From the discussion on Yvain's blog of a recent meta-analysis trying to compare simple reaction times from Galton to now, I learned that apparently consumer computers have serious issues with displaying images and recording timings down to the ms precision and that one has to configure a setup specifically for the task to compete accuracy-wise with special-purpose reaction-time gear.

John Carmack, in video game / VR contexts, has some interesting writings; here's two: http://www.altdevblogaday.com/2013/02/22/latency-mitigation-strategies/ http://superuser.com/questions/419070/transatlantic-ping-faster-than-sending-a-pixel-to-the-screen/419167#419167