Systems and methods are disclosed for selectively reinforcing or weakening memory associations. At least one current generator provides an electrical current including a plurality of oscillating pulses with at least one predetermined frequency. A user interface includes at least one output device for delivering a sensory stimulus to a user and at least one user input device for registering a response to the stimulus. At least one processor determines from the response, based on at least one predetermined standard, whether an underlying memory association is desired or undesired and respectively sets the at least one predetermined frequency to be a beta or theta frequency. Consequently, the electrical current is generated and administered, via at least one electrode pair, thereby stimulating at least one specific portion of the user's brain so as to reinforce or weaken the underlying memory association.