Food Pictures Research Articles

Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals

In the current study we examined an associative learning mechanism by which food cues (signaling low- versus high-calorie food) can bias instrumental responses directed toward those foods. To investigate the clinical relevance of this mechanism, we used a computerized Pavlovian-to-instrumental transfer task and compared performance of 19 severely obese individuals to that of 19 healthy-weight controls matched for age, education and gender. During the response-priming test we exposed participants to both food pictures and to Pavlovian cues predictive of those food pictures, and examined their biasing effect on instrumental choice. As expected, obese participants showed higher priming rates for palatable, high-calorie foods (potato chips and chocolate) relative to low-calorie foods (lettuce and courgette) whereas healthy-weight individuals did not show a difference between priming rates for these two food types. We also included various measures of impulsivity as well as a slips-of-action task designed to investigate the balance between goal-directed and habitual behavioral control in these two groups. We did not find any evidence of increased impulsivity or reliance on a habitual strategy during the slips-of-action task, in obese participants.General Scientific Summary: Our environment is full of cues signaling the availability of tasty, but often unhealthy, foods. This study suggests that severely obese individuals are particularly sensitive to high-calorie food cues whereas low-calorie food cues have little effect on their behavior.

Food craving, food choice and consumption: The role of impulsivity and sham-controlled tDCS stimulation of the right dlPFC

BackgroundImpulsivity has been found to be associated with overeating and obesity. Transcranial direct current stimulation (tDCS) may enhance inhibitory control while reducing food craving and intake. Thus, the aim of the present study was to investigate whether tDCS stimulation modifies food choice, craving and consumption as a function of trait impulsivity. MethodsForty-two predominantly healthy-weight women received active tDCS stimulation to the right dorsolateral prefrontal cortex and sham stimulation in a within participant design. Trait impulsivity was measured with a short form of the Barratt Impulsiveness Scale. Participants completed a computerized food-choice task, during which their mouse movements were traced. Current food craving was measured by a modified version of the Food Cravings Questionnaire-State as well as by desire to eat ratings for food pictures. Food intake was measured in a taste test. ResultsThere were no tDCS effects on any of the dependent variables. Trait impulsivity (and non-planning impulsivity in particular) was positively associated with higher calorie intake in the taste test, irrespective of tDCS stimulation. ConclusionThe current findings question the efficacy of single-session tDCS stimulation of the right dLPFC to reduce food craving, high caloric food choice and calorie intake in non-selected, predominantly healthy weight women. However, they do support the idea that trait impulsivity is related to overeating and, therefore, may be a risk factor for obesity. Future research needs to specify which appetitive behaviors can be modulated by brain stimulation and which populations might profit from it the most.

Validation of a food quantification picture book and portion sizes estimation applying perception and memory methods

We tested the applicability of EPIC-SOFT food picture series used in the context of a Hungarian food consumption survey gathering data for exposure assessment, and investigated errors in food portion estimation resulted from the visual perception and conceptualisation-memory. Sixty-two participants in three age groups (10 to <74 years) were presented with three different portion sizes of five foods. The results were considered acceptable if the relative difference between average estimated and actual weight obtained through the perception method was ≤25%, and the relative standard deviation of the individual weight estimates was <30% after compensating the effect of potential outliers with winsorisation. Picture series for all five food items were rated acceptable. Small portion sizes were tended to be overestimated, large ones were tended to be underestimated. Portions of boiled potato and creamed spinach were all over- and underestimated, respectively. Recalling the portion sizes resulted in overestimation with larger differences (up to 60.7%).

Testing food-related inhibitory control to high- and low-calorie food stimuli: Electrophysiological responses to high-calorie food stimuli predict calorie and carbohydrate intake.

