Kate Tchanturia

A systematic review and meta-analysis of set-shifting ability in eating disorders

BACKGROUND The aim was to critically appraise and synthesize the literature relating to set-shifting ability in eating disorders. PsycINFO, Medline, and Web of Science databases were searched to December 2005. Hand searching of eating-disorder journals and relevant reference sections was also undertaken. METHOD The 15 selected studies contained both eating disorder and healthy control groups, and employed at least one of the following six neuropsychological measures of set-shifting ability; Trail Making Test (TMT), Wisconsin Card Sort Test (WCST), Brixton task, Haptic Illusion, CatBat task, or the set-shifting subset of the Cambridge Neuropsychological Test Automated Battery (CANTAB). The outcome variable was performance on the set-shifting aspect of the task. Pooled standardized mean differences (effect sizes) were calculated. RESULTS TMT, WCST, CatBat and Haptic tasks had sufficient sample sizes for meta-analysis. These four tasks yielded acceptable pooled standardized effect sizes (0.36; TMT -1.05; Haptic) with moderate variation within studies (as measured by confidence intervals). The Brixton task showed a small pooled mean difference, and displayed more variation between sample results. The effect size for CANTAB set shifting was 0.17. CONCLUSION Problems in set shifting as measured by a variety of neuropsychological tasks are present in people with eating disorders.

Emotional functioning in eating disorders: attentional bias, emotion recognition and emotion regulation.

BACKGROUND Interpersonal processes, anxiety and emotion regulation difficulties form a key part of conceptual models of eating disorders (EDs), such as anorexia nervosa (AN) and bulimia nervosa (BN), but the experimental findings to support this are limited. METHOD The Reading the Mind in the Eyes task, the Difficulties in Emotion Regulation Scale (DERS) and a computerized pictorial (angry and neutral faces) Stroop task were administered to 190 women [50 with AN, 50 with BN and 90 healthy controls (HCs)]. RESULTS Those with an ED showed attentional biases to faces in general (medium effect), but specifically to angry faces over neutral faces (large effect) compared to HCs. The ED group also reported significantly higher emotion regulation difficulties (large effect) than HCs. There was a small difference between the ED and HC groups for the emotion recognition task (small-medium effect), particularly in the restricting AN (RAN) group. Depression and attentional bias to faces significantly predicted emotion regulation difficulties in a regression model. CONCLUSIONS The data provide support for conceptualizations of EDs that emphasize the role of emotional functioning in the development and maintenance of EDs. Further research will concentrate on exploring whether these findings are state or trait features of EDs.

Emotion Recognition and Regulation in Anorexia Nervosa

It is recognized that emotional problems lie at the core of eating disorders (EDs) but scant attention has been paid to specific aspects such as emotional recognition, regulation and expression. This study aimed to investigate emotion recognition using the Reading the Mind in the Eyes (RME) task and emotion regulation using the Difficulties in Emotion Regulation Scale (DERS) in 20 women with anorexia nervosa (AN) and 20 female healthy controls (HCs). Women with AN had significantly lower scores on RME and reported significantly more difficulties with emotion regulation than HCs. There was a significant negative correlation between total DERS score and correct answers from the RME. These results suggest that women with AN have difficulties with emotional recognition and regulation. It is uncertain whether these deficits result from starvation and to what extent they might be reversed by weight gain alone. These deficits may need to be targeted in treatment.

Cognitive flexibility in anorexia nervosa and bulimia nervosa

The aim of this study was to determine if there are differences in cognitive flexibility in anorexia nervosa and bulimia nervosa. Fifty-three patients with an eating disorder (34 with anorexia nervosa and 19 with bulimia nervosa) and 35 healthy controls participated in the study. A battery of neuropsychological tests for cognitive flexibility was used, including Trail Making B, the Brixton Test, Verbal Fluency, the Haptic Illusion Test, a cognitive shifting task (CatBat) and a picture set test. Using exploratory factor analysis, four factors were obtained: 1: Simple Alternation; 2: Mental Flexibility; 3: Perseveration; and 4: Perceptual Shift. Patients with anorexia nervosa had abnormal scores on Factors 1 and 4. Patients with bulimia nervosa showed a different pattern, with significant impairments in Factors 2 and 4. These findings suggest that differential neuropsychological disturbance in the domain of mental flexibility/rigidity may underlie the spectrum of eating disorders.

Poor Cognitive Flexibility in Eating Disorders: Examining the Evidence using the Wisconsin Card Sorting Task

Background People with eating disorders (ED) frequently present with inflexible behaviours, including eating related issues which contribute to the maintenance of the illness. Small scale studies point to difficulties with cognitive set-shifting as a basis. Using larger scale studies will lend robustness to these data. Methodology/Principal Findings 542 participants were included in the dataset as follows: Anorexia Nervosa (AN) n = 171; Bulimia Nervosa (BN) n = 82; Recovered AN n = 90; Healthy controls (HC): n = 199. All completed the Wisconsin Card Sorting Task (WCST), an assessment that integrates multiple measurement of several executive processes concerned with problem solving and cognitive flexibility. The AN and BN groups performed poorly in most domains of the WCST. Recovered AN participants showed a better performance than currently ill participants; however, the number of preservative errors was higher than for HC participants. Conclusions/Significance There is a growing interest in the diagnostic and treatment implications of cognitive flexibility in eating disorders. This large dataset supports previous smaller scale studies and a systematic review which indicate poor cognitive flexibility in people with ED.

