Anxiety sensitivity and trait anxiety are associated with response to 7.5% carbon dioxide challenge

The 7.5% carbon dioxide (CO(2)) inhalation model is used to provoke acute anxiety, for example to investigate the effects of anxiety on cognitive processes, or the efficacy of novel anxiolytic agents. However, little is known about the relationship of baseline anxiety sensitivity or trait anxiety (i.e., anxiety proneness), with an individual’s response to the 7.5% CO(2) challenge. We examined data from a number of 7.5% CO(2) challenge studies to determine whether anxiety proneness was related to subjective or physiological response. Our findings indicate anxiety proneness is associated with greater subjective and physiological responses. However, anxiety-prone individuals also have a greater subjective response to the placebo (medical air) condition. This suggests that anxiety-prone individuals not only respond more strongly to the 7.5% CO(2) challenge, but also to medical air. Implications for the design and conduct of 7.5% CO(2) challenge studies are discussed

Effects of acute alcohol consumption and processing of emotion in faces:Implications for understanding alcohol-related aggression

The negative consequences of chronic alcohol abuse are well known, but heavy episodic consumption ("binge drinking") is also associated with significant personal and societal harms. Aggressive tendencies are increased after alcohol but the mechanisms underlying these changes are not fully understood. While effects on behavioural control are likely to be important, other effects may be involved given the widespread action of alcohol. Altered processing of social signals is associated with changes in social behaviours, including aggression, but until recently there has been little research investigating the effects of acute alcohol consumption on these outcomes. Recent work investigating the effects of acute alcohol on emotional face processing has suggested reduced sensitivity to submissive signals (sad faces) and increased perceptual bias towards provocative signals (angry faces) after alcohol consumption, which may play a role in alcohol-related aggression. Here we discuss a putative mechanism that may explain how alcohol consumption influences emotional processing and subsequent aggressive responding, via disruption of OFC-amygdala connectivity. While the importance of emotional processing on social behaviours is well established, research into acute alcohol consumption and emotional processing is still in its infancy. Further research is needed and we outline a research agenda to address gaps in the literature

Conditioned cognitive and mood effects of caffeine in humans

Findings from animal studies suggest that stimuli present during the administration of psycho stimulant drugs can acquire the ability to elicit drug-like conditioned increases in locomotor activity. Human pharmacological drug-like conditioned responses are less well researched. There is evidence suggesting that stimuli paired with psycho stimulant administration can elicit drug-like physiological and subjective changes, as well as increases in drug craving. However, to date, no study has explicitly examined whether drug-induced facilitation of cognitive performance can be conditioned to drug-associated stimuli. The studies in the present thesis set out to test this and examine the extent to which the pattern of results conformed to the principles of Pavlovian classical conditioning. Caffeine was used as a model psycho stimulant drug, due to its well-reported ability to facilitate various aspects of cognitive performance. However, due to difficulties obtaining reliable effects of caffeine, the factors that may influence the effects of caffeine in a caffeine consumer sample were also investigated and reviewed. These factors included dose, expectancy, absorption interval, type of task, withdrawal and level of habitual consumption. It was concluded that caffeine can enhance cognitive performance, however these effects are inconsistent and may be influenced by individual differences. In addition, findings from a screening procedure indicated that responses to caffeine differ even within an overnight-deprived caffeine consumer population, an effect that appears to be dependent on the level of habitual caffeine intake. Due to such individual variation in the responses to caffeine, the conditioned effects were examined using a differential (i.e. within-subjects) conditioning procedure in which one set of environmental stimuli were paired with caffeine, and another set were paired with placebo. When subsequently tested free of drug, there were no differences in performance or mood responses at the conditioning test. However, there was evidence of caffeine facilitation on performance and mood during early conditioning trials that was lost on later conditioning trials due to a systematic improvement in the placebo condition. It was argued that this may be due to a conditioned response being acquired in the caffeine paired context which generalised to the placebo paired context. To test this hypothesis a second differential conditioning paradigm was conducted with fewer trials to establish whether evidence of a conditioned response could be observed in the caffeine-paired context during a placebo challenge. Evidence of a conditioned facilitation of reaction time was found, suggesting that the environment in which caffeine is ingested can acquire drug-like facilitations of cognitive performance

The Effect of Glass Shape on Alcohol Consumption in a Naturalistic Setting: A Feasibility Study

BACKGROUND: Alcohol-related harms are a major public health concern, and population-level interventions are needed to reduce excessive alcohol consumption. Glass shape is an easily modifiable target for public health intervention. Laboratory findings show beer is consumed slower from a straight glass compared to a curved glass, but these findings have not been replicated in a naturalistic setting. The purpose of this study is to investigate the feasibility of conducting a randomised controlled trial investigating the effect of glass shape on alcohol consumption in public houses. METHODS: Straight and curved half-pint and pint glasses were delivered to three public houses over two weekends. Glass type was counterbalanced over the two weekends and between the public houses. Monetary takings were recorded as an indirect measure of consumption. RESULTS: Replacing stocks of glassware in public houses was feasible and can be enacted in a short space of time. One landlord found the study too disruptive, possibly due to a laborious exchange of glassware and complaints about the new glassware from some customers. One public house’s dishwasher could not accommodate the supplied curved full-pint glasses. Obtaining monetary takings from public house staff was a feasible and efficient way of measuring consumption, although reporting absolute amounts may be commercially sensitive. Monetary takings were reduced by 24 % (95 % confidence interval 77 % reduction to 29 % increase) when straight glasses were used compared to curved glasses. CONCLUSIONS: This study shows that it is feasible to carry out a trial investigating glass shape in a naturalistic environment, although a number of challenges were encountered. Brewery owners and landlords are willing to engage with public health research in settings where alcohol is consumed, such as public houses. Good communication with stakeholders was vital to acquire good data, and highlighting the potential commercial benefits of participating was vital to the study’s success. A full scale evaluation of the effects of glass shape on alcohol consumption could inform local and national policy

