Influence of Visceral Interoceptive Experience on the Brain's Response to Food Images in Anorexia Nervosa

Abstract

Objective To determine how visceral sensations affect responses to food stimuli in anorexia nervosa (AN). Methods Twenty weight-restored, unmedicated adolescent and young adult women with AN and twenty healthy control participants completed an interoceptive attention task during which they focused on sensations from the heart, stomach, and bladder and made ratings of these sensations. They then underwent fMRI scanning while viewing pictures of food and non-food objects. Between-groups t-tests were employed to investigate group differences in the relationship between interoceptive sensation ratings and brain hemodynamic response to food pictures, and, specifically, to highly palatable foods. Results In response to food pictures, AN participants exhibited a positive relationship between stomach sensation ratings and posterior insula activation (peak t=4.30). AN participants displayed negative relationships between stomach sensation ratings and amygdala activation (peak t=−4.05) and heart sensation ratings and ventromedial prefrontal cortex activation (peak t=−3.52). In response to highly palatable foods, AN was associated with positive relationships between stomach sensation ratings and activity in the subgenual anterior cingulate (peak t=3.88) and amygdala (peak t=4.83), and negative relationships in the ventral pallidum (peak t=−3.99) and ventral tegmental area (peak t=−4.03). AN participants also exhibited negative relationships between cardiac sensations and activation in response to highly palatable foods in the putamen (peak t=−3.41) and ventromedial prefrontal cortex (peak t=−3.61). Healthy participants exhibited the opposite pattern in all of these regions. Conclusions Hedonic and interoceptive inferences made by individuals with AN at the sight of food may be influenced by atypical visceral interoceptive experience, which could contribute to restrictive eating.

What can food-image tasks teach us about anorexia nervosa? A systematic review

“…Two studies reported alterations within visual processing areas in AN when high-calorie food was viewed, although exact loci and direction of difference was inconsistent [ 48 , 79 ]. One study did not find differences in neural activity between AN and HC, but did report that neural activity during food-image viewing was differentially associated with stomach sensation ratings measured outside of the scanner in AN vs HC [ 80 ]. Collectively passive viewing studies have produced a diverse set of findings that are difficult to interpret.…”

“…Quality Index scores were again affected by recruitment methods or descriptions (e.g. [ 79 , 80 , 82 ]). The majority of the studies involved very small numbers of participants, by current standards for fMRI investigations.…”

“…Conclusions may be more robust for investigations with sample sizes greater than 20 per group (e.g. [ 61 , 80 , 83 ]). Some studies have the additional methodological strength of standardizing time since meals [ 43 , 45 , 47 – 50 , 61 , 79 , 81 , 84 , 85 ], and of including non-food stimulus comparisons [ 44 , 45 , 47 – 50 , 79 – 85 ].…”

Interoception and disordered eating: A systematic review

“…The study that found no difference (Krieg et al, 1993) . However, activation in other limbic areas also appeared to be dysfunctional in anorexia (Kerr et al 2017, Berner et al 2018, Strigo et al 2013.…”

“…Two studies (Kerr et al, 2106;Kerr et al, 2017) used fMRI to assess interoceptive processing of cardiac signals and both found differences in neural processing of interoception in patients recovered from AN and healthy controls One study (Khalsa et al, 2015) used infusions of isoproterenol (a non-selective  adrenoceptor agonist) to elicit changes in cardiac activity and found that participants with anorexia reported increased cardiac sensations under low arousal states.…”