The method is for training a working memory of a user. A maximum ability of a user is established. A first sequence of stimuli of a first trial is displayed to the user. The user is requested to remember the first sequence of stimuli. A delay of a predetermined time is established during which the first sequence of stimuli is not visible to the user. The user is enabled to enter an answer sequence after an expiration of the delay in response to the request to remember the first sequence of stimuli displayed prior to the delay. A first difficulty level of the first stimulus presentation sequence is determined. The first difficulty level is compared to the maximum ability of the user to develop a difficulty ratio. The difficulty ratio is presented to the user.