Implications of neuropsychological test results of women in a new phase of anorexia nervosa

Neuropsychological functioning in adult anorexia nervosa: A meta-analysis

Several studies have conceptualized neuropsychological dysfunction as part of the core pathology and defining behaviors seen in the eating disorder anorexia nervosa (AN). The aim of the current review was to synthesize the differences in neuropsychological test performance between individuals with AN and healthy controls, quantify and explain their heterogeneity. The search and screening procedures resulted in fifty studies that comprised 186 neuropsychological test results. Utilizing random-effects meta-analyses, the results revealed evidence for significant, moderate underperformance in people with AN in overall neuropsychological functioning (g¯ = -0.43, 95 % CI [-0.50, -0.36]). Weighted mean effect sizes ranged from g¯ = -0.53 for visuospatial abilities to g¯ = -0.10 for planning. Study and participant characteristics, including body mass index (BMI) and age, had significant moderator effects, especially on executive function, memory, and visuospatial abilities. The findings from the current study provide an extensive and comprehensive overview of the possible impairments in neuropsychological functioning in adult patients diagnosed with AN.

Is poor global processing a transdiagnostic feature of Body Dysmorphic Disorder and Anorexia Nervosa? A meta-analysis

Body dysmorphic disorder (BDD) and anorexia nervosa (AN) are characterised by body image disturbance. It has been suggested that poor global integration in visual processing may underlie distorted body image, but empirical studies have yielded mixed results. The current study involved two meta-analyses aimed at examining the extent to which poor global processing is evident in BDD and AN. Studies were identified through a systematic literature search up to October 2020. The BDD search yielded 16 studies and the AN search yielded 18 studies. Random-effect models demonstrated a small pooled effect size for BDD (g = -0.44, 95 % CI -0.70, -0.17, p < 0.001) and a moderate pooled effect size for AN (g = -0.63, 95 % CI -0.77, -0.49, p <  .001), with no evidence of significant publication bias for either. The results provide evidence that poor global processing is a transdiagnostic feature of both BDD and AN, although effects may be more pronounced in AN. Our findings highlight the possibility that interventions aimed at promoting global visual processing could prove beneficial in disorders characterised by distorted body image.

Central coherence and set-shifting between nonunderweight eating disorders and anorexia nervosa: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis compared previously documented inefficiencies in central coherence and set-shifting between people with nonunderweight eating disorders (bulimia nervosa and binge-eating disorder) and people with anorexia nervosa.

METHOD

We performed random-effects meta-analyses on 16 studies (1,112 participants) for central coherence and 38 studies (3,505 participants) for set-shifting. Random effects meta-regressions were used to test whether the effect sizes for people with nonunderweight eating disorders were significantly different from the effect sizes for people with anorexia nervosa.

RESULTS

People with anorexia nervosa (Hedge's g = -0.53, 95% CIs: -0.80, -0.27, p < .001) and bulimia nervosa (Hedge's g = -0.70, 95% CIs: -1.14, -0.25, p = .002), but not binge-eating disorder, had significantly poorer central coherence than healthy controls. Similarly, people with anorexia nervosa (Hedge's g = -0.38, 95% CIs: -0.50, -0.26, p < .001) and bulimia nervosa (Hedge's g = -0.55, 95% CIs: -0.81, -0.29, p < .001), but not binge-eating disorder, had significantly poorer set-shifting than healthy controls. The effect sizes for people with nonunderweight eating disorders did not significantly differ from those for people with anorexia nervosa.

DISCUSSION

Our meta-analysis was underpowered to make definitive judgments about people with binge-eating disorder. However, we found that people with bulimia nervosa clearly have central coherence and set-shifting inefficiencies which do not significantly differ from those observed in people with anorexia nervosa. Clinically, this suggests that people with bulimia nervosa might benefit from adjunctive approaches to address these inefficiencies, such as cognitive remediation therapy.

