Sign-tracking and alcohol consumption: A new translational, computerized task assessing individual differences in humans.

Individuals differ in their tendency to assign motivational value to reward-predictive cues. In animal studies, this tendency has been conceptualized as “sign-tracking” behavior and led to the discrimination of two phenotypes. “Sign-trackers” (STs), who approach and interact with the reward-predictive cue, and “goal-trackers” (GTs), who are preferentially attracted by the reward-delivery location. Sometimes, a third intermediate profile (INTs) is also included. These phenotypes have been linked to addiction vulnerability. Recently, there has been increasing interest in testing this model in humans. However, the literature in this area remains inconsistent, without agreement on the optimal experimental paradigm to discriminate these phenotypes.
In the present study, ninety-seven adults completed three computerized tasks, including a
conditioning task. Based on their visual attention measured through eye-tracking, they were divided into three groups (ST/INT/GT). The classification was performed using two
independent procedures: a classical response bias score and a latent profile analysis (LPA). Alcohol consumption and personality variables were assessed through questionnaires.
The three profiles significantly differed in their level of alcohol consumption, with STs
showing a heavier consumption than GTs. This difference is observed both when using the
response bias score and when using LPA-based profiles, with a medium sized effect. However, no significant effect was found regarding other alcohol-related or personality variables.
The experimental task successfully identified STs, GTs and INTs in humans. These profiles
had divergent levels of alcohol consumption, supporting the idea that sign-tracking could be related to alcohol consumption in humans (as a vulnerability factor or a consequence of consumption).