Executive function moderates the intention-behavior link for physical activity and dietary behavior

Early life cognitive abilities and body weight: cross-sectional study of the association of inhibitory control, cognitive flexibility, and sustained attention with BMI percentiles in primary school children

The objective of this study was to investigate the association of different cognitive abilities with children's body weight adjusted for further weight influencing sociodemographic, family, and lifestyle factors. Cross-sectional data of 498 primary school children (7.0 ± 0.6 years; 49.8% boys) participating in a health promotion programme in southwest Germany were used. Children performed a computer-based test battery (KiTAP) including an inhibitory control task (Go-Nogo paradigm), a cognitive flexibility task, and a sustained attention task. Height and weight were measured in a standardized manner and converted to BMI percentiles based on national standards. Sociodemographic features (migration background and parental education), family characteristics (parental body weight), and children's lifestyle (TV consumption, physical activity, consumption of sugar-sweetened beverages and breakfast habits) were assessed via parental questionnaire. A hierarchical regression analysis revealed inhibitory control and cognitive flexibility to be significant cognitive predictors for children's body weight. There was no association concerning sustained attention. The findings suggest that especially cognitive abilities known as executive functions (inhibitory control and cognitive flexibility) are associated with children's body weight. Future longitudinal and intervention studies are necessary to investigate the directionality of the association and the potential of integrating cognitive training in obesity prevention strategies. This trial is registered with ClinicalTrials.gov DRKS00000494.

Clinical characteristics, pathophysiology, and management of noncentral nervous system cancer-related cognitive impairment in adults

Answer questions and earn CME/CNE Over the past few decades, a body of research has emerged confirming what many adult patients with noncentral nervous system cancer have long reported-that cancer and its treatment are frequently associated with cancer-related cognitive impairment (CRCI). The severity of CRCI varies, and symptoms can emerge early or late in the disease course. Nonetheless, CRCI is typically mild to moderate in nature and primarily involves the domains of memory, attention, executive functioning, and processing speed. Animal models and novel neuroimaging techniques have begun to unravel the pathophysiologic mechanisms underlying CRCI, including the role of inflammatory cascades, direct neurotoxic effects, damage to progenitor cells, white matter abnormalities, and reduced functional connectivity, among others. Given the paucity of research on CRCI with other cancer populations, this review synthesizes the current literature with a deliberate focus on CRCI within the context of breast cancer. A hypothetical case-study approach is used to illustrate how CRCI often presents clinically and how current science can inform practice. While the literature regarding intervention for CRCI is nascent, behavioral and pharmacologic approaches are discussed.

A bidirectional relationship between physical activity and executive function in older adults

Physically active lifestyles contribute to better executive function. However, it is unclear whether high levels of executive function lead people to be more active. This study uses a large sample and multi-wave data to identify whether a reciprocal association exists between physical activity and executive function. Participants were 4555 older adults tracked across four waves of the English Longitudinal Study of Aging. In each wave executive function was assessed using a verbal fluency test and a letter cancelation task and participants reported their physical activity levels. Fixed effects regressions showed that changes in executive function corresponded with changes in physical activity. In longitudinal multilevel models low levels of physical activity led to subsequent declines in executive function. Importantly, poor executive function predicted reductions in physical activity over time. This association was found to be over 50% larger in magnitude than the contribution of physical activity to changes in executive function. This is the first study to identify evidence for a robust bidirectional link between executive function and physical activity in a large sample of older adults tracked over time.

Intentions and trait self-control predict fruit and vegetable consumption during the transition to first-year university

OBJECTIVE

To examine the independent and combined effects of Theory of Planned Behavior (TPB) variables and trait self-control (TSC) in the prediction of fruit and vegetable consumption (FVC) among first-year university students.

PARTICIPANTS

Seventy-six first-year undergraduate university students.

METHODS

In their first week of class (September 2011), participants completed baseline measures of TSC, attitudes, subjective norms, perceived behavioral control, and intentions about their FVC. One week later, students completed a 7-day food recall, from which daily FVC was calculated.

RESULTS

Baseline attitudes and perceived behavioral control predicted intentions (adjR(2) = .58). Intentions and TSC predicted FVC (adjR(2) = .24).