Cognitive flexibility in acute anorexia nervosa and after recovery: A systematic review

Difficulties in cognitive flexibility-the ability to adapt effectively to changes in the environment and/or changing task demands-have been reported in anorexia nervosa (AN). However, findings are inconsistent across studies and it remains unclear which specific aspects of cognitive flexibility patients with AN may struggle with. This systematic review aimed to synthesise existing research on cognitive flexibility in AN and clarify differences between patients with acute AN, patients who are weight-restored and patients who are fully recovered from AN. Electronic databases were searched through to January 2020. 3,310 papers were screened and 70 papers were included in the final review. Although adults with acute AN performed worse in perceptual flexibility tasks and self-report measures compared to HCs, they did not exhibit deficits across all domains of cognitive flexibility. Adolescents with acute AN did not differ to HCs in performance on neurocognitive tasks despite self-reporting poorer cognitive flexibility. Overall, significant differences in cognitive flexibility between acute and recovered participants was not evident, though, the findings are limited by a modest number of studies. Recovered participants performed poorer than HCs in some neurocognitive measures, however, results were inconsistent across studies. These results have implications for the assessment of cognitive flexibility in AN and targeted treatment approaches.

The set-shifting profiles of anorexia nervosa and autism spectrum disorder using the Wisconsin Card Sorting Test: a systematic review and meta-analysis

Difficulties in set-shifting are commonly reported in both autism spectrum disorder (ASD) and anorexia nervosa (AN) populations. Despite this, it is not known whether this cognitive profile persists across different ages, or whether the profiles seen in ASD and AN are comparable. This systematic review and meta-analyses aimed to compare the set-shifting profiles, as measured by the Wisconsin Card Sorting Test (WCST) in adults and younger people with either ASD or AN, relative to healthy controls (HCs) and to statistically compare performance on the WCST between ASD and AN. In all, 24 studies on ASD and 22 studies on AN were identified. In ASD, there were significant differences between the clinical group and HCs, with the ASD group making significantly more perseverative errors, indicating greater difficulty in set-shifting [pooled effect size of d = 0.67, 95% confidence interval (CI) 0.53-0.81, p ⩽ 0.001]. This effect was consistent across the age span. For AN studies, there was a significant difference between adults with AN and HCs (d = 0.52, 95% CI 0.36-0.68, p ⩽ 0.001) but a non-significant effect in child studies (d = 0.25, 95% CI -0.05 to 0.55, z = 1.66, p = 0.096). Meta-regression indicated no effect of diagnosis (AN or ASD) on performance in adult studies but there was a non-significant trend (p = 0.053) towards children with ASD performing worse than children with AN. While difficulties with set-shifting appear to be stable in ASD, there may be differences between children and adults with AN, which warrant further investigation.

Literature Review of Cognitive Neuroscience and Anorexia Nervosa

Studies published between the beginning of 2013 and May 2015 on the neuropsychological functioning of patients with anorexia nervosa compared with healthy participants framed in the context of the Research Domain Criteria matrix identifies evidence for functional differences in three domains: Negative Valance Systems-negative attentional biases and lack of neural responsivity to hunger; Cognitive Systems-limited congruence between clinical and cognitive performance, poorer non-verbal than verbal performance, altered attentional styles to disorder related stimuli, perceptual processing impairment in discriminating body images, weaknesses in central coherence, set shifting weaknesses at low weight status, decision-making weaknesses, and greater neural resources required for working memory; Systems for Social Processes-patients appear to have a different attentional response to faces, and perception and understanding of self and others. Hence, there is evidence to suggest that patients with anorexia nervosa have a specific neuropsychological performance style across tasks in three domains of functioning. Some current controversies and areas for future development are identified.

Comprehensive neurocognitive assessment of patients with anorexia nervosa

AIM: To utilise a comprehensive cognitive battery to gain a better understanding of cognitive performance in anorexia nervosa (AN).

METHODS: Twenty-six individuals with AN and 27 healthy control participants matched for age, gender and premorbid intelligence, participated in the study. A standard cognitive battery, the Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery, was used to investigate performance on seven cognitive domains with the use of 10 different tasks: speed of processing [Brief Assessment Of Cognition In Schizophrenia: Symbol Coding, Category Fluency: Animal Naming (Fluency) and Trail Making Test: Part A], attention/vigilance [Continuous Performance Test - Identical Pairs (CPT-IP)], working memory [Wechsler Memory Scale (WMS^®-III): Spatial Span, and Letter-Number Span (LNS)], verbal learning [Hopkins Verbal Learning Test - Revised], visual learning [Brief Visuospatial Memory Test - Revised], reasoning and problem solving [Neuropsychological Assessment Battery: Mazes], and social cognition [Mayer-Salovey-Caruso Emotional Intelligence Test: Managing Emotions]. Statistical analyses involved the use of multivariate and univariate analyses of variance.

