Individual Differences in Corticostriatal White-matter Tracts Predict Successful Daily-life Routine Formation.

Despite good intentions, people often fail to cross the "intention-behavior gap," especially when goal achievement requires repeated action. To bridge this gap, the formation of automatized routines may be crucial. However, people may differ in the tendency to switch from goal-directed toward habitual control. To shed light on why some people succeed in forming routines while others struggle, the present study related the automatization of a novel, daily routine to individual differences in white-matter connectivity in corticostriatal networks that have been implicated in goal-directed and habitual control. Seventy-seven participants underwent diffusion-weighted imaging and formed the daily routine of taking a (placebo) pill for 3 weeks. Pill intake was measured by electronic pill boxes, and participants filled out a daily online questionnaire on the subjective automaticity of this behavior. Automatization of pill intake was negatively related to striatal (mainly caudate) connectivity with frontal goal-directed and cognitive control regions, namely, ventromedial pFC and anterior cingulate gyrus. Furthermore, daily pill intake was positively related to individual differences in striatal (mainly caudate) connectivity with cognitive control regions, including dorsolateral and anterior pFC. Therefore, strong control networks may be relevant for implementing a new routine but may not benefit its automatization. We also show that habit tendency (assessed with an outcome-devaluation task), conscientiousness, and daily life regularity were positively related to routine automatization. This translational study moves the field of habit research forward by relating self-reported routine automatization to individual differences in performance on an experimental habit measure and to brain connectivity.

Competing influences on healthy food choices: Mindsetting versus contextual food cues.

Food choices are influenced by one's current mindset, suggesting that supporting health (vs. a palatability) mindsets could improve daily food choices. The question rises, however, to what extent internal mindsets still guide choices when people are exposed to external food-context stimuli in an obesogenic environment. To examine these two competing effects we induced health vs. palatability mindsets, and investigated the robustness of the mindset effect by presenting food-context stimuli during a Pavlovian-to-Instrumental-Transfer (PIT) task in two separate cohorts of 102 (76 females) Dutch and 120 (60 females) German participants. For the mindset induction, participants rated food items on visual analogue scales (VAS), based on healthiness and palatability, respectively. In each cohort, half of the participants received a health, the other half a palatability mindset induction. Additionally, we explored whether 'mindset triggers' could be used to further shape behavior. Triggers were established by placing unfamiliar logos at the extreme ends of the VASs used for the mindset inductions. Independent of the mindset, food-associated stimuli influenced food choices in accordance with the previously learned association in each test phase. Health mindset induction biased food choices towards healthier, palatability mindset towards unhealthier choices in the first cohort, but not in the second. The mindset triggers had a more robust effect. These induced healthier (triggers for healthy and not-palatable) and unhealthier (triggers for unhealthy and palatable) food choices in both cohorts alike. Interestingly, these effects did not tamper with the overall effect of Pavlovian cues and were thus true in the presence and absence of food-context stimuli. Therefore, we show that, in our experimental setting, food-associated mindset triggers can be used to bias food choices towards a healthy snack even in an obesogenic environment.

Failing to pay heed to health warnings in a food-associated environment.

People often fail to adhere to food-related health information. Increasing evidence suggests that environmental stimuli interfere with good intentions by triggering choices relatively automatically. Using a Pavlovian-instrumental transfer (PIT) task, we examined whether food-associated stimuli reduce health warnings' effectiveness. We expected that people adhere to health warnings in the absence, but not presence, of food-associated stimuli. In addition, we examined timing effects, i.e., whether health warnings are more effective when they are given prior to associative learning rather than afterwards. In the PIT task, participants learned to press keys for two food rewards (instrumental learning) and associations between stimuli and these rewards (Pavlovian learning) in separated phases. Health warnings about one reward were given after associative learning (Study 1), or before versus afterwards (Study 2). During test phase, participants pressed for food outcomes while occasionally food-related stimuli were presented. In absence of food-related stimuli, participants increased responding for rewards perceived as more healthy. However, when stimuli were present, responding was biased towards the signaled outcome, regardless of health warnings or timing. Health messages influence food choice behavior, but are no longer effective when food-associated stimuli are present. This provides important insights why health warning effects might be limited in an obesogenic environment.

