Rapid encoding of task regularities in the human hippocampus guides sensorimotor timing

Abstract

The brain encodes the statistical regularities of the environment in a task-specific yet flexible and generalizable format. Here, we seek to understand this process by converging two parallel lines of research, one centered on sensorimotor timing, and the other on cognitive mapping in the hippocampal system. By combining functional magnetic resonance imaging (fMRI) with a fast-paced time-to-contact (TTC) estimation task, we found that the hippocampus signaled behavioral feedback and sensorimotor learning in each trial along with reward-processing regions. Critically, these hippocampal learning signals generalized across tested intervals and accounted for the trial-wise regression-to-the-mean biases in TTC estimation. This suggests that the capacity of the hippocampus to generalize supports the rapid encoding of temporal context even on short time scales in a behavior-dependent manner. Our results emphasize the central role of the hippocampus in statistical learning, positioning it at the core of a brain-wide network balancing task specificity vs. generalization for flexible behavior.