Cognitive distortions in recovered burn patients: the emotional Stroop task and autobiographical memory test

Researches on cognitive sequelae of burn injury: Current status and advances

Burn injury is a devastating disease with high incidence of disability and mortality. The cognitive dysfunctions, such as memory defect, are the main neurological sequelae influencing the life quality of burn-injured patients. The post-burn cognitive dysfunctions are related to the primary peripheral factors and the secondary cerebral inflammation, resulting in the destruction of blood-brain barrier (BBB), as is shown on Computed Tomography (CT) and magnetic resonance imaging examinations. As part of the neurovascular unit, BBB is vital to the nutrition and homeostasis of the central nervous system (CNS) and undergoes myriad alterations after burn injury, causing post-burn cognitive defects. The diagnosis and treatment of cognitive dysfunctions as burn injury sequelae are of great importance. In this review, we address the major manifestations and interventions of post-burn cognitive defects, as well as the mechanisms involved in memory defect, including neuroinflammation, destruction of BBB, and hormone imbalance.

Association of attention and memory biases for negative stimuli with post-traumatic stress disorder symptoms

Cognitive models have highlighted the role of attentional and memory biases towards negatively-valenced emotional stimuli in the maintenance of post-traumatic stress disorder (PTSD). However, previous research has focused mainly on attentional biases towards distracting (task-irrelevant) negative stimuli. Furthermore, attentional and memory biases have been examined in isolation and the links between them remain underexplored. We manipulated attention during encoding of trauma-unrelated negative and neutral words and examined the differential relationship of their encoding and recall with PTSD symptoms. Responders to the World Trade Center disaster (N = 392) performed tasks in which they read negative and neutral words and reported the color of another set of such words. Subsequently, participants used word stems to aid retrieval of words shown earlier. PTSD symptoms were associated with slower response times for negative versus neutral words in the word-reading task (r = 0.170) but not color-naming task. Furthermore, greater PTSD symptom severity was associated with more accurate recall of negative versus neutral words, irrespective of whether words were encoded during word-reading or color-naming tasks (F = 4.11, p = 0.044, η_p² = 0.018). Our results show that PTSD symptoms in a trauma-exposed population are related to encoding of trauma-unrelated negative versus neutral stimuli only when attention was voluntarily directed towards the emotional aspects of the stimuli and to subsequent recall of negative stimuli, irrespective of attention during encoding.

Development of delirium: Association with old age, severe burns, and intensive care

BACKGROUND

Delirium is defined as a disturbance of attention and awareness that develops over a short period of time, is a change from the baseline, and typically fluctuates over time. Burn care involves a high prevalence of known risk factors for delirium such as sedation, inflammation, and prolonged stay in hospital. Our aim was to explore the extent of delirium and the impact of factors associated with it for adult patients who have been admitted to hospital with burns.

METHODS

In this retrospective study, all adult patients who had been admitted with burns during a four-year period were studied, including both those who were treated with intensive care and intermediate care only (no intensive care). Daily records of the assessment of delirium using the Nursing Delirium Screening Scale (Nu-DESC) were analysed together with age, sex, the percentage of total body surface area burned, operations, and numbers of wound care procedures under anaesthesia, concentrations of plasma C-reactive protein, and other clinical variables. Logistic regression was used to analyse factors that were associated with delirium and its effect on mortality, and linear regression was used to analyse its effect on the duration of hospital stay.

RESULTS

Fifty-one patients (19%) of the total 262 showed signs of delirium (Nu-DESC score of 2 or more) at least once during their stay in hospital. Signs of delirium were recorded in 42/89 patients (47%) who received intensive care, and in 9/173 (5%) who had intermediate care. Independent factors for delirium in the multivariable regression were: age over 74 years; number of operations and wound care procedures under anaesthesia; and the provision of intensive care (area under the curve 0.940, 95% CI 0.899-0.981). Duration of hospital stay, adjusted for age and burn size, was 13.2 (95% CI 7.4-18.9, p < 0.001) days longer in the group who had delirium. We found no independent effects of delirium on mortality.

CONCLUSION

We found a strong association between delirium and older age, provision ofr intensive care, and number of interventions under anaesthesia. A further 5% of patients who did not receive intensive care also showed signs of delirium, which is a finding that deserves to be thoroughly investigated in the future.

