Bromantan (20 mg/kg, p.o.) and sydnocarb (10 mg/kg, p.o.) augment the efficacy of a 5-h operant activity in rats, the effect being achieved through different pathways. Sydnocarb increases the number of operant reactions and exhausts the sympathico adrenal system reserves. Bromantan favors the activity optimization by reducing the number of errors at a smaller number of operant reactions. Bromantan increases the tension of motivational component (electric pain irritation avoidance), whereas sydnocarb decreases this component of the operant behavior. None of the two drugs affects the degree of functional activation of the cardiovascular system.