ag ▁ref lex ▁in ▁stroke ▁patients ▁was ▁a ▁good ▁predict or ▁for ▁d ys ph ag ia ▁( diff icult y ▁with ▁sw allow ing ) ▁or ▁l ary n ge al ▁asp iration ▁( fo od ▁or ▁drink ▁entering ▁the ▁l ary nx ), ▁and ▁was ▁therefore ▁commonly ▁checked ▁for . ▁However , ▁in ▁one ▁study , ▁ 3 7 % ▁of ▁health y ▁people ▁did ▁not ▁have ▁a ▁g ag ▁ref lex , ▁yet ▁all ▁subjects ▁except ▁for ▁one ▁still ▁retained ▁an ▁int act ▁ph ary n ge al ▁sens ation . ▁These ▁results ▁suggest ▁that ▁the ▁mus cles ▁that ▁control ▁the ▁g ag ▁ref lex ▁remain ▁independent ▁of ▁those ▁that ▁control ▁normal ▁sw allow ing . ▁Since ▁this ▁ref lex ▁is ▁commonly ▁not ▁found ▁in ▁health y ▁people , ▁its ▁predict ive ▁value ▁in ▁determ ining ▁the ▁risk ▁for ▁sw allow ing ▁dis orders ▁is ▁sever ely ▁limited . ▁Ph ary n ge al ▁sens ation , ▁on ▁the ▁other ▁hand , ▁as ▁seen ▁by ▁this ▁study , ▁is ▁rarely ▁absent , ▁and ▁could ▁prove ▁better ▁at ▁predict ing ▁future ▁problems ▁with ▁sw allow ing . ▁ ▁Ref lex ive ▁ph ary n ge al ▁sw allow ▁Cl os ely ▁related ▁to ▁the ▁g ag ▁ref lex , ▁in ▁which ▁food ▁or ▁other ▁foreign ▁subst ances ▁are ▁forced ▁back ▁out ▁of ▁the ▁ph ary nx , ▁sw allow ing ▁generally ▁push es ▁food ▁through ▁the ▁dig est ive ▁system ▁into ▁the ▁st om ach . ▁This ▁ref lex ▁in ▁particular