THIS STUDY WAS DESIGNED TO INVESTIGATE THE EFFECT OF INCENTIVE MOTIVATIONAL CONDITIONS ON SELECTED ASPECTS OF PERCEPTION AND CONCEPT TRANSFER PERFORMANCE OF SLOW LEARNING, AVERAGE, AND BRIGHT CHILDREN. THE TOTAL POPULATION OF THE FOURTH-GRADE CHILDREN IN A PUBLIC ELEMENTARY SCHOOL SYSTEM WAS ADMINISTERED THE TEST OF EDUCATIONAL ABILITY. CHILDREN WHO SCORED WITHIN THE THREE PRESELECTED RANGES OF INTELLIGENCE LEVEL WERE ADMINISTERED THE WECHSLER INTELLIGENCE SCALE FOR CHILDREN. THE SCORES ON THE TWO TESTS WERE USED TO SELECT THREE GROUPS OF SUBJECTS REPRESENTING LOW, MEDIUM, AND HIGH INTELLIGENCE GROUPS. EACH OF THESE GROUPS WAS FURTHER SUBDIVIDED BY RANDOMLY ASSIGNING ONE-HALF OF THE SUBJECTS TO THE TWO PERCEPTUAL STUDIES AND THE REMAINING SUBJECTS TO THE CONCEPT TRANSFER EXPERIMENTS. THE RESULTS OF THE EXPERIMENTS LENT GENERAL SUPPORT TO THE HYPOTHESIS THAT INCENTIVE MOTIVATION REDUCES THE RANGE AND VARIETY OF STIMULI TO WHICH AN INDIVIDUAL RESPONDS. FURTHER, THE FACILITATIVE EFFECTS OF INCENTIVES OF THE PERCEPTUAL AND CONCEPT TRANSFER TASKS SUGGESTED A "NARROWING OF ATTENTION" UNDER THESE CONDITIONS SUCH THAT IN INCREASED PROPORTION OF RELEVANT TASK CUES ARE ASSIMILATED. (JL)