ConductCognition

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.

Processing Speed2-3 minHosted browser workflow
+
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

Why researchers use ConductCognition

  • Hosted browser delivery with no local install burden for participants.
  • Study setup, scoring, exports, and participant links in one workflow.
  • Transparent pricing instead of opaque enterprise quoting for solo labs.
  • Free entry tier plus Academic Pro when you need the full battery and raw exports.

Paradigm overview

The Simple Reaction Time task is the most fundamental measure of processing speed in cognitive neuroscience. A single stimulus (a blue 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

ms

Average reaction time across valid trials, excluding anticipatory responses (<100ms).

Lower is better

Median Reaction Time

ms

Median reaction time, more robust to outliers than the mean. Preferred when the RT distribution is skewed.

Lower is better

RT Standard Deviation

ms

Standard deviation of reaction times. Reflects response consistency (intraindividual variability). Elevated IIV is a biomarker for cognitive decline.

Lower is better

Minimum RT

ms

Fastest response recorded. Useful for detecting anticipatory or invalid responses.

Informational

Maximum RT

ms

Slowest response recorded. May indicate lapses in attention.

Informational

Accuracy

proportion

Proportion of trials with a valid response. Expected near ceiling for healthy participants.

Higher is better

Normative and citation context

Woods DL, Wyma JM, Yund EW, Herron TJ, Reed B (2015). Age-related slowing of response selection and production in a visual choice reaction time task. Frontiers in Human Neuroscience, 9:131.

N 146918-79

Computerized SRT paradigm. Large community sample stratified by decade.

Ready to Run This Test?

Set up a study, share participant links, collect data, and export results — all in one place. Free to start.

Related task pages

Choice Reaction TimeTrail Making Test A