Research Roundup Spring 2014

Welcome to the latest research roundup from the Addiction Research Group based in the Department of Psychological Sciences, University of Liverpool. As ever, we have been working hard over the past few months on many different research topics, and in this blog post we have condensed some of our recent publications and activities into bite-size portions for your enjoyment. 

The first two publications reported investigations of how our drinking behaviour is influenced by that of other people.

A study conducted in our bar lab was published in Alcoholism: Clinical and Experimental Research. We examined how social acquaintances influence each other’s alcohol consumption using a confederate design. A pair of social drinkers was invited to the laboratory, and one of them (the confederate) was secretly informed to choose either alcoholic or soft drinks when offered them by the experimenter. Both individuals were subsequently offered drinks to consume while they played a game together (the popular ‘4 pics 1 word’ game). The key variable of interest was the amount of alcohol that the naïve participant chose to consume. We found that naïve participants were strongly influenced by their acquaintance’s choice: if the confederate chose alcoholic drinks, the naïve participant was much more likely to choose them as well. Furthermore, the majority of participants believed that their drinking was not influenced by their partner’s choices. This study was the first to use the confederate design in individuals who knew each other before the study, and it has important implications for the psychological mechanisms that underlie effects of imitation on drinking behaviour. The study was conducted by Rebecca Dallas, an undergraduate psychology student who is first author on the paper. The paper was the topic of a press release and it was covered by several print and online media outlets, including the Metro and science website RedOrbit.  The research was also covered by some other unexpected news sources, including ‘RealBollywood’, which surprised and excited us (mostly the former).  

The second paper, by Eric Robinson and colleagues, was published in Substance Use and Misuse. This Internet study investigated if there is an association between perceived drinking norms and usual drinking behaviour in UK students.  We also included interventions to correct misperceptions about the drinking behaviour of others, and increase intentions to drink responsibly. We found that peer drinking was associated with individual differences in drinking: individuals who believed other students drank responsibly also drank responsibly. However, interventions based on accurate norm messages did not influence intentions to drink responsibly, possibly because they were not seen as credible. This study adds to a growing literature suggesting that social norm interventions may have limited efficacy in reducing hazardous drinking in UK students.  

Speaking of bite-size portions, we have diversified from only studying alcohol. We recently published two papers that examined the motivation to obtain and consume chocolate and pizza. 

The first paper by Charlotte Hardman and colleagues was published in Appetite. This research continued previous work by our group (see here and here) examining whether the anticipation of receiving a reward, in this case delicious cheese and tomato pizza, would influence physiological (salivation) and attentional responses in hungry participants. Whilst there was no evidence for any effects of anticipation on salivation, we demonstrated that anticipation influenced initial attentional processing of pizza pictures. While this result wasn’t quite as clear cut as our previous studies with beer and chocolate, it does suggest that anticipation of reward plays a role in attentional bias for rewarding cues.  

Our second snack-themed paper was published by Jessica Werthmann, Matt Field and colleagues in Journal of Behavior Therapy and Experimental Psychiatry. In this study we examined whether manipulating attention towards or away from chocolate using a modified anti-saccade task could influence craving and consumption of chocolate. We found that participants who shifted attention towards chocolate cues subsequently ate more chocolate during an ad-libitum taste test compared to those shifted their attention away from chocolate.  These findings suggest that training attentional bias away from food-cues can reduce consumption of that food, although in other papers we have been sceptical about the clinical applications of ‘attentional bias modification’, particularly in addiction.

Last but no means least, Jasna Martinovic and colleagues published a paper in PLoS One (we support open access!). In this study we examined electrophysiological correlates of Pavlovian-to-Instrumental transfer (PIT) in individuals who regularly drink beer and eat chocolate. PIT is the phenomenon whereby drug-cues evoke an anticipation of drug reward and thereby increase instrumental responding for drug reward. The brain mechanisms that underlie PIT effects are poorly understood and this was the focus of this study. We examined whether electrophysiological indices of the motivational salience of beer and chocolate pictures (the P300 and Slow Potential) would be associated with behavioural PIT responses for beer and chocolate rewards. We found clear behavioural PIT effects and some indication of increased Slow Potentials in response to the beer and chocolate pictures, but unfortunately these were not related to each other. Possibly, behavioural PIT effects are generated by subcortical structures that cannot be detected using EEG, or maybe we just didn’t use the right method. 

As well as writing papers we also like to get out and see the world, all in the name of science of course...

Inge Kersbergen, Jay Duckworth and Natasha Clarke attended Alcohol Research UK’s first postgraduate and early career symposium in London in March. Natasha and Inge both gave oral presentations. Inge presented her own study, ‘Visual attention to health information on alcoholic drinks containers’ which was an eye-tracking study examining responses to warning labels on alcohol drinks containers, and Natasha presented the paper, ‘Alcohol-induced risk taking on the BART mediates alcohol priming’ which we discussed in a previous roundup. 

Matt Field discussed the role of attentional bias in addiction at the ‘Maastricht symposium on the role of attentional bias in psychopathology’, in March. After the conference, our former (temporary) colleague Jessica Werthmann successfully defended her PhD thesis, for which we offer our congratulations!!

That is all for this research roundup. Thank you for reading! As always, if you would like to get in touch about anything featured here please contact Prof. Matt Field, and if you are interested in taking part in our research please contact Andy Jones