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This study assessed whether olfactory familiarization can render food odors more pleasant, and consequently food more attractive, to children with autism spectrum disorder. Participants were first presented with a series of food odors (session 1). Then, they were familiarized on four occasions (time window: 5 weeks) with one of the two most neutral odors (the other neutral odor was used as control) (session 2). In session 3, participants smelled the entire series of odors again. Both verbal and facial responses were compared from session 1 to session 3. After session 3, the children were presented with two identical foods (one containing the familiarized odor and one the control odor) and were asked to choose between these foods. Results revealed (1) a specific increase in positive emotions for the familiarized odor and (2) that 68% of the children chose the food associated with the "familiarized odor" (children who chose the "familiarized odor" food exhibited significantly more sensory particularities). These findings suggest that it is possible to modulate olfactory emotions and expand the dietary repertoire of children with autism spectrum disorder. Application of this paradigm may enable innovative prospects for food education in autism.

Although previous findings point to the long-term impact of ethanol exposure during periadolescence on hippocampal-dependent learning tasks, comparisons considering different onset and exposure periods during this developmental range of ages are still needed. The aim of this experiment was to determine whether intermittent voluntary chronic ethanol consumption onset at different ages, beginning either in pre-adolescence or adolescence, differentially produces impairment in the hidden-platform-water-maze-task performance persisting in adult rats after a 27-day-long period of abstinence. The performance of two groups of adult Wistar rats of both sexes, whose ethanol drinking onset was at postnatal day 19 (preadolescent) or 28 (adolescent), was compared with that of an adult control non-ethanol exposed group. The results indicated that voluntary intermittent ethanol drinking during the periadolescent period caused dramatic long-term detrimental effects in female rats which were unable to learn. Male rats were also impaired during the initial training blocks, the impact being greater in the group exposed during adolescence, but they exhibited no differences with the non-ethanol exposed control group by the end of training (block 6) and in a probe trial. These data support a greater vulnerability in females during periadolescence and point to adolescence as an especially sensitive period during male development to the long-term detrimental effects of ethanol in learning. (Contains 3 figures and 2 tables.)

The aetiology of anorexia nervosa (AN) presents a puzzle for researchers. Recent research has sought to understand the behavioural and neural mechanisms of these patients' persistent choice of calorie restriction. This scoping review aims to map the literature on the contribution of habit-based learning to food restriction in AN. PRISMA-ScR guidelines were adopted. The search strategy was applied to seven databases and to grey literature. A total of 35 studies were included in this review. The results indicate that the habit-based learning model has gained substantial attention in current research, employing neuroimaging methods, scales, and behavioural techniques. Food choices were strongly associated with dorsal striatum activity, and habitual food restriction based on the self-report restriction index was associated with clinical impairment in people chronically ill with restricting AN. High-frequency repetitive transcranial magnetic stimulation (HF-rTMS) and Regulating Emotions and Changing Habits (REaCH) have emerged as potential treatments. Future research should employ longitudinal studies to investigate the time required for habit-based learning and analyse how developmental status, such as adolescence, influences the role of habits in the progression and severity of diet-related illnesses. Ultimately, seeking effective strategies to modify persistent dietary restrictions controlled by habits remains essential. [ABSTRACT FROM AUTHOR]

In two experiments, thirsty rats consumed a compound of sucrose and a non-preferred flavor. In Experiment 1, a conditioned preference was observed in the experimental group when animals were tested both thirsty and hungry, but not when they were tested just thirsty. Animals in the control group, which experienced the flavor and the sucrose unpaired, never showed a preference. Experiment 2 replicated the absence of a preference in the experimental group when rats were tested thirsty, but provided evidence that a flavor-taste association had been formed during training. After conditioning, sucrose was paired with LiCl in group Dev whereas it was unpaired in group NonDev. The sucrose devaluation produced a decrease in CS preference in group Dev, and an increment in group NonDev. Taken together, these results show that preference for a non-preferred flavor can be readily observed after pairings with the positive consequences of the US (calories or absence of an expected illness) rather than with a palatable flavor. (Contains 2 figures.)