Use of an estradiol-based combined oral contraceptives has no influence on attentional bias or depressive symptoms in healthy women

Combined oral contraceptive (COC) use is associated with small, albeit significant, increases in mental symptom scores, predominantly irritability, depressed mood, and anxiety. Yet, randomized prospective trials are needed to better characterize the women at risk for COC-induced negative mood change. Thus, the primary aim of this sub-study to a placebo-controlled randomized trial was to determine whether COC use influences emotional interference by negative and positive stimuli. Secondly, we wanted to evaluate what factors would predict depressive symptoms at the end of the trial, taking personality factors, history of mental disorders and other demographic factors into account. Sixty-nine women were included, randomized to three cycles of treatment with a COC (1.5 mg estradiol and 2.5 mg nomegestrolacetate) or placebo. An emotional verbal Stroop task was used to measure interference of emotional stimuli, in which participants were asked to only name the color of a presented word, while ignoring the meaning of the word. Four different word categories were used; neutral, positive, depression, and anxiety. For the second aim of the study, rating on the Montgomery-Åsberg Depression Rating Scale during the final days of the trial was used as outcome. We found no interaction between emotional verbal Stroop word category and treatment, indicating that COC treatment did not evoke any differences in emotional interference to the three word categories. Significant predictors for depressive symptoms at the end of the trial were trait anxiety at baseline and prior adverse mood effects by hormonal contraceptive use. Treatment (i.e. whether women had been treated with the COC or placebo) did not play a role in predicting depression scores at the end of the trial. In conclusion, we found no evidence that combined oral contraceptive use is associated with impaired cognitive-emotional processing. Instead, the main predictors of self-rated depression at the end of the trial were baseline trait anxiety and previous mental symptoms during hormonal contraceptive use.

Meta-Analysis of the Association Between Autobiographical Memory Specificity and Exposure to Trauma

Cognitive models of emotional disorders suggest that reduced autobiographical memory specificity that results from exposure to traumatic events may play an important role in the aetiology and maintenance of these disorders. However, there has yet to be a comprehensive meta-analysis of the association between trauma exposure and memory specificity, and the role of posttraumatic stress symptoms on this association. We searched PsycINFO and MEDLINE databases and extracted data from studies regarding the mean number or proportion of specific memories that participants with and without trauma exposure recalled on the Autobiographical Memory Test. We also extracted data on differences between groups in terms of posttraumatic stress and depressive symptoms, along with data on trauma timing and participants' ages at the time of assessment. The effect size of memory specificity between participants with and without exposure to trauma was large, d = 0.77, and differed significantly from zero, p < .001. In metaregression, trauma timing was a significant predictor of the heterogeneity in trauma-exposure specificity effect sizes, but posttraumatic stress and depressive symptoms were not. Compromised memory specificity represents an important cognitive consequence of trauma exposure that might have an important influence on risk for, and maintenance of, subsequent emotional pathologies.

Do Tonic Itch and Pain Stimuli Draw Attention towards Their Location?

BACKGROUND

Although itch and pain are distinct experiences, both are unpleasant, may demand attention, and interfere with daily activities. Research investigating the role of attention in tonic itch and pain stimuli, particularly whether attention is drawn to the stimulus location, is scarce.

METHODS

In the somatosensory attention task, fifty-three healthy participants were exposed to 35-second electrical itch or pain stimuli on either the left or right wrist. Participants responded as quickly as possible to visual targets appearing at the stimulated location (ipsilateral trials) or the arm without stimulation (contralateral trials). During control blocks, participants performed the visual task without stimulation. Attention allocation at the itch and pain location is inferred when responses are faster ipsilaterally than contralaterally.

RESULTS

Results did not indicate that attention was directed towards or away from the itch and pain location. Notwithstanding, participants were slower during itch and pain than during control blocks.

CONCLUSIONS

In contrast with our hypotheses, no indications were found for spatial attention allocation towards the somatosensory stimuli. This may relate to dynamic shifts in attention over the time course of the tonic sensations. Our secondary finding that itch and pain interfere with task performance is in-line with attention theories of bodily perception.

Different patterns of attentional bias in antenatal and postpartum depression

BACKGROUND

Biased information processing in attention, memory, and interpretation is proposed to be central cognitive alterations in patients with major depressive disorder, but studies in women with peripartum depression are scarce. Because of the many similarities with depression in nonperipartum states as regards symptom profile and risk factors, we hypothesized that women with antenatal and postpartum depression would display attentional bias to negatively and positively valenced words.

METHODS

One hundred and seventy-seven pregnant and 157 postpartum women were included. Among these, 40 suffered from antenatal depressive disorder and 33 from postpartum depressive disorder. An emotional Stroop task with neutral, positive, negative, and negatively valenced obstetric words was used.

