In a first-of-its-kind neuroscience milestone, the International Brain Laboratory, a massive collaboration of 22 labs, has charted a complete, brain-wide map of how decisions form in mammals. Across 139 mice, they recorded the activity of over 600,000 neurons across 279 brain regions far exceeding the typical focus on individual brain areas.

Mice were trained in a deceptively simple visual task: manipulating a steering wheel to center a flickering circle on a screen to receive a sweet liquid reward. As the mice processed the visual cue, neural activity started in sensory areas and progressively spread across the brain, eventually engaging movement-related regions and culminating in a surge of activation upon obtaining the reward.

The study shatters long-held assumptions that decision-making is localized showing that cognitive choices ripple across both "thinking" and "doing" areas in a dynamic, distributed network. With data openly available, this comprehensive resource lays the foundation for deeper insights into normal cognition and its disruptions (e.g., in psychiatric or neurological disorders).