Neural subspace reorganization reflects value-based decision making

Value-based decision making requires maintaining and comparing multiple option representations associated with different values. Then, the chosen option must be communicated to downstream regions to drive behavior. The neural circuits involved in value-based decisions are increasingly well understood, but less understood is how decisions shape option representations. We recorded from lateral prefrontal cortex (LPFC), a central hub for transforming options into actions, while non-human primates (NHPs) held two sequentially presented option-value pairs (spatial targets and abstract reward cues) in working memory, then chose the option with the higher value. This revealed how decisions dynamically reorganize option representations in LPFC. We found that, once decisions could be made, representations of chosen and unchosen options rotated into orthogonal subspaces and the chosen option representation was expanded. Before decisions, the first- and second-presented options were maintained separately. After decisions, the chosen option was rotated into a subspace with a consistent representation of the prescribed action, regardless of its presentation order. This suggests a mechanism for value-based decisions where the decision drives a neural subspace reorganization that facilitates selective and efficient readout of the chosen action.