Maintaining a healthy diet has important implications for physical and mental health. One factor that may influence diet and food consumption is inhibitory control-the ability to withhold a dominant response in order to correctly respond to environmental demands. We examined how N2 amplitude, an ERP that reflects inhibitory control processes, differed toward high- and low-calorie food stimuli and related to food intake. A total of 159 participants (81 female; M age = 23.5 years; SD = 7.6) completed two food-based go/no-go tasks (one with high-calorie and one with low-calorie food pictures as no-go stimuli) while N2 amplitude was recorded. Participants recorded food intake using the Automated Self-Administered 24-hour Dietary Recall system. Inhibiting responses toward high-calorie stimuli elicited a larger (i.e., more negative) no-go N2 amplitude; inhibiting responses toward low-calorie stimuli elicited a smaller no-go N2 amplitude. Participants were more accurate during the high-calorie than low-calorie task, but took longer to respond on go trials toward high-calorie rather than low-calorie stimuli. When controlling for age, gender, and BMI, larger high-calorie N2 difference amplitude predicted lower caloric intake (β = 0.17); low-calorie N2 difference amplitude was not related to caloric intake (β = -0.03). Exploratory analyses revealed larger high-calorie N2 difference amplitude predicted carbohydrate intake (β = 0.22), but not protein (β = 0.08) or fat (β = 0.11) intake. Results suggest that withholding responses from high-calorie foods requires increased recruitment of inhibitory control processes, which may be necessary to regulate food consumption, particularly for foods high in calories and carbohydrates.

How task demands shape brain responses to visual food cues.

Several previous imaging studies have aimed at identifying the neural basis of visual food cue processing in humans. However, there is little consistency of the functional magnetic resonance imaging (fMRI) results across studies. Here, we tested the hypothesis that this variability across studies might - at least in part - be caused by the different tasks employed. In particular, we assessed directly the influence of task set on brain responses to food stimuli with fMRI using two tasks (colour vs. edibility judgement, between-subjects design). When participants judged colour, the left insula, the left inferior parietal lobule, occipital areas, the left orbitofrontal cortex and other frontal areas expressed enhanced fMRI responses to food relative to non-food pictures. However, when judging edibility, enhanced fMRI responses to food pictures were observed in the superior and middle frontal gyrus and in medial frontal areas including the pregenual anterior cingulate cortex and ventromedial prefrontal cortex. This pattern of results indicates that task sets can significantly alter the neural underpinnings of food cue processing. We propose that judging low-level visual stimulus characteristics - such as colour - triggers stimulus-related representations in the visual and even in gustatory cortex (insula), whereas discriminating abstract stimulus categories activates higher order representations in both the anterior cingulate and prefrontal cortex. Hum Brain Mapp 38:2897-2912, 2017. © 2017 Wiley Periodicals, Inc.

Effects of a food-specific inhibition training in individuals with binge eating disorder-findings from a randomized controlled proof-of-concept study.

Impulsivity might contribute to the development and maintenance of obesity and eating disorders. Patients suffering from binge eating disorder (BED) show an impulsive eating pattern characterized by regular binge eating episodes. Novel behavioral interventions increasing inhibitory control could improve eating behavior in BED. We piloted a novel food-specific inhibition training in individuals with BED. N = 22 BED patients according to SCID-I were randomly assigned to three sessions of a training or control condition. In both conditions, pictures of high-caloric food items were presented in peripheral vision on a computer screen while assessing gaze behavior. The training group had to suppress the urge to turn their gaze towards these pictures (i.e., to perform antisaccades). The control group was allowed to freely explore the pictures. We assessed self-reported food craving, food addiction, and wanting/liking of food pictures pre- and post-intervention. Twenty participants completed the study. The training proved to be feasible and acceptable. Patients of the training group significantly improved inhibitory control towards high-caloric food stimuli. Both groups reported a significantly lower number of binge eating episodes in the last four weeks after termination of the study. No changes were found in food craving, food addiction, liking, and wanting ratings. A food-specific inhibition training could be a useful element in the treatment of BED and other eating disorders; however, larger efficacy studies in patient samples are needed to investigate the efficacy of this and similar training approaches.