CONCLUSIONS

The TPB may be a useful framework on which to base a FVC intervention for first-year undergraduate students; however, focusing solely on increasing positive intentions to consume FVC will not necessarily translate into FVC behavior, as other personal- and environmental-level variables may play a role.

Self-reported physical activity is associated with cognitive function in lean, but not obese individuals

Convergent evidence demonstrates that greater physical activity is associated with better cognitive functioning across many patient and healthy samples. However, this relationship has not been well examined among obese individuals and remains unclear. The present study examined the relationship between performance-based measures of attention/executive function and self-reported physical activity, as measured by the International Physical Activity Questionnaire, among lean (n = 36) and obese (n = 36) college students. Lean individuals performed better than obese individuals on measures of attention/executive function. No significant differences in self-reported physical activity emerged between weight groups. Higher self-reported physical activity was related to faster reaction time in lean individuals but slower reaction time in obese individuals. Additionally, in lean individuals, higher levels of self-reported physical activity were related to more errors on a task of speeded inhibitory control. The results are consistent with previous research demonstrating that greater physical activity is associated with faster attention and executive function abilities in healthy samples and highlight the importance of examining reaction time and accuracy indices separately on these measures. The lack of association among obese individuals may be due in part to inaccurate self-report in the current study. Additionally, the cognitive consequences of obesity may outweigh the benefits of physical activity in this group. Future work should investigate these associations in obese individuals using physical activity interventions, as well as a combination of self-report and objective measures to investigate discrepancies in reporting.

The association between obesity and fluid intelligence impairment is mediated by chronic low-grade inflammation

Published evidence suggests that obesity impairs cognition. Development of chronic low-grade inflammation (CLGI) represents the earliest consequence of obesity. The present study investigated the association between obesity and fluid intelligence impairment and assessed the potential mediating role of CLGI and psychological (depression/anxiety symptoms), lifestyle (exercise) and physiological (metabolic dysfunction indices) factors in this association. Clinically healthy participants (n 188), grouped as per BMI, underwent cognitive (General Ability Measure for Adults), psychological (Beck Depression Inventory-II and State-Trait Anxiety Inventory) and activity (Godin leisure-time physical activity) measurements. Biochemical parameters included the following: (a) indices of CLGI (high-sensitivity C-reactive protein, erythrocyte sedimentation rate and fibrinogen); (b) insulin resistance (Homeostasis Model Assessment of Insulin Resistance index); (c) adiposity (plasma adiponectin). An inverse association between elevated BMI and fluid intelligence was observed, with obese participants displaying significantly poorer performance compared with age-matched normal-weight peers. Structural equation modelling results were consistent with a negative impact of obesity on cognition that was mediated by CLGI. The results of the present study support the hypothesis that reduced general cognitive ability is associated with obesity, an adverse effect mainly mediated by obesity-associated activation of innate immunity.

Cognitive control in the self-regulation of physical activity and sedentary behavior

Cognitive control of physical activity and sedentary behavior is receiving increased attention in the neuroscientific and behavioral medicine literature as a means of better understanding and improving the self-regulation of physical activity. Enhancing individuals' cognitive control capacities may provide a means to increase physical activity and reduce sedentary behavior. First, this paper reviews emerging evidence of the antecedence of cognitive control abilities in successful self-regulation of physical activity, and in precipitating self-regulation failure that predisposes to sedentary behavior. We then highlight the brain networks that may underpin the cognitive control and self-regulation of physical activity, including the default mode network, prefrontal cortical networks and brain regions and pathways associated with reward. We then discuss research on cognitive training interventions that document improved cognitive control and that suggest promise of influencing physical activity regulation. Key cognitive training components likely to be the most effective at improving self-regulation are also highlighted. The review concludes with suggestions for future research.

The SNAPSHOT study protocol: SNAcking, Physical activity, Self-regulation, and Heart rate Over Time

Background

The cognitive processes responsible for effortful behavioural regulation are known as the executive functions, and are implicated in several factors associated with behaviour control, including focussing on tasks, resisting temptations, planning future actions, and inhibiting prepotent responses. Similar to muscles, the executive functions become fatigued following intensive use (e.g. stressful situations, when tired or busy, and when regulating behaviour such as quitting smoking). Therefore, an individual may be more susceptible to engaging in unhealthy behaviours when their executive functions are depleted. In the present study we investigate associations between the executive functions, snack food consumption, and sedentary behaviour in real time. We hypothesise that individuals may be more susceptible to unhealthy snacking and sedentary behaviours during periods when their executive functions are depleted. We test this hypothesis using real-time objective within-person measurements.

