack of spatial-numerical association of response codes (SNARC) effect. The SNARC effect was not found even when the performance in the comparison task did not decline, as indicated by a similar distance effect in all conditions. These results show a special role for the visuospatial component of working memory in the processing of spatial representation of numbers and an interesting dissociation between SNARC and distance effects.     

The nature and position of processing determines why forgetting occurs in working memory tasks

The effect of potentially distracting processing within working memory was examined by varying the nature and position of processing across conditions of a Brown-Peterson-like task. Separate groups of participants carried out verbal or visuospatial processing operations on identical stimuli, while retaining lists of to-be-remembered words. The number of words presented either before or after the processing interval was varied systematically. Results showed that although verbal processing was no more demanding than visuospatial processing, it led to greater forgetting. However, forgetting was confined to items presented prior to processing, and the difference in degree of forgetting shown by the two groups was maximal when four items occurred before processing. Temporal isolation effects were more marked in the verbal processing group. These findings indicate that individuals can keep active a limited number of items in primary memory during processing, unless processing blocks rehearsal, in which case retrieval occurs from secondary memory.     

“Why” or “How”: The Effect of Concrete Versus Abstract Processing on Intrusive Memories Following Analogue Trauma

Emergency service workers, military personnel, and journalists working in conflict zones are regularly exposed to trauma as part of their jobs and suffer higher rates of posttraumatic stress compared with the general population. These individuals often know that they will be exposed to trauma and therefore have the opportunity to adopt potentially protective cognitive strategies. One cognitive strategy linked to better mood and recovery from upsetting events is concrete information processing. Conversely, abstract information processing is linked to the development of anxiety and depression. We trained 50 healthy participants to apply an abstract or concrete mode of processing to six traumatic film clips and to apply this mode of processing to a posttraining traumatic film. Intrusive memories of the films were recorded for 1 week and the Impact of Events Scale–Revised (IES-R; Weiss & Marmar, 1997) was completed at 1-week follow-up. As predicted, participants in the concrete condition reported significantly fewer intrusive memories in response to the films and had lower IES-R scores compared with those in the abstract condition. They also showed reduced emotional reactivity to the posttraining film. Self-reported proneness to intrusive memories in everyday life was significantly correlated with intrusive memories of the films, whereas trait rumination, trait dissociation, and sleep difficulties were not. Findings suggest that training individuals to adopt a concrete mode of information processing during analogue trauma may protect against the development of intrusive memories.     

Electrophysiological evidence of central interference in the control of visuospatial attention

Visuospatial attention can be deployed to different locations in space without movement of the eyes. A large body of human electrophysiological studies reveals enhanced sensory-perceptual responses to stimuli that appear at an attended location. However, it is not clear that the mechanisms that underlie visuospatial attention are under the control of attention mechanisms that limit central processing in multiple-task situations. We investigated this question by incorporating a visual task that required the deployment of visuospatial attention as the second task of psychological refractory period (PRP) dual-task paradigms. The N2pc component of the event-related potential was used as an electrophysiological index of the moment-by-moment deployment of visuospatial attention to monitor when and where observers were attending while they performed concurrent central processing known to cause the PRP effect. Electrophysiological evidence shows that central processing interfered with the N2pc, suggesting that visuospatial attention is under the control of capacity-limited central mechanisms.     

Imagery-inducing distraction leads to cognitive tunnelling and deteriorated driving performance

The effects of imagery-induced distraction on hazard perception and eye movements were investigated in 2 simulated driving experiments. Experiment 1: sixty participants viewed and responded to 2 driving films containing hazards. Group 1 completed the task without distraction; group 2 completed a concurrent imagery inducing telephone task; group 3 completed a non imagery inducing telephone task. Experiment 2: eye-tracking data were collected from forty-six participants while they reacted to hazards presented in 16 films of driving scenes. 8 films contained hazards presented in either central or peripheral vision and 8 contained no hazards. Half of the participants performed a concurrent imagery-inducing task. Compared to undistracted participants, dual-taskers were slower to respond to hazards; detected fewer hazards; committed more “looked but failed to see” errors; and demonstrated “visual tunnelling”. Telephone conversations may interfere with driving performance because the two tasks compete for similar processing resources, due to the imagery-evoking aspects of phone use.     

Preferential processing of visual trauma-film reminders predicts subsequent intrusive memories

This study used an analogue design to test the hypothesis that preferential processing of visual trauma reminders in the aftermath of a stressful or traumatic event gives rise to subsequent intrusive memories. Shortly after the presentation of a stressful film fragment, participants (n=36) were asked to detect neutral targets (rotated buildings or nature scenes) in a single target rapid serial visual presentation (RSVP) paradigm. During half of the streams, the target was preceded by a distracter. The distracters consisted of visual images extracted from an earlier presented stressful film (e.g., persons and objects that figured in the film). The degree of interference by these film reminders predicted subsequent intrusions recorded in a one-week diary. The results provide evidence that a deficient ability to obtain attentional control over perceptual “trauma” reminders during goal-directed behaviour may set people at risk for persistent intrusive memories. Implications for research investigating attentional bias and intrusive memories in context of posttraumatic stress disorder (PTSD) are discussed.     

Tell me more: Can a memory test reduce analogue traumatic intrusions?

Information processing theories of post-traumatic stress disorder (PTSD) state that intrusive images emerge due to a lack of integration of perceptual trauma representations in autobiographical memory. To test this hypothesis experimentally, participants were shown an aversive film to elicit intrusive images. After viewing, they received a recognition test for just one part of the film. The test contained neutrally formulated items to rehearse information from the film. Participants reported intrusive images for the film in an intrusion diary during one week after viewing. In line with expectations, the number of intrusive images decreased only for the part of the film for which the recognition test was given. Furthermore, deliberate cued-recall memory after one week was selectively enhanced for the film part that was in the recognition test a week before. The findings provide new evidence supporting information processing models of PTSD and have potential implications for early interventions after trauma.