TMTTrail Making Test

The Trail Making Test, or TMT, is a test of drawing a path. Circles with numbers are scattered over a sheet, and you have to join them with one line in order as fast as you can: 1, 2, 3… In the second part letters are added to the numbers, and you have to alternate them: 1 — A — 2 — B — 3 — C…

It is one of the best-known tests in neuropsychology. It has been given for more than 70 years, because in a few minutes it shows how a person searches with their eyes, how fast they work and how they switch between two tasks.

On BB Gym, TMT is a trainer with three levels: 15, 25 and 35 circles. Each part starts with a short warm-up, and the result shows a score and a skill profile.

Where the test comes from

The forerunner of the TMT, a divided-attention test called Partington's Pathways Test, was described in 1938. During the Second World War the US Army needed quick ways to assess recruits, and in 1944 a modified version of the test was included in the Army Individual Test Battery.

The test was created at public expense, so it became public domain and spread around the world. That is probably why the TMT is so popular: any psychologist can use it without a licence.

Ralph Reitan and neuropsychology

The test owes its fame to the American neuropsychologist Ralph Reitan. In the 1950s he showed that people with brain damage complete the TMT noticeably more slowly, and he included it in the famous Halstead–Reitan test battery.

The test turned out to be sensitive because it engages several processes at once: visual search, hand speed, keeping a sequence in memory and switching. A weak link anywhere slows down the whole trail.

Parts A and B

Part A has 25 circles with the numbers 1 to 25. It mainly shows the speed of visual search and movement. Part B also has 25 circles, but with the numbers 1 to 13 and the letters A to L, which have to alternate. On top of the search comes switching between two sequences and remembering where you are in each of them.

In the classic procedure the examiner points out a mistake at once, the person goes back to the last correct circle and carries on, and the stopwatch keeps running. So mistakes are counted through time.

Besides the time of each part, specialists look at the difference B − A and the ratio B / A. They show how much the switching itself costs, regardless of a person's overall speed.

Relatives and variants

Letters tie the test to the alphabet, so versions without them appeared. In the Color Trails Test the numbers alternate by the colour of the circles, and it can be given to people who do not know the Latin alphabet.

A close relative of the TMT is the red-and-black Schulte–Gorbov table. There, too, two sequences have to alternate, but the numbers are found and tapped rather than joined with a line. Schulte tables are on BB Gym as well.

What the TMT trains

Part A loads processing speed and attention: quickly finding the right number among others without getting distracted. Part B adds cognitive flexibility (switching between numbers and letters) and working memory (keeping in mind which number and which letter come next).

Results improve noticeably within a few attempts, as people get used to the task. But to be honest, there is still little evidence that exercises like the TMT improve attention in everyday life. A large 2016 review of brain-training research found that people mostly get better at the very tasks they practise.

So the TMT is best seen as a short warm-up for attention and switching, and as a way to keep an eye on your own pace.

How to play and what to watch for

While drawing towards one circle, look for the next one. That way your hand and your eyes work at the same time.

In part B, say the pair to yourself: “3 — C, 4 — D”. That makes it harder to lose the alternation.

Don't draw at random. A mistake sends you back while the clock keeps running, so a short pause usually pays off.

Compare yourself with yourself. Times depend a lot on screen size, your hand and fatigue, so the trend of your results matters more than a single attempt.

Screen and paper: about norms

The paper TMT has published norms by age and education. On a screen everything is different: another board size, a finger instead of a pencil, a different layout of circles. So results on BB Gym cannot be compared directly with paper norms. Compare them only with your own attempts.

Results on BB Gym are not a medical diagnosis or a neuropsychological assessment. If you are worried about your memory, attention or speed of thinking, see a specialist.

Sources

1. Bowie C. R., Harvey P. D. (2006). Administration and interpretation of the Trail Making Test. Nature Protocols, 1(5), 2277–2281
2. Reitan R. M. (1958). Validity of the Trail Making Test as an indicator of organic brain damage. Perceptual and Motor Skills, 8(3), 271–276
3. Tombaugh T. N. (2004). Trail Making Test A and B: normative data stratified by age and education. Archives of Clinical Neuropsychology, 19(2), 203–214
4. Simons D. J. et al. (2016). Do "brain-training" programs work? Psychological Science in the Public Interest, 17(3), 103–186
5. Trail Making Test — Wikipedia