Rachel Pechey

The Prevalence of Delusion-Like Beliefs Relative to Sociocultural Beliefs in the General Population

Background: Delusions are defined as false beliefs different from those that almost everyone else believes. The aim was to develop a new measure (the Cardiff Beliefs Questionnaire, CBQ) to establish the range and prevalence of delusion-like beliefs (DLB) and compare these to other types of beliefs in the general population. Sampling and Methods: A total of 1,000 participants completed the CBQ, which uniquely assesses a broader range of currently held beliefs [delusion-like (bizarre and non-bizarre), paranormal and religious and general political/social beliefs) using this large stratified sample. Results: Strong belief in 1 or more DLB was reported by 39% of the participants (91% reporting ‘weak’, ‘moderate’ or ‘strong’ belief in at least 1 DLB). Moreover, 25% endorsed at least 1 bizarre DLB (76% one or more at any strength). Endorsements of DLB were strongly correlated with paranormal and religious beliefs but not general political/social beliefs. Conclusions: Both bizarre and non-bizarre DLB are frequently found in the general population, lending support to the psychosis continuum account and need to revise key clinical criteria used to diagnose delusions. The good psychometric properties demonstrated by the CBQ indicate that this measure is a useful tool to investigate the wider continuum of beliefs held in the general population.

Sales impact of displaying alcoholic and non-alcoholic beverages in end-of-aisle locations: An observational study

In-store product placement is perceived to be a factor underpinning impulsive food purchasing but empirical evidence is limited. In this study we present the first in-depth estimate of the effect of end-of-aisle display on sales, focussing on alcohol. Data on store layout and product-level sales during 2010–11 were obtained for one UK grocery store, comprising detailed information on shelf space, price, price promotion and weekly sales volume in three alcohol categories (beer, wine, spirits) and three non-alcohol categories (carbonated drinks, coffee, tea). Multiple regression techniques were used to estimate the effect of end-of-aisle display on sales, controlling for price, price promotion, and the number of display locations for each product. End-of-aisle display increased sales volumes in all three alcohol categories: by 23.2% (p = 0.005) for beer, 33.6% (p < 0.001) for wine, and 46.1% (p < 0.001) for spirits, and for three non-alcohol beverage categories: by 51.7% (p < 0.001) for carbonated drinks, 73.5% (p < 0.001) for coffee, and 113.8% (p < 0.001) for tea. The effect size was equivalent to a decrease in price of between 4% and 9% per volume for alcohol categories, and a decrease in price of between 22% and 62% per volume for non-alcohol categories. End-of-aisle displays appear to have a large impact on sales of alcohol and non-alcoholic beverages. Restricting the use of aisle ends for alcohol and other less healthy products might be a promising option to encourage healthier in-store purchases, without affecting availability or cost of products.

Impact of plain packaging of tobacco products on smoking in adults and children: an elicitation of international experts’ estimates

BackgroundGovernments sometimes face important decisions in the absence of direct evidence. In these cases, expert elicitation methods can be used to quantify uncertainty. We report the results of an expert elicitation study regarding the likely impact on smoking rates in adults and children of plain packaging of tobacco products.MethodsThirty-three tobacco control experts were recruited from the UK (n = 14), Australasia (n = 12) and North America (n = 7). Experts’ estimates were individually elicited via telephone interviews, and then linearly pooled. Elicited estimates consisted of (1) the most likely, (2) the highest possible, and (3) the lowest possible value for the percentage of (a) adult smokers and (b) children trying smoking, two years after the introduction of plain packaging (all other things being constant) in a target country in the expert’s region of residence.ResultsThe median estimate for the impact on adult smoking prevalence was a 1 percentage point decline (99% range 2.25 to 0), and for the percentage of children trying smoking was a 3 percentage point decline (99% range 6.1 to 0), the latter estimated impact being larger than the former (P < 0.001, sign test). There were no differences in either estimate by region (I2: Adults: 0; Children: 0) but there was considerable variability between experts’ estimates within regions (I2: Adults: 0.91; Children: 0.89).ConclusionsIn the absence of direct evidence for the impact of introducing plain packaging on smoking rates in adults and children, this study shows that tobacco control experts felt the most likely outcomes would be a reduction in smoking prevalence in adults, and a greater reduction in the numbers of children trying smoking, although there was substantial variability in the estimated size of these impacts. No experts judged an increase in smoking as a likely outcome.

