Reaction time

Reaction time (RT) is the elapsed time between the presentation of a sensory stimulus and the subsequent behavioral response. RT is often used in experimental psychology to measure the duration of mental operations, known as mental chronometry. The behavioral response is often a button press but can also be an eye movement, a vocal response, or some other observable behavior.

Types of RT tasks

*Simple reaction time is usually defined as the time required for an observer to detect the presence of a stimulus. For example, an observer might be asked to press a button as soon as a light or sound appears. Mean RT is approximately 180 to 200 milliseconds to detect visual stimuli, whereas for sound it is around 140-160 milliseconds. [http://biae.clemson.edu/bpc/bp/Lab/110/reaction.htm#Type%20of%20Stimulus] Verify credibility|date=August 2008
*Go/No-Go reaction time tasks require that the observer press a button when one stimulus type appears and withhold a response when other stimulus types appear. For example, the observer is to press the button when a red light appears and not respond when a green light appears.
*Choice reaction time tasks require distinct responses for each possible class of stimulus. For example, the observer may be asked to press one button if a red light appears and a different button if a yellow light appears.

History

Abū Rayhān al-Bīrūnī was the first to describe the concept of reaction time: [citation|first=Muhammad|last=Iqbal|author-link=Muhammad Iqbal|title=The Reconstruction of Religious Thought in Islam|chapter=The Spirit of Muslim Culture|url=http://www.allamaiqbal.com/works/prose/english/reconstruction|accessdate=2008-01-25]

Franciscus Donders was among the first to systematically analyze human RT to measure the duration of mental operations.

ee also

Mental chronometry

References

External links

Simple Reaction Time Tests: (note that the hardware/software setup will greatly affect measurements making the scores largely incomparable from user to user)
* [http://humanbenchmark.com/tests/reactiontime/index.php Reaction Time Test (Flash)] by HumanBenchmark
* [http://cognitivelabs.com/mydna_speedtestno.htm Reaction Time Test] by Cognitive Labs

Complex Reaction Time:
* [http://projectimplicit.com Project Implicit] by Harvard University

Simple Reaction Time:
* [http://www.chss.montclair.edu/psychology/museum/mrt.html Historical Background] by Museum of the History of Reaction Time Research
* [http://hypertextbook.com/facts/2006/reactiontime.shtml Fingertip Reaction Time] by The Physics Factbook
* [http://biae.clemson.edu/bpc/bp/Lab/110/reaction.htm A Literature Review on Reaction Time]