The present study protocol aims to examine the behavioral and EEG correlates of MI, specifically those related to the suppression of alcohol-related memories, among young BDs. For this purpose, 45 BDs and 45 age-matched non/low-drinkers (N/LDs) will be assessed by EEG while performing the Think/No-Think Alcohol (TNTA) task, a paradigm that evaluates alcohol-related MI (Pre-training EEG assessment). The TNTA is divided into three phases: 1) the Learning phase, 2) the Think/No-Think (TNT) phase and 3) the Memory-Test phase. During the learning phase, participants will be asked to associate and memorize 36 pairs of neutral objects + alcoholic/non-alcoholic pictures. Then, only the neutral objects will be presented, and participants will have to try to remember the picture (alcoholic/non-alcoholic image) that was associated with this neutral object and answer three questions about the beverage depicted, the orientation of the picture and the number of people present in it. After the learning phase, the Think/No -Think phase will comprehend two conditions: in the Think condition (depicted in the neutral images with a green frame),participants are presented with the object and they will be instructed to "think of the previously learned alcoholic/non-alcoholic picture and keep it in mind during the entire presentation of the object". In the No-Think condition (depicted by neutral images with a red frame) they will be asked "not to let the previously associated picture enter your consciousness". In the memory test phase, the 36 neutral images will be presented again, including the 12 neutral objects of the baseline condition that were not presented in the TNT phase. Participants will be asked to recall - answering the same three questions of the learning phase - the image (alcoholic/non-alcoholic) that was initially associated with the neutral object.
During this pre-training session, psychological (i.e., craving levels), behavioral (i.e., alcohol consumption, recall accuracy and MI performance), and neurofunctional (i.e., ERPs and FC) variables will be assessed.
In addition, this study aims to evaluate an alcohol-specific MI intervention protocol using cognitive training and tDCS while its effects on behavioral and EEG outcomes are assessed. For that, BDs will be randomly assigned to one of three training groups: combined intervention (active CT and active tDCS applied over the right DLPFC), cognitive intervention (active CT and sham tDCS), or control intervention (sham CT and sham tDCS). Training will occur in three consecutive days (i.e., Tuesday, Wednesday, and Thursday), in three sessions. MI will be re-assessed in BDs after the last training session through a post-training EEG assessment. N/LDs will only perform the pre-training EEG assessment. Alcohol use and craving will also be measured both 10-days and 3-months post-training in order to monitor short- and medium-term effects of the MI training in the alcohol craving and consumption levels. Furthermore, behavioral and EEG data will be collected during the performance of an alcohol cue reactivity (ACR) task before and after the MI training sessions, in order to evaluate potential attentional bias towards alcoholic stimuli. Overall, this intervention protocol aims to investigate whether this training is able 1) to enhance MI capabilities and to reduce alcohol attentional bias, and 2) to decrease craving and/or alcohol use -monitoring up to three months after protocol implementation- in trained BD participants.
