Temporal Processing of Joyful and Disgusting Food Pictures by Women With an Eating Disorder

Psychophysics over the counter: The effect of food preference on the perception of food quantity

Much research in food psychology has examined the influence of perceptual features - color, texture, packaging - on preference for that food. Here, we addressed the reverse question of the influence of food preference on the perception of its quantity. Does a portion of a loved food appear different than the same portion of a hated food? We probed this question by employing state-of-the-art tools of psychophysics, which allowed us the parallel examination of several long-standing issues of psychophysics. The latter included the difference between symbolic and non-symbolic number, the difference between the methods of Magnitude Estimation and Magnitude Production, the difference between under- or over-estimation and rate of growth measured by the (slope of) psychophysical function as well as the derivation of the Difference Threshold by the method of Constant Stimuli. We addressed the question of an effect on perception of food valence with four distinct experiments. Presenting real food items, we found that perceived quantity is a compressive function of objective quantity regardless of valence; both loved- and hated-food dynamics are governed by Stevens' power function with an exponent of 0.8. In absolute terms, applying Magnitude Estimation, we witnessed a gross underestimation for loved and hated food alike. In contrast, applying Magnitude Production, participants underproduced loved food, but overproduced hated food. For discrimination of food quantity, we found better resolving power for hated food. Collectively, our results show that, across diverse psychophysical evaluations, food valence affects its perception, especially when people actively regulate the to-be-consumed portion.

The Processing of Short Time Intervals: Some Critical Issues

Humans have the capability to make judgments about the relative duration of time intervals with accuracy (correct perceived duration) and precision (low variability). However, this capability has limitations, some of which are discussed in the present chapter. These limitations, either in terms of accuracy or precision, are obvious when there are changes in the physical characteristics of the stimuli used to mark the intervals to be judged. The characteristics are the structure (filled vs. empty) of the intervals and the sensory origin of the stimuli used to mark them. The variability of time estimates also depends on the use of single intervals by opposition to the use of sequences of intervals, and on the duration range under investigation. In addition to the effect caused by the physical characteristics of the stimuli, the perceived duration also relies on the way of presenting successive stimuli and on whether the intervals are marked by a single source or by different sources with distance (spatial effect) between them.

Me, myself and you: How self-consciousness influences time perception

Several investigations have shown that the processing of self-relevant information differs from processing objective information. The present study aimed to investigate the effect of social stimuli on subjective time processing. Here, social stimuli are images of an unknown male and female person and an image of participants' self. Forty university students were tested with a time reproduction task in which they were asked to reproduce the duration of the stimulus previously presented. Images of others or themselves were used to mark the temporal intervals. Participants also performed questionnaires to evaluate the level of anxiety and depression as well as self-consciousness. A generalised linear mixed-effects model approach was adopted. Results showed that male participants with higher Private Self-Consciousness scores showed higher time perception accuracy than females. Also, female participants reported higher scores for the Public Self-Consciousness subscale than male participants. The findings are discussed in terms of social context models of how attention is solicited and arousal is generated by social stimuli, highlighting the effect of social context on subjective perception of time.

Frontal lobe-related cognition in the context of self-disgust

Self- disgust is an adverse self-conscious emotion that plays an important role in psychopathology and well-being. However, self-disgust has received little attention in the emotion literature, therefore our understanding of the processes underlying the experience of self-disgust is relatively scarce, although neuropsychological and neuroimaging studies support the idea that this emotion may heavily rely on frontal lobe-related cognition. To test this hypothesis, in two studies we investigated the relationship between state and trait levels of self-disgust, cognition and emotion regulation in healthy adults. Specifically, in Study 1 we tested the hypothesis that emotion regulation strategies (avoidance, suppression, and cognitive reappraisal) mediate the relationship between inhibition ability and state and trait levels of self-disgust. In Study 2, we followed a more comprehensive approach to test the hypothesis that frontal lobe-related cognitive processes (updating, Theory of Mind-ToM-, and self-attention) are closely related to the experience of self-disgust in healthy adults. Overall, across these studies, we found evidence to support the idea that inhibition ability and ToM may play a role in the experience of state and trait self-disgust, respectively. However, we did not find consistent evidence across the two studies to support the notion held in the literature that the experience of self- conscious emotions, in this case self-disgust, is heavily dependent on frontal lobe-related cognition.

