Reaction Time

Single central circle that turns green; one tap anywhere. By default the circle stays green until the tap, and the next one turns green 1–3 s after the tap, as in the Deary–Liewald task (Deary et al., 2011).

Useful for fatigue, sleep, stress, intervention, and momentary attention studies where repeated low-burden measurement is needed.

Not ideal as a standalone measure of higher-order cognition or in studies that need strong construct specificity beyond alertness and motor response speed.

Keep the published defaults (Deary et al., 2011): 8 practice and 20 test trials, no response deadline, and a random wait of 1–3 s from each response to the next stimulus. Keep practice enabled for first exposure.

• Number of practice and test trials (Deary et al., 2011: 8 and 20)
• Waiting period: uniform between a shortest and a longest wait (default 1000–3000 ms, Deary et al., 2011), or five equally likely waits of 1000–1800 ms (Woods et al., 2015)
• Whether the wait is timed from the response (default, Deary et al., 2011) or starts after a short fixed pause (tasks set up before this option)
• Response deadline: none (default, Deary et al., 2011) or a deadline after which no tap counts as an omission (published value 1000 ms, Woods et al., 2015)
• Practice enabled / disabled
• Optional practice criterion: the practice repeats until its mean reaction time is below a threshold, up to a set number of rounds. No published value; the 1000 ms default comes from the RDoC version

• Median reaction time
• Reaction time variability
• Premature responses
• Missed responses (only with a deadline)

Sensitive to fatigue, distraction, and context. Most informative in repeated-measures designs rather than one-off interpretation. Each trial stores its drawn wait (foreperiodMs). Without a deadline there are no omissions; Woods et al. (2015) score responses under 110 ms as anticipations.

• The default procedure is the simple reaction time task of Deary, Liewald and Nissan (2011): 8 practice and 20 test trials, the stimulus on screen until the response, and 1–3 s from each response to the next stimulus.
• Woods et al. (2015) used five equally likely intervals of 1000–1800 ms, timed from one stimulus onset to the next, and a 1000 ms response window; both are available as options.
• Widely used in mobile cognitive assessment as a feasible low-burden attentional measure.

• Deary, Liewald & Nissan (2011), the Deary–Liewald reaction time task
• Woods et al. (2015), factors influencing simple reaction time
• Mobile cognitive testing review
• EMA cognition review

• Choice Reaction Time
• Go/No-Go
• Flanker