All I saw was the cake. Hunger effects on attentional capture by visual food cues

Effects of hunger and calorie content on visual awareness of food stimuli

Calorie content and hunger are two fundamental cues acting upon the processing of visually presented food items. However, whether and to which extent they affect visual awareness is still an open question. Here, high- and low-calorie food images administered to hungry or satiated participants were confronted in a breaking-Continuous Flash Suppression paradigm (Experiment 1), measuring the time required to access to visual awareness, and in a Binocular Rivalry paradigm (Experiment 2), quantifying the dominance time in visual awareness. Experiment 1 showed that high-calorie food accessed faster visual awareness, but mostly in satiated participants. Experiment 2 indicated that high-calorie food dominated longer visual awareness, regardless the degree of hunger. We argued that the unconscious advantage (Experiment 1) would represent a default state of the visual system towards highest-energy nutrients, yet the advantage is lost in hunger so to be tuned towards an increased need for any nutritional category. On the other hand, the conscious advantage of high-calorie food (Experiment 2) would represent a conscious perceptual and attentional bias towards highest energy-dense food useful for the actual detection of these stimuli in the environment.

You eye what you eat: BMI, consumption patterns, and dieting status predict temporal attentional bias to food-associated images

People know that overconsumption of high-fat high-sugar (HFHS) foods have negative consequences for physical and cognitive wellbeing but continue to consume these foods in excess, leading to recent proposals to model obesity as an addiction disorder. The current experiment tested, in a large undergraduate sample (N = 306), the hypothesis that obesity and overconsumption is linked with an oversensitivity to rewards that drives attentional biases towards foods and food-associated cues. Using a modified emotion-induced blindness task with food-related distractors, we examined the extent to which attentional biases to images of HFHS foods were accounted for by BMI, HFHS food intake, self-reported hunger, time since last meal, diet status, food preferences, and attentional control. We also examined whether the same individual differences predicted attentional priority to cues that have a learned association with HFHS foods (i.e., images of food logos). Contrary to our predictions, higher BMI predicted less attentional priority for images of food and food logos. At the same time, increased consumption of HFHS foods predicted increased attentional priority for food images, whereas dieting predicted increased attentional priority for food logo images. Our results suggest that different people may preferentially attend to food versus food logo imagery based on their relationships with food. More broadly, our results support the theoretical perspective that attentional biases to food-associated stimuli can be affected by various competing, state-related factors.

Effect of texture preference on food texture perception: Exploring the role of matching food texture and preference

This study aimed to investigate the influence of smooth texture preference on smoothness perception. An online questionnaire (Study 1, n = 464) and a sensory evaluation test (Study 2, n = 65) were administered to Japanese elderly participants (65-74 years), with common Japanese confectionery (Daifuku) as test foods. Through the online questionnaire, four distinct texture preference groups were formed based on the factors of preference for smoothness and firmness of the inner bean paste layer. Analysis of the food preference scale for imbalanced diet (FPSID) revealed that smooth-texture likers were more likely to be picky eaters than firm-texture likers. Furthermore, high (HiSm) and low smoothness preference groups (LoSm) were selected for the food sensory evaluation test to compare perceived textures (smoothness and firmness). Only the HiSm group exhibited a positive association between perceived smoothness and overall texture liking, perceiving smoothness significantly more intense than the LoSm group in situations where overall texture liking was high. This finding indicates that smooth texture preference does not act independently but rather interacts with food texture matching to affect perception. Our findings suggest that when food texture aligns with individuals' preferences, it elicits hedonic emotions and dynamically enhances food texture perception. This preference-involved perceptual process may contribute to the development of more explicit texture preferences.

No effect of hunger on attentional capture by food cues: Two replication studies

Food cues potently capture human attention, and it has been suggested that hunger increases their propensity to do so. However, the evidence for such hunger-related attentional biases is weak. We focus on one recent study that did show significantly greater attentional capture by food cues when participants were hungry, using an Emotional Blink of Attention (EBA) task [Piech, Pastorino, & Zald, 2010. Appetite, 54, 579-582]. We conducted online (N = 29) and in-person (N = 28) replications of this study with British participants and a Bayesian analytical approach. For the EBA task, participants tried to identify a rotated target image in a Rapid Serial Visual Presentation (RSVP). Targets were preceded by "neutral", "romantic", or "food" distractor images. Participants completed the task twice, 6-11 days apart, once hungry (overnight plus 6h fast) and once sated (after a self-selected lunch in the preceding 1h). We predicted that food images would create a greater attentional blink when participants were hungry than when they were sated, but romantic and neutral images would not. We found no evidence that hunger increased attentional capture by food cues, despite our experiments passing manipulation and quality assurance checks. Our sample and stimuli differed from the study we were replicating in several ways, but we were unable to identify any specific factor responsible for the difference in results. The original finding may not be generalisable. The EBA is more sensitive to the physical distinctiveness of distractors from filler and target images than their emotional valence, undermining the sensitivity of the EBA task for picking up subtle changes in motivational state. Moreover, hunger-related attentional bias shifts may not be substantial over the intensities and durations of hunger typically induced in laboratory experiments.

Attentional bias for high-calorie food cues by the level of hunger and satiety in individuals with binge eating behaviors

Introduction

The abnormal hyperreactivity to food cues in individuals with binge eating behaviors could be regulated by hedonic or reward-based system, overriding the homeostatic system. The aim of the present study was to investigate whether attentional bias for food cues is affected by the level of hunger, maintaining the normal homeostatic system in individuals with binge eating behaviors.

Methods

A total of 116 female participants were recruited and divided into four groups: hungry-binge eating group (BE) (n = 29), satiated BE (n = 29), hungry-control (n = 29), satiated control (n = 29). While participants completed a free-viewing task on high or low-calorie food cues, visual attentional processes were recorded using an eye tracker.

Results

The results revealed that BE group showed longer initial fixation duration toward high-calorie food cues in both hunger and satiety condition in the early stage, whereas the control group showed longer initial fixation duration toward high-calorie food cues only in hunger conditions. Moreover, in the late stage, the BE group stared more at the high-calorie food cue, compared to control group regardless of hunger and satiety.

