Verena Mainz

Structural Brain Abnormalities in Adolescent Anorexia Nervosa Before and After Weight Recovery and Associated Hormonal Changes

Objective The neurobiological mechanisms of structural brain abnormalities in patients with anorexia nervosa (AN) remain poorly understood. In particular, little is known about the changes in and the recovery of gray matter (GM) volumes after weight gain and the relation to hormonal normalization in adolescent patients with AN. Methods Nineteen female patients aged 12 to 17 years were assessed using magnetic resonance imaging at the time of admission to the hospital (T1) and after weight recovery (T2). Patients were compared with typically developing girls matched for age and intelligence quotient. Structural brain images were analyzed using a voxel-based morphometric approach. Circulating levels of cortisol and gonadotropins were assessed in blood samples. Results Compared with controls, patients with AN showed reduced GM in several brain regions along the cortical midline, reaching from the occipital cortex to the medial frontal areas. These GM reductions were mostly reversible at T1. Patients showed a GM increase from T1 to T2 along the cortical midline and in the occipital, temporal, parietal, and frontal lobes. GM increases at T2 correlated inversely with cortisol levels at T1 and positively with weight gain at T2. The strongest associations between regional GM increase and weight gain were found in the cerebellum. In addition, increases in GM volumes at T2 in the thalamus, hippocampus, and amygdala were associated with increases in follicle-stimulating hormone. Conclusions Our data suggest that brain alterations in adolescents with acute AN are mostly reversible at T1 and that GM recovery in specific brain regions is associated with weight and hormonal normalization. Abbreviations AN = anorexia nervosa MRI = magnetic resonance imaging WM = white matter GM = gray matter VBM = voxel-based morphometry CSF = cerebrospinal fluid BMI = body mass index FSH = follicle-stimulating hormone SPM = statistical parametric mapping ROI = region of interest

Theory of Mind and the Brain in Anorexia Nervosa: Relation to Treatment Outcome

OBJECTIVE Converging evidence suggests deficits in theory-of-mind (ToM) processing in patients with anorexia nervosa (AN). The present study aimed at elucidating the neural mechanisms underlying ToM-deficits in AN. METHOD A total of 19 adolescent patients with AN and 21 age-matched controls were investigated using functional magnetic resonance imaging during performance of a ToM-task at two time points (in-patients: admission to hospital and discharge after weight recovery). Clinical outcomes in patients were determined 1 year after admission. RESULTS Irrespective of the time point, AN patients showed reduced activation in middle and anterior temporal cortex and in the medial prefrontal cortex. Hypoactivation in the medial prefrontal cortex at admission to hospital (T1) was correlated with clinical outcome at follow-up. CONCLUSIONS Hypoactivation in the brain network supporting theory of mind may be associated with a social-cognitive endophenotype reflecting impairments of social functioning in anorexia nervosa which is predictive for a poor outcome at 1-year follow-up.

Influence of cue exposure on inhibitory control and brain activation in patients with alcohol dependence.

Alcohol dependence is a serious condition characterized by persistent desires to drink and unsuccessful efforts to control alcohol consumption despite the knowledge of dysfunction through the usage. The study at hand examined the influence of an alcohol exposure on inhibitory processes. Research provides evidence that trying to resist the temptation to drink exerts self-control, a limited resource which is used during all acts of inhibition. In line with this, studies demonstrate an impaired ability to regulate an already initiated response in alcohol-dependent and healthy subjects when confronted with alcohol-related stimuli. The related neuronal correlates in alcohol-dependent patients remain to be elucidated. The inhibition performance of 11 male alcohol-dependent patients during an alcohol exposure was compared with the task performance during a control condition. Behavioral data and neural brain activation during task performance were acquired by means of functional magnetic resonance imaging. The alcohol cue exposure led to subjectively stronger urges to drink which was accompanied by differential neural activation in amygdala and hippocampus. Moreover, the results revealed typical neural activation during inhibition performance across both conditions. Anyhow, we could not detect any behavioral deficits and only subtle neural differences between induction conditions during the performance of the inhibition task within the inferior frontal cortex. The results suggest that although the sample reports a subjectively stronger urge to drink after the alcohol cue exposure this effect was not strong enough to significantly impair task performance. Coherently, we discover only subtle differential brain activation between conditions during the inhibition task. In opposition to findings in literature our data do not reveal that an exposure to alcohol-related cues and thereby elicited cue reactivity results in impaired inhibition abilities.

