Biased towards food: Electrophysiological evidence for biased attention to food stimuli

Attention to food stimuli in binge eating disorder: Electrophysiological evidence

Attentional biases towards food play an important role in the pathology of binge eating disorder (BED). Later stage electrophysiological potentials (P300, late positive potential) present promising markers of motivated attention with high temporal, albeit low spatial resolution. Complementing this, the N2pc is an earlier-latency component providing the possibility of more directly analyzing visuospatial attention. Therefore, we tested a group with BED (N = 60), as well as an overweight (OW; N = 28) and normal weight (NW; N = 30) group without BED in a Go/No-Go paradigm using food and nonfood distractor images. Only the OW group in exclusively the Go trials displayed a stronger spatial attention allocation towards nonfood distractors as evidenced by an increased N2pc amplitude. In the P300's time window, the OW group displayed no attentional bias towards food and the NW group only did so in the absence of a target. Solely the BED group allocated more motivated attention towards food distractors both in Go and No-Go trials. In the following late positive potential (LPP), the OW group exhibited a general attentional bias towards food distractors, while the BED group only did so in the absence of a target. These results are discussed in light of the incentive sensitization theory and a potential early attentional suppression of potent distractors.

Does food recognition depend on color?

Color is considered important in food perception, but its role in food-specific visual mechanisms is unclear. We explore this question in North American adults. We build on work revealing contributions from domain-general and domain-specific abilities in food recognition and a negative correlation between the domain-specific component and food neophobia (FN, aversion to novel food). In Study 1, participants performed two food-recognition tests, one in color and one in grayscale. Removing color reduced performance, but food recognition was predicted by domain-general and -specific abilities, and FN negatively correlated with food recognition. In Study 2, we removed color from both food tests. Food recognition was still predicted by domain-general and food-specific abilities, but with a relation between food-specific ability and FN. In Study 3, color-blind men reported lower FN than men with normal color perception. These results suggest two separate food-specific recognition mechanisms, only one of which is dependent on color.

Neurocognitive predictors of food memory in healthy adults - A preregistered analysis

Memory processes have long been known to determine food choices (Rozin & Zellner, 1985) but recognition memory of food and its cognitive, homeostatic and neuroanatomical predictors are still largely understudied. 60 healthy, overweight, non-restrictive eating adults (20 females) took part in a food wanting and subsequent food recognition and lure discrimination task at four time points after a standardized breakfast shake. With advanced tractography of 3 T diffusion-weighted imaging data, we investigated the influence of the uncinate fasciculus' (UF) brain microstructure on the interplay of food wanting and memory processes. The analysis was preregistered in detail and conducted with Bayesian multilevel regression modeling. Target recognition (d') and lure discrimination (LDI) performance of food tended to be higher than of art images while single image food memory accuracy evidently dominated art memory. On this single item level, wanting enhanced recognition accuracy and caloric content enhanced food memory accuracy. The enhancement by reward anticipation was most pronounced during memory encoding. Subjective hunger level did not predict performance on the memory task. The microstructure of the UF did neither evidently affect memory performance outcomes nor moderate the wanting enhancement of the recognition accuracy. Interestingly, female participants outperformed males on the memory task, and individuals with stronger neuroticism showed poorer memory performance. We shed light on to date understudied processes in food decision-making: reward anticipation influenced recognition accuracy and food memory was enhanced by higher caloric content, both effects might shape food decisions. Our findings indicate that brain microstructure does not affect food decision processes in adult populations with overweight. We suggest extending investigation of this interplay to brain activity as well as to populations with eating behaviour disorders.