Improvements in the clinical management of anorexia nervosa (AN) are urgently needed. To do so, the search for innovative approaches continues at laboratory and clinical levels to translate new findings into more effective treatments. In this sense, modern learning theory provides a unifying framework that connects concepts, methodologies and data from preclinical and clinical research to inspire novel interventions in the field of psychopathology in general, and of disordered eating in particular. Indeed, learning is thought to be a crucial factor in the development/regulation of normal and pathological eating behaviour. Thus, the present review not only tries to provide a comprehensive overview of modern learning research in the field of AN, but also follows a transdiagnostic perspective to offer testable explanations for the origin and maintenance of pathological food rejection. This narrative review was informed by a systematic search of research papers in the electronic databases PsycInfo, Scopus and Web of Science following PRISMA methodology. By considering the number and type of associations (Pavlovian, goal-directed or habitual) and the affective nature of conditioning processes (appetitive versus aversive), this approach can explain many features of AN, including why some patients restrict food intake to the point of life-threatening starvation and others restrict calorie intake to lose weight and binge on a regular basis. Nonetheless, it is striking how little impact modern learning theory has had on the current AN research agenda and practice. [ABSTRACT FROM AUTHOR]

Individuals with impaired gustatory perception may have altered ingestive behaviors, which contribute to unhealthy weight status and disordered eating. Whether and to what extent weight status or eating symptomatology depend on flavor perception is still a controversial issue. Thus, the ability to discriminate among different levels of sweetness/fat content was compared in three studies using two‐alternative forced‐choice tasks and the standardized metrics of signal detection theory (SDT). In Study 1, three body mass index groups were included: underweight, healthy normal weight, and overweight. In Study 2, volunteers were currently‐ill and recovered (anorexia/bulimia nervosa) patients, and two age‐ and weight‐matched control groups. In Study 3, SDT metrics of both populations were compared. Results showed that SDT measures identified difficulties of underweight individuals to discriminate fat levels in sugary products, while patients with eating disorders exhibited outstanding discrimination of fat ingredients. Judgment biases were also detected in both populations. This highlights importance of using SDT methodology in flavor perception research in people with weight−/eating‐related problems. Practical Applications: This paper may serve as a starting point for the establishment of a consensual methodology in the field of flavor perception using the SDT approach. Especially in populations with eating‐ and weight‐related problems, it is both of considerable interest and a necessity to establish and promote standard metrics to provide more consistent and comparable results on the perception of sweet and fat inputs. On the one hand, SDT may be a valuable tool to deal with current methodological limitations and heterogeneity in methods used across studies. On the other, this should facilitate further study of the relationship between oral sensations and unhealthy eating and drinking behaviors to improve individuals' nutritional status and quality of life. [ABSTRACT FROM AUTHOR]

Summary: The aim of the present study was to compare the information provided by a discrete and continuous data analysis of two emotions (disgust and joy), elicited by bitter‐tasting beverages (coffee, yerba mate infusion and grapefruit juice) in two groups with different body mass index (BMI): overweight group (25 < BMI < 30), and healthy‐weight control group (18.5 < BMI ≤ 25). Participants (n = 66; 34 females, 32 males) evaluated a total of three consecutive sips of the same beverage (taking one sip every 20 s and registering a continuous video for 60 s). The Wilcoxon test (continuous analysis) showed some changes generated as the drinks were being consumed. The biggest difference was the expression of disgust for coffee in the high BMI group, at the first sip (0–10 s). It represented 27% compared to 2% in normal BMI. The continuous analysis allowed to observe the periods where the differences were greater (0–10 and 40–50 s). [ABSTRACT FROM AUTHOR]

The terms food avoidance and food aversion are often used interchangeably in the eating disorders (EDs) literature. However, they represent two different (but closely related) constructs that are the result of different processes. In patients suffering from anorexia nervosa, bulimia nervosa and avoidant/restrictive food intake disorder, food avoidance/restriction is usually assumed to be motivated by fear/anxiety (e.g., “intense fear of gaining weight or becoming fat” or “being afraid to eat after a frightening episode of choking”). In contrast, studies show that taste-aversion often leads to food avoidance. Unlike fear-motivated avoidance in which the flavour of food becomes a signal for danger, avoidance produced by taste aversions involves a reduction in the amount consumed due to a hedonic downshift. Here the attractiveness of the flavour changes by its association with a nauseogenic event. It is noteworthy that both sources of food avoidance exhibit different behavioural characteristics, contents of learning, and activate different brain regions and neuromodulators. This is especially important for the understanding and treatment of the EDs and their most serious behavioural manifestation: the life-threatening food refusal. Finally, the clinical implications of such a distinction and promising future research directions are discussed. [ABSTRACT FROM AUTHOR]