RESULTS

No significant difference in emotional interference scores was noted between women with antenatal depression and nondepressed pregnant women. In contrast, women with postpartum depression displayed shorter reaction times to both positive (p = .028) and negative (p = .022) stimuli, compared with neutral words. Pregnant women on antidepressant treatment displayed longer reaction times to negatively valenced obstetric words in comparison with untreated depressed women (p = .012), and a trend toward greater interference in comparison with controls (p = .061).

CONCLUSIONS

In contrast with the hypothesis, we found no evidence of attentional bias to emotionally valenced stimuli in women with untreated peripartum depression. However, the shorter reaction times to emotional stimuli in women with postpartum depression may indicate emotional numbing, which in turn, is a functional impairment that may have repercussions for child development and well-being. Our findings emphasize the need to identify and treat women with postpartum depression at the earliest possible time point to ensure swift recovery and support for the family.

Attentional processing of itch

Itch is a prevalent somatosensory symptom that can be highly disabling, because it is likely to draw attention and, as a result, may interfere with the performance of daily activities. Yet, research experimentally investigating attention to itch is lacking. In this study we aimed to investigate attentional processing of itch using multiple behavioral attention tasks. Forty-one healthy participants performed (1) a modified Stroop task with itch-related words, (2) a dot-probe task with itch-related pictures, and (3) a recently developed somatosensory attention task in which the effect of experimentally induced itch on the localization of visual targets was examined. Additionally, a number of self-report questionnaires related to somatosensory attentional processing were administered. Results indicated that participants’ attention was biased toward itch-related words and pictures assessed by means of the dot-probe and modified Stroop task, respectively. For the somatosensory attention task, results showed that itch did not significantly influence the allocation of attention. However, when taking into account the time course of attention during the itch stimulus, data suggested that participants tended to disengage attention away during the itch stimulus. This is the first study that indicates an attentional bias for itch, using methods that have previously been validated for other sensations such as pain. In addition, the newly developed somatosensory attention task may reflect the time course of attention toward a tonic itch stimulus.

Modification of cognitive biases related to posttraumatic stress: A systematic review and research agenda

Cognitive models of Posttraumatic Stress Disorder (PTSD) postulate that cognitive biases in attention, interpretation, and memory represent key factors involved in the onset and maintenance of PTSD. Developments in experimental research demonstrate that it may be possible to manipulate such biases by means of Cognitive Bias Modification (CBM). In the present paper, we summarize studies assessing cognitive biases in posttraumatic stress to serve as a theoretical and methodological background. However, our main aim was to provide an overview of the scientific literature on CBM in (analogue) posttraumatic stress. Results of our systematic literature review showed that most CBM studies targeted attentional and interpretation biases (attention: five studies; interpretation: three studies), and one study modified memory biases. Overall, results showed that CBM can indeed modify cognitive biases and affect (analog) trauma symptoms in a training congruent manner. Interpretation bias procedures seemed effective in analog samples, and memory bias training proved preliminary success in a clinical PTSD sample. Studies of attention bias modification provided more mixed results. This heterogeneous picture may be explained by differences in the type of population or variations in the CBM procedure. Therefore, we sketched a detailed research agenda targeting the challenges for CBM in posttraumatic stress.

Impact of Cognition on Burn Inpatient Rehabilitation Outcomes

BACKGROUND

A significant proportion of burn injury patients are admitted to inpatient rehabilitation facilities (IRFs). There is increasing interest in the use of functional variables, such as cognition, in predicting IRF outcomes. Cognitive impairment is an important cause of disability in the burn injury population, yet its relationship to IRF outcomes has not been studied.

OBJECTIVE

To assess how cognitive function affects rehabilitation outcomes in the burn injury population.

DESIGN

Retrospective study.

SETTING

Inpatient rehabilitation facilities in the United States.

PARTICIPANTS

A total of 5347 adults admitted to an IRF with burn injury between 2002 and 2011.

METHODS OR INTERVENTIONS

Multivariable regression was used to model rehabilitation outcome measures, using the cognitive domain of the Functional Independence Measure (FIM) instrument as the independent variable and controlling for demographic, medical, and facility covariates.

MAIN OUTCOME MEASUREMENTS

FIM total gain, readmission to an acute care setting at any time during inpatient rehabilitation, readmission to an acute care setting in the first 3 days of IRF admission, rate of discharge to the community setting, and length of stay efficiency.