RESULTS: Analyses conducted on the cognitive domain scores revealed no overall significant difference between groups nor any interaction between group and domain score [F(1,45) = 0.73, P = 0.649]. Analyses conducted on each of the specific tasks within the cognitive domains revealed significantly slower reaction times for false alarm responses on the CPT-IP task in AN [F(1,51) = 12.80, P < 0.01, Cohen’s d = 0.982] and a trend towards poorer performance in AN on the backward component of the WMS^®-III Spatial Span task [F(1,51) = 5.88, P = 0.02, Cohen’s d = -0.665]. The finding of slower reaction times of false alarm responses is, however, limited due to the small number of false alarm responses for either group.

CONCLUSION: The findings are discussed in terms of poorer capacity to manipulate and process visuospatial material in AN.

Set-shifting ability across the spectrum of eating disorders and in overweight and obesity: a systematic review and meta-analysis

BACKGROUND

In this meta-analysis we review the findings from neuropsychological studies on set-shifting in people with eating disorders (EDs) or overweight/obesity.

METHOD

Four databases (PubMed, PsycINFO, PSYNDEX and Web of Science) were searched for eligible studies. Effect sizes (ESs) were pooled using random-effects models. Moderator analyses were conducted for ED and overweight/obese subgroups, adult/adolescent samples and measures of set-shifting.

RESULTS

Sixty-four studies with a total of 1825 ED patients [1394 anorexia nervosa (AN), 376 bulimia nervosa (BN) and 55 binge eating disorder (BED)] and 10 studies with a total of 449 overweight/obese individuals were included. The meta-analysis revealed a small to medium ES for inefficient set-shifting across all three ED diagnoses (Hedges' g = -0.45). Subgroup analyses yielded small to medium ESs for each ED subtype (g = -0.44 for AN, -0.53 for BED, -0.50 for BN), which did not differ significantly. There was a medium ES for restricting type AN (ANR; g = -0.51) but no significant ES for binge/purge type AN (AN/BP; g = -0.18). A medium ES was found across obesity studies (g = -0.61). The ES across overweight studies was not significant (g = -0.07). Adult samples did not differ from adolescent samples in either ED or overweight/obesity studies. The different set-shifting measures were associated with largely varying ESs.

CONCLUSIONS

The meta-analysis provides strong support that inefficient set-shifting is a salient neuropsychological phenomenon across ED subtypes and obesity, but is less prominent in AN/BP and overweight. Compulsivity seems to be a common underlying factor supporting a dimensional and transdiagnostic conceptualization of EDs and obesity.

Central coherence in eating disorders: an updated systematic review and meta-analysis

OBJECTIVES

A bias towards local information over the global "gist" (weak central coherence, WCC), has been identified as a possible contributing and maintaining factor in eating disorders (ED). The present study aimed to provide an updated review of the WCC literature and examine the hypothesis that individuals with ED have WCC.

METHODS

The new search found 12 eligible studies. Meta-analyses were performed on nine of these 12 studies, the remaining three were commented on individually. Data were combined with data from the previous 2008 review, and meta- analyses were performed on 16 studies (nine studies from the new search and seven studies from 2008 review).

RESULTS

Meta-analysis of the Group Embedded Figures Task provided evidence of superior local processing across all ED subtypes (pooled effect size of d = -0.62 (95% CI = -0.94, -0.31), P < 0.001). Evidence of poorer global processing in ED groups was found from meta-analyses of the Rey-Osterrieth Complex Figures task (d = -0.63 (95% CI = -0.77, -0.49, P < 0.001), and the Object Assembly Task (d = -0.65 (95% CI = -0.94, -0.37), P < 0.0001).

CONCLUSIONS

As well as supporting the results of previous studies by providing evidence of inefficient global processing, this review has provided evidence of superior local processing, which supports the WCC hypothesis in ED.

Neuropsychological variables and clinical status in anorexia nervosa: relationship between visuospatial memory and central coherence and eating disorder symptom severity

AIM

To explore the relationship between visuospatial memory, weak central coherence, and eating disorder (ED) symptoms in anorexia nervosa (AN) inpatients.