Discussion

The findings suggest that automatic attentional bias for food cues in individuals with binge eating behaviors occurred without purpose or awareness is not affected by the homeostatic system, while strategic attention is focused on high-calorie food. Therefore, the attentional processing of food cues in binge eating group is regulated by hedonic system rather than homeostatic system, leading to vulnerability to binge eating.

Autobiographical memory specificity and restrained eating: examining the influence of priming with images of healthy and unhealthy foods

BACKGROUND

Dietary restraint has been linked to deficits in the ability to recall detailed memories of personally experienced events (referred to as autobiographical memory specificity). As priming with healthy foods increases the salience of restraint it would be expected to lead to greater deficits in memory specificity.

OBJECTIVE

To determine if priming word cues with images of healthy or unhealthy foods would influence the specificity of memory retrieval, and if deficits in memory specificity would be more evident in those reporting higher levels of dietary restraint, or currently dieting.

METHODS

Sixty female undergraduates self-reported if they were currently dieting and completed measures of mood, restraint, and disinhibition, and a modified version of the autobiographical memory task. Participants were presented with positive and negative words (unrelated to eating concerns) and asked to retrieve a specific memory in response to each cue. A food image was shown prior to each word cue; half of the participants were primed with images of healthy foods and half with images of unhealthy foods.

RESULTS

As expected, participants primed with healthy foods retrieved fewer specific memories than did those primed with unhealthy foods. However, neither restraint nor current dieting behaviour was associated with memory specificity.

CONCLUSIONS

Differences in memory specificity between the priming conditions cannot be explained in terms of increased salience of restraint. However, it is plausible that unhealthy images led to an increase in positive affect, which in turn improved memory specificity.

LEVEL OF EVIDENCE

Level I: Evidence obtained from: at least one properly designed experimental study.

Functional connectivity between interoceptive brain regions is associated with distinct health-related domains: A population-based neuroimaging study

Interoception is the sensation, perception, and integration of signals from within the body. It has been associated with a broad range of physiological and psychological processes. Further, interoceptive variables are related to specific regions and networks in the human brain. However, it is not clear whether or how these networks relate empirically to different domains of physiological and psychological health at the population level. We analysed a data set of 19,020 individuals (10,055 females, 8965 males; mean age: 63 years, age range: 45-81 years), who have participated in the UK Biobank Study, a very large-scale prospective epidemiological health study. Using canonical correlation analysis (CCA), allowing for the examination of associations between two sets of variables, we related the functional connectome of brain regions implicated in interoception to a selection of nonimaging health and lifestyle related phenotypes, exploring their relationship within modes of population co-variation. In one integrated and data driven analysis, we obtained four statistically significant modes. Modes could be categorised into domains of arousal and affect and cardiovascular health, respiratory health, body mass, and subjective health (all p < .0001) and were meaningfully associated with distinct neural circuits. Circuits represent specific neural "fingerprints" of functional domains and set the scope for future studies on the neurobiology of interoceptive involvement in different lifestyle and health-related phenotypes. Therefore, our research contributes to the conceptualisation of interoception and may lead to a better understanding of co-morbid conditions in the light of shared interoceptive structures.

Temporary Self-Deprivation Can Impair Cognitive Control: Evidence From the Ramadan Fast

During Ramadan, people of Muslim faith fast by not eating or drinking between sunrise and sunset. This is likely to have physiological and psychological consequences for fasters, and societal and economic impacts on the wider population. We investigate whether, during this voluntary and temporally limited fast, reminders of food can impair the fasters' reaction time and accuracy on a non-food-related test of cognitive control. Using a repeated measures design in a sample of Ramadan fasters (N = 190), we find that when food is made salient, fasters are slower and less accurate during Ramadan compared with after Ramadan. Control participants perform similarly across time. Furthermore, during Ramadan performances vary by how recently people had their last meal. Potential mechanisms are suggested, grounded in research on resource scarcity, commitment, and thought suppression, as well as the psychology of rituals and self-regulation, and implications for people who fast for religious or health reasons are discussed.

Sporadic fasting reduces attentional control without altering overall executive function in a binary classification task

Diets with intermittent fasting are an efficient method for producing clinically significant weight loss and preventing the development of obesity. However, individuals following intermittent fasting must face the difficulty of avoiding eating when experiencing the feeling of hunger. In this study, we investigated which aspects of executive function were affected following a prolonged period of food deprivation in participants that have never previously undergone intermittent fasting. Twenty-six participants with normal weight performed two binary classification tasks (Stop Signal (SST) and Go/NoGo) after either a 12 h fasting or a nonfasting period in separate sessions. We measured their performance in several underlying decision-making processes, such as response inhibition and attentional control. In line with previous studies, our results revealed that decision-making processes to resolve the classification task were unaffected by fasting. Response inhibition, as indexed by the stop signal reaction time in the SST, remained as well unaltered after food deprivation. Rather, we observed a higher error rate in NoGo trials following a fasting period, which was associated with disrupted attentional control. Overall, these results indicate that when a hunger feeling reaches consciousness, it induces deficits over certain aspects of attentional control. Our findings hint at the importance of structured behavioral change strategies to cope with fasting-induced difficulties in attentional control, to help achieve weight management goals through successful self-monitoring of food intake.

Spatiotemporal profile of altered neural reactivity to food images in obesity: Reward system is altered automatically and predicts efficacy of weight loss intervention

Introduction

Obesity presents a significant public health problem. Brain plays a central role in etiology and maintenance of obesity. Prior neuroimaging studies have found that individuals with obesity exhibit altered neural responses to images of food within the brain reward system and related brain networks. However, little is known about the dynamics of these neural responses or their relationship to later weight change. In particular, it is unknown if in obesity, the altered reward response to food images emerges early and automatically, or later, in the controlled stage of processing. It also remains unclear if the pretreatment reward system reactivity to food images is predictive of subsequent weight loss intervention outcome.

