Abstract: A time perception test instrument for performing a self-administered time perception test by a test subject, including a plurality of individual flashing lights arranged in an array and with all of the lights except one flashing intermittently at regular intervals and with one of the lights flashing at irregular intervals and with a plurality of test buttons corresponding in number to the flashing lights and with one test button associated with each flashing light to allow the test subject to select any individual one of the flashing lights judged by the test subject to be the light flashing at irregular intervals and with a random selector for randomly selecting one of the plurality of lights to flash at irregular intervals after each selection by the test subject. A coincidence detector produces a coincidence signal when the test subject selects a particular one of the flashing lights which is flashing at irregular intervals.