system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What's behind that reflex to immediately shake one's hand vigorously after, for example, closing the sliding glass door on a fingernail?
gpt
Because shaking it causes a focus shift of the pain intensity. The nerves that control that kind of pain get drowned out by motor nerves telling your muscles to work and by your brain concentrating on proprioception (where your hand is relative to your body). We only have limited tracts to the brain to process information and the proprioception tract is much faster than the one carrying dull aching pain.