Investigating sex differences in psychological predictors of snack intake among a large representative sample.

OBJECTIVE: It is often assumed that there are substantial sex differences in eating behaviour (e.g. women are more likely to be dieters or emotional eaters than men). The present study investigates this assumption in a large representative community sample while incorporating a comprehensive set of psychological eating-related variables. DESIGN: A community sample was employed to: (i) determine sex differences in (un)healthy snack consumption and psychological eating-related variables (e.g. emotional eating, intention to eat healthily); (ii) examine whether sex predicts energy intake from (un)healthy snacks over and above psychological variables; and (iii) investigate the relationship between psychological variables and snack intake for men and women separately. Snack consumption was assessed with a 7d snack diary; the psychological eating-related variables with questionnaires. SETTING: Participants were members of an Internet survey panel that is based on a true probability sample of households in the Netherlands. SUBJECTS: Men and women (n 1292; 45 % male), with a mean age of 51·23 (sd 16·78) years and a mean BMI of 25·62 (sd 4·75) kg/m2. RESULTS: Results revealed that women consumed more healthy and less unhealthy snacks than men and they scored higher than men on emotional and restrained eating. Women also more often reported appearance and health-related concerns about their eating behaviour, but men and women did not differ with regard to external eating or their intentions to eat more healthily. The relationships between psychological eating-related variables and snack intake were similar for men and women, indicating that snack intake is predicted by the same variables for men and women. CONCLUSIONS: It is concluded that some small sex differences in psychological eating-related variables exist, but based on the present data there is no need for interventions aimed at promoting healthy eating to target different predictors according to sex.

It's my party and I eat if I want to. Reasons for unhealthy snacking.

Investigating the reasons that people give for unhealthy snacking behavior is important for developing effective health interventions. Little research, however, has identified reasons that apply to a large audience and most studies do not integrate multiple factors, precluding any conclusions regarding their relative importance. The present study explored reasons for unhealthy snacking among a representative community sample. Participants (N = 1544) filled out the newly developed Reasons to Snack inventory assessing an elaborate range of motives at baseline and 1-month follow-up. Exploratory and replication factor analyses identified six categories: opportunity induced eating, coping with negative emotions, enjoying a special occasion, rewarding oneself, social pressure, and gaining energy. The highest mean scores were obtained for enjoying a special occasion and opportunity induced eating. Regression analyses with participant characteristics as independent variables and each category of reasons as dependent variables showed differences for age. For all reasons except to enjoy a special occasion, younger people reported a higher score. Women indicated a higher score than men on coping with negative emotions, enjoying a special occasion and gaining energy. People who diet to a stronger extent reported a higher score for snacking because of social pressure, to reward oneself and to cope with negative emotions, with the latter also being related to a higher BMI. Finally, a higher education was associated with enjoying a special occasion. Future health interventions could allocate more attention to diminishing unhealthy snacking with regard to the six identified categories, specifically focusing on enjoying a special occasion and opportunity induced eating.

An experimental investigation of breaking learnt habits with verbal implementation intentions.

The interplay between inflexible habits and flexible goal-directed control can be modelled in lab-settings using the slips-of-action task. In this task, participants are required to selectively respond to still-valuable outcomes while suppressing responding towards no-longer valuable outcomes, thereby overriding learned stimulus-response associations. Here we examined in the slips-of-action task whether learnt habits can be changed using a planning technique - so-called implementation intentions - whereby people instruct themselves to enact a certain behaviour (or not) in the presence of a specific critical stimulus. Such simple 'if-then' instructions have previously been shown to support behavioural change in real-life settings, possibly because people verbally create new stimulus-response associations. Across four experiments we manipulated the intrinsic value of the stimuli and outcomes in the slips-of-action task: abstract stimuli and outcomes (Experiment 1), snack food stimuli and outcomes (Experiment 2), or a combination of both types (Experiment 3-4). Implementation intentions improved the ability to suppress previously learnt responses towards no-longer-valuable abstract outcomes (Experiment 1 and 3). However, when snacks were used as outcomes (Experiment 2 and 4) no beneficial effect of implementation intentions versus goal intentions was observed. The slips-of-action task is thus sensitive to planning techniques under certain circumstances. Yet, the absence of effects when using snacks as outcomes implies the possible importance of its hedonic outcome value for implementation intentions' effectiveness, which warrants further investigation.

