Three manipulanda for the study of human infants operant play.
D005106:Exploratory Behavior; D005246:Feedback; D006309:Hearing; D006801:Humans; D007223:Infant; D009048:Motor Skills; D010988:Play and Playthings; D011589:Psychology, Experimental / Q000295:instrumentation*; D012054:Reinforcement, Psychology; D014785:Vision, Ocular