The role and trainability of executive function in the context of healthy eating

Minimising intake of dietary fats and consuming appropriate amounts of fruit and vegetables reduce the risk of numerous negative health consequences. Self-regulation, and the processes underlying this capacity, namely executive functions, have been proposed to influence the adoption and maintenance of such healthy eating behaviours. In this thesis, a multi-method approach was taken to establish which facets of executive function were involved in healthy eating behaviour and whether these could be modified to improve eating behaviour. The results of a series of focus groups and a prospective study revealed that inhibitory control was specifically involved in fat intake, while updating ability was involved in fruit and vegetable consumption. A meta-analysis of current inhibitory control training studies revealed the need to assess change in eating behaviour using ecologically valid measures of eating behaviour, and to assess the mechanisms by which inhibitory control training influence eating behaviour. Results of an intervention based on these findings revealed that behaviour-specific stop-signal training led to a reduction in body mass index, which was mediated by changes in vulnerability to depletion. However, training did not result in a reduction in fat intake or an increase in inhibitory control capacity. The intervention was replicated to assess the reliability and longevity of the effects and to address methodological limitations. Results revealed that both behaviour-specific and general inhibitory control training improved inhibitory control capacity and decreased vulnerability to depletion; however, these improvements did not result in behaviour change, nor did they persist over time. While it appears that inhibitory control training alone may not be a suitable technique to change everyday eating behaviour, this technique may be efficacious for short-term improvement in self-regulatory outcomes, or when combined with other behaviour change techniques

Closing the intention-behaviour gap for sunscreen use and sun protection behaviours

Objective: Two studies were conducted with the aim of closing the intention– behaviour gap for sunscreen use and sun protection behaviours by examining the influence of self-regulatory capacity on the prediction of sunscreen use (Study 1) and self-regulatory capacity and habit on sun protection behaviours (Study 2). Design: Studies were conducted online. Participants completed questionnaires and cognitive measures and then reported behaviour one week later. Main Outcome Measures: Questionnaires measuring intention and cognitive tasks measuring self-regulatory capacity were administered to 209 university students. One week later, participants reported behaviour. In Study 2, questionnaires measuring intentions, and habit and cognitive tasks measuring selfregulatory capacity were administered to 178 university students who reported behaviour one week later. Results: Intention accounted for 7.1% of variance in sunscreen use, no measures of self-regulation accounted for variance in behaviour or moderated the intention–behaviour gap (Study 1). Intention, self-regulatory capacity and habit accounted for 56.1% of variance in sun protection behaviours (Study 2). Intention, self-regulatory ability and habit predicted behaviour, while habit moderated the intention–behaviour gap. Conclusion: Interventions aimed at increasing sun protection behaviours should take into account level of intention, self-regulatory capacity and habit. Individuals may benefit from habit formation strategies and self-regulation training

Does inhibitory control training improve health behaviour? A meta-analysis

Objectives: Inhibitory control training has been hypothesised as a technique that will improve an individual's ability to overrule impulsive reactions in order to regulate behaviour consistent with long-term goals. Methods: A meta-analysis of 19 studies of inhibitory control training and health behaviours was conducted to determine the effect of inhibitory control training on reducing harmful behaviours. Theoretically driven moderation analyses were also conducted to determine whether extraneous variables account for heterogeneity in the effect; in order to facilitate the development of effective intervention strategies. Moderators included type of training task, behaviour targeted, measurement of behaviour and training duration. Results: A small but homogeneous effect of training on behaviour was found, d+ = 0.378, CI95 = [0.258, 0.498]. Moderation analyses revealed that the training paradigm adopted, and measurement type influenced the size of the effect such that larger effects were found for studies that employed go/no-go (GNG) training paradigms rather than stop-signal task paradigms, and objective outcome measures that were administered immediately yielded the largest and most consistent effects on behaviour. Conclusions: Results suggest that GNG inhibitory control training paradigms can influence health behaviour, but perhaps only in the short-term. Future research is required to systematically examine the influence of training duration, and the longevity of the training effect. Determining these factors could provide the basis for cost-effective and efficacious health-promoting interventions

Building habit strength: A pilot intervention designed to improve food-safety behavior

The purpose of this study was to firstly design an intervention to decrease cross-contamination in the home by the development of the habitual behavior of microwaving the dishcloth/sponge and secondly to determine if this behavior could be maintained over time. Participants were randomly assigned to either a high-frequency or low-frequency reminder habit building condition or a control condition. Results indicated that for both habit building conditions, food-safety behavior significantly increased compared to the control group and these changes were maintained at follow-up. Additionally, improvement in behavior was mediated by anincrease in habit strength. The major conclusion of this study is that providing a cue to action and reminders builds food-safety habits that result in changes in food-safety behaviors. This has major implications for other food-safety interventions

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-report and behavioural approaches to the measurement of self-control: Are we assessing the same construct?

