Stroop and task switching

Reading is so automatic that you can't switch it off. Ask someone to name the ink of the word RED printed in blue and they slow down, an effect Stroop described in 1935 and one of the most studied in psychology (MacLeod, 1991). The gap between clashing and matching words is your interference cost: the price of holding back a habit.

Task switching adds a second price. Changing rules from one trial to the next is slower than repeating one, even when you know the change is coming (Monsell, 2003). That gap is your switch cost. Both measure how your attention works. They are not scores to beat at any price: a fast round full of mistakes tells you nothing.

D red · F yellow · J green · K blue · tap the buttons on a phone