Cortical beta power reflects the influence of Pavlovian cues on human decision-making

Reward-predictive cues can affect decision-making by enhancing instrumental responses towards the same (Specific transfer) or similar (General transfer) rewards. The main theories on cue-guided decision-making consider Specific transfer as driven by the activation of previously learned instrumental actions induced by cues sharing the sensory-specific properties of the reward they are associated with. However, to date, such theoretical assumption has never been directly investigated at the neural level. We hypothesize that such reactivation occurs within the premotor system and could be mapped by lateralized beta (12-30 Hz) desynchronization, a widely used marker of action selection and decision-making policy. To test this hypothesis, 42 participants (22 females) performed a Pavlovian-to-Instrumental Transfer paradigm, while electroencephalographic (EEG) activity was recorded. We anticipated increased beta desynchronization during the transfer phase when cues promoting Specific transfer were presented, compared to cues predicting General transfer and neutral cues. The evidence collected confirmed our hypothesis, thus providing the first neural evidence in favor of the theorized reactivation of instrumental actions and corroborating the presence of two dissociable neural pathways underpinning Specific and General transfer.Significance statement Our study provides direct evidence that Pavlovian (reward-predictive) cues can influence decision-making through two independent and separable pathways: one is the ability of cues to convey sensory-motor information about the impending outcome and is mediated by the premotor system (specific transfer); the other is the ability of cues to indirectly influence performance by increasing motivational arousal and appears to be independent of premotor activity (general transfer). The present findings will have strong implications for the study of decision-making and associative learning.