Gyroscope Benchmarks / Mind
Trail Making Test: how fast can you switch?
This test measures visual scanning speed first, then the extra cost of switching between two ordered sets.
Why it matters
Switching is the skill of holding two rules at once and moving between them without losing your place. You use it every hour of a normal day: cooking while someone asks you a question, driving while the directions talk, reading a message and finding your way back to the paragraph you were in. The Trail Making Test strips that down to numbers and letters, which is why neuropsychologists have relied on it for decades. Part A shows how fast you scan and tap. Part B shows what it costs you to alternate.
That cost rises with age, and it rises faster than plain scanning speed does. In Tombaugh's sample, the Part A mean climbs by about nine seconds between the 18–24 and 45–54 groups, while Part B climbs by about fifteen. The gap between the two parts widens along the way. A slow Part B with a normal Part A is the pattern worth watching, because it points at switching itself rather than at your hand.
You are a poor judge of this from the inside. In one study, two weeks of six-hour nights produced deficits equal to two full nights without sleep, while the people involved rated themselves only mildly impaired. A ratio measured the same way each month catches what your own sense of sharpness misses, and it tells you whether a change in sleep, training, or stress actually reached your thinking.
Van Dongen et al., Sleep, 2003
What this test measures
Number Trail is inspired by the classic Trail Making Test. Part one asks you to connect scattered numbers in order, combining visual search, motor speed, and sequencing. Part two alternates between numbers and letters, such as 1, A, 2, B. That added rule makes you switch mental sets while continuing to scan.
Completion time matters for both parts. The extra time in Part B can be read as B minus A, but the B-to-A ratio better separates switching cost from a generally fast or slow hand. A ratio is still task-specific, especially on a touchscreen.
Tombaugh tested 911 adults and found that age explained 34 percent of the variance in Part A and 38 percent in Part B. Education mattered more for Part B after age 54, while gender accounted for less than 1 percent.
Do the test right now
- 1Open Number Trail in Gyroscope and place the phone on a stable surface. The full two-part test takes about 90 seconds.
- 2For Part A, tap the numbered bubbles in order as quickly and accurately as possible.
- 3For Part B, alternate numbers and letters: 1, A, 2, B, continuing the pattern without skipping.
- 4Keep the completion time for each part and calculate Part B divided by Part A. If you make an error, correct the sequence and continue, because the correction time belongs in the result.
Reference bands
These published means come from the paper-and-pencil test. The app has a different layout, path length, and input method, so use the values only as historical context.
| Age | Part A mean | Part B mean |
|---|---|---|
| 18–24 | 22.93 s | 48.97 s |
| 25–34 | 24.40 s | 50.68 s |
| 35–44 | 28.54 s | 58.46 s |
| 45–54 | 31.78 s | 63.76 s |
Tombaugh, Archives of Clinical Neuropsychology, 2004. Table 2 means.
For repeated phone runs, Gyroscope uses the ratio as the more portable signal. These are practical bands, not clinical cutoffs.
| Part B / Part A | Practical band |
|---|---|
| Under 2.0 | Flexible |
| 2.0–3.0 | Typical |
| Over 3.0 | High switching cost |
Tombaugh, Archives of Clinical Neuropsychology, 2004. Research context for Gyroscope's practical ratio bands.
What moves your score
Number Trail combines several processes, so a slow day can reflect scanning, tapping, or switching. A meta-analysis of short-term sleep deprivation found the largest effect in lapses of simple attention, Hedges's g -0.776, with meaningful effects also present in complex attention and working memory.
Lim and Dinges, Psychological Bulletin, 2010
- Sleep loss and fatigue can make scanning less steady.
- Practice teaches the alternating rule and the phone layout.
- Stress can increase corrections when you rush.
- Screen size and touch latency change absolute completion times.
How to improve
Your Part A time is mostly hand speed and eye speed, and it moves a little with practice. The ratio moves when you keep the alternating rule active without stalling, and that is a habit you can train.
- Say the sequence. Whisper it as you go, 1, A, 2, B. Speaking the rule keeps it in working memory, so your eyes are free for the search instead of reconstructing what comes next.
- Look two ahead. Find the next target before your finger lands on this one. The eyes lead and the hand follows, and the pause between taps is where most of the extra Part B time hides.
- Pair them up. Treat each number and its letter as one unit, 3 then C, 4 then D. You still alternate, but there are fewer moments where the rule has to be recalled from nothing.
- Fix mistakes the same way every time. Go back to the last correct tap and carry on. Guessing forward after a wrong tap costs more time than a clean correction, and it adds a second error more often than you would expect.
- Test rested. A short night slows switching before it slows anything else you can feel. Run the test on an ordinary morning, not the day after a late flight or a bad sleep, so your baseline is you at your usual.
- Move most days. Regular aerobic exercise supports executive function, and task switching is part of it. A brisk walk counts. Ask a doctor first if you have a heart condition.
Retest once a month, on the same phone, at the same time of day, with the same finger, after a normal night's sleep. Absolute times depend on the screen and the layout, so the ratio is the number to follow, and it only compares like with like when the protocol does not change between runs.
Track it
Log it in the app.
Download Gyroscope and run Number Trail in about a minute. See how you compare to your peers, to the studies, and to your own baseline over time.
Download the appGet Gyroscope One