Effect of striatal dopamine on Pavlovian bias. A large [18F]-DOPA PET study

Interaction between Pavlovian and instrumental control systems is key for adaptive motivated behavior, but also plays an important role in various neuropsychiatric disorders, including depression, addiction and anxiety. Here, we employed [18F]-DOPA positron emission tomography (PET) in healthy participants (N=100) to assess whether dopamine synthesis capacity, specifically in the ventral striatum, accounts for individual variation in Pavlovian-to-instrumental transfer (PIT). Surprisingly, this was not the case. Rather, the relationship of ventral striatal dopamine synthesis capacity with PIT depended on working memory capacity. Ventral striatal dopamine boosted the effects of Pavlovian cues on instrumental responding to a greater degree in participants with higher working memory capacity. While caution was emphasized when interpreting, these results chime with prior findings demonstrating that dopaminergic drugs boost Pavlovian biases to a greater degree in participants with greater working memory capacity and highlight the importance of interactions between striatal dopamine and working memory capacity.