By indicating order of inputting by two rackets RK1 and RK2 in a task displaying area 178 displayed on a television monitor 100 and having a user memorize the order, and further by having the user perform input operation at indicated timing, it is possible to test extent of short term memory of the user based on whether or not the input operation is performed using the indicated racket in the indicated order. Since the input operation is performed by swinging the rackets RK1 and RK2, it is possible to test the short term memory of the user while moving a body.