Modulation of attentional networks by food-related disinhibition

The risk of weight gain is especially related to disinhibition, which indicates the responsiveness to external food stimuli with associated disruptions in eating control. We adapted a food-related version of the attention network task and used functional magnetic resonance imaging to study the effects of disinhibition on attentional networks in 19 normal-weight participants. High disinhibition scores were associated with a rapid reorienting response to food pictures after invalid cueing and with an enhanced alerting effect of a warning cue signalizing the upcoming appearance of a food picture. Imaging data revealed activation of a right-lateralized ventral attention network during reorienting. The faster the reorienting and the higher the disinhibition score, the less activation of this network was observed. The alerting contrast showed activation in visual, temporo-parietal and anterior sites. These modulations of attentional networks by food-related disinhibition might be related to an attentional bias to energy dense and palatable food and increased intake of food in disinhibited individuals.

Affective Responses in Different Stages of Anorexia Nervosa: Results from a Startle-reflex Paradigm.

There is an evolving debate about pathological affective responses in patients with anorexia nervosa (AN). We examined startle responses in different stages of AN. We applied a startle reflex paradigm with standardized visual stimuli (International Affective Pictures System; food and body pictures) in 64 female participants (17 acute AN, 16 chronically ill AN, 15 long-term recovered AN, 16 healthy controls). We measured subjective ratings of valence and anxiety, and electromyographic startle responses. Participants with acute and chronic AN displayed the same subjective valence ratings to affective stimuli but showed less startle reactivity to affective pictures (F(6, 116) = 2.75, p = .02) compared with healthy control. Food pictures were rated as more unpleasant and higher anxiety provoking by currently ill AN (F(3, 59) = 3.32, p=.03). We observed diverging subjective and psychophysiological reactions in different stages of AN. Psychophysiological methods can help to attain a more comprehensive understanding of biological alterations in the long-term course of AN. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.

Weakening self-control biases the emotional evaluation of appetitive cues.

Exerting self-control in a first task weakens self-control in a second completely unrelated task (ego-depletion). It has been proposed that ego-depletion increases approach motivation which would amplify positive emotions to appetitive cues. Here we investigated the effect of the depletion of cognitive self-control on the subsequent emotional evaluation of appetitive cues. Participants of the depletion group copied a text omitting frequent letters and thereby exerting self-control to inhibit automated writing habits. Participants of the control group just copied the text. In a subsequent task participants had to rate valence and arousal of their responses to neutral vs. positive pictures of humans, animals, food, or sceneries. Ego-depletion caused more positive valence ratings of neutral pictures and lower arousal ratings of positive pictures. The findings do not support the notion that ego-depletion increases approach motivation in general. Rather they suggest that—without a specific motivational context—depletion of cognitive self-control differentially alters the immediate emotional evaluation of appetitive cues.

Preliminary support for the role of alcohol cues in food cravings and attentional biases.

This study examined whether alcohol odors, in isolation or when combined with pictures, would influence food attentional biases and cravings. Participants' cravings and attentional biases to food and alcohol pictures were assessed after exposure to alcohol or water odors ( n = 77; mean age = 30.84 years, 51.9% female, 83.1% Caucasian). Food attentional biases were increased by alcohol odors, but food cravings were increased only by a combination of alcohol odors and food pictures. These effects were related with self-reported problematic food consumption. These findings support a research program for further examining the effect of alcohol cues on problematic food consumption.

社会性高趋近积极情绪调节认知控制：对稳定性的增强作用

已有研究考察了积极情绪趋近动机强度对认知控制的影响，证明高趋近积极情绪增强认知的保持性，低趋近积极情绪促进认知灵活性。以往的研究主要考察生理性高趋近动机的积极情绪(如：对食物的渴望)的作用，而社会依附性相关的高趋近积极情绪(如：对人脸笑容的亲近)对认知控制影响的研究较少，且相关研究结果不明确。因此本研究通过微笑的人物图片和美食图片分别诱发社会性和生理性趋近积极情绪，并记录被试在不同情绪条件下AX-连续操作任务(CPT)的成绩。结果显示生理性趋近积极情绪影响BX试次的错误率，而社会性趋近积极情绪影响AY试次的反应时。表明社会性高趋近积极情绪对认知控制的作用与生理性高趋近积极情绪的作用类似，两种情绪都增强了认知控制的保持性。 Previous studies have examined the effect of positive emotional approach motivation on cognitive control, demonstrating that high approach positive affects increase cognitive retention, low approach positive affects promote cognitive flexibility. The previous researches mainly investigated the effects of physiological high approach motivational positive affect (such as: the desire for food), but the impacts of social attachment related high reaching positive affects (such as: tending to approach the smile face) on cognitive control had been examined rarely, and related research results is not clear. Therefore, this study induced social and physiological positive emotions by smiling characters pictures and food pictures, and recorded the subjects’ performances on AX-continuous performance task (CPT) under different affective conditions. The results showed that the physiological approach positive affects influenced the error rate of the BX trial, while the social approach positive affects influenced the reaction times of the AY trial. These demonstrated that the social high approach positive affects had similar effects on cognitive control with the physiological high approach positive affects. These two affects both enhanced the retention of cognitive control.