Methods

In this study, we presented high-calorie and low-calorie food, and nonfood images to individuals with obesity, who were then prescribed lifestyle changes, and matched normal-weight controls, and examined neural reactivity using magnetoencephalography (MEG). We performed whole-brain analysis to explore and characterize large-scale dynamics of brain systems affected in obesity, and tested two specific hypotheses: (1) in obese individuals, the altered reward system reactivity to food images occurs early and automatically, and (2) pretreatment reward system reactivity predicts the outcome of lifestyle weight loss intervention, with reduced activity associated with successful weight loss.

Results

We identified a distributed set of brain regions and their precise temporal dynamics that showed altered response patterns in obesity. Specifically, we found reduced neural reactivity to food images in brain networks of reward and cognitive control, and elevated reactivity in regions of attentional control and visual processing. The hypoactivity in reward system emerged early, in the automatic stage of processing (< 150 ms post-stimulus). Reduced reward and attention responsivity, and elevated neural cognitive control were predictive of weight loss after six months in treatment.

Discussion

In summary, we have identified, for the first time with high temporal resolution, the large-scale dynamics of brain reactivity to food images in obese versus normal-weight individuals, and have confirmed both our hypotheses. These findings have important implications for our understanding of neurocognition and eating behavior in obesity, and can facilitate development of novel integrated treatment strategies, including tailored cognitive-behavioral and pharmacological therapies.

Event-related potentials of food-induced blindness in the rapid serial visual presentation paradigm

Emotion-induced blindness is known as the impairment in the identification of targets that follow shortly after emotional distractors in the rapid serial visual presentation (RSVP) paradigm. Besides negative or erotic stimuli, food distractors have also been found to elicit a similar effect. This indicates an attentional bias for food stimuli in the temporal dimension of visual attention, which is highly relevant in the context of eating behaviour. So far, the neural mechanisms of this food-induced blindness are widely unknown. In the present study (N = 53), we investigated event-related potentials (ERPs) in response to food distractors and non-food targets in a single-target RSVP task. Automatic capture of visual attention by task-irrelevant food distractors was evident in enhanced Distractor Negativity (N2) and Early Food Positivity (P1). However, food distractors did not elicit a P3b. Thus, apparently, not the encoding of food distractors in working memory but alternative attentional processes are responsible for the food-induced blindness. Reduced target P3b reflected errors in target identification but was unaffected by the preceding distractor. In contrast, target N2 was specifically reduced for unidentified targets preceded by food distractors. Presumably, the attentional capture of food distractors may have caused a reduction of target N2, thereby contributing to the impairment in target identification. However, future research is needed to confirm this assumption and bridge the gap between the food-induced blindness on the behavioural level and the attentional capture of food stimuli reflected in the distractor ERPs.

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.

"Neurotic people tend to eat less when disinhibited": The mediating role of food-related cognitive flexibility in restrained eaters

OBJECTIVES

This study aims to reveal the individual differences in Neuroticism and cognitive flexibility among successful restrained eaters (SREs), unsuccessful restrained eaters (UREs), and non-restrained eaters (NREs). Moreover, this study is dedicated to investigating whether certain personality traits and cognitive flexibility could concurrently influence disinhibited eating behaviors among restrained eaters and reveal the pathways through which they interact.

METHODS

Female participants aged 17 and 24 years (NREs = 23; SREs = 24; UREs = 23) were assessed with body mass index (BMI) and appetite state measurement, the Dutch Eating Behavior Questionnaire (DEBQ), the NEO Five-Factor Inventory (NEO-FFI), and the Positive and Negative Affect Schedule. To measure behavioral and neural responses related to cognitive flexibility, participants were required to complete a food-related switching task, and their brain activities were recorded through the technique of electroencephalography (EEG). Here we analyzed two widely investigated components-the N2 and P3 components that separately relate to conflict monitoring and response inhibition.

RESULTS

The behavioral performance of food-related task switching did not show significant between-group differences. However, in comparison to NREs and SREs, UREs elicited larger N2 and lower P3 amplitudes during task switching. In addition, UREs exhibited a lower level of Neuroticism than SREs and NREs. Furthermore, food-related task switching induced N2 amplitude fully mediated the association between Neuroticism and disinhibited eating behavior in restrained eaters controlled for BMI and negative affect. Importantly, when a parallel mediation model with N2 and P3 was built concurrently, N2 was still able to fully mediate the association.

CONCLUSION

According to behavioral and neural evidence, increased N2 amplitude induced by food-related task switching totally mediated the negative association between Neuroticism and disinhibited eating in restrained eaters.

Intranasal oxytocin reduces attentional bias to food stimuli

Attentional biases to food-related stimuli have been demonstrated in response to hunger as well as during restrained eating. Such biases are often associated with obesity, but healthy-weight individuals who do not self-report hunger have also demonstrated attentional biases to stimuli signalling food using laboratory-based cognitive tasks. Levels of the anorectic neuropeptide oxytocin are elevated by food intake and, when administered intranasally, oxytocin inhibits food intake in the laboratory. To investigate whether oxytocin can affect appetite via an action on attentional processes, 40 adults (29 women; mean age 24.0 years old) self-administered 24 IU of oxytocin or placebo intranasally. Forty minutes after administration, participants ate a small snack to maintain alertness and ameliorate deprivation-induced hunger before starting a computerized dot-probe attentional bias task that presented 180 trials of paired visual stimuli comprising neutral, food, social and/or romantic images (500 ms presentation time). Reaction times to probe stimuli that appeared after the offset of the visual images indicated a significant attentional bias to food pictures after placebo; this effect was significantly attenuated by oxytocin, p < .001. The effect of oxytocin on attentional bias to the food pictures was not altered by the type of stimulus paired with the food image, and was independent of BMI, age, sex, self-rated eating behaviour, and self-reported parental bonding; however, the effect was modulated by self-reported food cravings and trait stress. The findings support and extend previous work which has suggested that oxytocin can counteract attentional biases to food-related stimuli in a sample with anorexia by demonstrating the same effect for the first time in a cohort who do not have an eating disorder.

