Sensorimotor encoding of epistemic value during goal-directed causal learning

Abstract

Understanding the neural and computational mechanisms underlying goal-directed causal learning is a central challenge in both cognitive neuroscience and artificial intelligence. This cognitive function depends on balancing reward maximization with information seeking. Although substantial progress has been made in characterizing the neural basis of reward-driven learning, it remains unclear whether and how intrinsic informational value is represented in the brain and propagated through cortico-cortical interactions. Here, we dissociate information-seeking from reward maximisation during goal-directed causal learning using a novel behavioural paradigm in which participants estimate action-outcome contingencies without extrinsic incentives. Bayesian computational modelling reveals that while random exploration dominates behaviour, expected information gain (EIG) explains a significant proportion of exploratory choices in a subset of sessions. Using magnetoencephalography combined with information-theoretic analyses of high-gamma activity, we show that EIG is encoded in the left sensorimotor cortex at the time of action execution, specifically in dorsal premotor and primary motor cortex, and broadcast to primary somatosensory cortex. These findings are consistent with Active Inference predictions that EIG constitutes a key computational drive for exploratory action selection. However, they challenge the view that epistemic valuation exclusively recruits prefrontal reward circuits, and instead they support an embodied account in which the premotor and sensorimotor system mediates the intrinsic valuation during first-personal interventional causal learning.