Participants
60 participants (34 female) with a mean age of 21.15 (±3.30) years took part in the study. Participants were recruited using advertisements placed around the university campus and on the intranet. Participants were informed that they were signing up for a study on taste and olfactory perceptions of different drinks. Inclusion criteria were: heavy drinking according to UK government guidelines (consumption of over 14 UK units per week if female, 21 UK units if male (Edwards, 1996)) with no history of alcohol problems, aged between 18-30 and beer as a preferred alcoholic beverage. All participants provided informed consent before taking part in the study, which was approved by the University of Liverpool Research Ethics committee. Materials and Equipment
Questionnaires Urge to drink scales
Urge to drink scales were taken from Kambouropoulos and Staiger (2004). Two statements ‘How much do you want to drink alcohol at this moment for its positive effect?” (positive urge) and “How much do you want to drink alcohol at this moment to take away an unpleasant feeling or mood?” (negative urge) were presented with 11 anchors ranging from 0 (not at all) to 10 (extremely).
Approach and Avoidance of Alcohol Questionnaire (AAAQ).
The AAAQ (McEvoy et al., 2004) is a 14 item questionnaire in which participants indicate how strongly they agree (0 ‘not at all’ to 8 ‘very strongly’) with statements about drinking ‘right now’. The AAAQ measures self-reported craving on three dimensions: mild inclinations to drink (Inclined / Indulgent), intense inclinations to drink (Obsessed / Compelled) and inclinations to avoid alcohol (Resolved /
Regulated).
122 The BMIS (Mayer and Gaschke, 1988) is a 16 item questionnaire in which
participants indicate how they feel ‘right now’ in response to various adjectives using a 4 point scale labelled ‘definitely do not feel’, ‘do not feel’, ‘slightly feel’ and ‘definitely feel’. The BMIS measures self-reported mood and arousal states, along four continuums; pleasant-unpleasant, arousal-calm, positive-tired, and negative- relaxed.
Stop-signal task.
The stop-signal task (Logan and Cowan, 1984) was used as a measure of
disinhibition. The task was programmed using Inquisit 3.0 (Millisecond Software, 2008) and was presented on a laptop computer. Each trial began with the
presentation of a fixation cross (‘+’) for 500ms. Following this, one of two visual ‘go’ stimuli (‘X’ or ‘O’) appeared in the centre of the screen. Participants were required to rapidly categorise these stimuli by pressing a correspondingly labelled key on the keyboard. Seventy five percent of trials were ‘go’ trials; on these trials, the stimulus remained on screen until participants made a response or until a 1500 ms timeout had elapsed. The remaining 25% of trials were ‘stop’ trials. On these trials, an auditory tone occurred at one of four latencies (50 ms, 150 ms, 250 ms or 350 ms) after onset of the visual ‘go’ stimulus. This tone acted as a stop-signal and participants were required to inhibit their response whenever they heard the tone. Before completing the task, participants received standard instructions which emphasised the equal importance of rapid responding to ‘go’ stimuli and successful inhibition of responses whenever they heard the stop-signal. Participants were explicitly instructed not to wait for the stop-signal.
The task was split into four blocks. During an initial practice block of 16 trials (12 go trials, 4 stop trials), participants received feedback after each trial. The practice block was only included to familiarise participants with the task, so data from this block were not analysed. The remaining three blocks were identical and each
consisted of 64 trials: 48 go trials and 16 stop trials (four at each stop latency). Trials were presented in a new random order within each block. The task took
approximately 15 minutes to complete. Procedure
123 Testing sessions took place between the hours of 12pm and 6pm, within the School of Psychology at the University of Liverpool. Participants were randomly allocated to one of two conditions: alcohol cue exposure in a ‘simulated bar’ (N=30, 17 female) or water cue exposure in a teaching room (N = 30, 17 female). The simulated bar environment was a purpose built laboratory designed to resemble a typical European bar, including beer pumps, posters advertising alcohol and shelves of spirits. The teaching room was approximately the same size and contained only tables and chairs.
Upon arrival participants provided informed consent before being given a
questionnaire battery consisting of a two week Timeline Follow-Back diary (Sobell and Sobell, 1992) to measure alcohol consumption in the previous two weeks, followed by the Alcohol Use Disorders Identification Test (Saunders et al., 1993). Participants also completed the Temptation and Restraint Inventory (Collins and Lapp, 1992) and the Barratt Impulsivity Scale v. 11 (Patton et al., 1995). Participants then completed the AAAQ, urge to drink scales, and the BMIS (baseline
assessment).
Participants were then taken into their designated laboratory (simulated bar vs. teaching room). They were seated in front of a laptop computer and were told to open either a bottle of beer (Budweiser Budvar, ABV 5%) and pour it into a glass (alcohol cues group) or pour water from a jug into a glass (water cues group). All participants were then instructed to hold the glass in their dominant hand before pressing the space bar on the laptop, which initiated the instructions for cue
exposure. The cue exposure procedure was based on Gauggel and colleagues (2010). Instructions required participants to hold the beverage in their drinking hand and think about the temptation to consume the beverage whilst sniffing it. The task consisted of 10 sniffing episodes lasting for 15 seconds each, with a break of 10 seconds between each episode.
Following cue exposure, the glass containing the beverage was removed from sight and both groups of participants were given a second BMIS, AAAQ and urge to drink scales (post-sniffing task assessment). They were also given post-task feedback questionnaires taken from Jones and colleagues (2011b), which were a set of adjectives and statements, scored from 0 (not at all) to 7 (extremely), assessing
124 difficulty, unpleasantness and how much the task required suppression of urges. The BMIS, AAAQ and post-task feedback questionnaires took approximately 5 minutes to complete. Participants then completed the stop-signal task on the laptop computer, before completing the BMIS, AAAQ, urge to drink scales and post task feedback again (post-stop-signal task assessment). Finally, participants completed the bogus taste test procedure. They were presented with 250ml of chilled beer (Budweiser Budvar ABV 5%) and 250ml of chilled fruit juice (J20 orange and passion fruit) in unmarked glasses (drinks were prepared out of sight). Participants were asked to taste and rate these drinks on 10 adjectives including pleasantness, bitterness and fruitiness, and explicitly told they could drink as much or as little as they liked of each drink and take as long as they needed. This methodology has been used in previous experimental studies to unobtrusively quantify alcohol-seeking behaviour (Field and Eastwood, 2005; Jones et al., 2011a, b). The dependent variable in the taste test was beer as a percentage of total fluid consumed. Following the taste test participants were given a funnelled debriefing (based on Jones et al., (2011b)) which assessed participants’ awareness of the aims and hypotheses of the study on three levels: overall, stop-signal task, and taste test. Overall awareness was assessed using an open ended question (‘What do you think the experiment was about?’).
Awareness of the computer task and taste test were assessed using multiple choice questions (‘What was the purpose of the computer task?’ and ‘What was the purpose of the taste test?’) with six possible answers, only one of which was correct, for both questions. Participants were then debriefed before being discharged; they received either course credit or £10 as compensation for travel expenses and time.