Influencing the Insulin System by Placebo Effects in Patients With Diabetes Type 2 and Healthy Controls: A Randomized Controlled Trial.

OBJECTIVE: The objective of this study was to investigate whether placebo effect induced by pharmacological conditioning with intranasal insulin can affect glucose, insulin, C-peptide, hunger, and memory in patients with diabetes type 2 and healthy controls. METHODS: Placebo effect was induced by pharmacological conditioning. Thirty-two older patients (mean age = 68.3 years) with diabetes type 2 and age- and sex-matched thirty-two healthy older adults (mean age = 67.8 years) were randomly assigned to a conditioned or a control group. On day 1, conditioned group received six administrations of intranasal insulin with a conditioned stimulus (CS; smell of rosewood oil), whereas the control group received a placebo with the CS. On day 2, both groups received a placebo spray with the CS. Glucose, insulin, and C-peptide were repeatedly measured in blood. Hunger and memory were assessed with validated measures. RESULTS: Intranasal insulin stabilized dropping glucose levels in patients ( B = 0.03, SE = 0.02, p = .027) and healthy men ( B = 0.046, SE = 0.02, p = .021), and decreased C-peptide levels in healthy controls ( B = 0.01, SE = 0.001, p = .008). Conditioning also prevented the drop of glucose levels but only in men (both healthy and patients; B = 0.001, SE = 0.0003, p = .024). Conditioning significantly decreased hunger in healthy participants ( B = 0.31, SE = 0.09, p < .001). No effects were found on other measures. CONCLUSIONS: Placebo effect induced by conditioning with intranasal insulin modifies blood glucose levels and decreases hunger in older adults, but its effects depend on health status and sex. Insulin conditioning might be beneficial for groups suffering from intensive hunger but seems not be particularly suitable for blood glucose reduction. TRIAL REGISTRATION: Netherlands Trial Register, NL7783 ( https://www.trialregister.nl/trial/7783 ).

The effect of cognitive load on preference and intensity processing of sweet taste in the brain.

Distracted eating can cause overconsumption. Whereas previous work has shown that cognitive load suppresses perceived taste intensity and increases subsequent consumption, the mechanism behind distraction-induced overconsumption remains unclear. To elucidate this, we performed two event-related fMRI experiments that examined how cognitive load affects neural responses and perceived intensity and preferred intensity, respectively, to solutions varying in sweetness. In Experiment 1 (N = 24), participants tasted weak sweet and strong sweet glucose solutions and rated their intensity while we concurrently varied cognitive load using a digit-span task. In Experiment 2 (N = 22), participants tasted five different glucose concentrations under varying cognitive load and then indicated whether they wanted to keep, decrease or increase its sweetness. Participants in Experiment 1 rated strong sweet solutions as less sweet under high compared to low cognitive load, which was accompanied by attenuated activation the right middle insula and bilateral DLPFC. Psychophysiological interaction analyses showed that cognitive load moreover altered connectivity between the middle insula and nucleus accumbens and DLPFC and middle insula while tasting strong sweet solutions. In Experiment 2, cognitive load did not affect participants' preferred sweetness intensity. fMRI results revealed that cognitive load attenuated DLPFC activation for the strongest sweet solutions in the study. In conclusion, our behavioral and neuroimaging results suggest that cognitive load dampens the sensory processing of strong sweet solutions in particular, which may indicate higher competition for attentional resources for strong sweet than weak sweet solutions under high cognitive load. Implications for future research are discussed.

Test-retest reliability of a smartphone-based approach-avoidance task: Effects of retest period, stimulus type, and demographics.

The approach-avoidance task (AAT) is an implicit task that measures people's behavioral tendencies to approach or avoid stimuli in the environment. In recent years, it has been used successfully to help explain a variety of health problems (e.g., addictions and phobias). Unfortunately, more recent AAT studies have failed to replicate earlier promising findings. One explanation for these replication failures could be that the AAT does not reliably measure approach-avoidance tendencies. Here, we first review existing literature on the reliability of various versions of the AAT. Next, we examine the AAT's reliability in a large and diverse sample (N = 1077; 248 of whom completed all sessions). Using a smartphone-based, mobile AAT, we measured participants' approach-avoidance tendencies eight times over a period of seven months (one measurement per month) in two distinct stimulus sets (happy/sad expressions and disgusting/neutral stimuli). The mobile AAT's split-half reliability was adequate for face stimuli (r = .85), but low for disgust stimuli (r = .72). Its test-retest reliability based on a single measurement was poor for either stimulus set (all ICC1s < .3). Its test-retest reliability based on the average of all eight measurements was moderately good for face stimuli (ICCk = .73), but low for disgust stimuli (ICCk = .5). Results suggest that single-measurement AATs could be influenced by unexplained temporal fluctuations of approach-avoidance tendencies. These fluctuations could be examined in future studies. Until then, this work suggests that future research using the AAT should rely on multiple rather than single measurements.