Impact on alcohol purchasing of a ban on multi-buy promotions: a quasi-experimental evaluation comparing Scotland with England and Wales

Aims To evaluate the impact of the 2011 Scottish ban on multi-buy promotions of alcohol in retail stores. Design and setting Difference-in-differences analysis was used to estimate the impact of the ban on the volume of alcohol purchased by Scottish households, compared with those in England and Wales, between January 2010 and June 2012. Participants A total of 22 356 households in Scotland, England and Wales. Measurements Records of alcohol purchasing from each of four categories (beer and cider, wine, spirits and flavoured alcoholic beverages), as well as total volume of pure alcohol purchased. Findings Controlling for general time trends and household heterogeneity, there was no significant effect of the multi-buy ban in Scotland on volume of alcohol purchased either for the whole population or for individual socio-economic groups. There was also no significant effect on those who were large pre-ban purchasers of alcohol. Most multi-buys were for beer and cider or for wine. The frequency of shopping trips involving beer and cider purchases increased by 9.2% following the ban (P < 0.01), while the number of products purchased on each trip decreased by 8.1% (P < 0.01). For wine, however, these effects were not significant. Conclusions Banning multi-buy promotions for alcohol in Scotland did not reduce alcohol purchasing in the short term. Wider regulation of price promotion and price may be needed to achieve this.

Making food labels social: The impact of colour of nutritional labels and injunctive norms on perceptions and choice of snack foods☆

Highlights • Red and green labels have no significant effect on snack perceptions and choice.• Emoticon labels implying injunctive norms affect perceptions of health and taste.• Frowning emoticons may be more potent than smiling emoticons for certain foods.

Prevalence and correlates of anomalous experiences in a large non-clinical sample

BACKGROUND Anomalous experiences occur in many psychiatric conditions, but are also reported by non-patients. Given the continuum account of psychiatric symptoms and reports of dissociation between delusions and anomalous experiences, we predicted that anomalous experiences in a large non-clinical sample would (1) associate with delusion-like beliefs but not with socio-cultural beliefs and (2) that anomalous experiences would also show examples of dissociation with anomalous beliefs. A particular focus was the association between beliefs and experiences theoretically predicted to co-occur in Capgras syndrome. METHODS The study examined the distribution and correlates of differential levels of self-reported anomalous experience in a British sample of 1,000 individuals. RESULTS Anomalous experiences were found to be relatively common in the general population and were reported (occurring sometimes/often) by 48% of the sample. Being female and endorsing a non-Christian religion were the only two demographic factors related to higher experience scores. Significant relationships were found between anomalous experiences and anomalous beliefs (i.e., delusion-like and paranormal/religious), but not general societal beliefs. Dissociations between anomalous experiences and anomalous beliefs also were present but not common. No significant relationship was found between Capgras-type beliefs and experiences. CONCLUSIONS This large scale study demonstrated significant association between anomalous experiences and anomalous beliefs in the general population. The relationship was not, however present in all cases similar to cases reported in the clinical literature.

Does Glass Size and Shape Influence Judgements of the Volume of Wine

Background Judgements of volume may influence the rate of consumption of alcohol and, in turn, the amount consumed. The aim of the current study was to examine the impact of the size and shape of wine glasses on perceptions of wine volume. Methods Online experiment: Participants (n = 360; recruited via Mechanical Turk) were asked to match the volume of wine in two wine glasses, specifically: 1. the Reference glass holding a fixed reference volume, and 2. the Comparison glass, for which the volume could be altered until participants perceived it matched the reference volume. One of three comparison glasses was shown in each trial: ‘wider’ (20% wider but same capacity); ‘larger’ (same width but 25% greater capacity); or ‘wider-and-larger’ (20% wider and 25% greater capacity). Reference volumes were 125ml, 175ml and 250ml, in a fully factorial within-subjects design: 3 (comparison glass) x 3 (reference volume). Non-zero differences between the volumes with which participants filled comparison glasses and the corresponding reference volumes were identified using sign-rank tests. Results Participants under-filled the wider glass relative to the reference glass for larger reference volumes, and over-filled the larger glass relative to the reference glass for all reference volumes. Results for the wider-and-larger glass showed a mixed pattern across reference volume. For all comparison glasses, in trials with larger reference volumes participants tended to fill the comparison glass less, relative to trials with smaller reference volumes for the same comparison glass. Conclusions These results are broadly consistent with people using the relative fullness of glasses to judge volume, and suggest both the shape and capacity of wine glasses may influence perceived volume. Perceptions that smaller glasses contain more than larger ones (despite containing the same volume), could slow drinking speed and overall consumption by serving standard portions in smaller glasses. This hypothesis awaits testing.