Eating Motives and Other Factors Predicting Emotional Overeating during COVID-19 in a Sample of Polish Adults

We hypothesised that the higher levels of emotion-related predictors (eating motive in the form of affect regulation and COVID-19-related stress) would be associated with higher emotional overeating, after accounting for the effects of demographic variables (gender and BMI) and other eating motives (visual- and attitude-related predictors: liking, pleasure, visual appeal; body- and health-related predictors: need and hunger, health, weight control). Participants (N = 868; Mage = 33.53 years, SD = 11.98) completed: the Eating Motivation Survey, the Emotional Overeating Questionnaire, a COVID-19-related stress measure and a socio-demographic survey. The final step of the regression with emotional overeating was significant; affect regulation and COVID-19-related stress were significantly related to emotional overeating (ΔF p < 0.001, Adj. ΔR2 = 0.13). During the COVID-19 pandemic, eating can, on the one hand, help to cope with the current difficult situation and the negative emotions associated with it; on the other hand, frequent use of this tendency can lead to rigid regulation of affect and use of this mechanism as the dominant mechanism. Therefore, limited social contact, related disruptions in daily activities and stress resulting from COVID-19 should generate appropriate interventions, not necessarily focusing only on emotional eating, but also on the resources of the individual. It is worth encouraging specialists to implement alternative methods of contact with their patients, e.g., online.

How Digital Food Affects Our Analog Lives: The Impact of Food Photography on Healthy Eating Behavior

Obesity continues to be a global issue. In recent years, researchers have started to question the role of our novel yet ubiquitous use of digital media in the development of obesity. With the recent COVID-19 outbreak affecting almost all aspects of society, many people have moved their social eating activities into the digital space, making the question as relevant as ever. The bombardment of appetizing food images and photography – colloquially referred to as “food porn” – has become a significant aspect of the digital food experience. This review presents an overview of whether and how the (1) viewing, (2) creating, and (3) online sharing of digital food photography can influence consumer eating behavior. Moreover, this review provides an outlook of future research opportunities, both to close the gaps in our scientific understanding of the physiological and psychological interaction between digital food photography and actual eating behavior, and, from a practical viewpoint, to optimize our digital food media habits to support an obesity-preventive lifestyle. We do not want to rest on the idea that food imagery’s current prevalence is a core negative influence per se. Instead, we offer the view that active participation in food photography, in conjunction with a selective use of food-related digital media, might contribute to healthy body weight management and enhanced meal pleasure.

Does hunger promote the detection of foods? The effect of value on inattentional blindness

Although human perception has evolved into a potent and efficient system, we still fall prey to astonishing failures of awareness as we miss an unexpected object in our direct view when our attention is engaged elsewhere (inattentional blindness). While specific types of value of the unexpected object have been identified to modulate the likelihood of this failure of awareness, it is not clear whether the effect of value on inattentional blindness can be generalized. We hypothesized that the combination of hunger and food-stimuli might increase a more general type of value so that food stimuli have a higher probability to be noticed by hungry participants than by satiated participants. In total, 240 participants were assigned towards a hungry (16 h of fasting) or satiated (no fasting) manipulation and performed afterward a static inattentional blindness task. However, we did not find any effect of value on inattentional blindness based on hunger and food stimuli. We speculate that different underlying mechanisms are involved for different types of value and that value manipulations need to be strong enough to ensure certain value strengths.

Neural Correlates of Attentional Bias to Food Stimuli in Obese Adolescents

Adolescent obesity is an increasingly prevalent problem in several societies. Researchers have begun to focus on neurocognitive processes that may help explain how unhealthy food habits form and are maintained. The present study compared attentional bias to food stimuli in a sample of obese (n = 22) and Normal-weight (n = 18) adolescents utilizing an Attention Blink (AB) paradigm while electroencephalography (EEG) was recorded. We found lower accuracy and Event-Related Potential (ERP) P3 amplitudes during the presentation of food stimuli in AB trials for obese adolescents. These findings suggest an impaired ability of their brains to flexibly relocate attentional resources in the face of food stimuli. The results were corroborated by lower P3s also being associated with higher body mass index (BMI) values and poorer self-reported self-efficacy in controlling food intake. The study is among the few examining neural correlates of attentional control in obese adolescents and suggests automatic attentional bias to food is an important aspect to consider in tackling the obesity crisis.

Computational Models of Interoception and Body Regulation

To survive, organisms must effectively respond to the challenge of maintaining their physiological integrity in the face of an ever-changing environment. Preserving this homeostasis critically relies on adaptive behavior. In this review, we consider recent frameworks that extend classical homeostatic control via reflex arcs to include more flexible forms of adaptive behavior that take interoceptive context, experiences, and expectations into account. Specifically, we define a landscape for computational models of interoception, body regulation, and forecasting, address these models' unique challenges in relation to translational research efforts, and discuss what they can teach us about cognition as well as physical and mental health.

Unseen food images capture the attention of hungry viewers: Evidence from event-related potentials

Motivationally relevant visual targets appear to capture visuospatial attention. This capture is evident behaviorally as faster and more accurate responses, and neurally as an enhanced-amplitude of the N2pc - an index of spatial attention allocation, which is observed even when observers are unaware of the target. In the case of reinforcers such as food or substances of dependence, it is likely that the motivational state of craving accompanying deprivation potentiates this capture. The automaticity of such attentional capture by reward-associated stimuli, as well as its possible interaction with craving, is as yet not completely understood, though it is likely a major explanatory factor in motivated behaviors. For the present experiment, participants completed two EEG recording sessions: one just after eating lunch (sated/non-craving), and the other following a minimum 12-h period of fasting (hungry/craving). For both sessions, participants identified food- and clothing-related targets embedded in an object-substitution masking paradigm, which yielded trials of full target visibility, as well as trials for which targets were present but undetected. Although masking equally disrupted visual awareness of both classes of targets as measured behaviorally, a three-way hunger by visibility by target interaction was observed in the neural data, with unseen food targets eliciting an enhanced N2pc. Interestingly, this subliminal attentional capture by food-related items was observed only during the "hungry" session. No such capture was evident under conditions of full visibility. These findings indicate that attentional capture by food-related images, and reflected in enhancements of the N2pc, is spurred by hunger, and that this effect can be viewed as automatic, or independent of explicit awareness of food-relevant target content.