ERP and attachment dimensions as predictors of seeking care or food comfort in stressful situations

In this study, we aimed to test the association of the Late Positive Potential (LPP) response and attachment dimensions in the choice of care/food pictures and its reaction time (RT) in threatening versus neutral conditions. Fifty-two participants (38 females, M_age 22.62) responded to the ECR questionnaire and were exposed to adequate visual stimuli, during EEG recording. Results showed that threatening stimuli increase the choice of care, decrease RT, and increase LPP magnitude in centro-parietal areas (Cpz, Pz, P3 and P4). Food choice was lower, with increased RT. Furthermore, larger LPP magnitude in centro-parietal cluster was associated with increased RT in the choice of care. Considering the dimensions of attachment, in threatening conditions, while anxiety was not associated with RT and care/food choice, avoidance was associated with an increase in care choice and RT. In conclusion, the specific association of increased RT in care choice with high LPP magnitude centro-parietal cluster may be explained in terms of a functional interference of these areas in the choice of care, but not of food. Further, we postulate that the increased RT of avoidant individuals may reflect a more articulated choice process.

Selectivity for food in human ventral visual cortex

Visual cortex contains regions of selectivity for domains of ecological importance. Food is an evolutionarily critical category whose visual heterogeneity may make the identification of selectivity more challenging. We investigate neural responsiveness to food using natural images combined with large-scale human fMRI. Leveraging the improved sensitivity of modern designs and statistical analyses, we identify two food-selective regions in the ventral visual cortex. Our results are robust across 8 subjects from the Natural Scenes Dataset (NSD), multiple independent image sets and multiple analysis methods. We then test our findings of food selectivity in an fMRI "localizer" using grayscale food images. These independent results confirm the existence of food selectivity in ventral visual cortex and help illuminate why earlier studies may have failed to do so. Our identification of food-selective regions stands alongside prior findings of functional selectivity and adds to our understanding of the organization of knowledge within the human visual system.

Adult Avoidant Attachment, Attention Bias, and Emotional Regulation Patterns: An Eye-Tracking Study

Proximity-seeking in distress situations is one of attachment theory's primary strategies; insecure individuals often also develop secondary strategies. The mechanisms implied in attachment deactivation constitute a key issue in the current debate related to their role in support-seeking. The main aim of this study is to investigate the attachment deactivation strategy and the processes of proximity/support-seeking under distress conditions by analyzing the attentional processes (i.e., an essential emotion-regulation strategy), using eye-tracking techniques. Seventy-two participants (45 female; Mage 23.9 ± 3.97) responded to the ECR-R questionnaire in order to identify their attachment style. They participated in an experimental situation in which they had to choose between pictures of care or pictures of food, following the presentation of threatening or neutral prime conditions (via the pictures' stimuli). Results showed that a care-consistency response pattern was the most frequent pattern of response, particularly under a threatening condition; on the contrary, only avoidant individuals showed a lower care-consistency response pattern by choosing food pictures. The overall findings demonstrate that avoidant individuals used the deactivation strategy to process comfort-related attachment pictures, suggesting that they considered these stimuli to be threatening. The implications for attachment theory and particularly for avoidant strategies are discussed.

EXPRESS: Olfactory habituation for food and non-food odours

Olfactory perception can be modulated by the repeated exposure to odours. Olfactory habituation is a reduced behavioural response to repetitive stimulation. Edibility is considered an important top-down feature that can affect olfactory perception, but whether it could modulate olfactory habituation when food or non-food odours are repeatedly smelled remains unclear. Indeed, due to their ecological salience, food odours attract attention automatically which might slow down habituation. This registered report aimed to determine whether olfactory habituation shows a different pattern when participants are presented with food or non-food odours. In a within-subject design, 50 participants were tested under satiated and fasted states in separated experimental sessions. In each session, participants were exposed to the same food and non-food odour in different blocks of 20 trials each. Participants rated the perceived odour intensity and pleasantness after each trial. We used an intermittent odour presentation to reduce olfactory fatigue while capitalising on the effect of cognitive states on habituation. Linear mixed-effects models showed that the perceived odour intensity decreased over time only for non-food odours. Conversely, the perceived odour pleasantness decreased significantly more across trials for food odours. These effects were retrieved regardless of the participant's hunger state. Our results are in line with the olfactory specific satiety theory which posits a specific decrease in the perceived pleasantness of food odours, without changes in the perceived odour intensity. In short, our findings indicate that perceived odour edibility modulates olfactory habituation, extending the previous literature on the impact of top-down factors on olfactory perception.

