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

Abstract

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.

Neural responsiveness to Chinese versus Western food images: An functional magnetic resonance imaging study of Chinese young adults

“…In relation to possible applied implications, food stimuli can trigger significant neural, physiological and psychological changes (96). Therefore, food images can be used in research and clinical practice to detect and treat disordered eating behaviors.…”

Examining relationships among thin-ideal internalization, eating pathology, and motivational reactions to high- and low-calorie food

“…Conversely, many studies have also reported enhanced defensive reactions to food stimuli in people with EDs and disordered eating behaviours (Erdur et al, THIN-IDEAL INTERNALIZATION AND REACTIONS TO FOOD 5 2017;Rodriguez et al, 2007;Soussignan et al, 2010). In line with the motivational conflict hypothesis, there is evidence to suggest that food elicits both positive and negative emotional reactions in individuals with eating pathology, particularly those who experience binge eating (for a review, see Burmester et al, 2021). Evidence from laboratory-based studies indirectly supports a link between thin-ideal internalization and reactions to food.…”

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

“…Due to the high salience of food and body shape in patients with eating disorders, research on stimulus processing has been conducted on different levels [ 7 ]. Studies on physiological responses, such as HR, have mainly focused on food stimuli.…”

“…The absence of group differences regarding affective stimuli was not only seen in those non-clinical groups but also in a study with participants with BN [ 12 ]. A recent review reports a decoupling between self-reported emotional responses and physiological responses to affective stimuli across eating disorders [ 7 ]. Using a task employing HR self-counting and objective measurement, a deficit in interoceptive awareness was observed for subjects suffering from AN both at rest and in an emotional context [ 13 ].…”

“…Therefore, in previous studies on HR and other psychophysiological responses to body stimuli, a heterogeneous picture emerges. Patient self-reporting may be biased by social desirability or diminished introspective abilities and lack of emotional awareness [ 7 , 21 ]. Higher alexithymic tendencies are observed in AN in general and specifically in adolescent patients [ 22 ].…”