Ire and punishment: Incidental anger and costly punishment in children, adolescents, and adults.

Why do children, adolescents, and adults engage in costly punishment to sanction fairness violations? Two studies investigated the differential impact of incidental anger on the costly punishment of 8-year-olds, 13-year-olds, and adults. Focusing on experimentally manipulated incidental anger allows for a causal investigation as to whether and how anger affects costly punishment in these age groups in addition to other motives such as inequity aversion. Study 1 (N = 210) assessed the effect of incidental anger (vs. a neutral emotion) on second-party punishment, where punishers were direct victims of fairness violations. Study 2 (N = 208) examined third-party punishment, where the punisher was an observer unaffected by the violation. Across ages, incidental anger increased the second-party punishment of unequal offers but not equal offers. Thus, anger seems to play a causal role in the punishment of unfairness when fairness violations are self-relevant. As predicted, adults' third-party punishment of unequal offers was higher in the incidental anger condition than in the neutral emotion condition. Children's third-party punishment of unfairness was not affected by the emotion condition, but incidental anger increased adolescents' third-party punishment across offers. Overall, our data suggest that the association between anger and costly punishment is based on the self-relevance of the violation. In third-party situations, where unfairness does not affect the self, social-cognitive processes that develop well into adulthood, such as emotional appraisals, might be necessary for third parties to engage in costly punishment.

Daily distracted consumption patterns and their relationship with BMI.

The rapidly increasing prevalence of overweight and obesity has heightened the need for a better understanding of obesity-related eating patterns and dietary behaviours. Recent work suggests that distracted eating is causally related to increased immediate and later food, pushing the need for a better understanding of the prevalence of distracted consumption and how this relates to body weight. To extract insights in the relationship between demographics, daily consumption settings, and BMI, we performed secondary data analyses on data from 1011 individuals representative of the Dutch population (adults, 507F, BMI 17-50 kg/m2). The most commonly reported distractions were talking to others (32.7%) and watching television (21.7%). Only 18.4% of respondents reported no distractions during meals. To examine how different distractions related to BMI, we performed OLS regression which showed, among other things, that watching tv while eating lunch (η2 = 0.37) and working during dinner were associated with a higher BMI (η2 = 1.63). To examine the robustness of these findings, machine learning techniques were used. A random forest analysis (RMSE = 4.09) showed that next to age and education level, distraction during lunch and snack was amongst the largest predictors of BMI. Multiple linear regression with lasso penalty (RMSE = 4.13) showed that specifically watching tv while eating lunch or snacks was associated with a higher BMI. In conclusion, our analyses confirmed the assumption that people are regularly distracted during their daily meals, with distinct distractors relating to BMI. These findings provide a starting point for evidence-based recommendations on which consumption settings are associated with healthier eating patterns and body weight.

Choice architecture meets motivation science: How stimulus availability interacts with internal factors in shaping the desire for food.

Recent research on choice architecture has highlighted the role of external aspects such as stimulus proximity or availability on consumption. How such external factors interact with internal, intraindividual factors, however, is very poorly understood. Here we show how the wanting for palatable food emerges from the interplay of one key external factor, availability, and two key internal factors central to motivation science, need state and learning history. Across three experiments in the food domain, we find converging evidence for a main effect of stimulus availability which is qualified in theoretically predicted ways by a three-way interaction such that food desire peaks when the availability of tempting food stimuli is accompanied by high need states and a positive learning experience. A pooled analysis across the three studies supported this general conclusion. We conclude that nudging effects are strongest when external factors of choice architecture synergize with internal factors in critical ways.

A mobile approach-avoidance task.

