Overview

• Researchers recorded activity from 621,733 neurons across 279 brain areas in 139 mice, covering roughly 95% of the brain, with 75,708 well-isolated neurons used for core analyses.
• Decision-related signals were distributed across many regions rather than localized to a single decision center, indicating a coordinated, brain-wide process.
• Prior expectations were encoded throughout the brain, including early sensory relays such as the thalamus, showing that expectations shape processing from the earliest stages.
• The International Brain Laboratory used shared protocols, reproducible pipelines, and 699 Neuropixels probes to assemble a standardized dataset across participating sites.
• All data, tools, and protocols are openly available, and the consortium reports that the resource is already being mined as it prepares to extend the approach to additional questions.