Methods/Design

A sample of approximately 50 Scottish adults from varied socio-economic, working, and cultural backgrounds will participate in the three phases of the SNAcking, Physical activity, Self-regulation, and Heart rate Over Time (SNAPSHOT) study. Phase one will require participants to complete home-based questionnaires concerned with diet, eating behaviour, and physical activity (≈1.5 hours to complete). Phase two will constitute a 2-3 hour psychological laboratory testing session during which trait-level executive function, general intelligence, and diet and physical activity intentions, past behaviour, and automaticity will be measured. The final phase will involve a 7-day ambulatory protocol during which objective repeated assessments of executive function, snacking behaviour, physical activity, mood, heart rate, perceived energy level, current context and location will be measured during participants’ daily routines. Multi-level regression analysis, accounting for observations nested within participants, will be used to investigate associations between fluctuations in the executive functions and health behaviours.

Discussion

Data from the SNAPSHOT study will provide ecologically valid information to help better understand the temporal associations between self-regulatory resources (executive functions) and deleterious health behaviours such as snacking and sedentary behaviour. If we can identify particular periods of the day or locations where self-regulatory resources become depleted and produce suboptimal health behaviour, then interventions can be designed and targeted accordingly.

A Daily Process Analysis of Physical Activity, Sedentary Behavior, and Perceived Cognitive Abilities

OBJECTIVES

This study evaluated the role of both physical activity and sedentary behavior in daily perceptions of cognitive abilities and whether these relations exist within-person, between-person, or both.

DESIGN

Non-experimental, intensive longitudinal research using ecological momentary assessments.

METHOD

College students wore accelerometers and provided end-of-day reports on physical activity, sedentary behavior, and perceived cognitive abilities for 14 days.

RESULTS

Across self-reports and objective measures of behavior, daily deviations in physical activity were positively associated with perceived cognitive abilities. Daily deviations in self-reported, but not objectively-assessed, sedentary behavior also were negatively associated with perceived cognitive abilities. Contrary to previous research, overall levels of physical activity and sedentary behaviors were not associated with perceived cognitive abilities.

CONCLUSIONS

These findings indicate that physical activity has a within- rather than between-person association with perceived cognitive abilities although between-person associations effects may require longer monitoring periods to manifest. Further research is needed to establish the direction of causality and resolve whether the nature (rather than quantity) of sedentary activities influences cognition.

Controlled versus automatic processes: which is dominant to safety? The moderating effect of inhibitory control

This study explores the precursors of employees' safety behaviors based on a dual-process model, which suggests that human behaviors are determined by both controlled and automatic cognitive processes. Employees' responses to a self-reported survey on safety attitudes capture their controlled cognitive process, while the automatic association concerning safety measured by an Implicit Association Test (IAT) reflects employees' automatic cognitive processes about safety. In addition, this study investigates the moderating effects of inhibition on the relationship between self-reported safety attitude and safety behavior, and that between automatic associations towards safety and safety behavior. The results suggest significant main effects of self-reported safety attitude and automatic association on safety behaviors. Further, the interaction between self-reported safety attitude and inhibition and that between automatic association and inhibition each predict unique variances in safety behavior. Specifically, the safety behaviors of employees with lower level of inhibitory control are influenced more by automatic association, whereas those of employees with higher level of inhibitory control are guided more by self-reported safety attitudes. These results suggest that safety behavior is the joint outcome of both controlled and automatic cognitive processes, and the relative importance of these cognitive processes depends on employees' individual differences in inhibitory control. The implications of these findings for theoretical and practical issues are discussed at the end.