Shifting the balance between goals and habits: Five failures in experimental habit induction.

Habits are repetitive behaviors that become ingrained with practice, routine, and repetition. The more we repeat an action, the stronger our habits become. Behavioral and clinical neuroscientists have become increasingly interested in this topic because habits may contribute to aspects of maladaptive human behavior, such as compulsive behavior in psychiatry. Numerous studies have demonstrated that habits can be induced in otherwise healthy rats by simply overtraining stimulus-response behaviors. However, despite growing interest in this topic and its application to psychiatry, a similar body of work in humans is absent. Only a single study has been published in humans that shows the effect of extensive training on habit expression. Here, we report five failed attempts to demonstrate that overtraining instrumental behavior leads to the development of inflexible habits in humans, using variants of four previously published outcome devaluation paradigms. Extensive training did not lead to greater habits in two versions of an avoidance learning task, in an appetitive slips-of-action task, or in two independent attempts to replicate the original demonstration. The finding that these outcome devaluation procedures may be insensitive to duration of stimulus-response training in humans has implications for prior work in psychiatric populations. Specifically, it converges with the suggestion that the failures in outcome devaluation in compulsive individuals reflect dysfunction in goal-directed control, rather than overactive habit learning. We discuss why habits are difficult to experimentally induce in healthy humans, and the implications of this for future research in healthy and disordered populations. (PsycINFO Database Record

Identifying the 'if' for 'if-then' plans: combining implementation intentions with cue-monitoring targeting unhealthy snacking behaviour.

Implementation intentions aimed at changing unwanted habits require the identification of personally relevant cues triggering the habitual response in order to be effective. To facilitate successful implementation intention formation, in the present study, planning was combined with cue-monitoring, a novel way to gain insight into triggers for unhealthy snacking. It was tested whether keeping a cue-monitoring diary and tailoring implementation intentions accordingly improves plan effectiveness. A 2 Monitoring (cue-monitoring, control) × 2 Planning (implementation intention, goal intention) between subjects design was adopted. Participants (N = 161) monitored their unhealthy snacking behaviour for a week using either a cue-monitoring or a control diary. Participants then formulated a goal intention or an implementation intention tailored to their personal cue. Snacking frequency and caloric intake from unhealthy snacks were examined using a seven-day snack diary. The results did not indicate an interaction but yielded a main effect of Monitoring. Cue-monitoring either or not combined with implementation intentions reduced unhealthy snacking behaviour compared with control. Findings emphasise the effectiveness of cue-monitoring, suggesting that on the short term, cue-monitoring suffices to decrease unhealthy snacking, without additional benefit from planning. Future research should examine whether supplementing cue-monitoring with implementation intentions is required to establish long-term behaviour change maintenance.

The power of habits: unhealthy snacking behaviour is primarily predicted by habit strength.

OBJECTIVE: Although increasing evidence shows the importance of habits in explaining health behaviour, many studies still rely solely on predictors that emphasize the role of conscious intentions. The present study was designed to test the importance of habit strength in explaining unhealthy snacking behaviour in a large representative community sample (N= 1,103). To test our hypothesis that habits are crucial when explaining unhealthy snacking behaviour, their role was compared to the 'Power of Food', a related construct that addresses sensitivity to food cues in the environment. Moreover, the relation between Power of Food and unhealthy snacking habits was assessed. DESIGN AND METHODS: A prospective design was used to determine the impact of habits in relation to intention, Power of Food and a number of demographic variables. One month after filling out the questionnaire, including measures of habit strength and Power of Food, participants reported their unhealthy snacking behaviour by means of a 7-day snack diary. RESULTS: Results showed that habit strength was the most important predictor, outperforming all other variables in explaining unhealthy snack intake. CONCLUSIONS: The findings demonstrate that snacking habits provide a unique contribution in explaining unhealthy snacking behaviour, stressing the importance of addressing habit strength in further research and interventions concerning unhealthy snacking behaviour.