Blunted emotion-modulated startle reflex in anorexia nervosa

Anorexia nervosa through the lens of a severe and enduring experience: 'lost in a big world'

BACKGROUND

Severe and enduring anorexia nervosa (SE-AN), is a serious and persistent illness, despite 'state of the art' treatment. Criteria have been theoretically proposed, but not tested, and may not adequately capture illness complexity, which potentially inhibits treatment refinements. The clinical reality of death as an outcome for some people who experience SE-AN (1 in 20) and broadening access to voluntary assisted dying, further complicates the field, which is undeveloped regarding more fundamental concepts such as nosology, treatment, recovery definitions and alternative conceptualisations of SE-AN. The present paper is in response to this and aims to build upon qualitative literature to enhance phenomenological understandings of fatal SE-AN.

METHOD

A published book, being the legacy of a 32-year-old professional artist offers a rich account of a life lived with AN, for 18 years with continuous treatment. A polysemous narrative via the interrelationship between the languages of the artist's words and visual art is translated via interpretative phenomenological analysis (IPA), offering rich insight into the SE-AN experience.

FINDINGS

The process of analysis induced three superordinate themes (1) Disappearing Self (2) Dialectical Dilemma (3) Death and Dying: Finding Meaning. Two cross cutting themes traversed these themes: (a) Colour and (b) Shifting Hope, where the former produced a visual representation via the 'SE-AN Kaleidoscope'. Collectively the themes produce a concept of SE-AN, grounded in the data and depicted visually through the artist's paintings.

CONCLUSIONS

The picture of SE-AN revealed in the analysis extends upon conceptualisations of SE-AN, highlighting key processes which are thus far under explored. These factors are implicated in illness persistence eliciting opportunities for further research testing including diagnostic considerations and treatment directions. In SE-AN, distorted body image extends to a global distortion in the perception of self. Additional criteria for the severe and enduring stages of illness related to (1) self and identity processes (2) measures of 'global impoverishment' across life domains are proposed for consideration in the future testing of putative defining features of SE-AN.

Heart Rate as a Correlate for the Emotional Processing of Body Stimuli in Anorexia Nervosa

In anorexia nervosa, aberrant emotional reactions toward body stimuli have been discussed. We investigated heart rate as a physiological marker when viewing body stimuli and hypothesized altered HR reactions toward those highly significant and emotional stimuli in anorexia nervosa. In total, 37 anorexia nervosa patients and 43 control participants viewed pictures of women of five different weight categories, while their cardiac activity was recorded. R-R intervals following picture onset were determined, and means were calculated for three distinct time periods. The overall change in HR relative to baseline across all picture categories was greater in the patient group than in the control group (significant effect of “group”, p = 0.002, partial η2 = 0.120). A significant decrease in HR 2 to 8 s after picture presentation was found for pictures of women of extreme weight in both participant groups (significant “category ∗ time segment interaction”, p = 0.01, partial η2 = 0.037) and correlated with scores of sociocultural attitudes toward the appearance for the extremely underweight category (r = −0.33, p = 0.005). Therefore, differential HR reactions for anorexia nervosa patients and control participants were found for body stimuli in general. The highest HR decelerations in response to pictures of strongly underweight and overweight women may reflect emotional processes such as anxiety due to social comparison.

Sensor technology in eating disorders research: A systematic review

OBJECTIVE

Sensor technologies offer exciting potential to objectively measure psychopathological correlates of eating pathology and eating disorder (ED) research utilizing sensors has rapidly proliferated in the past several years. The aims of the present review are: (1) characterize the types of sensors that have been utilized in ED research, (2) identify the psychopathological factors relevant to EDs that have been assessed using sensors, (3) describe the data supporting the validity and reliability of these sensors, (4) discuss limitations associated with these sensors, and (5) identify gaps that persist within the ED literature with regard to use of sensor technologies.

METHOD

A systematic search was conducted of PubMed, PsycINFO, Web of Science, ProQuest, and "gray" literature sources. Eligible publications were empirical studies that utilized sensors to measure at least one psychological variable among clinical ED populations.

