[DEF] A STUDY is a research investigation (therefore a CONCEPTUAL ACTION) involving human subjects that is designed to answer specific questions about brain functions or dysfunctions. [SA] STUDIES are divided into STUDIES WITH EXAMINATION and STUDIES WITHOUT EXAMINATION according to whether the STUDY includes at least one EXAMINATION. [SA] STUDIES are divided into MONO-CENTRE STUDIES and MULTI-CENTRE STUDIES according to whether the STUDY is performed by exactly one, or at least two, CENTRE(S). [SA] STUDIES are divided into FINISHED STUDIES and STUDIES IN PROGRESS according to whether they are finished or not.