The capacity for self-control has been consistently linked to successful execution of health behaviour. However, a lack of consensus remains in the conceptualisation and measurement of the construct. Notably, self-report measures relate to behavioural measures of self-control only weakly or not at all. The aim of the current research was to examine the relationship between self-report and behavioural measures of self-control to determine whether these differentially relate to health behaviour. Participants (N = 146) completed questionnaire and behavioural measures of self-control, and reported their physical activity. A direct effect of self-reported self-control on physical activity was observed, qualified by an interaction between self-reported self-control and behavioural measures, whereby greater self-reported self-control was associated with greater engagement in physical activity among those who performed poorly on the stop-signal task and those who performed well on the Stroop task. These results appear to indicate that the combination of trait self-control and behavioural factors leads to facilitative or debilitative effects on behaviour. Self-report and behavioural measures of self-control do not appear to assess the same elements of self-control and should not be used interchangeably. It is suggested that these measurement modes reflect a difference between trait self-control and specific self-control processes

The Effect of Non-specific Response Inhibition Training on Alcohol Consumption: An Intervention

Objective: Excessive alcohol consumption increases the risk of alcohol-related disease and injury. Poor response inhibition; the inability to intentionally override a pre-potent response, has been associated with greater alcohol consumption. The aim of the present study was to clarify if non-specific response inhibition training could improve response inhibition, and reduce alcohol consumption. Method: One hundred and sixty-eight undergraduates were randomly assigned to either an inhibition or active control condition, and completed a stop-signal task once a day for four consecutive days. The inhibition condition comprised a stop-signal task with a high target density (50% stop-signals), while the active control comprised a stop-signal task with a lower target density (25% stop-signals) and the instruction to ignore the signal. Before and after the intervention, participants completed measures of response inhibition, and alcohol consumption. Alcohol consumption was measured again at one month post-training. All parts of the study were completed online. Results: Contrary to the hypotheses, participants in the inhibition condition did not have lower levels of alcohol consumption, nor improved response inhibition after the intervention, compared to participants in the active control condition. Conclusion: It is suggested that response inhibition training needs to be specific to the target behaviour in order to be effective; however, that training did not improve response inhibition itself, calls into question the efficacy of this particular training paradigm. It is recommended that future response inhibition training paradigms consider how training intensity, and the format of administration, influences behavioural outcomes

The effects of implicit and explicit self-control on self-reported aggression

Aggression and violence have a large impact on society. Researchers have highlighted the need to incorporate impulsive processes into models of aggression. The current research is the first to investigate the role of self-control, measured by both explicit questionnaires and an implicit association test, on trait aggression. Results indicated higher levels of implicit and explicit self-control were associated with lower aggressive tendencies. We also investigated the role of sex in the current study and showed that while sex was associated with aggressive tendencies overall, such that men had higher levels of trait aggression, the relationship between self-control and aggression did not differ according to sex. The current findings provide the first indication that both implicit and explicit self-control have roles in aggressive tendencie

Assessing Audience Members' Ability to Identify the Media Source of a Health Campaign Disseminated via Different Media

Background: An important criterion for health campaign media selection is the ability to achieve campaign awareness among target audiences. However, existing campaign exposure metrics cannot be applied across both traditional and digital media, which complicates decision making. The present study assessed the validity of using self-report as a measure of the extent to which different types of media achieve campaign awareness to assist in determining appropriate media budget allocations.Methods: A quasi-experiment involving varying combinations of television, online video, and online display smoking cessation advertisements was conducted to determine whether audience members were able to accurately report the source of their exposure to the campaign.Results: Of the 719 Western Australian adults sampled (50% males, 50 females, 50% smokers, 50% non-smokers), 64% reported seeing the campaign in the previous 2 weeks. Of these, 91% reported seeing the advertisement on television, 8% on online video, and 21% on online display (respondents could select multiple media). Despite proportional scheduling of the three media over the discrete campaign periods, in most cases respondents assumed their exposure had occurred via television, regardless of the actual source of exposure.Conclusions: Among both smokers and non-smokers, television had primacy in memory regardless of the actual media used. As such, relying on self-reported recall is unlikely to constitute a reliable method of assessing target audience exposure to campaigns on different media where those media are all screen-based. The results highlight the need for alternative media effectiveness metrics that permit direct comparisons between traditional and digital media

Active behaviour change safety interventions in the construction industry: A systematic review

© 2015 Elsevier Ltd. The aims of this paper were to systematically review the evidence for the effectiveness of active behaviour change safety interventions in the construction industry; and to determine the intervention characteristics most commonly associated with effectiveness in reducing injury rates and improving safety behaviour - intensity/frequency/duration, behaviour change techniques (BCTs) and theory-base. An electronic literature search (June 2014) was conducted to identify eligible interventions: those involving active involvement from workers/management in the construction industry; targeted one/both of the primary outcomes. All intervention designs involving construction workers aged >18 years, published in English and in a peer-reviewed journal were included. Fifteen studies were included, half of which successfully improved injury rates. Longer interventions and those that included active/volitional BCTs (feedback/monitoring rather than instruction/information) were more effective. The methodological quality of the interventions was poor and use of theory was inconsistent and infrequent. Despite some positive results, very few interventions achieved all their aims. More rigorous, theory-driven research is needed to structure intervention efforts and determine the mechanism of action of effective interventions