RESULTS

Sensors have been utilized with ED samples to measure eating behaviors, physical activity, sleep, autonomic nervous system activity, eyeblink startle response, visual attention, and visual-haptic object integration. The reliability and validity of these sensors varies widely and there are a number of significant gaps that remain in the literature with regard to the types of sensors utilized, context in which sensors have been used, and populations studied.

DISCUSSION

The existing literature utilizing sensors within ED research largely support the feasibility and acceptability of these tools. Sensors should continue to be utilized within the field, with a specific focus on examining the reliability and validity of these tools within ED samples and increasing the diversity of samples studied.

PUBLIC SIGNIFICANCE STATEMENT

Sensor technologies, such as those included in modern smartwatches, offer new opportunities to measure factors that may maintain or contribute to symptoms of eating disorders. This article describes the types of sensors that have been used in eating disorders research, challenges that may arise in using these sensors, and discusses new applications of these sensors that may be pursued in future research.

Ethnic differences in behavioral and physiological indicators of sensitivity to threat

The clinical presentation of anxiety may differ between Hispanics/Latinx (H/L) and non-H/L, although findings on ethnic differences in self-reported anxiety symptoms have been mixed. Fewer studies have focused on ethnic differences in quick and relatively automatic laboratory-assessed indicators of anxiety symptoms, which have the potential to be more objective indicators than self-report. Therefore, the present study examined ethnic differences in two laboratory-assessed indicators of threat sensitivity (an important transdiagnostic mechanism of anxiety): attentional bias to threat and electromyography startle reactivity to threat. White H/L (n = 117) and White non-H/L (n = 168) adults who were matched on demographics and lifetime psychopathology (including anxiety) completed a dot-probe task to assess attentional bias to threat and the No-Predictable-Unpredictable threat (NPU) task to assess startle reactivity to threat. Results indicated that H/L displayed less Slow OrientationRB (β = -0.27, p = 0.032, R2β∗ = 0.02), and increased Slow DisengagementRB (β = 0.31, p = 0.016, R2β∗ = 0.02) compared to non-H/L. H/L exhibited blunted overall startle compared to non-H/L (β = -0.30, p = 0.014, R2β∗ = 0.02), but groups did not differ in startle reactivity to either predictable or unpredictable threat. In summary, H/L and non-H/L may differ in their experience and presentation of anxiety symptoms and such differences may vary across indicators of sensitivity to threat.

An updated transdiagnostic review of social cognition and eating disorder psychopathology

Existing data suggest that deficits in social cognitive functioning are transdiagnostic phenomena that are observed across various forms of psychopathology. The goal of the present review was to provide an updated systematic review of the literature on social cognitive functioning across eating disorders (EDs), including anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). Studies that assessed six areas of social cognition were included: theory of mind, social perception, social knowledge, attributional bias, emotion perception, and emotion processing. A systematic search identified 71 studies, the majority of which examined adult women with AN. Research typically focused on alexithymia, theory of mind, empathy, social processing, emotion recognition, or emotion processing. Results suggested some deficits in social cognition in EDs. AN had the most studies with some evidence for deficiencies in social cognition but a fair amount of variability. Research on BN and BED was limited and inconsistent, though there appear to be some deficits in social cognition. Together, the limited coverage across EDs and heterogeneous methodology preclude firm conclusions regarding general or ED-specific deficits, as well as understanding the role of social cognition in ED etiology and maintenance. Therefore, several key questions and future directions are outlined for research moving forward.

Reduced emotion recognition from nonverbal cues in anorexia nervosa

OBJECTIVE

Recent models of anorexia nervosa (AN) emphasise the role of reduced emotion recognition ability (ERA) in the development and maintenance of the disorder. However, methodological limitations impede conclusions from prior research. The current study tries to overcome these limitations by examining ERA with an audio-visual measure that focuses strictly on multimodal nonverbal cues and allows to differentiate between ERA for different emotion categories.

METHOD

Forty women with AN and 40 healthy women completed the Geneva Emotion Recognition Test. This test includes 83 video clips in which 10 actors express 14 different emotions while saying a pseudo-linguistic sentence without semantic meaning. All clips contain multimodal nonverbal cues (i.e., prosody, facial expression, gestures, and posture).

RESULTS

Patients with AN showed poorer ERA than the healthy control group (d = 0.71), particularly regarding emotions of negative valence (d = 0.26). Furthermore, a lower body weight (r = 0.41) and longer illness duration (ρ = -0.32) were associated with poorer ERA in the AN group.