SAMPLE

31 female AN inpatients.

METHODS

Rey complex figure test (RCFT) was used to assess both visuospatial memory and central coherence. RCFT consisted of copy and recall trials. ED symptoms were assessed by The Eating Disorder Examination-Questionnaire (EDE-Q) and The Clinical and Research Inventory for Eating Disorders (CR-EAT).

RESULTS

We found a statistically significant negative correlation between recall accuracy and the total EDE-Q score. Furthermore, recall accuracy and recall central coherence significantly negatively correlate with several EDE-Q and CR-EAT scales.

CONCLUSIONS

These findings may contribute to a better understanding of cognitive impairments specifically in ED, and to refining interventions aiming at their improvement.

Central coherence, organizational strategy, and visuospatial memory in children and adolescents with anorexia nervosa

The vast majority of studies in anorexia nervosa that have investigated the domains of central coherence, organizational strategy, and visuospatial memory have focused on adult samples. In addition, studies investigating visuospatial memory have focused on free recall. No study to date has reported the association between recognition memory and central coherence or organizational strategy in younger people with this disorder, yet the capacity to recognize previously seen visual stimuli may contribute to overall visuospatial ability. Therefore, we investigate these domains in children and adolescents with anorexia nervosa compared to age- and gender-matched healthy controls. There were no significant group differences in immediate, delayed, or recognition memory, central coherence, or organization strategy. When compared with controls, patients with anorexia nervosa scored significantly higher on accuracy and took significantly longer when copying the Rey Complex Figure Task. Caution must be taken when interpreting these findings due to lower-than-expected scores in memory performance in the control group and because of a potential lack of sensitivity in the measures used when assessing this younger population. For neuropsychological functions where no normative data exist, we need a deeper, more thorough knowledge of the developmental trajectory and its assessment in young people in the general population before drawing conclusions in anorexia nervosa.

Visual processing in anorexia nervosa and body dysmorphic disorder: similarities, differences, and future research directions

Anorexia nervosa (AN) and body dysmorphic disorder (BDD) are psychiatric disorders that involve distortion of the experience of one's physical appearance. In AN, individuals believe that they are overweight, perceive their body as "fat," and are preoccupied with maintaining a low body weight. In BDD, individuals are preoccupied with misperceived defects in physical appearance, most often of the face. Distorted visual perception may contribute to these cardinal symptoms, and may be a common underlying phenotype. This review surveys the current literature on visual processing in AN and BDD, addressing lower- to higher-order stages of visual information processing and perception. We focus on peer-reviewed studies of AN and BDD that address ophthalmologic abnormalities, basic neural processing of visual input, integration of visual input with other systems, neuropsychological tests of visual processing, and representations of whole percepts (such as images of faces, bodies, and other objects). The literature suggests a pattern in both groups of over-attention to detail, reduced processing of global features, and a tendency to focus on symptom-specific details in their own images (body parts in AN, facial features in BDD), with cognitive strategy at least partially mediating the abnormalities. Visuospatial abnormalities were also evident when viewing images of others and for non-appearance related stimuli. Unfortunately no study has directly compared AN and BDD, and most studies were not designed to disentangle disease-related emotional responses from lower-order visual processing. We make recommendations for future studies to improve the understanding of visual processing abnormalities in AN and BDD.

A review of cognitive neuropsychiatry in the taxonomy of eating disorders: state, trait, or genetic?

A greater understanding of neuropsychological traits in eating disorders may help to construct a more biologically based taxonomy. The aim of this paper is to review the current evidence base of neuropsychological traits in people with eating disorders. Evidence of difficulties in set shifting, weak central coherence, emotional processing difficulties, and altered reward sensitivity is presented for people both in the acute and recovered phase of the illness. These traits are also seen in first degree relatives. At present there is limited research linking these neuropsychological traits with genetic and neuroanatomical measures. In addition to improving the taxonomy of eating disorders, neuropsychological traits may be of value in producing targeted treatments.