Neural correlates of impaired cognitive-behavioral flexibility in anorexia nervosa

OBJECTIVE Impaired cognitive-behavioral flexibility is regarded as a trait marker in anorexia nervosa patients. The authors sought to investigate the neural correlates of this deficit in executive functioning in anorexia nervosa. METHOD Fifteen women with anorexia nervosa and 15 age-matched healthy comparison women underwent event-related functional MRI while performing a target-detection task. The task distinguished between shifts in behavioral response and shifts in cognitive set. It involved infrequent target and non-target distractor stimuli embedded in a sequence of prepotent standard stimuli. RESULTS Relative to comparison subjects, anorexia nervosa patients showed a significantly higher error rate in behavioral response shifting, independent of whether those runs also involved cognitive set shifting. During behavioral response shifting, patients showed reduced activation in the left and right thalamus, ventral striatum, anterior cingulate cortex, sensorimotor brain regions, and cerebellum that differed significantly from the comparison group but showed dominant activation in frontal and parietal brain regions. These differential activations in patients and comparison subjects were specific to shifts in behavioral response: except for thalamic activation, they were not observed in response to non-target distractor trials that required no alteration in behavioral response. CONCLUSION Impaired behavioral response shifting in anorexia nervosa seems to be associated with hypoactivation in the ventral anterior cingulate-striato-thalamic loop that is involved in motivation-related behavior. In contrast, anorexia nervosa patients showed predominant activation of frontoparietal networks that is indicative of effortful and supervisory cognitive control during task performance.

Exploring the neurocognitive signature of poor set-shifting in anorexia and bulimia nervosa.

Poor set-shifting has been implicated as a risk marker, maintenance factor and candidate endophenotype of eating disorders (ED). This study aimed to add clarity to the cognitive profile of set-shifting by examining the trait across ED subtypes, assessing whether it is a state or trait marker, and whether it runs in families. A battery of neuropsychological tasks was administered to 270 women with current anorexia (AN) and bulimia nervosa (BN), women recovered from AN, unaffected sisters of AN and BN probands, and healthy control women. Set-shifting was examined using both individual task scores and a composite variable (poor/intact/superior shifting) calculated from four neuropsychological tasks. Poor set-shifting was found at a higher rate in those with an ED particularly binge/purging subtypes. Some evidence for poor set-shifting was also present in those recovered from AN and in unaffected sisters of AN and BN. Clinically, poor set-shifting was associated with a longer duration of illness and more severe ED rituals but not body mass index. In sum, poor set-shifting is a transdiagnostic feature related to aspects of the illness but not to malnutrition. In part it is a familial trait, and is likely involved in the maintenance of the illness.

Cognitive Flexibility and Clinical Severity in Eating Disorders

Objectives The aim of this study was to explore cognitive flexibility in a large dataset of people with Eating Disorders and Healthy Controls (HC) and to see how patient characteristics (body mass index [BMI] and length of illness) are related to this thinking style. Methods A dataset was constructed from our previous studies using a conceptual shift test - the Brixton Spatial Anticipation Test. 601 participants were included, 215 patients with Anorexia Nervosa (AN) (96 inpatients; 119 outpatients), 69 patients with Bulimia Nervosa (BN), 29 Eating Disorder Not Otherwise Specified (EDNOS), 72 in long-term recovery from AN (Rec AN) and a comparison group of 216 HC. Results The AN and EDNOS groups had significantly more errors than the other groups on the Brixton Test. In comparison to the HC group, the effect size decrement was large for AN patients receiving inpatient treatment and moderate for AN outpatients. Conclusions These findings confirm that patients with AN have poor cognitive flexibility. Severity of illness measured by length of illness does not fully explain the lack of flexibility and supports the trait nature of inflexibility in people with AN.

Emotional theory of mind and emotional awareness in recovered anorexia nervosa patients.

Objectives: To examine whether an impaired ability to infer emotion in people with autism spectrum disorder (ASD) and difficulty with emotional theory of mind (eToM) are limited to the ill state or if this condition is a stable deficit that persists with recovery in adults with anorexia nervosa (AN). This is in keeping with observations of similarities between the disorders. Methods: Twenty-four participants fully recovered from AN were compared against a sample of currently ill AN patients (n = 40) and healthy controls (HCs) (n = 47) on forced-choice tasks assessing emotion recognition, basic or advanced eToM in other people, using sensory stimuli and on a written task measuring eToM ability for the self as well as for others. Results: Recovered participants performed well on eToM tasks and were significantly better than currently ill patients at inferring emotions in the self and in others. However, participants recovered from AN had some slight impairment in emotion recognition relative to HCs, particularly when recognizing positive emotions. Conclusions: These findings indicate almost complete normalization of emotion recognition ability as well as the restoration of eToM in recovered patients, despite the observation of difficulties in both domains in currently ill patients. Findings suggest that similarities between AN and ASD in poor eToM are restricted to the currently ill AN state and such difficulties in AN may be a factor of starvation. AN = anorexia nervosa; ASD = autism spectrum disorder; recAN = recovered anorexia nervosa; HC = healthy control; ToM = theory of mind; eToM = emotional theory of mind; BMI = body mass index; IQ = intelligence quotient; ANCOVA = analysis of covariance.

Cognitive Remediation Therapy for Eating Disorders: Development, Refinement and Future Directions

In this chapter, we aim to address some basic conceptual and practical questions about cognitive remediation therapy (CRT) for eating disorders. We begin by providing an overall historical, conceptual, and theoretical framework for CRT. Next, we discuss the specific indications for how and why CRT might be useful for eating disorders based on existing neuropsychological research evidence. We also provide an overview of the types of tasks and stimuli used in CRT and a general protocol for a manualized version of CRT. In addition, modifications of the adult CRT manual for use with adolescents as well as preliminary acceptability of the approach with this younger age group are described. We also propose various ways to integrate CRT in a variety of inpatient and outpatient programmes. Finally, a discussion of potential future directions in research using the tools of neurocognitive assessment, imaging and treatment research is provided.