Effect of nucleation on the likeability and drinking rate of lager in social alcohol drinkers

Background. The aim of these studies was to investigate the effect of nucleated glasses on the likeability and drinking rate of lager in social alcohol drinkers. Methods. In Study 1, participants (n = 116) were asked to taste two glasses of lager (280 ml each) in separate 5-minute taste tests and fill out a likeability questionnaire (items on a 100 mm visual analogue scale (VAS)) after each glass in a within-subjects design with one factor of glass (nucleated, non-nucleated). In Study 2, participants (n = 160) were asked to consume a pint of lager (568 ml) and fill out a likeability questionnaire in a between-subjects design with one factor of glass (nucleated, non-nucleated). Results. There was no clear evidence that likeability of lager differed between nucleated and non-nucleated glasses in either study. In Study 1, there was strong evidence (nucleated: 74.2, non-nucleated: 64.0, MD = 10.2, 95% CI: 6.1, 14.2, p < 0.001) that lager in nucleated glasses was more visually appealing (single item from likeability measure) than lager in non-nucleated glasses. In Study 2, there was no clear evidence (nucleated: 16.9 mins, non-nucleated: 16.3 mins, MD: 0.6 mins, p = 0.57) that lager was consumed at different rates from nucleated and non-nucleated glasses. Conclusions. Nucleated lager glasses do not appear to alter the likeability or consumption (volume consumed or drinking rate) of lager, although they do seem to increase the visual appeal of lager

Effects of 7.5% carbon dioxide (CO2) inhalation and ethnicity on face memory

AbstractThe ability to accurately verify facial identity has important forensic implications, but this ability is fallible. Research suggests that anxiety at the time of encoding can impair subsequent recall, but no studies have investigated the effects of anxiety at the time of recall in an experimental paradigm. This study addresses this gap using the carbon dioxide (CO2) model of anxiety induction. Thirty participants completed two inhalations: one of 7.5% CO2-enriched air and one of medical air (i.e., placebo). Prior to each inhalation, participants were presented with 16 facial images (50% own-ethnicity, 50% other-ethnicity). During the inhalation they were required to identify which faces had been seen before from a set of 32 images (16 seen-before and 16 novel images). Identification accuracy was lower during CO2 inhalation compared to air (F[1,29]=5.5, p=.026, ηp2=.16), and false alarm rate was higher for other-ethnicity faces compared to own-ethnicity faces (F[1,29]=11.3, p=.002, ηp2=.28). There was no evidence of gas by ethnicity interactions for accuracy or false alarms (ps>.34). Ratings of decision confidence did not differ by gas condition, suggesting that participants were unaware of differences in performance. These findings suggest that anxiety, at the point of recognition, impairs facial identification accuracy. This has substantial implications for eyewitness memory situations, and suggests that efforts should be made to attenuate the anxiety in these situations in order to improve the validity of identification

Digital phenotyping and the development and delivery of health guidelines and behaviour change interventions

Lovatt and colleagues make the case that drinking guidelines informed by the experiences and behaviours of drinkers are likely to have increased relevance, credibility and efficacy. There is reason to believe that digital technologies such as crowdsourcing, social media, mobile digital devices and biosensing devices measure behaviours such as drinking with a level of detail and on a scale that has not been possible previously. The intensive measurement of behaviours enabled by these approaches, combined with appropriate modelling techniques, can reveal patterns of behaviours that, together with knowledge of the resultant negative or harmful consequences, can inform the development of improved guidelines

The Role of State and Trait Anxiety in the Processing of Facial Expressions of Emotion

State anxiety appears to influence facial emotion processing (Attwood et al. 2017 R. Soc. Open Sci. 4, 160855). We aimed to (i) replicate these findings and (ii) investigate the role of trait anxiety, in an experiment with healthy UK participants (N = 48, 50% male, 50% high trait anxiety). High and low state anxiety were induced via inhalations of 7.5% carbon dioxide enriched air and medical air, respectively. High state anxiety reduced global emotion recognition accuracy (p = 0.01, [Formula: see text]), but it did not affect interpretation bias towards perceiving anger in ambiguous angry–happy facial morphs (p = 0.18, [Formula: see text]). We found no clear evidence of a relationship between trait anxiety and global emotion recognition accuracy (p = 0.60, [Formula: see text]) or interpretation bias towards perceiving anger (p = 0.83, [Formula: see text]). However, there was greater interpretation bias towards perceiving anger (i.e. away from happiness) during heightened state anxiety, among individuals with high trait anxiety (p = 0.03, dz = 0.33). State anxiety appears to impair emotion recognition accuracy, and among individuals with high trait anxiety, it appears to increase biases towards perceiving anger (away from happiness). Trait anxiety alone does not appear to be associated with facial emotion processing