The Formation of Hierarchical Decisions in the Visual Cortex

Intelligence relies on our ability to find appropriate sequences of decisions in complex problem spaces. The efficiency of a problem solver depends on the speed of its individual decisions and the number of decisions it can explore in parallel. It remains unknown whether the primate brain can consider multiple decisions at the same time. We therefore trained monkeys to navigate through a decision tree with stochastic sensory evidence at multiple branching points and recorded neuronal activity in visual cortical areas V1 and V4. We found a first phase of decision making in which neuronal activity increased in parallel along multiple branches of the decision tree. This was followed by an integration phase where the optimal overall strategy crystallized as the result of interactions between local decisions. The results reveal how sensory evidence is integrated efficiently for hierarchical decisions and contribute to our understanding of the brain mechanisms that implement complex mental programs. •Monkeys can integrate information in parallel for multiple decisions•During a later integration phase, different decisions influence each other•Hierarchical decisions influence neurons in V1 and V4 of the visual cortex•The interaction between decisions maximizes reward income Lorteije et al. found behavioral and physiological evidence that the primate brain can process multiple decisions in parallel. Besides decreasing overall processing time, parallel decisions can influence each other and, thereby, maximize the reward income.