Does food deprivation affect perceived size?

Exposure to food-related stimuli could lead to the triggering of a set of biological, emotional and cognitive responses. Such responses can be pronounced following food deprivation. Indeed, previous research showed that even a moderate period of food deprivation is sufficient to increase perceptual precision to detect changes along food size and to change the processing style of food-related stimuli. It is unclear, however, whether food deprivation also leads to systematic biases along the perception of food size. Here, we used two classic psychophysical methods, the method of constant stimuli and the method of adjustment, adapted to the field of food perception, to study the effect of food deprivation on average perceived food size. In two experiments, food deprived and non-deprived participants were asked to compare a series of food and non-food visual stimuli along their size. The results were inconsistent and depended upon the method used. When found, small bias effects resulted in food stimuli perceived as bigger following food deprivation. The results show that unlike the reliable effects motivational factors have on perceptual precision and on perceptual processing style, they have an inconsistent influence on average perceived food size.

Emotional distraction in working memory: Bayesian-based evidence of the equivalent effect of positive and neutral interference

Evidence has shown that negative distracting stimuli are most difficult to control when we are focused in a relevant task, while positive and neutral distractors might be equally overcome. Still, recent meta-analytic evidence has pointed out that differences in the ability to cope with positive or neutral distractors may be difficult to detect in healthy people and in laboratory sets. Here we re-analyse memory performance in four already published working memory experiments in which affective and non-affective distractors were used. We focused on the positive versus neutral contrast, which did not reveal differences in the original analysis, with the aim of quantifying evidence for the null hypothesis using a Bayesian approach. Bayes factor (BF) estimates show substantial evidence in favour to the absence of differences in three out of four datasets. Further, BF aggregated from the four studies shows stronger evidence for the null hypothesis. Results from this analysis show that WM performance after positive and neutral interference can be considered equivalent, suggesting that positive distractors can be overcome to the same extent as neutral ones.

Investigating the Effect of Use and Social Cues in Food Advertisements on Attention, Feelings of Social Support, and Purchase Intention

In an effort to understand how different types of food cues in food ads are automatically encouraging unhealthy eating behaviors, the current study examined how the presence of actual food consumption behaviors (use cues) and presence of multiple individuals indorsing food products (social cues) in fast food ads would influence individual attentional and behavioral responses. A use cue (2) x social cue (2) x repetition (3) fully within-subjects factorial design experiment with young adults (N = 164) was conducted. Findings demonstrated that participants paid greater attention to the fast food ads which contained multiple people (group cue) eating the advertised food products (use cue) when compared to other types of fast food ads. In addition, participants also self-reported greater social support and purchase intention when seeing use and group cues in ads. Understanding how these cues function in food advertising to encourage unhealthy eating may help health practitioners and individuals create more helpful intervention strategies. Further, applying these marketing tactics to ads for food products that are healthier (i.e., less energy dense and more nutrient dense) may help to maximize healthy food palatability, thereby increasing motivation for viewers to make autonomous decisions about eating healthier.

Food is special by itself: Neither valence, arousal, food appeal, nor caloric content modulate the attentional bias induced by food images

When food cues appear in a visual context, such information is likely to influence eating behavior by enhancing attention for food cues. We investigated whether active but task-irrelevant information could modulate the attentional bias for food stimuli using a novel paradigm in which participants were purposely deceived by being enrolled in a memory experiment. A set of images were first held in working memory and then used as task-irrelevant distractors in a subsequent single target rapid serial visual presentation (RSVP) task, allowing us to investigate the attentional blink (AB) effect elicited by those images. In Experiment 1, the results revealed that food images elicited a larger AB effect than nonfood images. In three follow-up experiments, we investigated whether valence or arousal (Experiment 2), food preparation (Experiment 3), or food caloric content (Experiment 4) were factors related to the attentional bias for food. Overall, our results demonstrated that when held in working memory, food images can easily capture attention, even in circumstances in which the information retained in memory is irrelevant to solve the task, as indicated by the strong correlation found between items that were recognized in the RSVP task and the AB effect. Nonetheless, none of the food-related properties we examined were found to be associated with this attentional bias for food.

The Emotional Attentional Blink as a Measure of Patriotism

This study aims to explore whether the implicit processing of emotional symbols related to patriotic feeling may exert some effects on attention. Here, we have conducted an experiment using two interrelated tasks. First, we use flags with different meanings to participants for measuring the strength of the emotional attentional blink (EAB) within a rapid serial visual presentation (RSVP) paradigm. Then, we use a "congruency judgments" subjective test, where we confront participants to judge the affinity between pairs of politician leaders and flags of different sign for community participants, while recording two physiological measures (Heart Rate Variance and Galvanic Skin Response) to evaluate the variations elicited by that confrontation. Results on the EAB task show a significant emotion induced blindness for emotional stimuli representing Catalan and Spanish patriotism (α = .05), while the effect does not appear for the stimulus representing neutral patriotism. The interaction "Flags x Patriotism" was significant, F(1, 51) = 4.62; p = .036; ηp2 = .083. Results on the second task show that measures derived from electrophysiological records are sensitive to patriotic feeling, both being complementary. In addition, by using measures of congruence, the "Leaders x Flags" interaction was significant, F(3.682, 125.204) = 53.55; p < .001; ηp2 = .612. Finally, a multiple linear regression model for each emotional inductor was verified for the Catalan case, using the EAB effect as criteria, R2Adjusted = .79; p < .001. Some theoretical and methodological aspects derived of this exploratory study are discussed.