积极情绪背景对词语记忆的影响

本研究采用学习－测验范式，以大学生为被试，通过两个实验考察了不同趋近强度的积极情绪背景材料对词语记忆的影响。研究表明，当使用情绪图片作为学习词语时的背景材料时，高趋近积极情绪背景(美食图片背景)可能比低趋近积极情绪背景(鲜花图片背景)更不利于学习者的编码加工，从而影响其再认表现。当使用真正的鲜花或食物作为学习和记忆测试过程中的背景材料时，低趋近的鲜花背景更可能干扰被试的再认反应。 Selecting undergraduates as participants, the present study examined the effects of low versus high approach-motivated positive affect on memory of words by employing the study-test para-digm. The results showed that, when emotional pictures were as context during learning, high approach-motivated positive affect pictures (delicious food pictures) were more likely to interfere with the encoding process of words and thus impaired recognition performance as compared to low approach-motivated positive affect pictures (flower pictures); when real flowers or delicious foods were as context during learning and test, low approach-motivated flower background was more likely to interfere with participants’ recognition as compared to high approach-motivated food background and neutral background.

Disparity in neural and subjective responses to food images in women with obesity and normal-weight women.

Self-reports tend to differ from objective measurements of food intake, particularly in adults with obesity; however, no studies have examined how neural responses to food (an objective measure) and subjective ratings of food differ by BMI status. This study tested normal-weight women (NWW) and women with obesity (OBW) for group differences in neural indices of attention towards food pictures, subjective ratings of these pictures, and the disparity between objective and subjective measurements. Twenty-two NWW (21.8 ± 1.7 kg/m2 ) and 22 OBW (37.0 ± 5.7 kg/m2 ) viewed food and flower pictures while late positive potential amplitude, an event-related potential, was recorded. Participants rated pictures for arousal and valence. Late positive potential amplitude was larger toward food than flower pictures. OBW self-reported flower pictures as more pleasant than food; NWW showed no difference for pleasantness. There were no significant main effects or interactions for arousal. Standardized scores showed that only on subjective, but not objective, measures did OBW compared with NWW disproportionately indicate food pictures as less pleasant than flowers. Compared with NWW, OBW showed larger discrepancies between neural and subjective reports of attention towards food. Inaccurate self-reports of attention towards food may reduce the efficiency of health interventions.

Dieting and Food Cue-Related Working Memory Performance.

Executive functioning (e.g., working memory) is tightly intertwined with self-regulation. For example, food cue-elicited craving has been found to impair working memory performance. Furthermore, current dieters have been found to show lower working memory performance than non-dieters. Recent research, however, suggests that it is crucial to consider dieting success in addition to current dieting status or restrained eating in order to reveal cognitive mechanisms that are associated with successful eating-related self-regulation. The current study investigated food cue-related working memory performance as a function of dieting status and dieting success in female students. Participants performed an n-back task with pictures of food and neutral objects. Reaction time in response to food pictures was slower than in response to neutral pictures, whereas omission errors did not differ between picture types. Current food craving was increased after performing the food block, but not after the neutral block. There was an indirect effect of current dieting status on higher food craving after the food block, which was mediated by slower reaction time to food vs. neutral pictures. Furthermore, higher dieting success was associated with fewer omission errors in the food vs. neutral block in current dieters. There were no relationships of restrained eating with current food craving and task performance. Results further highlight the need to differentiate between successful and unsuccessful dieting in addition to current dieting status or restrained eating when examining possible mechanisms of overeating or successful restraint. Although palatable food cues induce food craving regardless of dieting success, they may boost executive functioning in successful dieters, which helps them to overcome these temptations.

