I change my mind to get better: Process tracing-based microanalysis of food choice processes reveals differences between anorexia nervosa and bulimia nervosa during inpatient treatment

Emotional food-cue-reactivity in anorexia nervosa and bulimia nervosa: An electroencephalography study

OBJECTIVE

Food-cue-reactivity entails neural and experiential responses to the sight and smell of attractive foods. Negative emotions can modulate such cue-reactivity and this might be central to the balance between restrictive versus bulimic symptomatology in Anorexia Nervosa (AN) and Bulimia Nervosa (BN).

METHOD

Pleasantness ratings and electrocortical responses to food images were measured in patients with AN (n = 35), BN (n = 32) and matched healthy controls (HC, n = 35) in a neutral state and after idiosyncratic negative emotion induction while electroencephalography (EEG) was recorded. The EEG data were analyzed using a mass testing approach.

RESULTS

Individuals with AN showed reduced pleasantness for foods compared to objects alongside elevated widespread occipito-central food-object discrimination between 170 and 535 ms, indicative of strong neural cue-reactivity. Food-object discrimination was further increased in the negative emotional condition between 690 and 1200 ms over centroparietal regions. Neither of these effects was seen in individuals with BN.

DISCUSSION

Emotion modulated food-cue-reactivity in AN might reflect a decreased appetitive response in negative mood. Such specific (emotion-)regulatory strategies require more theoretical work and clinical attention. The absence of any marked effects in BN suggests that emotional cue-reactivity might be less prominent in this group or quite specific to certain emotional contexts or food types.

PUBLIC SIGNIFICANCE

Negative affectivity is a risk factor for the development of eating disorders and individuals with eating disorders experience problems with emotion regulation. To better understand the effects of negative emotions, the present study investigated how they affected neural correlates of food perception in anorexia nervosa and bulimia nervosa.

Mouse-cursor trajectories reveal reduced contextual influence on decision conflict during delay discounting in anorexia nervosa

OBJECTIVE

The capacity of individuals with anorexia nervosa (AN) to forgo immediate food rewards in their long-term pursuit of thinness is thought to reflect elevated self-control and/or abnormal reward sensitivity. Prior research attempted to capture an increased tendency to delay gratification in AN using delay-discounting tasks that assess how rapidly the subjective value of rewards decreases as a function of time until receipt. However, significant effects were mostly subtle or absent. Here, we tested whether the process leading to such decisions might be altered in AN.

METHOD

We recorded mouse-cursor movement trajectories leading to the final choice in a computerized delay-discounting task (238 trials) in 55 acutely underweight females with AN and pairwise age-matched female healthy controls (HC). We tested for group differences in deviations from a direct choice path, a measure of conflict strength in decision making, and whether group moderated the effect of several predictors of conflict strength (e.g., choice difficulty, consistency). We also explored reaction times and changes in trajectory directions (X-flips).

RESULTS

No group differences in delay-discounting parameters or movement trajectories were detected. However, the effect of the aforementioned predictors on deviations (and to a lesser extent reaction times) was reduced in AN.

DISCUSSION

These findings suggest that while delay discounting and conflict strength in decision making are generally unaltered in AN, conflict strength was more stable across different decisions in the disorder. This might enable individuals with AN to pursue (maladaptive) long-term body-weight goals, because particularly conflicting choices may not be experienced as such.

PUBLIC SIGNIFICANCE

The deviations from a direct path of mouse-cursor movements during a computerized delay-discounting task varied less in people with anorexia nervosa. Assuming such deviations measure decision conflict, we speculate that this increased stability might help people with anorexia nervosa achieve their long-term weight goals, as for them the struggle with the decision to eat high-calorie meals when hungry will be milder, so they would be more likely to skip them.