Effect of food cues on time perception: influence of calories and diet control

The aim of this study was to investigate the influence on individuals' time perception of observing a range of foods differing in calorific content. In a first experiment, 92 adult participants performed a temporal bisection task with stimulus durations presented in the form of high- or low-calorie food pictures as well as matched non-food control pictures. In a second experiment, 102 participants performed a strict replication of Experiment 1, without the low-calorie pictures condition as it showed less pronounced effects. Across the two experiments, the data revealed common results. An overestimation of time was observed in relation to high-calorie food pictures when compared with non-food pictures (Experiment 2), and the effect was a function of participants' diet control (Experiments 1 & 2). Contrary to our hypothesis, the more the participants reported controlling their diet, the less they overestimated the time when presented with food stimuli. The participants who controlled their diet reported being less aroused by the high-calorie food pictures, allowing the assumption that the modulation in time overestimation relies on the arousal response generated by high-calorie food pictures.

Time evaluation and its accuracy in eating disorders: differences in relation to interoceptive awareness

PURPOSE

Time evaluation has been poorly studied in eating disorder (ED) patients despite its relationship with body awareness, which is a core psychopathological feature in EDs and is influenced by impulsivity, interoception, and working memory. This study aims to evaluate time estimation and its accuracy across the ED spectrum in connection with specific and general psychopathology.

METHODS

A group of 215 women was enrolled in a computerized task involving the estimation of 1-min intervals. Impulsivity and body awareness constructs (self-monitoring, depersonalization, interoceptive deficit) were evaluated and examined for significant correlations with time estimation and the accuracy of the measure.

RESULTS

Patients with EDs showed an impaired ability to estimate time, with an accuracy that positively correlated with compulsive self-monitoring (p = 0.03). Differences between diagnostic subgroups showed an overestimation of time in anorexia nervosa patients and an underestimation of time in binge eating disorder patients, whose time estimation was also less accurate.

CONCLUSION

The relationship between time estimation and compulsive self- monitoring might corroborate the presence of an imbalanced integration of information in patients with EDs that was not present in the community women included in the study. Time perception should be further evaluated in the ED field, and longitudinal changes due to psychopathological recovery or BMI changes should be examined.

LEVEL OF EVIDENCE

Level III: Evidence obtained from a well-designed cohort or case-control analytic study.

Phonological working memory is adversely affected in adults with anorexia nervosa: a systematic literature review

PURPOSE

Cognitive restraint has potentiating and deleterious effects on working memory (WM) in anorexia nervosa (AN). Conflicting evidence may be due to heterogeneity of tasks examining different WM components (e.g., verbal/auditory versus visuospatial), and differences in adolescent versus adult AN. Additionally, differential cognitive profiles of restricting versus binge/purging subtypes, comorbid psychiatric disorders and psychotropic medication use may confound findings.

METHODS

To address these conflicts, 25 studies, published between 2016 and 2021, investigating WM in children, adolescents and adults with AN were systematically reviewed using PRISMA guidelines.

RESULTS

In 71% of WM tasks, no difference in performance between AN patients and age-matched controls was reported, while 29% of WM tasks showed worse performance. Adults with AN displayed deficits in 44% of the verbal/auditory tasks, while performance remained unaffected in 86% of visuospatial tasks.

CONCLUSION

Examining age groups and WM subsystems separately revealed novel findings of differentially affected WM components in AN. Comorbidities and psychotropic medications were common among AN participants and should be regarded as critical confounding factors for WM measures. Future studies examining different components of WM, acknowledging these confounding factors, may reveal specific deficits in AN to aid treatment improvement strategies.

LEVEL OF EVIDENCE

I, systematic review.

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.

Politically Biased Time Perception and Perspective

The main objective of this study was to determine if the estimation of time could be used to reveal an implicit political bias. The study also aimed at determining if a political bias is related to a specific temporal perspective or to other personality factors. The main demonstration is based on a bisection temporal task where the participants were asked to say if the duration of the presentation of a politician’s photo is short or long. There were three independent variables of interest: the location of politicians on the left (liberal) or right (conservative) on the political axis, the emotions expressed on a politician’s photo (joy, anger or neutral), and the political allegiances of the participants. Overall, compared to conditions with neutral faces or faces expressing joy, participants overestimated the duration of faces expressing anger. This effect, however, depends on the political allegiance of the participants. Compared to the neutral face condition, liberal participants overestimated the length of presentation of politicians’ faces in the joy and anger conditions. The results also showed that, compared to the condition in which photos of conservative politicians are presented, conservative participants underestimated the presentation duration of liberal politicians’ photos; such an influence of the orientation of presented politicians was not observed with liberal participants. The results also reveal that conservative participants differed from liberal participants on the future-oriented scale and on the past-positive-oriented scale of the Zimbardo Time Perspective Inventory (ZTPI). The study shows that time perception can be used to reveal a kind of implicit political bias.