Approach and avoidance tendencies have helped explain phenomena as diverse as addiction (Mogg, Field, & Bradley, 2005), phobia (Rinck & Becker, 2007), and intergroup discrimination (Bianchi, Carnaghi, & Shamloo, 2018; Degner, Essien, & Reichardt, 2016). When the original approach-avoidance task (AAT; Solarz, 1960) that measures these tendencies was redesigned to run on regular desktop computers, it made the task much more flexible but also sacrificed some important behavioral properties of the original task-most notably its reliance on physical distance change (Chen & Bargh, 1999). Here, we present a new, mobile version of the AAT that runs entirely on smartphones and combines the flexibility of modern tasks with the behavioral properties of the original AAT. In addition, it can easily be deployed in the field and, next to traditional reaction time measurements, includes the novel measurement of response force. In two studies, we demonstrate that the mobile AAT can reliably measure known approach-avoidance tendencies toward happy and angry faces both in the laboratory and in the field.

Tuning down the hedonic brain: Cognitive load reduces neural responses to high-calorie food pictures in the nucleus accumbens.

The present research examined whether cognitive load modulates the neural processing of appetitive, high-calorie food stimuli. In a functional magnetic resonance imaging (fMRI) study, participants quickly categorized high-calorie and low-calorie food pictures versus object pictures as edible or inedible while they concurrently performed a digit-span task that varied between low and high cognitive load (memorizing six digits vs. one digit). In line with predictions, the digit-span task engaged the dorsolateral prefrontal cortex (DLPFC) when cognitive load was high compared to low. Moreover, exposure to high-calorie compared to low-calorie food pictures led to increased activation in the nucleus accumbens (NAcc), but only when cognitive load was low and not when it was high. In addition, connectivity analyses showed that load altered the functional coupling between NAcc and right DLPFC during presentation of the high-calorie versus low-calorie food pictures. Together, these findings indicate that loading the cognitive system moderates hedonic brain responses to high-calorie food pictures via interactions between NAcc and DLPFC. Our findings are consistent with the putative cognitive nature of food motivation. Implications for future research are discussed.

Looking into the crystal ball of our emotional lives: emotion regulation and the overestimation of future guilt and shame.

In the present study, we examined the impact of emotion regulation on the intensity bias in guilt and shame. Fifty-two undergraduates either forecasted their emotions and emotion regulation following a guilt- and shame-eliciting situation or reported their actual experienced emotions and employed emotion regulation. Results showed a clear intensity bias, that is, forecasters predicted to experience more guilt and shame than experiencers actually experienced. Furthermore, results showed that forecasters predicted to employ less down-regulating emotion regulation (i.e. less acceptance) and more up-regulating emotion regulation (i.e. more rumination) than experiencers actually employed. Moreover, results showed that the intensity differences between forecasted and experienced guilt and shame could be explained (i.e. were mediated) by the differences between forecasted and actually employed emotion regulation (i.e. acceptance and rumination). These findings provide support for the hypothesis that the intensity bias can-at least in part-be explained by the misprediction of future emotion regulation.

Derailing the streetcar named desire. Cognitive distractions reduce individual differences in cravings and unhealthy snacking in response to palatable food.

People who are sensitive to food temptations are prone to weight gain and obesity in food-rich environments. Understanding the factors that drive their desire to eat is key to limiting their reactions to available food. This study tested whether individual differences in sensitivity to hedonic food cues are cognitively based and, accordingly, can be regulated by blocking cognitive resources. To this end, one lab study (Study 1; N = 91) and one field study (Study 2; N = 63) measured sensitivity to hedonic food cues using the Power of Food Scale (PFS; Lowe et al., 2009) and assessed participants' appetitive responses to high-calorie food options. To test the role of cognitive elaboration of food cues, participants completed a menu-selection task to induce food cravings and then were free to elaborate those cravings (control group) or were blocked from doing so by cognitive distraction (playing Tetris, solving puzzles; experimental group). Compared to non-sensitive participants, sensitive participants displayed a greater attentional bias to high-calorie food (Study 1), reported stronger cravings (Study 2), and more often chose an unhealthy snack (Studies 1 & 2), but only when they had not been distracted. When distracted, all participants were similarly unresponsive to high-calorie food. This finding suggests that temptation can be effectively controlled by blocking people's cognitive resources, even for people highly sensitive to hedonic food cues.

Looking with different eyes: The psychological meaning of categorisation goals moderates facial reactivity to facial expressions.