Can executive control be influenced by performance feedback? Two experimental studies with younger and older adults

Executive control describes a wide range of cognitive processes which are critical for the goal-directed regulation of stimulus processing and action regulation. Previous studies have shown that executive control performance declines with age but yet, it is still not clear whether different internal and external factors—as performance feedback and age—influence these cognitive processes and how they might interact with each other. Therefore, we investigated feedback effects in the flanker task in young as well as in older adults in two experiments. Performance feedback significantly improved executive performance in younger adults at the expense of errors. In older adults, feedback also led to higher error rates, but had no significant effect on executive performance which might be due to stronger interference. Results indicate that executive functions can be positively influenced by performance feedback in younger adults, but not necessarily in older adults.

Resting vagal tone is negatively associated with suicide ideation.

BACKGROUND The present study aimed at investigating whether resting vagally mediated heart rate variability (HRV) as a trait-like biomarker of cognitive inhibitory control capacity is related to suicide ideation in a sample without suicide attempt history. METHODS Thirty-seven healthy students participated voluntarily (18 to 34 years, M=24.5, SD=4.1; 73.0% female). Time and frequency measures of HRV were derived from an electrocardiogram that was recorded using Einthovens Triangle lead II. Participants filled in the Rasch-based Depression Screening and four questions concerning lifetime suicide ideation (SI). Bivariate Pearsons and partial (controlling for depression severity) correlation coefficients were calculated between SI and measures of vagally mediated HRV. RESULTS A significant correlation between the ln10-transformed high-frequency band of resting vagally mediated HRV and SI was found (r=-.33, p<.05). Correlations did not change substantially when controlling for depression. Mean heart rate as a time domain measure also significantly correlated with SI while controlling for depression (r=.36, p<.05). A trend correlation between SI and Root Mean Square of Successive Differences between interbeat intervals emerged. LIMITATIONS SI was assessed with a composite score of four items measuring SI. Future studies should consider using more comprehensive assessment instruments. CONCLUSIONS The relation between resting vagally mediated HRV and suicide ideation may be interpreted as indicating that reduced inhibitory cognitive control capacity may be a risk factor for suicidality. It may act already early in the suicidal process, before suicidal behavior develops and should be further investigated as potentially clinically important physiological predictor of suicidality.

Measuring decentering in self-reports: Psychometric properties of the Experiences Questionnaire in a German sample

Abstract Decentering is described as referring to ones current mental experiences from an objective perspective. This study presents a psychometric evaluation of a German version of the Experiences Questionnaire (EQ-D), a self-report instrument designed to measure decentering. Confirmatory factor analysis on a sample of 506 university students indicates acceptable-to-good model fit (χ 2=58.3; TLI=.92; CFI=.95; RMSEA=.067) for a second-order factor Overall Decentering comprising the two first-order factors Accepting Self-Perception and Distanced Perspective. Preliminary evidence for the validity of the EQ-D was demonstrated via negative correlations with measures of depression and depressive rumination. The present results stress the multidimensional nature of decentering and provide important suggestions for future research on how to investigate and operationalize the decentering construct.