Exploring Mindfulness and Mindful Eating and Visual Attention Towards Food Cues: Preliminary Findings

Continual exposure to energy dense foods is suggested to promote overeating and obesity. The aim of the present research was to explore whether or not mindfulness could reduce visual attention towards food cues. In two laboratory studies, participants with a normal weight range completed an eye-tracking paradigm, and their eye-movements were recorded. In study 1, participants were exposed to either mindfulness meditation or a control condition, and their eye-movements towards low energy density (LED) vs high energy density (HED) food cues were measured. In study 2, participants were assigned to a mindful eating condition using a Mindful Construal Diary (MCD) or a control condition, and their eye-movements towards LED or HED food vs. non-food cues were recorded. In study 1, participants in the mindfulness meditation condition had greater attention duration towards LED food cues, whilst those in the control condition exhibited greater attention duration towards HED food cues. In study 2, there were no significant differences in the maintenance of attentional biases towards food cues between the two conditions. Mindfulness meditation may be beneficial in increasing attention towards LED food cues. Future research should further explore the effect of mindfulness and mindful eating on visual attention towards food cues with people who suffer from excess weight or have obesity, and also within naturalistic settings.

Using event-related potentials to study food-related cognition: An overview of methods and perspectives for future research

Electroencephalography (EEG), and the measure of event-related potentials (ERPs) in particular, are useful methods to study the cognitive and cerebral mechanisms underlying the perception and processing of food cues. Further research on these aspects is necessary to better understand how cognitive functioning may influence food choices in different populations (e.g. obese individuals, individuals with eating disorders). To help researchers in designing future studies, this article provides an overview of the methods used in the current literature on ERPs and food-related cognition. Several methodological aspects are explored to outline interesting perspectives for future research, including discussions on the main experimental tasks used, the cognitive functions assessed (e.g. inhibitory control, attentional processing), the characteristics of the participants recruited (e.g. weight status, eating behaviors), and the stimuli selected (e.g. food pictures, odors). The issues generated by some of these methodological choices are discussed, and a few guidelines are provided.

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.

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.

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.

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.

Neural correlates of top-down guidance of attention to food: An fMRI study

We investigated the neural correlates of working memory guided attentional selection of food versus non-food stimuli in young women. Participants were thirty-two women, aged 20.6y (± 0.5) who were presented with a cue (food or non-food item) to hold in working memory. Subsequently, they had to search for a target in a 2-item display where target and distractor stimuli were each flanked by a picture of a food or a non-food item. The behavioural data showed that attention is particularly efficiently drawn to food stimuli when thinking about food. Using fMRI, we found that holding a non-food versus food stimulus in working memory was associated with increased activity in occipital gyrus, fusiform, inferior and superior frontal gyrus. In the posterior cingulum, retrosplenial cortex, a food item that re-appeared in the search array when it was held in memory led to a reduced response, compared to when it did not re-appear. The reverse effect was found for non-food stimuli. The extent of the reappearance effect correlated with the attentional capture of food as measured behaviourally. In conclusion, these results suggest that holding food in mind may bias attention because thinking of food facilitated neuronal responses to sensory input related to food stimuli and because holding food-related information in mind is less taxing on memory.

