Development of the smiling response in early infancy.
D002547:Cerebral Palsy; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D004569:Electroencephalography; D004576:Electromyography; D005149:Facial Expression; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male