Executive functioning and the metabolic syndrome: a project FRONTIER study

Decrements in cognitive functioning have been linked to the metabolic syndrome (MetS), a risk factor for cardiovascular disease defined by the presence of three of the following: elevated blood pressure, increased waist circumference, elevated blood glucose, elevated triglycerides, and low high-density lipoprotein cholesterol. We examined the relationship between four measures of executive functioning (EF) and MetS as diagnosed by National Heart, Lung, and Blood Institute-American Heart Association criteria. MetS was examined in a rural population of 395 persons with a mean age of 61.3 years, 71.4% women, 37.0% Hispanic, 53.7% White non-Hispanic. There was a 61.0% prevalence of MetS. We derived a factor score from the four executive function measures which was used to compare those with and without the syndrome, as well as any additive effects of components of the syndrome. Those with MetS exhibited significantly poorer performance than those without the syndrome. However, there was no additive effect, having more components of the syndrome was not related to lower performance. The presence of MetS was associated with poorer EF in this rural cohort of community dwelling volunteers.

Implementation intention and action planning interventions in health contexts: state of the research and proposals for the way forward

The purpose of this paper is to provide an overview of the literature on two planning intervention techniques in health behaviour research, implementation intentions and action planning, and to develop evidence-based recommendations for effective future interventions and highlight priority areas for future research. We focused our review on four key areas: (1) definition and conceptualisation; (2) format and measurement; (3) mechanisms and processes; and (4) design issues. Overall, evidence supports the effectiveness of planning interventions in health behaviour with advantages including low cost and response burden. There is, however, considerable heterogeneity in the effects across studies and relatively few registered randomised trials that include objective behavioural measures. Optimally effective planning interventions should adopt "if-then" plans, account for salient and relevant cues, include examples of cues, be guided rather than user-defined, and include boosters. Future studies should adopt randomised controlled designs, report study protocols, include fidelity checks and relevant comparison groups, and adopt long-term behavioural follow-up measures. Priority areas for future research include the identification of the moderators and mediators of planning intervention effects. Future research also needs to adopt "best practice" components of planning interventions more consistently to elucidate the mechanisms and processes involved.

Antioxidant effectiveness of vegetable powders on the lipid and protein oxidative stability of cooked Turkey meat patties: implications for health

Lipid and protein oxidation decreases the shelf-life of foods and may result in formation of end-products potentially detrimental for health. Consumer pressure to decrease the use of synthetic phenolic antioxidants has encouraged identification of alternative compounds or extracts from natural sources. We have assessed whether inclusion of dried vegetable powders improves the oxidative stability of turkey meat patties. Such powders are not only potentially-rich sources of phenolic antioxidants, but also may impart additional health benefits, as inadequate vegetable consumption is a risk factor for heart disease and several cancers. In an accelerated oxidation system, six of eleven vegetable powders significantly (p < 0.05) improved oxidative stability of patties by 20%-30% (spinach < yellow pea < onion < red pepper < green pea < tomato). Improved lipid oxidative stability was strongly correlated with the decreased formation of protein carbonyls (r = 0.747, p < 0.01). However, improved lipid stability could not be ascribed to phenolic acids nor recognized antioxidants, such as α- and γ-tocopherol, despite their significant (p < 0.01) contribution to the total antioxidant capacity of the patties. Use of chemically complex vegetable powders offers an alternative to individual antioxidants for increasing shelf-life of animal-based food products and may also provide additional health benefits associated with increased vegetable intake.

Neurobehavioural correlates of body mass index and eating behaviours in adults: a systematic review

The worldwide increase in obesity has spurred numerous efforts to understand the regulation of eating behaviours and underlying brain mechanisms. These mechanisms can affordably be studied via neurobehavioural measures. Here, we systematically review these efforts, evaluating neurocognitive tests and personality questionnaires based on: (a) consistent relationship with obesity and eating behaviour, and (b) reliability. We also considered the measures' potential to shed light on the brain mechanisms underlying these individual differences. Sixty-six neurocognitive tasks were examined. Less than 11%, mainly measures of executive functions and food motivation, yielded both replicated and reliable effects. Several different personality questionnaires were consistently related to BMI. However, further analysis found that many of these questionnaires relate closely to Conscientiousness, Extraversion and Neuroticism within the Five-Factor Model of personality. Both neurocognitive tests and personality questionnaires suggest that the critical neural systems related to individual differences in obesity are lateral prefrontal structures underpinning self-control and striatal regions implicated in food motivation. This review can guide selection of the highest yield neurobehavioural measures for future studies.