Value-driven attentional capture is modulated by the contents of working memory: An EEG study

Attention and working memory (WM) have previously been shown to interact closely when sensory information is being maintained. However, when non-sensory information is maintained in WM, the relationship between WM and sensory attention may be less strong. In the current study, we used electroencephalography to evaluate whether value-driven attentional capture (i.e., allocation of attention to a task-irrelevant feature previously associated with a reward) and its effects on either sensory or non-sensory WM performance might be greater than the effects of salient, non-reward-associated stimuli. In a training phase, 19 participants learned to associate a color with reward. Then, participants were presented with squares and encoded their locations into WM. Participants were instructed to convert the spatial locations either to another type of sensory representation or to an abstract, relational type of representation. During the WM delay period, task-irrelevant distractors, either previously-rewarded or non-rewarded, were presented, with a novel color distractor in the other hemifield. The results revealed lower alpha power and larger N2pc amplitude over posterior electrode sides contralateral to the previously rewarded color, compared to ipsilateral. These effects were mainly found during relational WM, compared to sensory WM, and only for the previously rewarded distractor color, compared to a previous non-rewarded target color or novel color. These effects were associated with modulations of WM performance. These results appear to reflect less capture of attention during maintenance of specific location information, and suggest that value-driven attentional capture can be mitigated as a function of the type of information maintained in WM.

Rapid-onset anorectic effects of intranasal oxytocin in young men

Although the neuropeptide oxytocin exhibits many of the characteristics that would support its use as an anorectic agent for overeaters, studies of oxytocin's effectiveness at reducing eating in humans remain limited. In a double-blind, placebo-controlled crossover study, under the pretext of examining oxytocin's effects on various aspects of sensory perception, 20 men were given 24 IU of oxytocin and took a taste test of sweet, salty, and neutral snacks 45 min later. Participants self-rated appetite, anxiety, and other mood parameters, and then were left alone for 10 min with the pre-weighed snack food and invited to help themselves. To minimize the influence of hunger-driven eating, lunch had been provided immediately after oxytocin administration. In line with Ott et al. (2013), oxytocin significantly reduced the consumption of sweet foods; however, it also reduced consumption of salty snacks. Self-reported anxiety did not differ across drug conditions. The study is the first to demonstrate an effect of oxytocin on snack eating at 45 min post administration and on salty snacks. The anorectic efficacy of oxytocin after 45 min cannot easily be explained by the same mechanism as the one presumed to underpin its effects in previous studies that adopted much longer intervals between drug administration and testing.

What makes the hedonic experience of a meal in a top restaurant special and retrievable in the long term? Meal-related, social and personality factors

Knowing what makes a top gastronomy experience unique and retrievable in the long term is of interest for scientific and economic reasons. Recent attempts to isolate predictors of the hedonic evaluation of food have afforded several factors, such as individual and social attributes, or liking/disliking profiles. However, in these studies relevant variables have been examined in isolation without an integrative perspective. Here we investigated 80 guests enjoying a 23-course meal in a top gastronomy restaurant, in groups of four. Our main question concerned the factors driving the overall evaluation of the meal at its conclusion and after three months. To this aim we administered the Big Five Personality Inventory before the meal, dish-by-dish hedonic ratings, and a multi-dimensional Meal Experience Questionnaire (MEQ) at the end of the meal. Hedonic evaluations of the meal were collected immediately after the meal and three months later. Better immediate overall evaluations were predicted by both the number of peaks in dish-by-dish ratings and by positive ratings of the final dish. Both factors and the number of troughs were also critical for the long-term evaluation after three months. The MEQ dimensions overall interest, valence and distraction predicted immediate evaluations, while the long-term evaluations were determined by interest and high scores on the personality traits agreeableness and conscientiousness. High consistency of the hedonic ratings within quartets indicated the relevance of commensality for the meal experience. The present findings highlight the simultaneous relevance of food- and personality-related factors and commensality for a top gastronomy meal experience in the short and long-run. The uncovered relationships are of theoretical interest and for those involved in designing meals for consumers in various settings.

Cognitive Control of Eating: the Role of Memory in Appetite and Weight Gain

PURPOSE OF REVIEW

The present review organises the recent literature on the role of memory in eating behaviours and provides an overview of the current evidence relating to the associations between memory and weight gain.