Post-Ingestive Sensations Driving Post-Ingestive Food Pleasure: A Cross-Cultural Consumer Study Comparing Denmark and China

Culture is one of the main factors that influence food assessment. This cross-cultural research aimed to compare Chinese and Danish consumers in their post-ingestive drivers of Post-Ingestive Food Pleasure (PIFP). We define PIFP as a “subjective conscious sensation of pleasure and joy experienced after eating”. We conducted two in-country consumer studies in Denmark (n = 48) and in China (n = 53), measuring post-ingestive sensations and PIFP using visual analogue scale, for three hours following consumption of a breakfast meal. Key results revealed perceived Satisfaction, Mental, Overall and Physical wellbeing to be highly influential on PIFP in both countries. Moreover, Danish consumers perceived appetite-related sensations such as Satiety, Hunger, Desire-to-eat and In-need-of-food to be influential on PIFP, which was not the case in China. In China, more vitality-related sensations such as Energized, Relaxation and Concentration were found to be drivers of PIFP. These results suggest similarities but also distinct subtleties in the cultural constructs of PIFP in Denmark and in China. Focusing on Food Pleasure as a post-ingestive measure provides valuable output, deeper insights into what drives Food Pleasure, and, importantly, takes us beyond the processes only active during the actual eating event.

Internet-delivered attentional bias modification training (iABMT) for the management of chronic musculoskeletal pain: a protocol for a randomised controlled trial

INTRODUCTION

Chronic musculoskeletal pain is a complex medical condition that can significantly impact quality of life. Patients with chronic pain demonstrate attentional biases towards pain-related information. The therapeutic benefits of modifying attentional biases by implicitly training attention away from pain-related information towards neutral information have been supported in a small number of published studies. Limited research however has explored the efficacy of modifying pain-related biases via the internet. This protocol describes a randomised, double-blind, internet-delivered attentional bias modification intervention, aimed to evaluate the efficacy of the intervention on reducing pain interference. Secondary outcomes are pain intensity, state and trait anxiety, depression, pain-related fear, and sleep impairment. This study will also explore the effects of training intensity on these outcomes, along with participants' perceptions about the therapy.

METHODS AND ANALYSIS

The study is a double-blind, randomised controlled trial with four arms exploring the efficacy of online attentional bias modification training versus placebo training theorised to offer no specific therapeutic benefit. Participants with chronic musculoskeletal pain will be randomised to one of four groups: (1) 10-session attentional modification group; (2) 10-session placebo training group; (3) 18-session attentional modification group; or (4) 18-session placebo training group. In the attentional modification groups, the probe-classification version of the visual-probe task will be used to implicitly train attention away from threatening information towards neutral information. Following the intervention, participants will complete a short interview exploring their perceptions about the online training. In addition, a subgroup analysis for participants aged 16-24 and 25-60 will be undertaken.

ETHICS AND DISSEMINATION

This study has been approved by the University of Southampton Research Ethics Committee. Results will be published in peer-reviewed journals, academic conferences, and in lay reports for pain charities and patient support groups.

TRIAL REGISTRATION NUMBER

NCT02232100; Pre-results.

Modulation of brain activity by hormonal factors in the context of ingestive behaviour

INTRODUCTION

Metabolic and hormonal signals have been shown to be associated with brain activity in the context of ingestive behaviour. However, this has mostly been seen in studies using external administration of hormones or glucose. We therefore studied endocrine-brain interaction in a physiological setting with hormone levels determined by metabolic conditions such as normal food intake vs. prolonged fasting.

METHODS

24 healthy, normal weight men participated in two sessions, one involving a 38-hour fasting period and one a non-fasting control condition with standardized meals. Functional magnetic resonance imaging was performed at the end of the experiment with participants being required to rate pictures of food. Brain activation was compared between conditions in predefined regions of interest (ROIs). Multiple blood samples were taken to determine levels of insulin, C-peptide, cortisol, ACTH, glucose and adiponectin. These were used as a predictor variable in a regression analysis on brain activations in the different ROIs.

RESULTS

Food pictures were rated as more desirable in the fasting condition. Univariate analysis of ROI activations revealed mainly effects of food rating and no significant effects of the metabolic state. Multiple regression analysis revealed associations between orbitofrontal cortex activation and blood glucose in the non-fasting condition. In the fasting condition adiponectin was associated with the signal from the caudate nucleus and insulin and C-peptide were associated with functional activity of orbitofrontal regions.

DISCUSSION

Associations of endocrine signals and functional neural regions could be demonstrated in a realistic setting without external administration of hormones. As the current approach was correlational, further studies need to address the causal role of hormonal signals.

Assessing the Overlap Between Three Measures of Food Reward

Food reward is an important concept for research in eating behaviors. Many food reward tasks have been developed and are in active use. However, little is known how much these tasks overlap. Here, we sought to compare three promising food reward tasks: (1) the Leeds Food Preference Questionnaire (LFPQ; a procedure combining explicit ratings of wanting and liking and an implicit wanting task based on forced choice), (2) a hand grip force task, and (3) an emotional attentional blink (EAB) task. Specifically, we assessed whether the tasks are sensitive to changes in hunger, correlate with each other, and correlate with trait binge eating and snack food calorie intake. Thirty-nine women aged 25.51 ± 5.99 years, with a BMI of 22.51 ± 3.58 kg/m² completed the three tasks twice: after a 6-h fast and following a breakfast meal. In the fasted condition, participants were also given ad libitum access to snack foods to assess calorie intake. Prior to the two laboratory sessions, participants completed a trait binge eating questionnaire. Results revealed that the LFPQ’s explicit wanting and explicit liking subscales, as well as grip force reflected higher food reward scores in the fasted condition. The three metrics also correlated positively with each other. Explicit wanting and liking correlated with snack food intake, while grip force did not. None of the tasks were related to trait binge eating. Reaction times in the forced choice procedure did not reflect changes in hunger, but the task was nevertheless able to differentiate between foods varying in taste and fat content. The EAB was not sensitive to the hunger manipulation; neither did the task correlate with binge eating or energy intake. Collectively, our findings suggest that the explicit wanting and liking scales and the grip force task measure the same construct, whereas EAB results may be obscured by a variety of potential confounding factors. Future research could include additional food reward tasks in comparisons, measure covariates that may moderate the variables’ associations, and compare hunger-dependent changes in food reward in different subgroups.

