Development of a methodology to combine fMRI and EMG to measure emotional responses in patients with anorexia nervosa

Disgust and Self-Disgust in Eating Disorders: A Systematic Review and Meta-Analysis

Disgust and self-disgust are aversive emotions which are often encountered in people with eating disorders. We conducted a systematic review and meta-analysis of disgust and self-disgust in people with eating disorders using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The systematic review of the literature revealed 52 original research papers. There was substantial heterogeneity regarding the research question and outcomes. However, we found 5 articles on disgust elicited by food images, 10 studies on generic disgust sensitivity, and 4 studies on self-disgust, and we proceeded to a meta-analytic approach on these studies. We found that women with eating disorders have significantly higher momentary disgust feelings in response to food images (1.32; 95% CI 1.05, 1.59), higher generic disgust sensitivity (0.49; 95% CI 0.24, 0.71), and higher self-disgust (1.90; 95% CI 1.51, 2.29) compared with healthy controls. These findings indicate the potential clinical relevance of disgust and self-disgust in the treatment of eating disorders.

Beyond vernacular: Measurement solutions to the lexical fallacy in disgust research

Disgust may play an important role in several mental disorders, in part because disgust seems impervious to corrective information, a feature noted long before it was studied by clinical psychologists. A deeper understanding of disgust could improve not only the treatment of mental disorders, but also other societal problems involving this peculiar emotion. In this paper, we review the measurement of disgust and identify issues that hold back progress in understanding how to treat this emotion. First, self-report measures of disgust, although optimized in terms of reliability, are compromised in terms of validity due to the "lexical fallacy," that is, the assumption that vernacular usage of emotion terms reveals natural kinds. Improved self-report measures that parse disgust from neighboring states of discomfort and disapproval can address this limitation, but these approaches are absent in clinical psychology. Second, "objective" measures of disgust, although free of vernacular limitations, require greater psychometric scrutiny. In a critical review, we find that most instrument-based measures fail to demonstrate adequate reliability, rendering them unsuitable for the individual differences research crucial to clinical psychology. In light of this assessment, we provide several recommendations for improving the reliability and validity of disgust measurement, including renewed attention to theory.

RYGB and flavor-consequence learning

Flavor-consequence learning refers to learned associations between flavor stimuli and post-oral consequences of food that affect food selection, amount eaten and affect. Forms of flavor-consequence learning include flavor aversions, flavor avoidance, conditioned satiety, expected satiety and appetition. Roux-en-Y gastric bypass surgery (RYGB) and other bariatric procedures alter gastrointestinal processing of food in a number of ways. Thus, it is plausible that these procedures alter post-oral unconditioned stimuli that support flavor-consequence learning, leading to altered food selection, amount eaten, and affect. Surprisingly, however, there is almost no research on the role of flavor-consequence learning in the effects of bariatric surgery on appetite. This issue urgently warrants investigation.