Executive functioning as a mediator of the relationship between premorbid verbal intelligence and health risk behaviors in a rural-dwelling cohort: a Project FRONTIER study

Limited research is available regarding the impact of neuropsychological functioning on health risk behaviors in rural-dwelling elderly populations. This cross-sectional study examined the relationships between estimated premorbid verbal IQ (AMNART), executive functioning impairment (EXIT25), and health risk behaviors including alcohol use (AUDIT), smoking, compliance with recommended cancer screenings, and obesity (BMI). The total sample included 456 English-speaking adults and older adults of non-Hispanic White and Hispanic origin seen as part of an ongoing study of rural cognitive aging, Project FRONTIER. Regression analyses revealed significant independent effects of AMNART and EXIT25 on most health risk behaviors, and supported the hypothesized mediating role of EXIT25 on the relationships between AMNART and smoking, cancer screenings, and BMI in both cognitively impaired and healthy subgroups. This study clarifies the relationships between executive functioning, premorbid IQ, and health risk behaviors in diverse groups, and confirms that premorbid IQ represents an important determinant of health behaviors and neurocognitive outcomes.

A profile for predicting attrition from exercise in older adults

The purpose of this study was to determine a profile for predicting attrition among older adults involved in a 12-month exercise program. The parent study was a single-blinded randomized controlled trial. The study took place between 2006 and 2009 within a university setting. Older adults (N = 179) completed baseline assessments of functional performance and psychosocial measures. Participants who were randomized, elected to receive treatment, and did not complete the exercise program were considered "dropouts" (n = 35). Those who completed the program (n = 144) were classified as "completers." A latent profile analysis revealed two distinct patterns of memory complaints, self-efficacy to overcome barriers to exercise, balance performance, and stair performance. Dropouts were nearly twice as likely to be members of the profile that exhibited a higher degree of memory complaints, lower self-efficacy for overcoming exercise barriers, poorer single leg balance, and longer times to walk down stairs. The results provide an initial validation of a profile for discriminating between "dropouts" and "completers," one that may have considerable utility for screening older adults prior to study entry.

Influence of personal mobile phone ringing and usual intention to answer on driver error

Given evidence of effects of mobile phone use on driving, and also legislation, many careful drivers refrain from answering their phones when driving. However, the distracting influence of a call on driving, even in the context of not answering, has not been examined. Furthermore, given that not answering may be contrary to an individual's normal habits, this study examined whether distraction caused by the ignored call varies according to normal intention to answer whilst driving. That is, determining whether the effect is more than a simple matter of noise distraction. Participants were 27 young drivers (18-29 years), all regular mobile users. A Theory of Planned Behaviour questionnaire examined predictors of intention to refrain from answering calls whilst driving. Participants provided their mobile phone number and were instructed not to answer their phone if it were to ring during a driving simulation. The simulation scenario had seven hazards (e.g. car pulling out, pedestrian crossing) with three being immediately preceded by a call. Infractions (e.g. pedestrian collisions, vehicle collisions, speed exceedances) were significantly greater when distracted by call tones than with no distraction. Lower intention to ignore calls whilst driving correlated with a larger effect of distraction, as was feeling unable to control whether one answered whilst driving (Perceived Behavioural Control). The study suggests that even an ignored call can cause significantly increased infractions in simulator driving, with pedestrian collisions and speed exceedances being striking examples. Results are discussed in relation to cognitive demands of inhibiting normal behaviour and to drivers being advised to switch phones off whilst driving.

The role of prospective memory in medication adherence: a review of an emerging literature

Although neurocognitive impairment is an established risk factor for medication nonadherence, standard neurocognitive tests developed for clinical purposes may not fully capture the complexities of non-adherence behavior or effectively inform theory-driven interventions. Prospective memory, an innovative cognitive construct describing one's ability to remember to do something at a later time, is an understudied factor in the detection and remediation of medication non-adherence. This review orients researchers to the construct of prospective memory, summarizes empirical evidence for prospective memory as a risk factor for non-adherence, discusses the relative merits of current measurement techniques, and highlights potential prospective memory-focused intervention strategies. A comprehensive literature review was conducted of published empirical studies investigating prospective memory and medication adherence. Overall, reviewed studies suggest that prospective memory is an important component of medication adherence, providing incremental ecological validity over established predictors. Findings indicate that prospective memory-based interventions might be an effective means of improving adherence.

