Reflex vs Reaction Time | What Neuroscience Actually Says

A reflex is an involuntary spinal response (think: knee-jerk). Reaction time is a cognitive decision: stimulus → brain → motor action. They share words but not biology — and only one of them can be trained.

Reflex: Spinal Cord, Not Brain

A reflex bypasses conscious thought. Signals travel through the spinal cord in 20–40 ms and return a motor response. You cannot meaningfully train a reflex in the way you can train cognitive skill.

Reaction Time: Cognition + Motor Output

Reaction time runs the full loop: stimulus → primary cortex → decision → motor cortex → muscle. It takes 150–250 ms in healthy adults and is trainable. Esports, driving, sports — all rely on this loop.

Which One Does SERO Measure?

SERO measures cognitive reaction time — the trainable one. Sub-millisecond precision, age-banded benchmarks, free.

Test your real reaction time

FAQ

Are reflex and reaction the same thing?

No. Reflex is a spinal-cord response; reaction is a cognitive decision involving the brain.

Can I train my reflexes?

Not in any meaningful way. You can train reaction time — the cognitive part most people call "reflex" in everyday speech.

Is SERO measuring the trainable one?

Yes — cognitive reaction time, the metric that responds to practice.