Exploratory behavior in Down's syndrome and normal infants.
D000161:Acoustic Stimulation; D004314:Down Syndrome / Q000523:psychology*; D005106:Exploratory Behavior; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009055:Mouth; D010988:Play and Playthings; D013997:Time Factors; D014110:Touch; D014796:Visual Perception