The Nature and Organization of Individual Differences in Executive Functions: Four General Conclusions

Executive functions (EFs)-a set of general-purpose control processes that regulate one's thoughts and behaviors-have become a popular research topic lately and have been studied in many subdisciplines of psychological science. This article summarizes the EF research that our group has conducted to understand the nature of individual differences in EFs and their cognitive and biological underpinnings. In the context of a new theoretical framework that we have been developing (the unity/diversity framework), we describe four general conclusions that have emerged from our research. Specifically, we argue that individual differences in EFs, as measured with simple laboratory tasks, (1) show both unity and diversity (different EFs are correlated yet separable); (2) reflect substantial genetic contributions; (3) are related to various clinically and societally important phenomena; and (4) show some developmental stability.

Executive function and latent classes of childhood obesity risk

Executive function (EF) is the set of neuro-cognitive processes associated with self-regulation, decision-making, and goal-directed behavior. The goal of this study is to examine cross-sectional relationships between EF and latent classes of youth characterized by patterns of obesity-related health behaviors (i.e., high fat/high sugar intake, fruit and vegetable intake, physical activity, sedentary behavior, and dieting). Participants were 997 4th grade youth in a school-based obesity prevention program. Cross-sectional relationships at study baseline between established latent classes of obesity risk and EF problems were assessed. General linear models demonstrated that EF problems were associated with classification into two unhealthy latent obesity risk classes. One potential implication of study findings is that obesity intervention efforts include EF promotion content tailored for latent classes of youth at different levels of obesity risk.

The role of executive function in bridging the intention-behaviour gap for binge-drinking in university students

BACKGROUND

Alcohol consumption contributes to a significant proportion of disease and the high prevalence amongst young adults is a worldwide health concern.

PURPOSE

To determine which aspects of executive function (EF) distinguish binge-drinkers from non binge-drinkers and to establish the role of EF in predicting behaviour.

METHODS

Self-report questionnaires, four tests of self-regulation and a behaviour measure were administered to 153 students.

RESULTS

The Theory of Planned Behaviour model was significant in predicting both intentions and behaviour. Although binge-drinkers and non binge-drinkers were found to differ on three of the four measures of EF, none predicted additional variance in behaviour. Planning ability and inhibition control moderated the relationship between intention and behaviour such that for individuals who intended to binge-drink, those with high planning ability or high inhibitory control were more likely to avoid doing so.

CONCLUSIONS

Interventions targeting binge-drinking behaviour should aim to develop planning skills and inhibitory control.

Self-regulatory processes and exercise adherence in older adults: executive function and self-efficacy effects

BACKGROUND

Self-efficacy and the use of self-regulatory strategies are consistently associated with physical activity behavior. Similarly, behavioral inhibition and cognitive resource allocation-indices of executive control function-have also been associated with this health behavior.

PURPOSE

The purpose of this study was to examine the hypothesis that self-efficacy mediates the relationship between self-regulatory processes, such as executive function, and sustained exercise behavior.

METHODS

Older adults (N=177, mean age=66.44 years) completed measures of executive function, self-reported use of self-regulatory strategies, and self-efficacy prior to and during the first month of a 12-month exercise intervention. Percentage of exercise classes attended over the following 11 months was used to represent adherence. Data were collected from 2007 to 2010 and analyzed in 2010-2011. Structural equation models were tested examining the effect of executive function and strategy use on adherence via efficacy.

RESULTS

As hypothesized, results showed significant direct effects of two elements of executive function and of strategy use on self-efficacy and of efficacy on adherence. In addition, there were significant indirect effects of strategy use and executive function on adherence via self-efficacy.

CONCLUSIONS

Higher levels of executive function and use of self-regulatory strategies at the start of an exercise program enhance beliefs in exercise capabilities, which in turn leads to greater adherence.

