Abstract: The present invention provides a system for selecting appropriate brain-training content for each user. The selection system includes: a storage unit for storing detection values obtained by detecting blood flow rates in the head of a user, identifiers for predetermined test content to be performed by the user at the time of the detection of the detection values, and an identifier for the user in association with one another; a calculation unit for calculating, on the basis of the detection values stored in the storage unit, brain-activity values indicating the degree of brain-activity of the user when the predetermined test content is performed by the user; and a selection unit for selecting, on the basis of the brain-activity values calculated by the calculation unit during performance of the predetermined test content, brain-training content to be performed by the user.