1. A method for improving cognitive function within a human by means of an implantable signal generator and a lead having a proximal end coupled to the signal generator and a distal portion having at least one electrode, the method comprising: (A) implanting at least one electrode so that the stimulation portion lies at least in communication with tissue elements wherein the tissue elements are selected from the group consisting of tissue within a Papez circuit of a human brain, tissue within a downstream target of the Papez circuit, and tissue within an upstream input to the Papez circuit; (B) coupling the proximal end of the implanted electrode to the signal generator; and (C) improving cognitive function by the human by operating the signal generator to deliver stimulation to the tissue elements of the Papez circuit.