Reaction Test Cognitive Decline Early Warning What Slowing Reflexes Actually Signal

Your average reaction time to a visual stimulus is 215 milliseconds. Last month it was 210. Three months ago it was 205. The trend is slow — 10 milliseconds over three months — but it's consistent. Is this normal aging, or is something wrong?

Reaction time is one of the most sensitive measures of brain function, and tracking it over time can reveal problems before you notice them in daily life. Here's what the numbers mean and when to pay attention.

What's Normal for Your Age

Simple visual reaction time (see a light, press a button) averages: 20s: 190-200ms, 30s: 200-215ms, 40s: 215-230ms, 50s: 230-250ms, 60s: 250-270ms, 70s+: 270-300ms. These are population averages — individual baselines vary by 30-50ms. What matters is your personal trend, not the population number.

F1 drivers can react in 150-180ms. That's not "faster than normal humans" — it's the result of training anticipation, not raw reaction speed. They're not reacting faster; they're predicting better. Your reaction time test measures raw reaction, not anticipation, so don't compare yourself to Lewis Hamilton.

When Slowing Reaction Time Is a Red Flag

A gradual slowdown of 1-3ms per year after age 30 is normal aging. A sudden slowdown of 20-30ms over a month is not normal and can indicate: (1) sleep debt — just one night of poor sleep increases reaction time by 20-50ms, equivalent to being legally drunk in some jurisdictions; (2) medication side effects — antihistamines, benzodiazepines, and some blood pressure medications slow reaction time measurably; (3) early cognitive decline — a 2018 study in the journal Neurology found that reaction time slowing preceded other cognitive symptoms by 2-3 years in some patients; or (4) concussion recovery — reaction time is one of the last functions to return to baseline after a concussion, often lagging 2-4 weeks behind symptom resolution.

How to Track Reaction Time Properly

Test at the same time of day. Reaction time varies by 10-15ms throughout the day — fastest in late morning, slowest in early morning and late evening. Pick a consistent time.

Use the same device and test. Different screens have different input lag. Your phone touchscreen might have 50ms of latency; your laptop trackpad might have 30ms. The absolute number matters less than the trend on the same setup.

Take the average of 5-10 trials. Single-trial reaction time is too noisy. A 10-trial average gives a reliable measure. Discard any trial where you anticipated the stimulus (reaction under 100ms is almost certainly anticipation, not reaction).

Track weekly, not daily. Daily fluctuation is noise. Weekly averages over 3+ months reveal trends. If your 4-week moving average is consistently declining, mention it to your doctor.

For measuring your reaction time, use our reaction time test with multi-trial averaging. For timing your test sessions consistently, our stopwatch and timer helps schedule regular testing. And for tracking scores over time, our scoreboard records your history.