A missed diagnosis carries real costs, because clinicians may prescribe medications that worsen the very problem they are trying to treat.

From diagnosing epilepsy to powering brain-computer interfaces, the EEG has shaped more than a century of neuroscience and clinical medicine. The central questions are what we are actually measuring and how we make sense of the signal.

György Buzsáki argued, with decades of evidence behind him, that brain rhythms are not passive reflections of "brain states" but functional organizing tools that help the brain coordinate large populations of neurons in time.