Relaxing and stimulating effects of odors on time perception and their modulation by expectancy

Although several studies have reported relaxing and stimulating effects of odors on physiology and behavior, little is known about their underlying mechanisms. It has been proposed that participant expectancy could explain these activation effects. Since emotional stimuli are known to modulate time perception, here we used the temporal bisection task to determine whether odors have objective relaxing and stimulating effects by respectively slowing down or speeding up the internal clock and whether prior expectancy could alter these effects. In Experiment 1, 118 participants were presented either with a strawberry odor or an odorless blank. In Experiment 2, 132 participants were presented either with a lemon odor or an odorless blank. In both experiments, expectancy was manipulated using suggestion (verbal instructions). The stimulus was either described as relaxing or stimulating, or was not described. In the absence of prior suggestion, findings showed that, compared to participants presented with an odorless blank, participants presented with the strawberry odor underestimated sound durations (i.e., a relaxing effect) whereas participants presented with the lemon odor overestimated them (i.e., a stimulating effect). These results confirm that pleasant odors can have objective relaxing and stimulating effects by themselves, which are better explained by arousal-based mechanisms rather than attentional distraction. Furthermore, in both experiments, incongruent suggestions undid the effects of both odors without reversing them completely (i.e., strawberry did not become stimulating even if participants were told so). Both these bottom-up and top-down influences should be considered when investigating the emotional impact of odors on human behavior.

Do I dislike what you dislike? Investigating the effect of disgust on time processing

Time perception can be distorted by emotional stimuli. The present study aims to investigate the effect of disgust on time perception in young adults. Here, we report two experiments in which a time bisection task was used with intervals lasting 400 ms (short standard) to 1600 ms (long standard). In Experiment 1, temporal intervals were marked by neutral images or images from food (rotten, joyful), and facial (disgust, happy) categories. In Experiment 2, disgust-eliciting and neutral stimuli belonging to seven different domains were used: faces, food, animals, body products, injury/infections, death and hygiene. Results showed temporal overestimations when, compared to neutral conditions, disgusted faces (Experiments 1 and 2) and disgusting death and hygiene stimuli (Experiment 2) were used, and a temporal underestimation when images of rotten food (Experiment 1) were used. Results are discussed in terms of arousal-based and attention-based processes and showed that the degree of the emotional component influences time perception.

A systematic and methodological review of attentional biases in eating disorders: Food, body, and perfectionism

OBJECTIVE

The current systematic and methodological review aimed to critically review existing literature utilizing implicit processing, or automatic approach- and/or avoidance-related attentional biases between eating disorder (ED) and nonclinical samples, which (a) highlights how psychophysiological methods advance knowledge of ED implicit bias; (b) explains how findings fit into transdiagnostic versus disorder-specific ED frameworks; and (c) suggests how research can address perfectionism-related ED biases.

METHOD

Three databases were systematically searched to identify studies: PubMed, Scopus, and PsychInfo electronic databases. Peer-reviewed studies of 18- to 39-year-olds with both clinical ED and healthy samples assessing visual attentional biases using pictorial and/or linguistic stimuli related to food, body, and/or perfectionism were included.

RESULTS

Forty-six studies were included. While behavioral results were often similar across ED diagnoses, studies incorporating psychophysiological measures often revealed disease-specific attentional biases. Specifically, women with bulimia nervosa (BN) tend to approach food and other body types, whereas women with anorexia nervosa (AN) tend to avoid food as well as overweight bodies.

CONCLUSIONS

Further integration of psychophysiological and behavioral methods may identify subtle processing variations in ED, which may guide prevention strategies and interventions, and provide important clinical implications. Few implicit bias studies include male participants, investigate binge-eating disorder, or evaluate perfectionism-relevant stimuli, despite the fact that perfectionism is implicated in models of ED.