“SWIPE”: A Personalised brain-training app to reduce alcohol cravings and consumption

The intervention involves delivery of alcohol approach bias modification via a smartphone app. Once participants download the app to their phone, but prior to commencing the intervention, participants will be prompted to select 6 alcohol-related pictures that represent the drinks they most frequently consume. Participants can either take and upload photographs using their phone or select pictures from a library of alcohol-related images chosen to represent a broad range of alcoholic beverages commonly consumed in Australia. Participants will then be prompted to select 6 pictures that “represent your goals and motivations”. Again, participants can either take and upload photographs or select pictures from a library of pictures representing a range of healthy activities or positive goals and sources of pleasure (including family or friends enjoying time together; financial success; employment; exercise, sports, and recreational activities; healthy foods; pets; travel and holidays) which do not contain any depiction of alcohol. Once the participant selects their 12 pictures, they will be presented with instructions for the ABM task. Pictures (200 x 200 pixels) will be displayed with a white “frame” around them which will be in either landscape or portrait orientation. When the frame is in landscape orientation, the participant is required to swipe downwards (i.e., towards themself), which (if the movement is at least 40 pixels downward) causes the picture to expand, increasing to 600 x 600 pixels over a period of 500 milliseconds (ms), as if the participant has “pulled” the picture “towards” themselves. When the frame is in portrait orientation, the participant is instructed to swipe upwards (i.e., away from themself), which (if the movement is at least 40 pixels upwards) causes the picture to shrink until it disappears, which takes 500 ms, as if they have “pushed” it “away”. If the participant swipes (at least 40 pixels) in the wrong direction, a red “X” is displayed to inform them that they made an error. After the picture expands/shrinks to its maximum/minimum extent, there is a 250 ms inter-stimulus interval before presentation of the next picture. Following the display of the instructions, participants complete 10 practise trials (including 5 images in portrait frames and 5 in landscape frames, in random order) to familiarise them with the task before commencing scored trials. Following the practise trials, participants will complete the first session of ABM. Each session consists of 156 trials, comprising 13 presentations of each picture. For alcohol pictures, 12 of the 13 presentations are framed in portrait orientation, and one is framed in landscape orientation. This is reversed for positive pictures, whereby 12 of the 13 presentations of each positive picture are framed in landscape orientation, while one is framed in portrait orientation. Thus, participants are supposed to push away 92.3% of alcohol images and pull 92.3% of positive images towards themselves. If participants make the incorrect response, they are informed that it was an error, but the trial is not repeated. To increase engagement and encourage participants to respond both quickly and accurately, the task is gamified with a scoring system. Each time the participant swipes an image in the correct direction, they are awarded 10 points. Additionally, they score 'bonus points' for correct responses if their response is fast enough. If they swipe correctly and within 500 milliseconds (ms) of picture onset, they receive 30 bonus points (yielding a total of 40 points for that trial). If they swipe correctly within 500-1000 ms of picture onset they receive 20 bonus points (i.e., 30 points total). If they respond correctly within 1000-1500ms they receive 10 bonus points (i.e., 20 points total). Correct responses that are slower than 1500 ms following picture onset earn only 10 points. If they swipe an image incorrectly (i.e., swipe down for portrait or swipe up for landscape), they lose 100 points, regardless of their reaction time. Note that reaction time is recorded as the time taken to complete the swipe movement (i.e., the interval between picture display and the time at which the participant has moved their finger at least 40 pixels upwards/downwards). Participants’ score will be displayed on the screen as they perform the task. Upon completion of the task, the final point score is displayed. At the end of these sessions, their final score for that session will be shown (and, if it not their first session, their previous personal best score will also be displayed, so they can compare their performance). On the second and subsequent sessions, participants are offered the opportunity to review the task instructions and complete the 10 practise trials, but from the second session onwards they are provided with the option to skip these steps. Participants will be prompted by the app to complete a minimum of two ABM sessions each week for four weeks, as the target number of sessions is 8 sessions over 4 weeks. App analytical data that will be saved by the app and exported for analysis will include the date and start time of each ABM session, and whether or not the session was completed. This will allow assessment of adherence to the app (e.g., number of sessions commenced each week and in total; whether any sessions were left uncompleted).