In the present research we examined whether the psychological meaning of people's categorisation goals affects facial muscle activity in response to facial expressions of emotion. We had participants associate eye colour (blue, brown) with either a personality trait (extraversion) or a physical trait (light frequency) and asked them to use these associations in a speeded categorisation task of angry, disgusted, happy and neutral faces while assessing participants' response times and facial muscle activity. We predicted that participants would respond differentially to the emotional faces when the categorisation criteria allowed for inferences about a target's thoughts, feelings or behaviour (i.e., when categorising extraversion), but not when these lacked any social meaning (i.e., when categorising light frequency). Indeed, emotional faces triggered facial reactions to facial expressions when participants categorised extraversion, but not when they categorised light frequency. In line with this, only when categorising extraversion did participants' response times indicate a negativity bias replicating previous results. Together, these findings provide further evidence for the contextual nature of people's selective responses to the emotions expressed by others.

Leaving a flat taste in your mouth: task load reduces taste perception.

In recent years, people have tended to pay less attention to their meals, often consuming them while engaging in other activities. At the same time, foods have become increasingly sweet and salty. We therefore investigated how performing concurrent activities affects taste perception and how this relates to actual consumption. Participants tasted sour, sweet, and salty substances in various concentrations under differing task loads. Our results demonstrated that under high task load (relative to low task load), participants rated the substances as less intense, consumed more of the substances, and preferred stronger tastants. Our findings suggest that increased task load reduces people's taste perception by limiting attentional capacity to assess taste intensity and that people adjust their consumption accordingly.

Food approach dynamics in daily life: Speed and force of food approach movements fluctuate with hunger, but less so for people with high BMI.

Researchers have suggested that the overconsumption of food, alcohol, and drugs could be explained by chronically elevated approach tendencies to rewarding but unhealthy stimuli. Here, we use the example of food to show that dysregulated rather than chronically elevated approach tendencies are associated with adverse health outcomes. To this end, we developed a new smartphone-based paradigm to measure dynamic changes in food approach tendencies outside the laboratory (piloted with n = 48). We demonstrated in three preregistered experiments (total N = 367) that food approach tendencies decrease from before to after people have eaten. We further show that in overweight and obese participants, these dynamics are disrupted as their food approach tendencies increase rather than decrease after meals. In addition to showing these effects based on traditional reaction time-based food approach tendencies, we also demonstrate these patterns in a novel measure of response force-a measure that has long been used to study motivation in animals but has received little attention in humans. Together, our findings suggest that both reaction time-based and force-based approach tendencies change dynamically in accordance with people's need states and that disruptions in these dynamics are associated with adverse health outcomes, such as overweight and obesity. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The role of financial stress in mental health changes during COVID-19.

Using longitudinal data before and during the first six months of the COVID-19 pandemic for a representative sample of Dutch households, we examined the role of financial stress, defined as the subjective experience of lacking financial resources to cope with demands, in mental health changes. Also, we examined financial stress and mental health relations with households' income, savings, and debts. The data revealed that average mental health did not change during the first six months of the pandemic but showed considerable underlying heterogeneity. Results showed that financial stress changes significantly explained this heterogeneity. Increases in financial stress predicted decreases in mental health, whereas decreases in financial stress predicted increases in mental health. While income did not explain financial stress changes, fewer savings and more debts were related to increased financial stress, which was, in turn, negatively related to mental health. We discuss the implications of our findings for mental health care and financial security policy and provide suggestions for future research.

Jumping on the 'bad'wagon? How group membership influences responses to the social exclusion of others.

In four studies, we addressed whether group membership influences behavioral and neural responses to the social exclusion of others. Participants played a modified three-player Cyberball game (Studies 1-3) or a team-selection task (Study 4) in the absence or presence of a minimal group setting. In the absence of a minimal group, when one player excluded another player, participants actively included the excluded target. When the excluder was from the in-group and the excluded player from the out-group, participants were less likely to intervene (Studies 1-3) and also more often went along with the exclusion (Study 4). Functional magnetic resonance imaging results (Study 3) showed that greater exclusion in the minimal group setting concurred with increased activation in the dorsolateral pre-frontal cortex, a region associated with overriding cognitive conflict. Self-reports from Study 4 supported these results by showing that participants' responses to the target's exclusion were motivated by group membership as well as participants' general aversion to exclude others. Together, the findings suggest that when people witness social exclusion, group membership triggers a motivational conflict between favoring the in-group and including the out-group target. This underscores the importance of group composition for understanding the dynamics of social exclusion.