Verbal fluency in anorexia nervosa

Verbal fluency performance is commonly evaluated in clinical neuropsychology, in particular for assessment of executive functioning. Fluency is usually assessed by the person's ability to produce as many words as possible from a given cue within a specific timeframe. The cues are typically phonemic, e.g. words beginning with a specific letter, or semantic, e.g. words within a given category. Important components underlying fluency performance include clustering (the production of words within subcategories) and switching (the switch between clusters). Previous studies have demonstrated good performance on verbal fluency tasks in patients with anorexia nervosa (AN), but have not investigated the underlying components of this performance. The aim of the present study was to compare phonemic fluency performance in patients with AN to healthy controls (HC) and to investigate the use of clustering and switching in the two groups. Fifty-two patients with AN were compared with 37 HC on a phonemic fluency task. The patient group produced more words in total but the results were not significantly different compared to the HC sample. There were no differences between the two groups with regard to clustering, but patients with AN performed significantly more switches. In addition, switching was significantly more related to total output score in the patient sample. In contrast with previous studies of other areas of cognitive flexibility in AN, patients with AN appear to have good verbal set-shifting skills.

Neurobiological status at initial presentation predicts neuropsychological functioning in early onset anorexia nervosa at four-year follow up

This study explores whether neurobiological status (indexed by regional cerebral blood flow) at initial presentation predicts neuropsychological status at four-year follow up in a sample of children with early onset anorexia nervosa. Neuropsychological assessment was conducted on 15 females four years after their initial treatment, and matched controls. At follow up there were significant differences between subgroups (based on neurobiological status at initial presentation) and matched controls in long-term visual memory and cognitive inhibition. This study offers preliminary evidence that neurobiological abnormalities at initial presentation predict neuropsychological status at follow up, suggesting a distinct neurodevelopmental subtype of early onset anorexia nervosa.

The neuropsychological profile of children, adolescents, and young adults with anorexia nervosa

The neuropsychological profile of a sample of 155 patients with a clinical diagnosis of anorexia nervosa was assessed using a test battery specifically developed for such patients. The current findings suggest that the patients display a common neuropsychological profile including both strengths and weaknesses when compared with published norms. The patients displayed good verbal fluency skills, but performed poorly on tests of visuospatial memory, associated with relatively weak central coherence. They were within the average range on the assessment of executive functioning except for one measure of set-shifting. This study provides a valuable point of reference for clinicians when considering treatment options.

Measuring state trait properties of detail processing and global integration ability in eating disorders

OBJECTIVES

Women with eating disorders (EDs) are reported to have strengths in local or detailed information processing and difficulties with coherence or global processing/integration.

METHODS

This study aimed to replicate these findings and additionally explore a global integration task which has not previously been reported for an ED group, the Fragmented Pictures Task (FPT). Two hundred and twenty-two women (50 with anorexia nervosa (AN), 48 with bulimia nervosa (BN), 35 recovered from AN and 89 controls (HC)) completed the Rey-Osterrieth Complex Figure Task (RCFT) to measure global/local processing strategies, the Group Embedded Figures Task (GEFT) to measure local processing and the FPT to measure global integration.

RESULTS

Superior detail processing skills (GEFT) and a tendency to utilise detail processing strategies (RCFT) were associated with having AN, BN and being in recovery from AN. Global integration difficulties (FPT) were only observed in acute AN, whereas participants in the BN and recovered group performed similarly to HCs.

CONCLUSIONS

People currently ill with, and recovered from EDs are skilled at detail processing. The acute phase of AN is associated with difficulties in global integration.

The Ravello Profile: development of a global standard neuropsychological assessment for young people with anorexia nervosa

Recent research suggests that neuropsychological factors may play an important role in the development and maintenance of anorexia nervosa. However, it has been difficult to draw firm conclusions because of the wide range of assessments and norms that have been used. The aim of the Ravello Profile is to define a common shared neuropsychological assessment battery that can be adopted by researchers and clinicians working with young people. We describe the background to the Ravello Profile and the process of developing it, before specifying the recommended tests. We present an illustrative case example and consider some of the potential clinical and research applications of the profile with young people suffering from anorexia nervosa.

Estimated intelligence quotient in anorexia nervosa: a systematic review and meta-analysis of the literature

BACKGROUND

It has been hypothesised that people with anorexia nervosa have a higher intelligence quotient (IQ) level than the general population. The purpose of this review was to systematically appraise the research into reported IQ levels in people with anorexia nervosa.

