The International Brain Laboratory published the first full brain-wide single-neuron activity map during decision-making behavior in mice, recording over 500,000 neurons across 279 brain areas and 12 labs. This study, published in Nature, shows decision-related signals distributed broadly across cortical and subcortical regions rather than localized. It involved complex behavioral tasks probing sensory evidence and prior expectations. These findings challenge classical localized models and offer unprecedented resolution into the coordinated neural mechanisms that generate complex behaviors.