PROBLEM TO BE SOLVED: To prevent a cognitive function decline with higher efficiency.SOLUTION: A cognitive function decline prevention device includes: a heartbeat measuring part (101) for measuring a heartbeat of a subject a storage part (104) for storing a plurality of music and a plurality of test problems a task selection part (102) for selecting the music used for a first task in which the subject performs an exercise by adjusting it to a tempo of the music in accordance with the plurality of the music stored by the storage part (104) and selecting a test problem used for a second task in which the subject replies to the test problem from among the plurality of test problems stored by the storage part (104) and a presentation part (103) for presenting the test problem used for the second task while reproducing the music used for the first task.
