A system is configured to provide sensory stimuli to a subject at a first intensity level, determine the effectiveness of the provided sensory stimuli, and incrementally increase the intensity level of the sensory stimuli based on the determined effectiveness. The effectiveness determination and the corresponding intensity increase are repeated one or more times during a given slow wave sleep episode. The system is configured to continue the effectiveness determinations and the corresponding intensity increases during the slow wave sleep episode until the intensity level reaches a maximum level, until an arousal level of the subject breaches an arousal level threshold, and/or until expiration of the period of slow wave sleep.