Reward learning and attention in risky alcohol use: Absence of Pavlovian influences but altered response bias in high-risk drinkers.

Reward learning can contribute to addictive behaviors by shaping attention and action selection. While reward-associated stimuli are known to capture attention, it remains unclear whether such learning can also guide behavior without stimulus-outcome contingency awareness. This study examined whether implicitly learned reward associations influence both attention and action selection, and how these effects relate to risky alcohol use. Eighty university students (40 low-risk and 40 high-risk drinkers) completed a Pavlovian-to-instrumental transfer task combined with an emotional attentional blink paradigm. During learning, conditioned stimuli and responses were probabilistically paired with monetary rewards. Awareness of stimulus-outcome contingencies was assessed at the individual level, using the Bayesian Awareness Categorization Technique. Reward-related influences on attention and response selection were then tested in a transfer phase. We observe no evidence of Pavlovian-to-instrumental transfer in either participants aware or unaware of reward contingencies. Similarly, reward associations did not modulate attention. The absence of effects in both aware and unaware participants makes it difficult to determine whether Pavlovian influences on attention and behavior are truly absent or simply not detectable under the current task conditions. However, exploratory analyses show that high-risk drinkers present greater preference for high-probability, low-value responses in the transfer phase. The observed preference for high-probability rewards in high-risk drinkers may reflect altered reward sensitivity. Together, these findings underscore the importance of evaluating reward-driven attentional and behavioral biases under well-controlled conditions and highlight the value of publishing null results to refine theoretical models of Pavlovian influences in addiction.