CONCLUSIONS

Using an ecologically valid instrument, the findings of the study support illness models emphasising poor ERA in AN. Directly addressing ERA in the treatment of AN with targeted interventions may be promising.

Differences in the use of emotion regulation strategies between anorexia and bulimia nervosa: A systematic review and meta-analysis

OBJECTIVE

Research has identified abnormal emotion regulation (ER) as an underlying mechanism in the onset and maintenance of eating disorders. Yet, it still remains unclear whether different forms of ER, adaptive and maladaptive strategies, are similar across categories of eating disorders.

METHOD

A systematic review and meta-analysis were carried out to look at ER differences between anorexia nervosa (AN) and bulimia nervosa (BN), two common eating disorder pathologies with different eating patterns.

RESULTS

41 studies were included in the meta-analysis. The results revealed no differences in the use of maladaptive ER strategies between individuals with AN and BN, however patients with AN tend to use less adaptive ER strategies as compared to patients with BN.

CONCLUSIONS

Making less use of adaptive strategies in AN might be due to low body weight and high levels of alexithymia which define AN. In order to improve treatment outcome in individuals suffering from AN, these findings suggest to focus more on improving the use of adaptive ER strategies.

Physiological, emotional and neural responses to visual stimuli in eating disorders: a review

BACKGROUND

Overconcern with food and shape/weight stimuli are central to eating disorder maintenance with attentional biases seen towards these images not present in healthy controls. These stimuli trigger changes in the physiological, emotional, and neural responses in people with eating disorders, and are regularly used in research and clinical practice. However, selection of stimuli for these treatments is frequently based on self-reported emotional ratings alone, and whether self-reports reflect objective responses is unknown.

MAIN BODY

This review assessed the associations across emotional self-report, physiological, and neural responses to both food and body-shape/weight stimuli in people with anorexia nervosa (AN), bulimia nervosa (BN) and binge eating disorder (BED). For food stimuli, either an aversive or lack of physiological effect was generated in people with AN, together with a negative emotional response on neuroimaging, and high subjective anxiety ratings. People with BN showed a positive self-rating, an aversive physiological reaction, and a motivational neural response. In BED, an aversive physiological reaction was found in contrast to motivational/appetitive neural responses, with food images rated as pleasant. The results for shape/weight stimuli showed aversive responses in some physiological modalities, which was reflected in both the emotional and neural responses, but this aversive response was not consistent across physiological studies.

CONCLUSIONS

Shape/weight stimuli are more reliable for use in therapy or research than food stimuli as the impact of these images is more consistent across subjective and objective responses. Care should be taken when using food stimuli due to the disconnect reported in this review.

Cognitive and emotional regulation in adolescents and young women with eating disorders

BACKGROUND

Eating disorders (EDs) are associated with a reduced ability to regulate emotion and impulses during the life span. Working memory and executive functions (EFs) are cognitive regulatory systems supported by networks involving the pre-frontal cortex. Studies in EDs found impaired functioning in these domains, showing an association between EDs and the reduced ability to control emotions and impulses.

OBJECTIVE

To investigate EF in adolescents and young women with eating disorders (ED) using a quasi-experimental design, focusing on cognitive efficiency, emotional regulation (ER) and behavioural outcomes also taking into account pharmacological treatment and duration of illness.

METHODS

A sample of 151 females belonging to two groups took part in this study. Twenty-six girls and young women (M_age 22;8 years) with ED and 125 typically developed girls and young women (M_age 17;4 years) completed a battery of cognitive tasks (Go-no-go, Stop-signal task, Symmetry span, Reading Span) and the Youth Self-Report and the Difficulties in Emotional Regulation Scale Performance. A series of ANOVA with the Brown-Forsythe test was used to compare the groups.

RESULTS

Participants with ED and controls did not show significant differences in EF tasks, whereas differences between younger and older participants with ED emerged. Moreover, ER difficulties seem to be associated with mainly internalizing problems in EDs. Further analysis on the full ED sample did not reveal any significant differences associated with the disorder persistence. Considering pharmacological treatment effects over cognitive, emotional and behavioural measures emerged.

