Event:

Deciding when to act in the absence of external cues is essential for exploration, learning, and survival. Yet, the neural mechanisms underlying such decisions remain controversial, with current views favoring either deterministic or stochastic underpinnings. We simultaneously recorded from large neuronal populations across cortical, thalamic, pallidal, and cerebellar regions as mice self-initiated voluntary actions. We found that action onset timing is predictable seconds in advance, reflecting a prominent brain-wide deterministic drive. Computational modeling further revealed that this drive acts in concert with within-trial noise to time self-initiated actions. This synergy is observed brain-wide, suggesting a distributed decision-making process rather than a hierarchical, modular one.
Building upon these results, my proposed research program aims to uncover the canonical mechanisms of self-generated decisions across spatiotemporal scales. First, moving beyond correlational observations, I will present a closed-loop system for real-time optogenetic perturbation to causally dissect the decision process, focusing on the basal forebrain cholinergic system. Second, extending our approach to the spatial domain, we will then investigate the neural dynamics governing self-generated spatial choices. Finally, I will highlight how contrasting self-initiated and cue-guided actions through a behavioral paradigm I developed could offer a new entry point to mechanistically understand an intriguing feature of Parkinson’s disease: paradoxical akinesia. Ultimately, revealing the neural mechanisms of self-generated spatiotemporal decisions will shed light on the classic exploration-exploitation dilemma underlying agency: how subjects transition between exploratory unpredictability and optimal exploitation.