Evaluation of Diet-Related Infographics on Pinterest for Use of Behavior Change Theories: A Content Analysis.

BackgroundThere is increasing interest in Pinterest as a method of disseminating health information. However, it is unclear whether the health information promoted on Pinterest is evidence-based or incorporates behavior change theory.ObjectivesThe objective of the study was to determine the presence of health behavior theory (HBT) constructs in pins found on Pinterest and assess the relationship between various pin characteristics and the likelihood of inclusion of HBT.MethodsA content analysis was conducted on pins collected from Pinterest identified with the search terms “nutrition infographic” and “healthy eating infographic.” The coding rubric included HBT constructs, pin characteristics, and visual communication tools. Each HBT construct was coded as present or not present (yes=1, no=0). A total theory score was calculated by summing the values for each of the 9 constructs (range 0-9). Adjusted regression analysis was used to identify factors associated with the inclusion of health behavior change theory in pins (P<.05).ResultsThe mean total theory score was 2.03 (SD 1.2). Perceived benefits were present most often (170/236, 72%), followed by behavioral capability (123/238, 51.7%) and perceived severity (79/236, 33.5%). The construct that appeared the least was self-regulation/self-control (2/237, 0.8%). Pin characteristics associated with the inclusion of HBT included a large amount of text (P=.01), photographs of real people (P=.001), cartoon pictures of food (P=.01), and the presence of references (P=.001). The number of repins (P=.04), likes (P=.01), and comments (P=.01) were positively associated with the inclusion of HBT.ConclusionsThese findings suggest that current Pinterest infographics targeting healthy eating contain few HBT elements. Health professionals and organizations should create and disseminate infographics that contain more elements of HBT to better influence healthy eating behavior. This may be accomplished by creating pins that use both text and images of people and food in order to portray elements of HBT and convey nutritional information.

Developmental differences in the brain response to unhealthy food cues: an fMRI study of children and adults

Background: Food cues are omnipresent and may trigger overconsumption. In the past 2 decades, the prevalence of childhood obesity has increased dramatically. Because children’s brains are still developing, especially in areas important for inhibition, children may be more susceptible than adults to tempting food cues.Objective: We examined potential developmental differences in children’s and adults’ responses to food cues to determine how these responses relate to weight status.Design: We included 27 children aged 10–12 y and 32 adults aged 32–52 y. Functional magnetic resonance imaging data were acquired during a food-viewing task in which unhealthy and healthy food pictures were presented.Results: Children had a stronger activation in the left precentral gyrus than did adults in response to unhealthy compared with healthy foods. In children, unhealthy foods elicited stronger activation in the right inferior temporal and middle occipital gyri, left precentral gyrus, bilateral opercular part of the inferior frontal gyrus, left hippocampus, and left middle frontal gyrus. Adults had stronger activation in the bilateral middle occipital gyrus and the right calcarine sulcus for unhealthy compared with healthy foods. Children with a higher body mass index (BMI) had lower activation in the bilateral dorsolateral prefrontal cortex while viewing unhealthy compared with healthy foods. In adults there was no correlation between BMI and neural response to unhealthy compared with healthy foods.Conclusions: Unhealthy foods might elicit more attention both in children and in adults. Children had stronger activation while viewing unhealthy compared with healthy foods in areas involved in reward, motivation, and memory. Furthermore, children activated a motivation and reward area located in the motor cortex more strongly than did adults in response to unhealthy foods. Finally, children with a higher BMI had less activation in inhibitory areas in response to unhealthy foods, which may mean they are more susceptible to tempting food cues. This trial was registered at www.trialregister.nl as NTR4255.