METHODS

A search using the terms intelligence quotient, IQ, intelligence, cognition, eating disorders and anorexia was conducted in electronic databases only.

RESULTS

In all, 30 peer-reviewed studies written in English that used well established measures of intelligence quotient (the National Adult Reading Test and Wechsler Intelligence Scales) were identified. This review established that people with anorexia nervosa score 10.8 units and 5.9 units above the average intelligence quotient of the normative population on the National Adult Reading Test and Wechsler Intelligence Scales, respectively. An association was found between Body Mass Index and intelligence quotient, as measured by the National Adult Reading Test.

CONCLUSIONS

More studies including other eating disorder categories and recovered people are needed to explore important questions regarding the role of the intelligence quotient in treatment response.

Quantitative evidence for distinct cognitive impairment in anorexia nervosa and bulimia nervosa

It is generally agreed that at least some aspects of abnormal eating behaviour is indeed due in part to disordered cognition. The accumulated literature illustrates cognitive impairment in patients with anorexia nervosa (AN) and bulimia nervosa (BN). Yet beyond being inconsistent, these independent studies also do not reveal the magnitude of impairment within and across studies and fail to give due consideration to the magnitude of impairment so as to understand the severity and breadth of impairment and/or differences in cognitive profiles between patients with AN and BN. Hence, the present review on the subject sought to articulate the magnitude of cognitive impairment in patients with AN and BN by quantitatively synthesizing the existing literature using meta-analytic methodology. The results demonstrate modest evidence of cognitive impairment specific to AN and BN that is related to body mass index in AN in terms of its severity, and is differentially impaired between disorders. Together, these results suggest that disturbed cognition is figural in the presentation of eating disorders and may serve to play an integral role in its cause and maintenance. Implications of these findings with respects to future research are discussed.

Implications of starvation-induced change in right dorsal anterior cingulate volume in anorexia nervosa

OBJECTIVE

Converging evidence suggests a role for the anterior cingulate cortex (ACC) in the pathophysiology of anorexia nervosa (AN). This study sought to determine whether ACC volume was affected by starvation in active AN and, if so, whether this had any clinical significance.

METHOD

Eighteen patients with active AN and age- and gender-matched normal controls underwent magnetic resonance imaging (MRI). Sixteen patients (89%) with AN had intelligence quotients (IQ) testing at intake, 14 (78%) had repeat MRIs after weight normalization, and 10 (56%) had outcome data at 1-year posthospitalization.

RESULTS

Right dorsal ACC volume was significantly reduced in active AN patients versus controls and was correlated with lower performance IQ. While ACC normalization occurred with weight restoration, smaller change in right dorsal ACC volume prospectively predicted relapse after treatment.

CONCLUSION

Reduced right dorsal ACC volume during active AN relates to deficits in perceptual organization and conceptual reasoning. The degree of right dorsal ACC normalization during treatment is related to outcome.

Central coherence in eating disorders: a systematic review

BACKGROUND

This review systematically appraised the research evidence for local versus global information processing to test the hypothesis that people with eating disorders (ED) had weak central coherence.

METHOD

Searches on Medline, EMBASE, PsycINFO and ISI Web of Science databases were conducted in November 2006 and subsequently updated in September 2007. Each search was conducted in two steps: (1) neuropsychological tasks measuring central coherence and (2) words related to cognitive functioning in eating disorders. Data were summarized in a meta-analysis if the number of studies for a given test was >5.

RESULTS

Data were extracted from 16 studies. Meta-analyses were conducted for four tasks obtaining moderate effect sizes. The majority of studies found global processing difficulties across the ED spectrum. The results are less clear regarding local processing.

CONCLUSIONS

People with ED have difficulties in global processing. It is less certain as to whether they have superior local processing. Currently, there is insufficient evidence to refute the weak central coherence hypothesis.

An examination of the concept of central coherence in women with anorexia nervosa

OBJECTIVE

To examine central coherence (local and global processing) in women with anorexia nervosa (AN).

METHOD

42 women with AN and 42 healthy women (HC) completed neuropsychological testing measuring visuospatial and verbal aspects of central coherence: Rey-Osterrieth Complex Figure (RCFT), Embedded Figures Test (EFT), Homograph Reading Test (HRT), and Sentence Completion Task (SCT).