A hierarchical-drift diffusion model of the roles of hunger, caloric density and valence in food selection

Decisions based on affectively relevant stimuli, such as food items, hardly follow strictly rational rules. Being hungry, the food's caloric density, and the subjective valence attributed to various foods are known factors that modulate food choices. Yet, how these factors relatively and altogether contribute to the food choice process is still unknown. In this study, we showed 16 healthy young adults low- and high-calorie food when hungry or fed, and we asked them to evaluate the valence of each visually-presented food. To compute the relative influence of hunger, caloric density and valence on food choice, we applied a hierarchical drift diffusion model (HDDM). Results indicated that hunger, caloric density and valence affected how fast participants accumulated information in favor of the chosen item over the other. When fed, participants were faster in choosing low-calorie foods and foods with a higher valence. Conversely, when hungry, participants were faster in choosing high-calorie foods, including food items with lower subjective valence. All in all, these findings confirm the complex nature of food choices and the usefulness of nuanced computational models to address the multifaceted nature of decision-making and value assessment processes affecting food selection.

Effects of Hunger on Visual Perception in Binocular Rivalry

The effect of hunger on visual perception is largely absent from contemporary vision science. Using a well-established visual phenomenon termed binocular rivalry, this study was carried out to investigate the effects of hunger on visual perception. A within-subject design was applied in which participants attended two sessions before and after their lunch or dinner, i.e., a hunger state and a satiated state. In Experiment 1, we found that the mean dominance times to food-related pictures were larger in the hungry condition than that in the satiated condition, while the mean dominance time to the non-food stimuli were unaffected. In Experiment 2, we found the times to break through continuous flash suppression (b-CFS) for both food-related and non-food-related pictures were not affected by hunger. In Experiment 3, a probe-detection task was conducted to address possible response-biases. Our findings provide evidence that hunger biases the dynamic process of binocular rivalry to unsuppressed and visible food stimuli, while processing suppressed and invisible food-related was unaffected. Our results support the notion that the top-down modulation by hunger on food-related visual perception is limited to visible stimuli.

Positive emotions have a unique capacity to capture attention

Most of the previous research in the area of cognitive psychology or cognitive neuroscience focused on studying negative emotions and argued that the negative emotional stimuli capture attention involuntarily as compared to neutral stimuli. However, in the last decades, researchers started paying attention in studying positive emotions also as positive emotions have evolutionary significance and are essential for many aspects of our life. The theme of this chapter is to present an overview of research in the area of positive emotions, and make a case that positively-valenced stimulus is prioritized over others. Primarily, when attentional resources are not constrained, many studies have shown that similar to negative stimuli, positive stimuli also capture attention automatically irrespective of whether they are relevant or irrelevant to the primary task. It suggests a fundamental prioritization of these stimuli by the cognitive/motivational system. However, when attentional resources are constrained, only positive or high rewarding stimuli win the competition for attentional resources compared to negative or stimuli associated with high punishment. Positive or high rewarding stimuli also receive priority in temporal selection, when attention is constrained. Theoretical implications of these results have been discussed. Possible cognitive and neural mechanisms have been proposed underlying these effects.

Attending to the Chemical Senses

Theorizing around the topic of attention and its role in human information processing largely emerged out of research on the so-called spatial senses: vision, audition, and to a lesser extent, touch. Thus far, the chemical senses have received far less research interest (or should that be attention) from those experimental psychologists and cognitive neuroscientists interested in the topic. Nevertheless, this review highlights the key role that attentional selection also plays in chemosensory information processing and awareness. Indeed, many of the same theoretical approaches/experimental paradigms that were originally developed in the context of the spatial senses, can be (and in some cases already have been) extended to provide a useful framework for thinking about the perception of taste/flavour. Furthermore, a number of those creative individuals interested in modifying the perception of taste/flavour by manipulating product-extrinsic cues (such as, for example, music in the case of sonic seasoning) are increasingly looking to attentional accounts in order to help explain the empirical phenomena that they are starting to uncover. However, separate from its role in explaining sonic seasoning, gaining a better understanding of the role of attentional distraction in modulating our eating/drinking behaviours really ought to be a topic of growing societal concern. This is because distracted diners (e.g., those who eat while watching TV, fiddling with a mobile device or smartphone, or even while driving) consume significantly more than those who mindfully pay attention to the sensations associated with eating and drinking.

The emotional attentional blink is robust to divided attention

The emotional attentional blink (EAB) refers to a temporary impairment in the ability to identify a target when it is preceded by an emotional distractor. It is thought to occur because the emotional salience of the distractor exogenously captures attention for a brief duration, rendering the target unattended and preventing it from reaching awareness. Here we tested the extent to which the EAB can be attenuated by inducing a diffuse top-down attentional state, which has been shown to improve target identification in an analogous attentional phenomenon, the attentional blink. Rapid sequences of landscape images were presented centrally, and participants reported the orientation of a ± 90° rotation of a landscape target. To induce a diffuse state of attention, participants were given a secondary task of monitoring for the appearance of a colored dot in the periphery. We found that emotional distractors impaired target recognition performance to comparable extents, regardless of whether or not participants concurrently performed the peripheral-monitoring task. Moreover, we found that performance of the secondary task led to an impaired ability to ignore neutral distractors. Subjective ratings of target vividness mirrored the behavioral accuracy, with frequent reports of intermediate levels of vividness suggesting that the EAB might impair target visibility in a graded manner. Our results demonstrate that the EAB is robust to manipulations of top-down attention, suggesting that the temporary capture of attention by emotionally salient stimuli involves processes that are distinct from those that produce the attentional blink.

Food deprivation disrupts normal holistic processing of domain-specific stimuli

Food deprivation has been shown to lead to a set of biological and psychological responses, including a decrease in perceptual thresholds, and an increase in attentional allocation for domain-specific, food-related stimuli. Here, we tested whether food deprivation could lead to a qualitative change in the way food is perceived. To this purpose, we tested the effect of food deprivation on a basic feature of human perception, the holistic processing of object shape. In three experiments, we examined the effect of food deprivation on participants' susceptibility to the height-width illusion, which served as a maker for holistic processing. In all experiments, food deprivation led to an abnormal, non-holistic processing of shape, which resulted in a total reduction of the illusion for food-related, but not for control stimuli. These results show that food deprivation alters the way food is perceived, and propose that motivational factors modulate people's resistance to perceptual distortions for domain-specific stimuli.

