Brain-wide population activity during reaching integrates action-mediated goal expectation

Large scale recordings have revealed that neurons encoding motor and non-motor variables are highly distributed across the brain. While these neurons generate population level dynamics during spontaneous behavior, it remains unclear how these latent subspaces relate to the simultaneous motor and cognitive demands during ongoing goal-directed behavior. Here, we show that continuously anticipated action outcome, in addition to movement, drives ubiquitous latent dynamics during goal-directed movements. We used multiple Neuropixels probes to simultaneously record spiking activity from cortical and subcortical regions during a reaching task in head-fixed mice. Task-related population dynamics covaried within a common latent subspace across regions and was conserved across recording days and animals. These latent dynamics preceded movement onset and were modulated by reach distance and reward availability. Furthermore, their temporal progression continuously scaled with the timing of reward consumption and their activity decreased afterwards, despite ongoing stereotypical re-reaches. Our findings thus provide evidence for a brain-wide latent subspace for continuous representation of action-mediated proximity to goal, which could provide the basis for ubiquitous temporal difference learning based on predicted action outcome.