A 1000 Hz device is capable of reporting approximately one thousand times per second, corresponding to a nominal 1 ms interval. A 125 Hz device has an 8 ms interval between report opportunities.
For cursor movement, higher polling can also provide more frequent position updates.
The switch must actuate, the mouse firmware must process the event, the report must reach the operating system, the browser/game must handle it, and the display must eventually show the consequence.
Polling rate addresses only one stage.
It can change input timing by reducing the wait until the next report opportunity, especially when comparing very low and higher polling rates. But the average difference in a real browser test can be smaller than normal human trial-to-trial variability.
That is why many repeated trials are needed if you want to detect a small hardware effect.
For modern gaming systems, high polling rates are common, but extremely high rates can increase CPU/USB processing demands in some setups. The best choice depends on mouse support, system performance and the game.
For Reaction Lab, the main goal is consistency: record the setting if you are comparing sessions.
The nominal interval is 8 ms because 1000 ÷ 125 = 8.
The nominal report interval is 1 ms.
Not necessarily. The difference depends on where each click lands within the polling cycle and on the rest of the latency chain.