Deary-Liewald Task
Welcome to the Deary-Liewald Task - a standardized cognitive test measuring reaction time and processing speed.
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About the Task
Ian Deary is a renowned professor in psychology, particularly known for his work in differential psychology and general intelligence. Together with members of his Edinburgh (Scotland) research group, he published an article about a four-choice response task.
At the group level, reaction time correlates moderately with general intelligence, which is why an agreed standard procedure is useful, and the Deary-Liewald task provides this (in a similar way as the Jensen task, Jensen, 2006). Individual single sessions are noisy and say little about any one person.
References
- Deary, I. J., Liewald, D., & Nissan, J. (2011). A free, easy-to-use, computer-based simple and four-choice reaction time programme: The Deary-Liewald reaction time task. Behavior Research Methods, 43(1), 258-268. 10.3758/s13428-010-0024-1
- Donders, F. C. (1969). On the speed of mental processes. Acta Psychologica, 30, 412-431. (Original work published 1868) 10.1016/0001-6918(69)90065-1
- Jensen, A. R. (2006). Clocking the mind: Mental chronometry and individual differences. Elsevier.
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Frequently Asked Questions
Have another question? Let us know.
What does the Deary-Liewald task measure?
This online version benchmarks two conditions — simple reaction time and four-choice reaction time — adapted from the standard procedure published by Deary and Liewald in 2011 for reliable laboratory and online use.
Why are the two conditions compared?
The step from simple to choice reaction time reveals the cost of identifying which box the stimulus appeared in and of deciding between four responses — a rough measure of processing speed.
What influences the results?
Hardware (mouse, keyboard, screen latency), practice, and alertness all contribute. Compare your runs on the same device rather than across devices.
How is it used in research?
Processing-speed batteries in aging and health research use similar paradigms; slower choice reaction time is one of the most robust behavioral markers of cognitive aging.
About This Experiment
This experiment is an educational adaptation for demonstration purposes. It is not a clinical diagnostic tool. Results reflect your performance in this specific session and should not be interpreted as an assessment of your cognitive abilities.
Data Privacy
Your experiment data is processed and stored locally in your browser. No data is uploaded to any server unless you explicitly export it.
