title: The ontogenesis of smiling and laughter: a perspective on the organization of development in infancy.
mesh_terms: D000223:Adaptation, Psychological; D001288:Attention; D001307:Auditory Perception; D002540:Cerebral Cortex / Q000502:physiology; D002657:Child Development; D003071:Cognition; D003210:Concept Formation; D004576:Electromyography; D005149:Facial Expression / Q000502:physiology; D006339:Heart Rate; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007845:Laughter / Q000502:physiology; D012895:Sleep, REM; D012904:Smiling / Q000502:physiology; D012919:Social Behavior; D013315:Stress, Psychological; D014796:Visual Perception