Simple visual reaction time — pressing a button when a stimulus appears — averages around 250 milliseconds in young adults. It reflects the speed of your entire perception-action loop: retina, visual cortex, decision circuits, motor cortex, muscles. Because that loop touches so much of the nervous system, reaction time correlates with processing speed and even long-term health outcomes in large studies.
Age (fastest in the early 20s, slowing ~2-6 ms per decade), sleep deprivation, alcohol, caffeine, screen latency and time of day all shift results. Elite esports players and athletes often test near 150-180 ms.
Why do I get faster after a few tries? Anticipation and practice effects are real — your first attempt is usually your slowest. The test averages several trials to stabilize the estimate.
Can I train it? Modestly. Regular action-oriented practice can shave 10-20%, but genetics and age set the floor.