article human 456 adult 276 female 275 male 264 Humans 198 controlled study 188 human experiment 188 major clinical study 124 Female 95 Male 89 clinical article 81 questionnaire 72 Adult 64 child 57 adolescent 54 education 54 cross-sectional study 53 interview 51 perception 45 young adult 44 learning 42 Adolescent 41 nonhuman 40 qualitative research 40 aged 37 quantitative analysis 37 Middle Aged 36 Young Adult 36 psychology 36