Does cognitive behavior therapy alter emotion regulation in inpatients with a depressive disorder

Introduction Emotion regulation plays an important role in the development and treatment of depression. The present study investigated whether the emotion regulation strategies, expressive suppression (ES) and cognitive reappraisal (CR) change in the course of cognitive behavior therapy (CBT) of depressive inpatients. Furthermore, it also examined whether changes in CR and ES correlated with positive treatment outcomes. Methods Forty-four inpatients from a psychotherapeutic hospital who suffered from a depressive disorder (mean age =36.4 years, standard deviation =13.4 years; 63.6% female) filled in the Emotion Regulation Questionnaire and the Beck Depression Inventory at admission and discharge. To detect changes in emotion regulation, and depression across treatment, data were analyzed using multivariate analyses of variance (MANOVA) for repeated measures, effect sizes, and Spearman correlations. A P-value of ≤0.05 was considered statistically significant. Results Depression severity (F[1]=10.42, P=0.003; η2=0.22) and CR (F[1]=4.71, P=0.04; η2=0.11) changed significantly across CBT treatment. ES remained virtually stable. Post-treatment scores of CR were also positively correlated with reduction in depressive symptoms across treatment (ρ=0.30, P=0.05). Conclusion The results suggest that CBT affects emotion regulation in depressive inpatients only for CR and that higher post-treatment scores in CR were related to greater reduction in depressive symptoms across treatment.

Neural correlates of positive and negative performance feedback in younger and older adults

BackgroundRecent studies with younger adults have shown that performance feedback can serve as a reward, and it elicits reward-related brain activations. This study investigated whether performance feedback is processed similarly in younger and older adults and whether there are differential aging effects for positive and negative performance feedback.MethodsWe used event-related fMRI in a choice reaction-time task and provided performance feedback after each trial.ResultsAlthough younger and older adults differed in task-related activation, they showed comparable reward-related activation. Positive performance feedback elicited the strongest striatal and amygdala activation, which was reflected behaviorally in slightly faster reaction times.ConclusionsThese results suggest that performance feedback serves as a reward in both younger and older adults.

Implicit sequence learning in juvenile anorexia nervosa: neural mechanisms and the impact of starvation

BACKGROUND Previous studies have reported that cognitive deficits occur in patients with anorexia nervosa (AN) and that these deficits may represent a predisposition towards developing AN or perpetuate the disorder. Specifically, dysfunctional implicit learning may contribute to the development of highly resistant dieting behaviours that are fundamental to the persistence of the disorder. Thus, the aims of this study were (a) to investigate implicit sequence learning in adolescent patients with AN before and after weight recovery and (b) to elucidate the associated neural mechanisms in acute AN relative to healthy controls. METHODS In a behavioural study, implicit sequence learning was assessed using a serial reaction time task in 27 adolescents with AN before (T1) and after weight recovery (T2) compared with age-matched healthy controls (HC) who were assessed at similar time intervals. The neural correlates of implicit sequence learning were subsequently investigated in 19 AN patients shortly after they were admitted to the hospital and 20 HC using functional magnetic resonance imaging (fMRI). RESULTS At T1, AN patients showed reduced sequence learning compared with HC. However, no behavioural differences between HC and AN patients were found at T2. At the neural level, acute AN patients showed reduced thalamic activation during sequence learning compared with HC subjects. CONCLUSIONS Our data suggest that the impaired implicit learning observed in adolescent AN patients before weight gain is a state-related dysfunction that normalises with weight gain. Thus, implicit learning deficits do not appear to represent a predisposition towards developing AN; rather, these deficits should be considered when planning psychotherapeutic interventions for acute AN. Reduced thalamic activation during the acute stage of AN may indicate a starvation-induced dysfunction of the neural circuitry that is involved in behavioural flexibility.

Metacognitive monitoring of attention performance and its influencing factors

Metacognitive monitoring is a central element of metacognitive processing exerting widespread influences on information processing. Albeit being subject to numerous empirical investigations referring to memory performance, there is little research investigating metacognitive monitoring in other cognitive domains. The present study investigated in 45 healthy students whether factors that are known to influence monitoring of memory performance, i.e. task difficulty, time of assessment, and practice, also exhibit a significant impact on monitoring of attention performance. A multivariate analysis of variance with three within-subject repeated measures factors on two dependent variables (monitoring of (a) time, and (b) errors in an attention task) was conducted. Results showed that monitoring ability significantly decreased with increasing task difficulty, was significantly better for post than for pre-assessment, and significantly increased with practice. Therefore, results suggest that the examined factors influenced monitoring of attention performance equivalent to the influence of these factors found in metamemory research.