This paper reviews the early history of brain localisation of function. It analyses the doctrines professed in ancient times by philosophers and physicians, who believed that brain functions were carried out in the cerebral ventricles by the psychic pneuma, or animal spirit, a sort of special and light substance endowed with the power to perform sensory, motor and mental activities. This article by Tullio?Manzoni examines the early history of brain localization of function. The author discusses how, in ancient and medieval times, mental and physical functions of the brain were believed to occur via the cerebral ventricles, where a special substance (?animal spirits?, psychic pneuma) circulated. The work then traces the development of the so-called ?three?cell theory?, in which each of the three ventricles was thought to house specific mental functions, such as imagination, cognition, and memory ? a theory that persisted well into the Renaissance. Manzoni further explains how this ventricular theory was gradually replaced by modern ideas about localized brain structures and functions, and how the legacy of thinking in terms of animal spirits and ventricles continued to influence neuroscience for a long time. Tullio?Manzoni is an Italian physiologist and scholar specialized in the history of neuroscience and brain anatomy. He has authored several works on ancient and medieval conceptions of the brain, including the aforementioned 1998 article. His research interests include the evolutionary and philosophical aspects of nervous system and brain functions.