Curiosity-Motivated Incidental Learning With And Without Incentives: Early Consolidation And Midbrain-Hippocampal Resting-State Functional Connectivity

Human memory is selective and not all experiences are remembered. Both monetary rewards/incentives and curiosity have been found to motivate and facilitate learning by dopaminergic midbrain projections to the hippocampus during encoding. In this study, we examined potential brain mechanisms during early consolidation period that jointly or independently contribute to these facilitating effects. Participants (N = 50) watched 36 videos of magic tricks and rated their “subjective feelings of curiosity” while the availability of extrinsic incentives was manipulated between groups. Functional magnetic resonance imaging (fMRI) data were acquired before, during, and after learning, and memory for magic tricks was assessed one week after. Our analysis focused on the change in resting-state functional connectivity (RSFC) between the dopaminergic midbrain and the anterior hippocampus, a dopaminergic consolidation mechanism previously reported in the context of extrinsically motivated learning. Changes in RSFC were correlated with behavioural measures of learning, i.e., the total number of items encoded and the curiosity-driven memory benefit. We found that brain-behaviour correlations differed depending on the availability of extrinsic incentives. More specifically, the correlation between the total number of items encoded and RSFC change was significantly different in the incentivised compared to the control group. The curiosity-driven memory benefit, however, did not correlate with changes in RSFC in either of the groups. In sum, this suggests that curiosity-motivated learning might be supported by different consolidation mechanisms compared to extrinsically motivated learning and that extrinsic incentives influence consolidation mechanisms supporting learning. Key points A new curiosity-motivated incidental encoding paradigm was used to investigate how dopaminergic consolidation mechanisms support learning and whether this is further influenced by the availability of monetary incentives. Changes in resting-state functional connectivity between the dopaminergic midbrain and the anterior hippocampus, a dopaminergic consolidation mechanism, predicted learning outcomes significantly differently if monetary incentives were available. These results might suggest that learning motivated by curiosity might rely on different neural mechanisms during early consolidation than learning motivated by monetary incentives.