Male article human male 99 Humans 98 female 93 Female 92 adult 72 human experiment 59 Adult 53 controlled study 51 physiology 41 Young Adult 39 young adult 39 child 33 Middle Aged 29 major clinical study 29 middle aged 29 Child 24 psychology 23 Adolescent 22 adolescent 22 learning 19 clinical article 18 Child, Preschool 16 preschool child 16 questionnaire 14 Surveys and Questionnaires 13 language 13 Learning 12