Hygienic food handling behaviors: attempting to bridge the intention-behavior gap using aspects from temporal self-regulation theory

An estimated 25% of the populations of both the United States and Australia suffer from foodborne illness every year, generally as a result of incorrect food handling practices. The aim of the current study was to determine through the application of the theory of planned behavior what motivates these behaviors and to supplement the model with two aspects of temporal self-regulation theory--behavioral prepotency and executive function--in an attempt to bridge the "intention-behavior gap." A prospective 1-week design was utilized to investigate the prediction of food hygiene using the theory of planned behavior with the additional variables of behavioral prepotency and executive function. One hundred forty-nine undergraduate psychology students completed two neurocognitive executive function tasks and a self-report questionnaire assessing theory of planned behavior variables, behavioral prepotency, and intentions to perform hygienic food handling behaviors. A week later, behavior was assessed via a follow-up self-report questionnaire. It was found that subjective norm and perceived behavioral control predicted intentions and intentions predicted behavior. However, behavioral prepotency was found to be the strongest predictor of behavior, over and above intentions, suggesting that food hygiene behavior is habitual. Neither executive function measure of self-regulation predicted any additional variance. These results provide support for the utility of the theory of planned behavior in this health domain, but the augmentation of the theory with two aspects of temporal self-regulation theory was only partially successful.

Executive function and survival in the context of chronic illness

BACKGROUND

Individual differences in executive function (EF) have been shown to predict risk factors for chronic illness. It is not currently known whether EFs also predict survival time following a diagnosis of a chronic illness.

PURPOSE

The objective of this investigation was to examine the association between individual differences in EF and survival time among individuals suffering from one or more chronic illness.

METHODS

A sample of 162 community-dwelling older adults who suffered from a chronic illness at baseline underwent thorough medical and neurological examinations to ensure freedom from actual or probable dementia. Participants completed cognitive testing and were subsequently followed for 10 years; survival was assessed as survival time over the follow-up interval.

RESULTS

Findings indicated that individual differences in EF predicted survival time, and this association held when adjustments were made for demographic variables (age, sex), education, and body mass index.

CONCLUSION

Individual differences in EF may be important determinants of survival in the context of chronic illness.

Early behavioral adherence predicts short and long-term weight loss in the POUNDS LOST study

The primary aim of this study was to test the association of early (first 6 months) adherence related to diet, self-monitoring, and attendance with changes in adiposity and cardiovascular risk factors. This study used data from the 24-month POUNDS LOST trial that tested the efficacy of four dietary macronutrient compositions for short-and long-term weight loss. A computer tracking system was used to record data on eight indicator variables related to adherence. Using canonical correlations at the 6 and 24 month measurement periods, early behavioral adherence was associated with changes in percent weight loss and waist circumference at 6 months (R = 0.52) and 24 months (R = 0.37), but was not associated with cardiovascular disease risk factor levels. Early dietary adherence was associated with changes in insulin at 6 months (R = 0.19), but not at 24 months (R = 0.08, ns). Early dietary adherence was not associated with changes in adiposity.

Does inhibitory control capacity in overweight and obese children and adolescents predict success in a weight-reduction program?

It has been assumed that inhibitory control capacity might influence the success of overweight or obese subjects in reducing weight. However, empirical research on this association is scarce. The present study, therefore, examines whether success in an outpatient weight-reduction program for children and adolescents can be predicted by pre-intervention inhibitory control capacity. The study sample consisted of 111 overweight and obese children and adolescents (7.5-15 years) who attended an outpatient weight-reduction program of 1 year's duration. Inhibitory control was assessed by two computerized neuropsychological procedures, a Go-NoGo and an interference task. Principal component analysis revealed "impulsivity" (fast but less valid reactions) and "inattention" (slow and highly variable reaction times) component. Those who succeeded in the intervention (losing more than 5% of BMI-SDS; n = 63) scored significantly higher in the first component than those who failed, while controlling for pre-intervention BMI-SDS, age, gender, and maternal education level. The association was moderated by age. Although in younger children no effect was found, in adolescents high "impulsivity" predicted success. Our result supports the scant evidence for a role of inhibitory control. However, further studies are required to substantiate that weak inhibitory control, and thus high reactivity to external cues, entails a better outcome in behavior modification interventions.

Does executive function explain the IQ-mortality association? Evidence from the Canadian study on health and aging

OBJECTIVE

To assess the robustness of the association between intelligence quotient (IQ) and mortality in older adults and to examine whether or not the association can be explained by more specific cognitive processes, including individual differences in executive functioning.