RECENT FINDINGS

Research over the last few years has highlighted working memory as an important cognitive process that underpins many aspects of appetite control. Recent work on episodic memory and appetite has replicated work showing that manipulating memory for recent eating affects later consumption and extended this work to examine associations between individual differences in memory and eating behaviours. Poorer episodic memory ability is related to a reduced sensitivity to internal states of hunger and satiety and a tendency towards uncontrolled eating. There is also recent evidence to suggest that working memory and episodic memory impairments are related to weight gain and high BMI. Working memory and episodic memory are core cognitive processes that are critical for food-related decision-making, and disruption to these processes contributes to problems with appetite control and weight gain, which suggests that weight loss programmes might be improved by the addition of cognitive training.

Attentional capture by alcohol-related stimuli may be activated involuntarily by top-down search goals

Previous research has found that the attention of social drinkers is preferentially oriented towards alcohol-related stimuli (attentional capture). This is argued to play a role in escalating craving for alcohol that can result in hazardous drinking. According to incentive theories of drug addiction, the stimuli associated with the drug reward acquire learned incentive salience and grab attention. However, it is not clear whether the mechanism by which this bias is created is a voluntary or an automatic one, although some evidence suggests a stimulus-driven mechanism. Here, we test for the first time whether this attentional capture could reflect an involuntary consequence of a goal-driven mechanism. Across three experiments, participants were given search goals to detect either an alcoholic or a non-alcoholic object (target) in a stream of briefly presented objects unrelated to the target. Prior to the target, a task-irrelevant parafoveal distractor appeared. This could either be congruent or incongruent with the current search goal. Applying a meta-analysis, we combined the results across the three experiments and found consistent evidence of goal-driven attentional capture, whereby alcohol distractors impeded target detection when the search goal was for alcohol. By contrast, alcohol distractors did not interfere with target detection, whilst participants were searching for a non-alcoholic category. A separate experiment revealed that the goal-driven capture effect was not found when participants held alcohol features active in memory but did not intentionally search for them. These findings suggest a strong goal-driven account of attentional capture by alcohol cues in social drinkers.

Thoughts for food in cognitive neuroscience: An introduction to the special issue

Food is essential to our survival. It is also one of the greatest pleasures of life. Over the last decade, our understanding about how the brain responds to food cues and guides food search and intake has greatly increased. This special issue brings together various perspectives and research approaches on food cognitive neuroscience, encompassing a wide variety of techniques and methods. As these studies will add substantially to the ever-growing research on food cognitive neuroscience, we hope that they will also inspire new and useful ideas to fill the gaps that remain in this critical area of inquiry. By providing nutrients to generate energy and sustain life, food is an essential fuel for our survival and a pervasive element of our daily environment. Food also represents one of the greatest pleasures that we experience in life. More recently, numerous cognitive neuroscientific studies about how the brain responds to food cues and guides food search and consumption have been published. Evidence points to several and closely interrelated neural circuits underlying the homeostatic and hedonic mechanisms that regulate food intake.

Fat Content Modulates Rapid Detection of Food: A Visual Search Study Using Fast Food and Japanese Diet

Rapid detection of food is crucial for the survival of organisms. However, previous visual search studies have reported discrepant results regarding the detection speeds for food vs. non-food items; some experiments showed faster detection of food than non-food, whereas others reported null findings concerning any speed advantage for the detection of food vs. non-food. Moreover, although some previous studies showed that fat content can affect visual attention for food, the effect of fat content on the detection of food remains unclear. To investigate these issues, we measured reaction times (RTs) during a visual search task in which participants with normal weight detected high-fat food (i.e., fast food), low-fat food (i.e., Japanese diet), and non-food (i.e., kitchen utensils) targets within crowds of non-food distractors (i.e., cars). Results showed that RTs for food targets were shorter than those for non-food targets. Moreover, the RTs for high-fat food were shorter than those for low-fat food. These results suggest that food is more rapidly detected than non-food within the environment and that a higher fat content in food facilitates rapid detection.