Emotional eating: elusive or evident? Integrating laboratory, psychometric and daily life measures

PURPOSE

Emotional eating (EE) refers to eating in response to (negative) emotions. Evidence for the validity of EE is mixed: some meta-analyses find EE only in eating disordered patients, others only in restrained eaters, which suggest that only certain subgroups show EE. Furthermore, EE measures from lab-based assessments, ecological momentary assessment (EMA), and psychometric measures often diverge. This paper tested whether the covariance of these three different EE methods can be modeled through a single latent variable (factorial validity), and if so, how this variable would relate to restrained eating (construct validity), Body-Mass-Index (BMI), and subclinical eating disorder symptomatology (concurrent validity).

METHODS

102 non-eating disordered female participants with a wide BMI range completed EE measures from three methods: psychometric questionnaires, a laboratory experiment (craving ratings of food images in induced neutral vs. negative emotion) and EMA questionnaires (within-participant correlations of momentary negative emotions and momentary food cravings across 9 days). Two measures for each method were extracted and submitted to confirmatory factor analysis.

RESULTS

A one-factor model provided a good fit. The resulting EElat factor correlated positively with subclinical eating disorder symptoms and BMI but not with restrained eating.

CONCLUSIONS

The one-factor solution shows that the EE construct can validly be assessed with three different methods. Individual differences in EE are supported by the data and are related to eating and weight problem symptomatology but not to restrained eating. This supports learning accounts of EE and underscores the relevance of the EE construct to physical and mental health.

LEVEL OF EVIDENCE

II (Evidence obtained from well-designed controlled trials without randomization).

Can you learn to starve yourself? Inducing food avoidance in the laboratory

The restriction of energy intake is a central and persistent symptom of anorexia nervosa. Recent models of the disorder suggest that food restrictions are learned avoidance behaviours, which are acquired and maintained by classical and operant conditioning. The present study aims to test this learning model of food restriction. It investigates whether introducing negative consequences for the intake of tasty high-calorie food and introducing positive consequences for its avoidance can create food avoidance, increase fear of food, and decrease eating desires in healthy individuals. 104 women were randomly assigned to an experimental or control condition and completed an appetitive conditioning and avoidance learning task. While the experimental condition received money after avoiding the tasty high-calorie food item and heard an aversive sound after not avoiding food intake, the control condition never received these consequences. In the extinction phase, reward and punishment discontinued for both conditions. We measured avoidance frequency, mouse movements, fear, eating desires and stimulus liking. Participants in the experimental condition avoided the food more often than controls and showed increased fear, reduced eating desires and less liking for cues associated with food intake. These results support the notion that food avoidance behaviours, reduced eating desires and fear of food can be learned via classical and operant conditioning. Conditioning paradigms might be a useful tool to study the development and maintenance of food restriction in anorexia nervosa.

(Mouse cursor)-Tracking food decisions in binge eating disorder reveals preference for high-energy foods and a role of BMI

Binge Eating Disorder (BED) has been associated with deficits in cognitive control and decision-making. Yet, no study has yet investigated the characteristics of food choice and the involved choice conflict in this disorder. In the present study individuals with BED (N = 22) and without BED (N = 61), with a body mass index (BMI) between 21 and 44 completed 153 binary food decisions among foods varying in palatability and energy density. To assess conflict during choice we recorded computer mouse paths and reaction times. Subsequently, participants rated all foods on liking and energy content. Finally, participants completed a bogus taste test with the same foods to measure actual consumption. Predictors were modelled continuously using Bayesian mixed-effects modelling. Individuals with BED liked foods with higher energy content more and chose them more often in the choice task. Yet, actual consumption in the taste test did not differ between groups, neither regarding total consumption, nor of foods with higher energy. Mouse cursor-tracking revealed that control participants with higher BMIs showed more choice conflict than those with lower BMIs. This pattern was reversed in those with BED. The high-energy preference in ratings and food choice represent the first evidence in a controlled laboratory context for disorder-congruent food choice in BED. The fact that this was not reflected in actual consumption might have methodological implications for measuring laboratory eating behaviour. Mouse cursor-tracking gave further insights into choice processes and showed a less conflicted food choice in those with BED with higher BMI compared to those with lower BMI.