Trail Making Test

The trail making task is one of the most used tasks in psychology research. Part A, numbers in order, is mostly visual search and speed of movement. Part B adds switching between two sequences, numbers and letters. A study that looked at what drives each part found that the extra time on part B mainly reflects task switching, while part A reflects visual search and motor speed [1]. That is why the difference between the two parts (B minus A) is often looked at on its own.

• Part A: 20 circles numbered 1 upwards. Tap them in order as fast as you can.
• Part B: numbers and letters. Switch between them in order: 1, A, 2, B, 3, C and so on, up to 10 and J.
• A short untimed sample comes before each part (you can skip them). The clock for each part starts when its circles appear. A wrong tap flashes red and is counted; carry on from the last right circle.
• Every run has a new layout. On a phone the board is turned on its side so it fills the screen. Leaving the page ends the run, because the test is timed.

• Part A and part B times: lower is faster.
• B minus A: how much longer part B took. This takes out most of your tapping speed and leaves the cost of switching.

The original test is done with a pencil on paper, and the published reference values come from that version. Tapping on a screen changes the movement part of the task, and screen size changes how far you move, so these times can't be compared with paper results or used to judge anything about health. We show no norms. Compare with your own runs on the same device. For another test of switching off a habit, try the Stroop test.