Using Co-Occurrence to Evaluate Belief Coherence in a Large Non Clinical Sample

Much of the recent neuropsychological literature on false beliefs (delusions) has tended to focus on individual or single beliefs, with few studies actually investigating the relationship or co-occurrence between different types of co-existing beliefs. Quine and Ullian proposed the hypothesis that our beliefs form an interconnected web in which the beliefs that make up that system must somehow “cohere” with one another and avoid cognitive dissonance. As such beliefs are unlikely to be encapsulated (i.e., exist in isolation from other beliefs). The aim of this preliminary study was to empirically evaluate the probability of belief co-occurrence as one indicator of coherence in a large sample of subjects involving three different thematic sets of beliefs (delusion-like, paranormal & religious, and societal/cultural). Results showed that the degree of belief co-endorsement between beliefs within thematic groupings was greater than random occurrence, lending support to Quine and Ullian’s coherentist account. Some associations, however, were relatively weak, providing for well-established examples of cognitive dissonance.

Physical micro-environment interventions for healthier eating in the workplace: protocol for a stepped wedge randomised controlled pilot trial

BackgroundAn estimated one third of energy is consumed in the workplace. The workplace is therefore an important context in which to reduce energy consumption to tackle the high rates of overweight and obesity in the general population. Altering environmental cues for food selection and consumption—physical micro-environment or ‘choice architecture’ interventions—has the potential to reduce energy intake. The first aim of this pilot trial is to estimate the potential impact upon energy purchased of three such environmental cues (size of portions, packages and tableware; availability of healthier vs. less healthy options; and energy labelling) in workplace cafeterias. A second aim of this pilot trial is to examine the feasibility of recruiting eligible worksites, and identify barriers to the feasibility and acceptability of implementing the interventions in preparation for a larger trial.MethodsEighteen worksite cafeterias in England will be assigned to one of three intervention groups to assess the impact on energy purchased of altering (a) portion, package and tableware size (n = 6); (b) availability of healthier options (n = 6); and (c) energy (calorie) labelling (n = 6). Using a stepped wedge design, sites will implement allocated interventions at different time periods, as randomised.DiscussionThis pilot trial will examine the feasibility of recruiting eligible worksites, and the feasibility and acceptability of implementing the interventions in preparation for a larger trial. In addition, a series of linear mixed models will be used to estimate the impact of each intervention on total energy (calories) purchased per time frame of analysis (daily or weekly) controlling for the total sales/transactions adjusted for calendar time and with random effects for worksite. These analyses will allow an estimate of an effect size of each of the three proposed interventions, which will form the basis of the sample size calculations necessary for a larger trial.Trial registrationISRCTN52923504

Do Executive Function and Impulsivity Predict Adolescent Health Behaviour after Accounting for Intelligence? Findings from the ALSPAC Cohort

Objective Executive function, impulsivity, and intelligence are correlated markers of cognitive resource that predict health-related behaviours. It is unknown whether executive function and impulsivity are unique predictors of these behaviours after accounting for intelligence. Methods Data from 6069 participants from the Avon Longitudinal Study of Parents and Children were analysed to investigate whether components of executive function (selective attention, attentional control, working memory, and response inhibition) and impulsivity (parent-rated) measured between ages 8 and 10, predicted having ever drunk alcohol, having ever smoked, fruit and vegetable consumption, physical activity, and overweight at age 13, after accounting for intelligence at age 8 and childhood socioeconomic characteristics. Results Higher intelligence predicted having drunk alcohol, not smoking, greater fruit and vegetable consumption, and not being overweight. After accounting for intelligence, impulsivity predicted alcohol use (odds ratio = 1.10; 99% confidence interval = 1.02, 1.19) and smoking (1.22; 1.11, 1.34). Working memory predicted not being overweight (0.90; 0.81, 0.99). Conclusions After accounting for intelligence, executive function predicts overweight status but not health-related behaviours in early adolescence, whilst impulsivity predicts the onset of alcohol and cigarette use, all with small effects. This suggests overlap between executive function and intelligence as predictors of health behaviour in this cohort, with trait impulsivity accounting for additional variance.