What research found
An Australian study (Williamson and Feyer, 2000, Occupational and Environmental Medicine) reported that after 17–19 hours without sleep, performance on some tests was equivalent to or worse than at a blood alcohol concentration of 0.05%, with response speed up to 50% slower on some tests. Longer without sleep, performance reached levels equal to 0.1%.
Source: Williamson AM, Feyer AM. Occup Environ Med 2000;57:649–655 (doi:10.1136/oem.57.10.649)
Two-week rules
- Same time: once a day at a fixed time, e.g. before work
- Same difficulty: stick to Normal (changing it breaks comparison)
- Same posture, same phone: seated, same finger
- One practice run, then one real run: Practice mode isn’t recorded
Log template
The app has no notes field, so keep a notebook or spreadsheet like this and match it to the date and time stamps in the app.
| Day | Sleep | Coffee | Time measured | Average (ms) | Feeling |
|---|---|---|---|---|---|
| Mon | 7 h | after test | 08:10 | OK | |
| Tue | 5 h | 1 cup before | 08:05 | Tired | |
| Wed | 7.5 h | none | 08:15 | Good |
Reading results
- A 10–20 ms difference on a single day can be noise from posture or device. Look for a trend across days.
- Some days the round-to-round spread grows before the average does. That’s a sign focus wavered.
- Don’t use this app to decide whether you’re fit to drive. If you’re drowsy, the answer is rest, not a test.
In the app
Daily reminder
In Reflex Lab Settings, turn on Daily reminder and set the reminder time to your measuring time.
All records and the weakness report
From Stats, All records lists every attempt with date and time, filtered by 7 days, 30 days or all, and by test. The Detailed analysis (round breakdown on the result screen and the weakness report in Stats) unlocks for 24 hours with one ad.
Brain score trend
The Brain score trend chart in Stats plots, for each date, the score based on your best records up to that day. Day-to-day condition shows up better in your daily averages than in this chart.
FAQ
Does coffee make me faster?
It varies. This method isn’t a general claim; it’s an experiment on yourself. Compare several days under the same conditions.
Can I get my records into a spreadsheet?
The backup export (JSON) contains every record with a timestamp. See the backup file structure.
Reflex Lab: Brain Speed Test
No sign-up, fully offline, records stay on your device. Free on Android.