Animals are used in many other kinds of behavioral studies. Animal experiments have produced valuable information on the effects of visual stimulation on brain development, biofeedback techniques, memory loss, programmed instruction in education, aggression, stress, and recovery after strokes or brain injury. We would know much less about these aspects of human life without animal research, and continued animal research is essential if new ways are to be found to cope with behavioral problems. Nonhuman primates are particularly valuable in behavioral research, as they are in a wide range of biomedical research, because of their many similarities to humans.¹⁹