In this study, the participants had extensive practice with two tasks, both of which were choice reaction time tasks. For Task 1, participants were briefly shown a digit on a display, the digit being either a "1" or a "2". If the presented digit was a "1", participants were to respond by pressing a key with the little finger of their left hand, whereas for a "2" the key was pressed with the ring finger. Task 2 was also a two-choice reaction with button-press responses. Participants heard either a low tone (600 Hz) or a high tone (3000 Hz) and responded with a right-handed button press, either with the middle and index fingers, respectively. Twelve different SOAs were used, ranging form 90 to 1150 ms.

ACT-R/PM Model