Simple Reaction Time

Simple reaction time is the latency between the appearance of a single expected stimulus and the execution of a single pre-planned response. Because there is no selection among alternatives, the task primarily indexes perceptual detection and motor initiation speed rather than decision-making. Donders (1869) labelled this the a-reaction and treated it as the baseline against which more complex reaction variants are compared.

Reference: Donders, 1869. The NeuroRank implementation holds the canonical form and scales interference via task-irrelevant stimulus density.

1. Pulling the trigger the instant a model steps out of a known pre-aimed corner in CS2, where the player's crosshair is already placed and only detection speed matters.
2. Jumping the moment a Super Smash Bros. opponent throws a known grab animation, a scripted stimulus and a scripted response.
3. Clicking the first frame an Overwatch ultimate animation becomes visible when you already intend to interrupt it.

The simple RT phase of the Reaction module presents a single stimulus after a variable warning interval. Mean RT across valid trials is percentile-ranked to produce the Reaction Speed dimension score. Performance here is the cleanest single-number estimate of raw neural transmission plus motor initiation speed.