The words ‘cognitive’ and ‘biology’ are also used together as the name of a category. The category of cognitive biology has no fixed content but, rather, the content varies with the user. If the content can only be recruited from cognitive science, then cognitive biology would seem limited to a selection of items in the main set of sciences included by the interdisciplinary concept—cognitive psychology, artificial intelligence, linguistics, philosophy, neuroscience, and cognitive anthropology.[39] These six separate sciences were allied “to bridge the gap between brain and mind” with an interdisciplinary approach in the mid-1970s.[40] Participating scientists were concerned only with human cognition.