Adding a decision adds time
A simple reaction test has one signal and one response, so there is nothing to decide. A choice test makes you identify the signal before you can act on it, and that identification costs real time — typically 50 to 150 milliseconds on top of your simple reaction time, depending on how many options there are and how easy they are to tell apart.
This relationship has a name: Hick's law. Response time grows roughly with the logarithm of the number of alternatives, which is a precise way of saying that going from one option to two costs you a lot, and going from eight to nine costs you almost nothing. It is the reason interface designers argue about menu structure, and the reason this mode feels noticeably harder than the main test even though the tap itself is identical.
Why the hold trials matter
Roughly a third of the signals in this mode say HOLD. They are not filler. Without them you could stop reading the signal entirely and just tap on any change, which turns a choice test back into a simple one and inflates your score.
Tapping a hold is recorded as a false start and dropped from your average, in exactly the same way as tapping before the signal. That means the score you get is your speed on the trials where you actually made the right call — and your false-start count tells you what that speed cost you. A 240 ms average with three fouls is a worse result than a 290 ms average with none.
Inhibition — stopping an action you have already started — is a separate skill from speed, and it is the one most people are worse at than they expect.
What a good choice reaction time looks like
| Choice reaction average | Reading |
|---|---|
| Under 300 ms with no fouls | Fast, and you are genuinely reading the signal |
| 300 to 400 ms with no fouls | Normal for an adult on a screen |
| Under 300 ms with two or more fouls | You are anticipating, not deciding |
| Over 450 ms | Usually fatigue, an unfamiliar device, or over-caution after a foul |
Using it to train rather than to score
Choice reaction is the mode worth repeating. Simple reaction time is close to a fixed property of your nervous system and barely moves with practice. Decision speed does move: the more familiar the mapping between a signal and a response becomes, the less of that 50 to 150 ms penalty you pay. That is what a gamer means by "game sense" and what a driver gains in their second year on the road.
Run five sets across a week rather than twenty in one sitting. Fatigue shows up in this mode faster than in any other, and a tired choice score tells you about your evening, not about you.