To learn or to gain: neural signatures of exploration in human decision-making.

Individuals not only take actions to obtain immediate rewards but also to gain more information to guide future choices. An ideal exploration-exploitation balance is crucial for maximizing reward over the long run. However, the neural signatures of exploration in humans remain unclear. Using quantitative meta-analyses of functional magnetic resonance imaging experiments on exploratory behaviors, we sought to identify the concordant activity pertaining to exploration over a range of experiments. The results revealed that exploration activates concordant brain activity associated with risk (e.g., dorsal medial prefrontal cortex and anterior insula), cognitive control (e.g., dorsolateral prefrontal cortex and inferior frontal gyrus), and motor processing (e.g., premotor cortex). These stereotaxic maps of exploration may indicate that exploration is highly linked to risk processing, but is also specifically associated with regions involved in executive control processes. Although this explanation should be treated as exploratory, these findings support theories positing an important role for the prefrontal-insular-motor cortical network in exploration.