How long does the Simple Reaction Time Task take?
About 2 to 3 minutes, as listed in the test library.
Processing Speed
Simple Reaction Time Task
Measure psychomotor speed and baseline alertness with a fast browser-native paradigm suitable for remote research workflows.
Useful for fatigue, concussion, aging, and intervention studies that need a clean baseline speed measure.
Free to start: 10 free participants per account, then $0.99 per participant for academic research, or any yearly plan. Preview any test free after you sign up.
Processing speed2-3 minTimed: desktop or laptop with a mouse or trackpad
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Press SPACE when you see the circle
What this task measures
Measures basic processing speed by asking participants to respond as quickly as possible when a stimulus appears on screen.
Core constructs
- Psychomotor speed
- Alertness and vigilance
- Basic sensorimotor processing
- Peripheral and central processing speed
Research fit
- Baseline processing speed assessment
- Fatigue and drowsiness monitoring
- Medication side-effect screening (sedation)
- Traumatic brain injury recovery tracking
- Age-related cognitive slowing detection
Paradigm overview
The Simple Reaction Time task is the most fundamental measure of processing speed in cognitive neuroscience. A single stimulus (a colored circle) appears on screen after a variable delay, and the participant must press the spacebar as quickly as possible upon detection.
The variable inter-stimulus interval (1000-3000ms) prevents anticipatory responses and ensures each trial requires genuine stimulus detection. Practice trials allow participants to calibrate their responses before scored trials begin.
SRT provides a baseline measure of the sensorimotor processing chain: visual detection, signal transduction to motor cortex, and motor execution. Because the response mapping is fixed (one stimulus, one response), decision-making load is minimal, isolating pure processing speed from higher-order cognitive demands.
Key scoring outputs
Mean Reaction Time
msAverage reaction time across valid trials, excluding anticipatory responses (<100ms).
Lower is better
Median Reaction Time
msMedian reaction time, more robust to outliers than the mean. Preferred when the RT distribution is skewed.
Lower is better
RT Standard Deviation
msStandard deviation of reaction times. Reflects response consistency (intraindividual variability). Elevated IIV is a biomarker for cognitive decline.
Lower is better
Minimum RT
msFastest response recorded. Useful for detecting anticipatory or invalid responses.
Informational
Maximum RT
msSlowest response recorded. May indicate lapses in attention.
Informational
Accuracy
proportionProportion of trials with a valid response. Expected near ceiling for healthy participants.
Higher is better
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Number of trials | 30 | 20 to 60 |
Yearly plans can change settings within these limits. Free and pay-as-you-go studies use the standard settings.
Need a setting this test does not have?
Devices and languages
- Timed test: participants need a desktop or laptop with a mouse or trackpad. Participant devices
- Task text: English and Italian.
- Available on: Every plan, including the free plan.
- Recruiting online? See the setup guides for Prolific, Sona Systems, CloudResearch Connect and Qualtrics.
Cite this test
Paradigm source: Donders (1869).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
Source papers
Woods DL, Wyma JM, Yund EW, Herron TJ, Reed B (2015). Factors influencing the latency of simple reaction time. Frontiers in Human Neuroscience, 9:131.
Paradigm source
Research FAQ
Common questions about this online cognitive test
What device does a participant need?
Timed test: participants need a desktop or laptop with a mouse or trackpad. The browser must be Chrome, Edge, Firefox or Safari.
What scores does it produce?
Mean Reaction Time, Median Reaction Time, RT Standard Deviation, Minimum RT, Maximum RT and Accuracy. Each session is also marked valid, needs review or invalid, with the reason.
Which settings can a researcher change?
Number of trials (20 to 60). Settings can be changed on yearly plans; free and pay-as-you-go studies use the standard settings.
Which languages can participants use?
The test's own text is in English and Italian. Italian participant pages come with yearly plans.
Is this a clinical test?
No. ConductCognition is for research use only. It runs, scores and exports the test; clinical interpretation is outside the platform.
Every test: the full test list.
Run this test in your next study
Start free with 10 free participants on any test, then use participant credits or a yearly plan.
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