RESULTS

Cognitive FIM total at admission was a significant predictor of FIM total gain, length of stay efficiency, and acute readmission at 3 days (P < .05). Cognitive FIM total scores did not have an impact on acute care readmission rate or discharge to the community setting.

CONCLUSIONS

Cognitive status may be an important predictor of rehabilitation outcomes in the burn injury population. Future work is needed to further examine the impact of specific cognitive interventions on rehabilitation outcomes in this population.

LEVEL OF EVIDENCE

II.

Fear-avoidance in Recovered Burn Patients: Association with Psychological and Somatic Symptoms

Fear-avoidance, an important model in the understanding of chronic pain, has not yet been studied in patients with burns. The purpose of this study was to investigate if recovered burn patients have fear-avoidance beliefs and to explore the association with psychological and somatic symptoms. Eighty-four recovered burn patients completed self-report questionnaires. The results showed that there were fear-avoidance beliefs, but not to a large extent. Beta coefficients from multiple regression analyses indicated a strong association between fear-avoidance and problems with work, heat sensitivity and arousal symptoms. The model was capable of explaining 73 per cent of the variance in fear-avoidance beliefs.

Autobiographical memory specificity in patients with tinnitus versus patients with depression and normal controls

Several studies show that patients with depression and post-traumatic stress disorder respond with fewer specific autobiographical memories in a cued memory task (i.e. the autobiographical memory test; AMT) compared to healthy controls. One previous study found this phenomenon among tinnitus patients as well (Andersson, Ingerholt, & Jansson, 2003). The aim of this study was to replicate the previous study with an additional control group of depressed patients and memory errors as measured with the AMT as an additional outcome. We included 20 normal hearing tinnitus patients, 20 healthy controls and 20 persons diagnosed with clinical depression. The AMT was administered together with self-report measures of depression, anxiety and tinnitus distress. Both the tinnitus and depression groups differed from the healthy control group in that they reported fewer specific autobiographical memories. There were, however, differences between the tinnitus and depression groups in terms of the errors made on the AMT. The depression group had more overgeneral memories than the normal control group, whereas the tinnitus group did not differ from the control group on this memory error. The tinnitus group had more semantic associations and non-memories than the other two groups, suggesting that executive functioning may play a role for the tinnitus group when completing the AMT. Clinical and theoretical implications of the findings are discussed.

Autobiographical memory specificity in child sexual abuse victims

The present study examined the specificity of autobiographical memory in adolescents and adults with versus without child sexual abuse (CSA) histories. Eighty-five participants, approximately half of whom per age group had experienced CSA, were tested on the autobiographical memory interview. Individual difference measures, including those for trauma-related psychopathology, were also administered. Findings revealed developmental differences in the relation between autobiographical memory specificity and CSA. Even with depression statistically controlled, reduced memory specificity in CSA victims relative to controls was observed among adolescents but not among adults. A higher number of posttraumatic stress disorder criteria met predicted more specific childhood memories in participants who reported CSA as their most traumatic life event. These findings contribute to the scientific understanding of childhood trauma and autobiographical memory functioning and underscore the importance of considering the role of age and degree of traumatization within the study of autobiographical memory.

Guidelines for vocational evaluation following burns: integrated review of relevant process and factors

PURPOSE

A systematic literature review was undertaken to gather evidence to develop a guideline for vocational evaluation following burn injuries (BI). This review aimed to identify the key processes evaluators should follow and the key factors they should consider when completing such evaluations.

METHODS

Steps outlined in Cochrane Handbook of Systematic Review were followed including: development of review question; search strategies and selection criteria; quality appraisal; data extraction; analysis & synthesis; drawing conclusions. Four databases (Pubmed, Medline, CINHAL, PsycINFO) and 14 websites were searched for relevant articles and studies (quantitative, qualitative), reviews and guidelines. Two reviewers independently completed reviews, performed quality assessments and extracted data into evidence tables. Using the ICF model and directed content analysis, key processes and factors were analyzed and synthesized across the evidence.

RESULTS

A total of 138 articles were identified using the key words (e.g. burns, work). Studies, reviews and guidelines were retrieved if they focused on adults and discussed the processes relevant to vocational evaluation and/or factors associated with successful return to work (RTW) following a BI. Items were excluded if they did not address adults who had suffered a burn, the process of work or RTW, or challenges related to work after a BI. Using the above criteria 76 items were retrieved for full review. Fifty-six items remained after the quality appraisal. Results were integrated to develop the Evidence-based Framework for Vocational Evaluation Following Burn Injury.

