At One Place

Withdrawal reflex

Withdrawal reflex
70 ms–150 ms
Reflex — does not reach the brain

Pulling your hand off a hot pan is a polysynaptic spinal reflex, so it takes longer than a knee-jerk but still runs without the brain. The sequence people report — feeling the heat, then pulling away — is the opposite of what happens: the hand is already moving when the pain signal arrives at the cortex, which takes a few hundred milliseconds more. The conscious experience of deciding to move is constructed afterwards.

The numbers

Typical
90 ms
Range
70 ms to 150 ms
What it is
Reflex — does not reach the brain
What is measured
Touching something painfully hot or sharp; time to the limb starting to move away.

Why this is a reflex

A reflex arc turns round in the spinal cord or brainstem and never involves conscious processing. That is why reflex latencies are an order of magnitude shorter than reaction times, and why you cannot train a reaction down to a reflex figure.

Where it sits against everything else

Reflexes at the top, reactions in the middle, design values off the end of the scale.

Vestibulo-ocular reflex — Reflex 10 ms
Knee-jerk (patellar) reflex — Reflex 22 ms
Latency added by your screen and mouse — Physical limit 35 ms
Blink reflex — Reflex 40 ms
Withdrawal reflex — Reflex 90 ms
Time a jab takes to land — Physical limit 110 ms
Sprint start reaction — Reaction 140 ms
Simple tactile reaction time — Reaction 155 ms
Simple auditory reaction time — Reaction 170 ms
Professional gamer reaction time — Reaction 190 ms
Formula One start reaction — Reaction 200 ms
Simple visual reaction time — Reaction 250 ms
How reaction time changes with age — Reaction 250 ms
What sleep loss does to reaction time — Reaction 300 ms
What alcohol does to reaction time — Reaction 320 ms
Recognition reaction time — Reaction 340 ms
Choice reaction time — Reaction 380 ms
Time to hit a 95 mph fastball — Physical limit 400 ms
Time a goalkeeper has on a penalty — Physical limit 450 ms
Time to play a 90 mph delivery — Physical limit 500 ms
Driver reaction to an expected event — Reaction 850 ms

Reflexes

What Typical Range Kind
Vestibulo-ocular reflex 10 ms 7 ms–15 ms Reflex
Knee-jerk (patellar) reflex 22 ms 18 ms–24 ms Reflex
Blink reflex 40 ms 30 ms–60 ms Reflex

Common questions

How long is withdrawal reflex?
Typically 90 ms, with a real range of 70 ms to 150 ms. Touching something painfully hot or sharp; time to the limb starting to move away.
Is that a reflex or a reaction?
Reflex — does not reach the brain. A reflex arc turns round in the spinal cord or brainstem and never involves conscious processing. That is why reflex latencies are an order of magnitude shorter than reaction times, and why you cannot train a reaction down to a reflex figure.

Related pages

Sources

  1. Typical range compiled from manufacturer specifications — At One Place

How these figures are compiled and checked