Stop overeating: The effect of training inhibition on eating behavior

More and more people in the world are getting fatter and are having trouble to lose weight. When people lack inhibitory control, they are more prone to indulge in highcaloric food. In this study, the effect of training inhibitory control on eating behavior was investigated. Expected was that inhibition training would increase inhibition ability and would lead to less food intake. To investigate the effect of training inhibitory control on eating behavior, participants were divided into three training conditions: The first group of participants had to inhibit a response for neutral stimuli and only responded to foodrelated stimuli, the second group consistently responded to neutral stimuli and inhibited a response for food-related stimuli. The third group never inhibited a response. Food intake was measured using a food diary and a taste test. The Restraint scale was used to measure restrained eating behavior, which could have influenced the results of the study. Results showed that the three groups of participants in the different training conditions did not differ significantly after the training on inhibitory control and food-intake. In conclusion, the inhibition training did not have an effect on inhibitory control neither on the food intake of the participants. A possible explanation for the lack of effect of the training could be that using non-specific food pictures and not consistently having to stop for a food item does not lead to better inhibitory control concerning food, because no association will then be learned between the stopping goal and different kinds of food.

Diffusive and Specific Searches on Eye Fixation in Opinion Test with Paired Food Pictures by Stimulus-Comparison

Diffusive and Specific Searches on Eye Fixation in Opinion Test with Paired Food Pictures by Stimulus-Comparison

Attentional bias to unhealthy food in individuals with severe obesity and binge eating

Attentional bias is an implicit cognition relevant to development and maintenance of obesity, but little is known of how binge eating modulates attentional bias in severe obesity. This study investigated attentional bias towards unhealthy foods at different stages of attentional processing in a clinical sample, comparing obese patients (Body Mass Index, BMI>35 kg/m2) with and without binge eating behaviors. Participants were separated into two groups according to their score on the Binge Eating Scale (BES): no binge eating (NB; score ≤17; n = 23) and binge eating (BE; score > 17; n = 19). Participants performed a computerized visual probe task designed to evaluate attentional bias in different stages of attentional process; matching pairs of unhealthy food and matching non-food pictures concealed a target for 100, 500 or 2000 ms. Reduced reaction times to targets following food-related images are indicative of attentional bias towards food images. BE group exhibited a greater bias towards food than NB. Both groups showed positive attentional bias to food in the initial orientation stage (100 ms), whereas bias was close to zero in the maintenance of attention stage (2000 ms), suggesting ambivalent approach-avoidance responses to food stimuli. Only the BE group showed a bias towards food images when displayed for 500 ms, indicating disengaging from food-related stimuli was faster in NB group. Although both groups were ambivalent about attending to food cues, slower attentional disengagement from unhealthy food might be a cognitive marker of binge eating behavior in severe obesity.

Differential activation of the frontal pole to high vs low calorie foods: The neural basis of food preference in Anorexia Nervosa?

Neuroimaging studies in anorexia nervosa (AN) suggest that altered food reward processing may result from dysfunction in both limbic reward and cortical control centers of the brain. This fMRI study aimed to index the neural correlates of food reward in a subsample of individuals with restrictive AN: twelve currently ill, fourteen recovered individuals and sixteen healthy controls. Participants were shown pictures of high and low-calorie foods and asked to evaluate how much they wanted to eat each one following a four hour fast. Whole-brain task-activated analysis was followed by psychophysiological interaction analysis (PPI) of the amygdala and caudate. In the AN group, we observed a differential pattern of activation in the lateral frontal pole: increasing following presentation of high-calorie stimuli and decreasing in during presentation of low-calorie food pictures, the opposite of which was seen in the healthy control (HC) group. In addition, decreased activation to food pictures was observed in somatosensory regions in the AN group. PPI analyses suggested hypo-connectivity in reward pathways, and between the caudate and both somatosensory and visual processing regions in the AN group. No significant between-group differences were observed between the recovered group and the currently ill and healthy controls in the PPI analysis. Taken together, these findings further our understanding of the neural processes which may underpin the avoidance of high-calorie foods in those with AN and might exacerbate the development of compulsive weight-loss behavior, despite emaciation.