Background: Difficulties in emotion regulation have been related to psychological and physiological stress responses such as lower mood and lower parasympathetic activation (HF-HRV) under resting condition, but evidence on the potential link to the hypothalamic-pituitary-adrenal (HPA) axis functioning and to physiological stress responses during a stress task is still scarce. The aim of the study was to investigate stress responses in young women when confronted to a daily stressor such as exposure to thin ideals and to understand the role of correlates of self-reported trait-like emotion regulation difficulties (ERD). Methods: Heart rate variability (HRV) and salivary cortisol data were collected in a sample of 273 young women aged 18–35 with and without mental disorders during a vivid imagination of thin ideals (experimental condition) or landscapes (control condition). Changes in mood states were measured on a visual analogue scale (0–100). Correlates of trait-like ERD were self-reported using the Difficulties in Emotion Regulation Scale (DERS). Results: Participants with higher ERD showed a stronger decline in self-reported mood after vivid imagination of thin ideals compared to participants with lower ERD in the experimental condition but also a stronger increase of positive mood with increasing ERD in the control condition. ERD were not related to baseline HF-HRV or baseline salivary cortisol levels nor to any physiological response during and after the imagination of thin ideals. Discussion and conclusion: The results corroborate the role of ERD regarding the immediate psychological impact of daily stressors. Exposition to daily stressors in the laboratory results in discrepant psychological and physiological reactivity. Future studies should investigate under what conditions the complex interrelations between immediate and long-term ERD and biological activation are amenable to assessment in a laboratory setting. The additive effects of multiple exposition to stressors, such as thin ideals in daily life, also need to be addressed. [ABSTRACT FROM AUTHOR]

Background: Despite on-going efforts to better understand dysregulated eating, the olfactory-gustatory deficits and food preferences in eating disorders (ED), and the mechanisms underlying the perception of and responses to food properties in anorexia nervosa (AN) and bulimia nervosa (BN) remain largely unknown; both during the course of the illness and compared to healthy populations. It is, therefore, necessary to systematically investigate the gustatory perception and hedonics of taste in patients with AN and BN. To this end, we will examine whether aversions to the taste of high-calorie food is related to the suppression of energy intake in restricting-type AN, and whether an increased hedonic valence of sweet, caloric-dense foods may be part of the mechanisms triggering binge-eating episodes in BN. In addition, the role of cognitions influencing these mechanisms will be examined. Method: In study 1, four mixtures of sweet-fat stimuli will be presented in a sensory two-alternative forced-choice test involving signal detection analysis. In study 2, a full-scale taste reactivity test will be carried out, including psychophysiological and behavioral measures to assess subtle and covert hedonic changes. We will compare the responses of currently-ill AN and BN patients to those who have recovered from AN and BN, and also to those of healthy normal-weight and underweight individuals without any eating disorder pathology. Discussion: If taste response profiles are differentially linked to ED types, then future studies should investigate whether taste responsiveness represents a useful diagnostic measure in the prevention, assessment and treatment of EDs. The expected results on cognitive mechanisms in the top-down processes of food hedonics will complement current models and contribute to the refinement of interventions to change cognitive aspects of taste aversions, to establish functional food preferences and to better manage food cravings associated with binge-eating episodes. No trial registration was required for this protocol, which was approved by the Swiss ethics committee (CER-VD, n° 2016-02150) and the Ethics Review Panel of the University of Luxembourg. [ABSTRACT FROM AUTHOR]

An increasing body of research has investigated the effect of emotions on judgments concerning moral transgressions. Yet, few studies have controlled for arousal levels associated with the emotions. High arousal may affect moral processing by triggering attention to salient features of transgressions, independently of valence. Therefore previously documented differences in effects of negative and positive emotions may have been confounded by differences in arousal. We conducted two studies to shed light on this issue. In Study 1 we developed a questionnaire including vignettes selected on the basis of psychometrical properties (i.e., mean ratings of the actions and variability). This questionnaire was administered to participants in Study 2, after presenting them with selected pictures inducing different valence but equivalent levels of arousal. Negative pictures led to more severe moral judgments than neutral (p = .054, d = 0.60) and positive pictures (p = .002, d = 1.02), for vignettes that were not associated with extreme judgments. In contrast, positive pictures did not reliably affect judgments concerning such vignettes. These findings suggest that the observed effects of emotions cannot be accounted for by an increase in attention linked to the arousal which accompanies these emotions. [ABSTRACT FROM AUTHOR]

Highlights: [•] Flavor–taste preference learning may be not susceptible to the flavor preexposure effect. [•] The expression of the flavor preexposure effect depends on the motivational state on test. [•] Learning that underlies latent inhibition effect depends on the class of reinforcer. [•] Two different mechanisms seem to underlie flavor–taste and flavor–nutrient learning. [ABSTRACT FROM AUTHOR]