Food deprivation reduces the susceptibility to size-contrast illusions

Hunger, caused by mild amount of food deprivation, is an everyday physiological state familiar to us all. Ongoing research has pinpointed the way hunger affects people's physiological functions as well as their attitudes and allocation of attention toward domain-specific, food-related objects. Yet, little is known about the way food deprivation affects basic perceptual abilities. Here, we utilized size-contrast visual illusions commonly associated with food to explore the way deprivation affects relative processing of food size. In two experiments (N_exp1 = 32 females, mean age: 24.31; N_expt2 = 41 females, 40 males, mean age: 23.84), we examined the effect food deprivation has on participants' susceptibility to the Delboeuf illusion, which biases the perceived size of a neutral or of a food-related object when it is placed within the context of another object (e.g., a pizza is perceived as smaller when placed on a larger plate or tray). The results showed that food deprivation reduces the illusory bias for food-related but not for neutral stimuli. Such reduction in the illusory effect indicates reliance on analytic, rather than on relative processing style, for domain-specific stimuli when in the state of hunger.

Of Meat and Men: Sex Differences in Implicit and Explicit Attitudes Toward Meat

Modern attitudes to meat in both men and women reflect a strong meat-masculinity association. Sex differences in the relationship between meat and masculinity have not been previously explored. In the current study we used two IATs (implicit association tasks), a visual search task, and a questionnaire to measure implicit and explicit attitudes toward meat in men and women. Men exhibited stronger implicit associations between meat and healthiness than did women, but both sexes associated meat more strongly with 'healthy' than 'unhealthy' concepts. As 'healthy' was operationalized in the current study using terms such as "virile" and "powerful," this suggests that a meat-strength/power association may mediate the meat-masculinity link readily observed across western cultures. The sex difference was not related to explicit attitudes to meat, nor was it attributable to a variety of other factors, such as a generally more positive disposition toward meat in men than women. Men also exhibited an attention bias toward meats, compared to non-meat foods, while females exhibited more caution when searching for non-meat foods, compared to meat. These biases were not related to implicit attitudes, but did tend to increase with increasing hunger levels. Potential ultimate explanations for these differences, including sex differences in bio-physiological needs and receptivity to social signals are discussed.

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

The present study used the presentation of food pictures and judgements about their duration to assess the emotions elicited by food in women suffering from an eating disorder (ED). Twenty-three women diagnosed with an ED, namely anorexia (AN) or bulimia nervosa (BN), and 23 healthy controls (HC) completed a temporal bisection task and a duration discrimination task. Intervals were marked with emotionally pre-rated pictures of joyful and disgusting food, and pictures of neutral objects. The results showed that, in the bisection task, AN women overestimated the duration of food pictures in comparison to neutral ones. Also, compared to participants with BN, they perceived the duration of joyful food pictures as longer, and tended to overestimate the duration of the disgusting ones. These effects on perceived duration suggest that AN women experienced an intense reaction of fear when they were confronted to food pictures. More precisely, by having elevated the arousal level and activated the defensive system, food pictures seemed to have speeded up the rhythm of the AN participants’ internal clock, which led to an overestimation of images’ duration. In addition, the results revealed that, in both tasks, ED women presented a lower temporal sensitivity than HC, which was related to their ED symptomatology (i.e., BMI, restraint and concern) and, particularly, to their weaker cognitive abilities in terms of attention, processing speed and working memory. Considered all together, the findings of the present experiment highlight the role of fear and anxiety in the manifestations of AN and point out the importance of considering non-temporal factors in the interpretation of time perception performance.

Visual Attention to Pictorial Food Stimuli in Individuals With Night Eating Syndrome: An Eye-Tracking Study

Night eating syndrome (NES) is characterized by excessive evening and/or nocturnal eating episodes. Studies indicate an attentional bias towards food in other eating disorders. For NES, however, evidence of attentional food processing is lacking. Attention towards food and non-food stimuli was compared using eye-tracking in 19 participants with NES and 19 matched controls without eating disorders during a free exploration paradigm and a visual search task. In the free exploration paradigm, groups did not differ in initial fixation position or gaze duration. However, a significant orienting bias to food compared to non-food was found within the NES group, but not in controls. A significant attentional maintenance bias to non-food compared to food was found in both groups. Detection times did not differ between groups in the search task. Only in NES, attention to and faster detection of non-food stimuli were related to higher BMI and more evening eating episodes. The results might indicate an attentional approach-avoidance pattern towards food in NES. However, further studies should clarify the implications of attentional mechanisms for the etiology and maintenance of NES.

Pre- and postprandial variation in implicit attention to food images reflects appetite and sensory-specific satiety

Implicit attentional processes are biased toward food-related stimuli, with the extent of that bias reflecting relative motivation to eat. These interactions have typically been investigated by comparisons between fasted and sated individuals. In this study, temporal changes in implicit attention to food were assessed in relation to natural, spontaneous changes in appetite occurring before and after an anticipated midday meal. Non-fasted adults performed an emotional blink of attention (EBA) task at intervals, before and after consuming preferred, pre-selected sandwiches to satiety. Participants were required to detect targets within a rapid visual stream, presented after task-irrelevant food (preferred or non-preferred sandwiches, or desserts) or non-food distractor images. All categories of food distractor preferentially captured attention even when appetite levels were low, but became more distracting as appetite increased preprandially, reducing task accuracy maximally as hunger peaked before lunch. Postprandially, attentional capture was markedly reduced for images of the specific sandwich type consumed and, to a lesser extent, for images of other sandwich types that had not been eaten. Attentional capture by images of desserts was unaffected by satiation. These findings support an important role of selective visual attention in the guidance of motivated behaviour. Naturalistic, meal-related changes in appetite are accompanied by changes in implicit attention to visual food stimuli that are easily detected using the EBA paradigm. Preprandial enhancement of attention capture by food cues likely reflects increases in the incentive motivational value of all food stimuli, perhaps providing an implicit index of wanting. Postprandial EBA responses confirm that satiation on a particular food results in relative inattention to that food, supporting an important attentional component in the operation of sensory-specific satiety.