human 457 infant 404 Humans 399 female 363 Infant 311 male 298 Female 277 child 261 Male 220 preschool child 212 Child, Preschool 196 Child 190 adult 171 newborn 167 Article 164 Infant, Newborn 140 controlled study 138 adolescent 133 Adult 117 Adolescent 108 major clinical study 106 article 99 young adult 76 Young Adult 68 procedures 65 psychology 64 human experiment 63 physiology 59 clinical article 52 retrospective study 52