Neuroscientists have developed the first comprehensive brain-wide map of decision-making in mice. This collaborative effort involved 22 laboratories and monitored over 620,000 neurons across nearly 280 brain regions. The research revealed that decision-making processes are distributed far more widely than previously understood. Key cognitive centers were implicated, as expected, but surprisingly, regions involved in movement also played a significant role. The study used a simple task where mice had to identify and move a striped circle on a screen to earn a reward. This task allowed researchers to observe how mice made quick decisions, sometimes relying on past experiences when the visual cue was faint. Brain activity was recorded using high-density electrodes, enabling simultaneous monitoring of numerous neurons across multiple brain areas. Each participating lab focused on mapping activity within specific regions of the mouse brain. The aggregated data from 139 mice and 12 labs provides an unprecedented overview of neural activity during decision-making. These groundbreaking findings, published in the journal Nature, redefine our understanding of how the brain makes choices.