CONCLUSIONS

This framework outlines 7 key processes relevant to vocational evaluation following burn injuries.

A computerized Stroop task to assess cancer-related cognitive biases

Biases in processing information related to sources of stress have widely been demonstrated with the use of Stroop emotional color word tasks. One study reported such biases among women with histories of breast cancer in a first-degree relative (FH+) who were given a Stroop cancer word task. This study aimed to replicate and extend these findings with a computerized version of the task. Response latencies and errors were recorded during administration of the task to FH+ and FH- women. A cancer list and 5 comparison lists were administered. Results indicated that FH+ women exhibited longer response latencies for cancer words than did FH- women (p < 0.04), providing further support for cognitive biases in FH+ women. Confirming the psychometric properties of the task, lists exhibited high reliability for both latency (alphas 0.96-0.98) and error rate (alphas 0.61-0.79). In sum, results support the favorable psychometrics and predictive validity of the Stroop cancer word task.

Attentional bias and symptoms of posttraumatic stress disorder one year after burn injury

Trauma-related attentional bias is suggested to play a role in maintaining posttraumatic stress disorder (PTSD). Although being burn injured is a traumatic event for many patients, there are no prospective studies investigating attentional bias. The aims were to assess burn-specific attentional bias 1 year after burn, and its associations with risk factors for PTSD and symptoms of PTSD. A total of 38 adult patients with burns were assessed with a structured clinical interview and a Swedish version of the Impact of Event Scale-Revised up to 1-year after burn. The Emotional Stroop Task was used to assess attentional bias 1 year after burn. In total 29 participants displayed burn-specific attentional bias. This group had more previous life events, perceived life threat, larger burns, and higher PTSD symptom severity. In conclusion, the majority of the patients had burn-specific attentional bias 1 year after burn and this was related to symptoms of PTSD.

Overgeneral autobiographical memory and traumatic events: an evaluative review

Does trauma exposure impair retrieval of autobiographical memories? Many theorists have suggested that the reduced ability to access specific memories of life events, termed overgenerality, is a protective mechanism helping attenuate painful emotions associated with trauma. The authors addressed this question by reviewing 24 studies that assessed trauma exposure and overgenerality, examining samples with posttraumatic stress disorder, acute stress disorder, depression, traumatic event exposure, and other clinical disorders. Limitations are discussed, including variations in assessment of events, depression, and overgenerality and the need for additional comparison groups. Across studies, there was no consistent association between trauma exposure and overgenerality, suggesting that trauma exposure is unlikely to be the primary mechanism leading to overgenerality. Instead, psychopathology factors such as depression and posttraumatic stress appear to be more consistently associated with overgenerality. Alternative overgenerality theories may help identify key overgenerality mechanisms, improving current understanding of autobiographical memory processes underlying psychopathology.

Autobiographical memory specificity and emotional disorder

The authors review research showing that when recalling autobiographical events, many emotionally disturbed patients summarize categories of events rather than retrieving a single episode. The mechanisms underlying such overgeneral memory are examined, with a focus on M. A. Conway and C. W. Pleydell-Pearce's (2000) hierarchical search model of personal event retrieval. An elaboration of this model is proposed to account for overgeneral memory, focusing on how memory search can be affected by (a) capture and rumination processes, when mnemonic information used in retrieval activates ruminative thinking; (b) functional avoidance, when episodic material threatens to cause affective disturbance; and (c) impairment in executive capacity and control that limits an individual's ability to remain focused on retrieval in the face of distraction.

The effect of burn injury on adolescents autobiographical memory

Autobiographical memory recall was investigated in two female adolescent groups; one group who had experienced a burn injury and a matched control group. The Burn group was not currently depressed or anxious, but scored significantly higher on the intrusion subscale of the impact of event scale compared to controls. Two autobiographical memory tasks, the autobiographical memory cueing task and the Children's Autobiographical Memory Inventory (CAMI), were used. For the cueing task, the Burn group was significantly slower to recall specific memories. This group also recalled significantly fewer specific memories and significantly more extended overgeneral memories. For the CAMI, the burns group produced significantly lower semantic and episodic recall. The Burn group also produced significant correlations between sub-scales of the impact of event scale and selected measures on the autobiographical memory tasks. Higher intrusion scores were associated with less detailed episodic recall. Higher avoidance scores were associated with longer latencies to recall memories to negative cue words and fewer specific memories to all cue words. These results are discussed from the perspective that the Burn group experienced intrusive thoughts which interfered with normal autobiographical functioning.