Broad brain networks support curiosity-motivated incidental learning of naturalistic dynamic stimuli with and without...

Curiosity-the intrinsic desire to know-is a concept central to thehuman mind and knowledge acquisition. Experimental studies oninformation-seeking have found that curiosity facilitates memory encoding andexhibits similar rewarding properties as extrinsic rewards/incentives, byeliciting a dopaminergic response in the reward network. However, it is notclear whether these findings hold with more naturalistic dynamic stimuli and howthe joint effect of curiosity and extrinsic incentive manifests in learning andneural activation patterns. Herein, we presented participants with videos ofmagic tricks across two behavioural (N₁= 77, N₂= 78) and one fMRI study (N = 50) and asked them to ratesubjective feelings of curiosity, while also performing a judgement task thatwas incentivised for the half of participants. Incidental memory for the magictrick was tested a week later. The integrated results showed that both curiosityand availability of extrinsic incentives enhanced encoding but did not interactwith each other. However, curiosity influenced only high-confidence recognitionmemory, whereas extrinsic incentives affected memory regardless of confidence,suggesting the involvement of different encoding mechanisms. Analysis of thefMRI data using the intersubject synchronisation framework showed that, whilethe effects of curiosity on memory were located in the hippocampus anddopaminergic brain areas, neither the effects of curiosity nor incentivesthemselves were found in the often-implicated reward network. Instead, they wereassociated with cortical areas involved in processing uncertainly and attention.These results challenge a traditional focus on reward networks in curiosity andhighlight the involvement of broader brain networks.