Transitions in dynamical regime and neural mode during perceptual decisions

Using deep-learning to track hundreds of neurons in rats making decisions, we found that brain activity shifts abruptly from a regime driven by sensory evidence to an autonomously driven regime where the decision is finalized. This sudden shift is marked by the neurally inferred time of commitment (nTc). Behavioral analysis shows that only the information received before nTc matters to the final choice, confirming this transition is the moment the animal makes up its mind.

Brain-wide coordination of decision formation and commitment

As decisions unfold, many brain areas show choice-related activity, but how they work together remains unclear. By recording thousands of neurons across up to twenty regions in rats performing an auditory decision-making task, we found that decision signals across the brain fluctuated together along a single shared dimension. These signals emerged first in frontal cortex and striatum before spreading widely. The moment when the animal made up its mind—marked by the neurally inferred time of commitment (nTc)—appeared first in motor cortex and coincided with a sharp transition in brain-wide activity. Together, these findings show that decisions arise from coordinated computations across the brain, driven by a core subnetwork.

An approach for long-term, multi-probe Neuropixels recordings in unrestrained rats

Neuropixels probes are powerful tools for recording brain activity. We developed a method to record for months in freely moving rats using multiple probes per animal and reusing probes across experiments. Hundreds of neurons could be recorded over months. Reused probes showed only minor noise increases that did not affect performance. This approach enables cost-effective, long-term, multi-region recordings in freely moving animals.