Sharda and Onyedikachi are participating in a psychology study. Sharda's task is to press a button as rapidly as possible whenever she sees a circle on the computer screen. Onyedikachi's task is to press a red button if he sees a circle and a green button if he sees a square, also as rapidly as possible. Sharda's study is measuring reaction time, and Onyedikachi's study is measuring reaction time