METHODS

We examined the associations among Full Scale IQ, individual IQ subtest scores, and 10-year mortality among older community-dwelling, adult participants in the Canadian Study of Health and Aging, who were verified as disease and cognitive-impairment free at baseline via comprehensive medical and neurological evaluation (n = 516). Survival analysis including Cox proportional hazards regression models were used to examine mortality risk as a function of Full Scale IQ and its specific subcomponents.

RESULTS

An inverse association was found between IQ and mortality, but this did not survive adjustment for demographics and education. The association between IQ and mortality seemed to be predominantly accounted for by performance on one specific IQ subtest that taps executive processes (i.e., Digit Symbol (DS)). Performance on this subtest uniquely and robustly predicted mortality in both unadjusted and adjusted models, such that a 1-standard deviation difference in performance was associated with a 28% change in risk of mortality over the 10-year follow-up interval in adjusted models.

CONCLUSIONS

The association between IQ and mortality in older adults may be predominantly attributable to individual differences in DS performance.

Predicting breakfast consumption: an application of the theory of planned behaviour and the investigation of past behaviour and executive function

OBJECTIVES

The objective of the current study is to examine the determinants of breakfast consumption with the application of the Theory of Planned Behaviour (TPB; 1991) and investigate the additional variables of past behaviour and executive function.

DESIGN

A prospective 1-week study investigating the predictive ability of TPB variables, past behaviour and executive function was utilized.

METHODS

Ninety-six participants were administered two measures of executive function (response inhibition and planning) and completed self-report questionnaires regarding their attitudes, subjective norms, perceived control, intentions and past behaviour of breakfast consumption. One week later, participants returned a follow-up questionnaire on their behaviour.

RESULTS

The result of the study showed that the TPB significantly predicted intentions and prospective behaviour of breakfast consumption, however, past behaviour was found to be the strongest predictor of future behaviour. Considering executive function, response inhibition was not found to predict behaviour, however, planning ability explained unique variance in behaviour and moderated the association between intention and behaviour.

CONCLUSIONS

The findings support the use of the TPB in explaining breakfast eating habits, and suggest that executive function of planning may be somewhat useful to predict this behaviour. The significance of past behaviour also suggests that breakfast consumption may commonly be a stable, habitual behaviour that may undermine the need for self-regulation. Implications for creating behavioural-change interventions are discussed.

Why do people fail to turn good intentions into action? The role of executive control processes in the translation of healthy eating intentions into action in young Scottish adults

Background

Despite the significant health benefits associated with eating healthily, diet is extremely difficult to change, with the majority of people who intend to eat more healthily failing to do so. Recent evidence has suggested that the ability to turn intentions into actions may be related to individual differences in one facet of executive control – cognitive inhibition (i.e. the ability to inhibit irrelevant information and suppress prepotent responses). The present study investigates the role of this and other executive processes (inhibition, task switching, planning and cognitive flexibility) in the translation of dietary intentions into action. In addition, as the literature suggests that weak executive control may be associated with hyper-responsivity to cues to action, the role of executive processes in susceptibility to environmental food cues and responses to If-Then plans designed to cue intended behaviour are investigated.

Methods

Future intentions about consumption of fruits and vegetables and snack foods will be measured in a sample of young adults. Actual consumption of the target foods will be recorded with computerised diaries over a subsequent 3-day period. Performance on a battery of established executive control tasks (Go-NoGo, Tower task, Verbal Fluency task and Trail-Making) will be used to predict the discrepancy between intended and actual dietary behaviour. In addition, executive control scores will be used to predict reported susceptibility to environmental food cues and benefit derived from the use of 'If-Then plans' designed to cue intended behaviour.

Discussion

Our findings will add to understanding about the role of executive control in translating intentions into actions and may demonstrate potential for future public health interventions. If participants with weak executive control are found to be less likely to eat as they intend than those with strong executive control, then interventions that reduce the load on these executive processes may increase chances of successful intention-behaviour translation. If those with weak executive control are found to be more responsive to cues to action they may also benefit more from the use of If-Then plans designed to cue intended behaviour.