RESULTS

People with AN displayed superior performance on the EFT and poorer performance in RCFT with the exception of accuracy in the copy trial. Long hesitations in the SCT were observed. Verbal coherence tasks were not sensitive enough to detect coherence anomalies in AN.

CONCLUSION

Women with AN have strengths in tasks requiring local processing (EFT) and weaknesses on tasks benefited by global processing (RCFT and SCT). These results are consistent with the weak central coherence account. This trait might play a role in the maintenance of AN and can be addressed in specific clinical interventions.

Preoccupation with detail contributes to poor abstraction in women with anorexia nervosa

The present study investigated preoccupation with detail as a potential mechanism underlying poor abstraction in anorexia nervosa (AN). Abstract thinking performance of 24 women with AN (16-31 years) was compared against that of 24 healthy controls matched for age, education and socio-economic status, using the Object Assembly subtest of the WAIS III. Participants also completed measures of two indices of preoccupation with detail: field dependence-independence (Group Embedded Figures Test) and obsessionality (Leyton Obsessional Inventory). Perfectionism (Perfectionism subscale of the EDI-II) and mental rigidity (Trail Making Test), sub-components of obsessionality, were also measured. Women with AN showed a significant deficit in abstract thinking performance, which could not be explained by a more general intellectual deficit or diminished information processing speed. The AN sample also showed a greater preoccupation with detail relative to the control group. Controlling for preoccupation with detail reduced the group difference in abstract thinking to non-significance. However, only field dependence-independence contributed significantly to the relationship between group membership and abstract thinking performance. Thus, poor abstract thinking in AN appears to be at least partly attributable to a field-independent cognitive style, characterised by a bias towards focusing on detail at the expense of considering the gestalt.

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.

Psychomotor performance and sequence planning in anorexia nervosa before and after weight restoration

BACKGROUND

In the study of psychomotor performance in anorexia nervosa (AN), motor control has not been studied extensively. The present study explores sequence planning in a sample of AN patients.

METHOD

A group of 26 female restricting AN inpatients, aged 14 to 25, was compared with 24 healthy women matched for age and educational level. During the performance of a simple copying task, in which movement planning, but not working capacity, was challenged, the ease with which generally favored graphic production rules could be applied was manipulated. Computerized recordings of the drawing movements allowed detailed analyses of reaction and movement times and of drawing sequences. Fifteen patients were retested after weight restoration, as were 15 controls.

RESULTS

Copying patterns that normally elicit a conflict between preferred graphic production rules induced significantly less slowing in the reaction times of the anorexia nervosa patients than in the controls, both before and after weight restoration. There were no group differences as regards the consistency with which the implicit production rules were applied.

DISCUSSION

AN patients seem to show a fast response style combined with good sequence planning capacity.

Cognitive impairment in anorexia nervosa is not due to depressed mood

OBJECTIVE

Previous research has revealed cognitive deficits in patients with anorexia nervosa. It is unclear whether these deficits are linked to co-morbid depression in this population. We examined the relationship between depressive symptoms and cognitive functioning.

METHOD

A large sample of subjects (N = 98) was examined using a common measure of cognitive ability and two measures of depression.

RESULTS

We confirmed that there is no relationship between depression and cognitive ability in this group.

DISCUSSION

This suggests that alternative explanations be explored for cognitive deficits in patients with anorexia nervosa.

Neuropsychological functioning pretreatment and posttreatment in an inpatient eating disorders program

OBJECTIVE

This study was conducted to determine whether neuropsychological dysfunction associated with anorexia nervosa resolves with inpatient treatment.

METHOD

Subjects were 28 women being treated for anorexia nervosa. Main study variables included body mass index (BMI), Beck Depression Inventory-II, and neuropsychological test scores. Subjects were tested at admission and discharge.

RESULTS

Neuropsychological functioning improved across the course of treatment, with significant changes on tests of memory and psychomotor speed. This improvement was not significantly associated with change in BMI or with the other variables that were studied.

DISCUSSION

Patients with anorexia nervosa exhibit subtle neuropsychological dysfunction, which resolves at least partially during treatment. This improvement does not appear to be associated with an increase in BMI. However, it is possible that BMI is not a sufficiently sensitive indicator of nutritional status or that longer-term follow-up is necessary to reveal the nutrition-cognition relationship that we were seeking.