The invention provides for a medical instrument (100, 400, 500, 600) comprising an activity measurement system (106) configured for measuring brain activity data (138) from a subject (102). The medical instrument further comprises a stimulus presentation system (108) configured for providing sensory stimulus to the subject. The medical instrument further comprises a memory (130) for storing machine executable instructions (132) and for storing a stimulus reinforcer database (134). The stimulus reinforcer database comprises entries. Each entry comprises commands configured for controlling the stimulus presentation system to provide the sensory stimulus to the subject. The medical instrument further comprises a processor (120) for controlling the medical instrument. Execution of the machine executable instructions causes the processor to: control (200) the stimulus presentation system with a set of entries (136) selected from the stimulus reinforcer database to repeatedly provide sensory stimulus to the subject； control (202) the activity measurement system for performing the measurement of the brain activity data during each sensor stimulus； select (204) a chosen entry (140) from the set of entries using the brain activity data； and store (206) the chosen entry in the memory.
