ONE TARGET OR FOUR CHOICES

Wait. See ×. Respond.

Early, ultra-fast, and slow responses outside the retained range are replaced. Use the same setup for any repeat you want to compare.

What this reaction-time test actually measures.

Simple reaction

One target box appears after a random 1–3 second interval. The round uses eight practice trials and retains twenty responses from 150–1500 ms. It reports the mean, median, and sample standard deviation.

Four-choice reaction

One of four aligned boxes receives the target. The round uses eight practice trials and forty retained responses from 200–1500 ms. Correct reaction statistics, accuracy, and wrong-position errors are reported separately.

Why trials are replaced

The published paradigm uses fixed retained counts. Responses outside its accepted timing interval are replaced rather than mixed into the summary. A wrong four-choice position remains in accuracy but is excluded from correct-response timing.

Device boundary

Browser scheduling, touchscreen or keyboard latency, display refresh, hardware, background load, practice, fatigue, sleep, and environment all affect absolute milliseconds. Results from unlike setups are not directly comparable.

Deary, Liewald & Nissan (2011) — simple and four-choice task design and validation in 150 adults.

University of Edinburgh task files and SOP record — published counts, timing windows, and instructions. ViewsMeet independently implements the paradigm and does not redistribute the licensed Windows program.

Browser timing experiment — web platforms can preserve experimental effects while adding system-specific timing offsets.

No IQ or safety verdict

Reaction time is one narrow behavioral measure. This browser task cannot establish intelligence, neurological health, medication effect, impairment, driving safety, occupational fitness, or clinical change.