Tuning down the emotional brain: an fMRI study of the effects of cognitive load on the processing of affective images.

The present research examines whether cognitive load can modulate the processing of negative emotional stimuli, even after negative stimuli have already activated emotional centers of the brain. In a functional magnetic resonance imaging (fMRI) study, participants viewed neutral and negative stimuli that were followed by an attention-demanding arithmetic task. As expected, exposure to negative stimuli led to increased activation in emotional regions (the amygdalae and the right insula). Subsequently induced task load led to increased activation in cognitive regions (right dorsolateral frontal cortex, right superior parietal cortex). Importantly, task load down-regulated the brain's response to negative stimuli in emotional regions. Task load also reduced subjectively experienced negative emotion in response to negative stimuli. Finally, coactivation analyses suggest that during task performance, activity in right dorsolateral frontal cortex was related to activity in the amygdalae and the right insula. Together, these findings indicate that cognitive load is capable of tuning down the emotional brain.

Clearing the mind: a working memory model of distraction from negative mood.

The present research examined whether and how loading working memory can attenuate negative mood. In three experiments, participants were exposed to neutral, weakly negative, or strongly negative pictures followed by a task and a mood scale. Working memory demands were varied by manipulating task presence (Study 1), complexity (Study 2), and predictability (Study 3). Participants in all three experiments reported less negative moods in negative trials with high compared to low working memory demand. Working memory demands did not affect mood in the neutral trials. When working memory demands were high, participants no longer reported more negative moods in response to strongly negative pictures than to weakly negative pictures. These findings suggest that loading working memory prevents mood-congruent processing, and thereby promotes distraction from negative moods.

Moral fixations: The role of moral integrity and social anxiety in the selective avoidance of social threat.

People derive their sense of belonging from perceptions of being a moral person. Research moreover suggests that social cues of rejection rapidly influence visual scanning, and result in avoidant gaze behavior, especially in socially anxious individuals. With the current eye-tracking experiment, we therefore examined whether moral integrity threats and affirmations influence selective avoidance of social threat, and how this varies with individual differences in social anxiety. Fifty-nine participants retrieved a memory of a past immoral, moral, or neutral act. Next, participants passively viewed angry, happy, and neutral faces, while we recorded how often they first fixated on the eyes. In addition, we administered the Liebowitz Social Anxiety Scale (1987). Participants first fixated less on angry eyes compared to happy or neutral eyes when their moral integrity was threatened, and this selective avoidance was enhanced with increasing social anxiety. Following a moral affirmation, however, participants no longer selectively avoided the eyes of angry faces, regardless of individual differences in social anxiety. The results thus suggest that both low and high socially anxious people adjust their social gaze behavior in response to threats and affirmations of their moral integrity, pointing to the importance of the social context when considering affective processing biases.

Turning a blind eye to temptation: how cognitive load can facilitate self-regulation.

The present research shows in 4 studies that cognitive load can reduce the impact of temptations on cognition and behavior and, thus, challenges the proposition that distraction always hampers self-regulation. Participants performed different speeded categorization tasks with pictures of attractive and neutral food items (Studies 1-3) and attractive and unattractive female faces (Study 4), while we assessed their reaction times as an indicator of selective attention (Studies 1, 3, and 4) or as an indicator of hedonic thoughts about food (Study 2). Cognitive load was manipulated by a concurrent digit span task. Results show that participants displayed greater attention to tempting stimuli (Studies 1, 3, and 4) and activated hedonic thoughts in response to palatable food (Study 2), but high cognitive load completely eliminated these effects. Moreover, cognitive load during the exposure to attractive food reduced food cravings (Study 1) and increased healthy food choices (Study 3). Finally, individual differences in sensitivity to food temptations (Study 3) and interest in alternative relationship partners (Study 4) predicted selective attention to attractive stimuli, but again, only when cognitive load was low. Our findings suggest that recognizing the tempting value of attractive stimuli in our living environment requires cognitive resources. This has the important implication that, contrary to traditional views, performing a concurrent demanding task may actually diminish the captivating power of temptation and thus facilitate self-regulation.