CONCLUSIONS

The present study documented no specific differences in EF between control and participants with EDs, whereas important differences emerged in ER and behavioural outcomes perception in the clinical sample, together with a partial influence of pharmacological treatment.

LEVEL OF EVIDENCE

No level of evidence.

Emotion regulation of others' positive and negative emotions is related to distinct patterns of heart rate variability and situational empathy

Although emotion regulation has been proposed to be crucial for empathy, investigations on emotion regulation have been primarily limited to intrapersonal processes, leaving the interpersonal processes of self-regulation rather unexplored. Moreover, studies showed that emotion regulation and empathy are related with increased autonomic activation. How emotion regulation and empathy are related at the autonomic level, and more specifically during differently valenced social situations remains an open question. Healthy adults viewed a series of short videos illustrating a target who was expressing positive, negative, or no emotions during a social situation (Positive, Negative, or Neutral Social Scenes). Prior to each video, participants were instructed to reappraise their own emotions (Up-regulation, Down-regulation, or No-regulation). To assess autonomic activation, RR intervals (RRI), high frequency (HF) components of heart rate variability (HRV), and electrodermal activity phasic responses (EDRs) were calculated. Situational empathy was measured through a visual analogue scale. Participants rated how empathic they felt for a specific target. Up- and Down-regulation were related to an increase and a decrease in situational empathy and an increase in RRI and HF, respectively, compared to the control condition (No-regulation). This suggests increased activity of the parasympathetic branch during emotion regulation of situational empathic responses. Positive compared to Negative Social Scenes were associated with decreased situational empathy, in addition to a slightly but non-significantly increased HF. Altogether, this study demonstrates that emotion regulation may be associated with changes in situational empathy and autonomic responses, preferentially dominated by the parasympathetic branch and possibly reflecting an increase of regulatory processes. Furthermore, the current study provides evidence that empathy for different emotional valences is associated with distinct changes in situational empathy and autonomic responses.

Improving emotion recognition in anorexia nervosa: An experimental proof-of-concept study

OBJECTIVE

Previous research has found increasing evidence for difficulties in emotion recognition ability (ERA) and social cognition in anorexia nervosa (AN), and recent models consider these factors to contribute to the development and maintenance of the disorder. However, there is a lack of experimental studies testing this hypothesis. Therefore, the present proof-of-concept study examined whether ERA can be improved by a single session of a computerized training in AN, and whether this has short-term effects on eating disorder symptoms.

METHOD

Forty inpatients (22.20 ± 7.15 years) with AN were randomly assigned to receive a single session of computerized training of ERA (TERA) or a sham training (training the recognition of different types of clouds). ERA, self-reported eating disorder symptoms, and body mass index (BMI) were assessed within 3 days before and after training.

RESULTS

After training, both groups showed improved ERA, reduced self-reported eating disorder symptoms, and an increased BMI. As compared to patients in the control group, patients who received TERA showed greater improvements in ERA and self-reported eating disorder symptoms.

DISCUSSION

ERA can be effectively trained in patients with AN. Moreover, short-term improvements in self-reported eating disorder symptoms provide tentative support for the hypothesis that difficulties in ERA contribute to the maintenance of AN, and that specific trainings of ERA hold promise as an additional component in AN treatment. Future studies are needed to replicate these findings in larger samples, and to investigate long-term effects and transfer into real-world settings.

Editorial to the virtual issue highlighting neuroscience based research in eating disorders to mark the 49th Society for Neuroscience Annual Meeting

OBJECTIVE

This virtual issue of the International Journal of Eating Disorders highlights recently published research that is based on neuroscience concepts, to mark the 49th Society for Neuroscience Annual Meeting in Chicago, IL, in November 2019.

METHODS AND RESULTS

The collection of articles includes research published between 2018 and 2019 that fall within the broader field of clinical neuroscience. Those articles span a broad range of themes, including food intake regulation and reward circuitry, taste perception, decision-making, cognitive and emotional bias, and targeting altered brain circuits using novel therapeutic methods.

DISCUSSION

The eating disorders field as a whole is increasingly incorporating neuroscience-based concepts when studying those disorders and developing disease models. We hope that this virtual issue will further stimulate discussion and research that is focused on brain circuits and neurobiology to study etiology and pathophysiology of eating disorders to develop more effective treatments.