There is a relationship between the effect of P/T depletion on delay discounting task ICR RT and WM n-back task RT. a) There is significant positive correlation between the effect of P/T depletion on the RT in 2- and 3-back trials in the n-back task and RT during the W and DW trials of the delay discounting task (r = 0.74, p = 0.003). b) There is no significant relationship between the effect of P/T depletion on RT in 0-back trials and RT in the CON trials of the delay discounting task (r = −0.01, p = .98). CON, control trials; DW, don’t want trials; ICR, impulsive choice ratio; P/T[−], phenylalanine/tyrosine-depletion; RT, reaction time; W, want trials; WM, working memory.