FACTOID # 14: North Carolina has a larger Native American population than North Dakota, South Dakota and Montana combined.
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 


FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:



(* = Graphable)



Encyclopedia > 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. Experimental psychology is an approach to psychology that treats it as one of the natural sciences, and therefore assumes that it is susceptible to the experimental method. ... // Definition and history Psychologists have investigated mental chronometry for over 100 years. ...


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 appears. Simple RT to detect the onset of a light flash is approximately 150 to 300 milliseconds[3].
  • 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.

One millisecond is one-thousandth of a second. ...


Abū Rayhān al-Bīrūnī was the first to describe the concept of reaction time:[1] (September 15, 973 in Kath, Khwarezm – December 13, 1048 in Ghazni) was a Persian[1][2][3] Muslim polymath[4] of the 11th century, whose experiments and discoveries were as significant and diverse as those of Leonardo da Vinci or Galileo, five hundred years before the Renaissance; al-Biruni was...

"Not only is every sensation attended by a corresponding change localized in the sense-organ, which demands a certain time, but also, between the stimulation of the organ and consciousness of the perception an interval of time must elapse, corresponding to the transmission of stimulus for some distance along the nerves."

Franciscus Donders was among the first to systematically analyze human RT to measure the duration of mental operations. Franciscus Cornelis Donders Franciscus Cornelis Donders (Tilburg, May 27, 1818 - Utrecht, March 24, 1889) was a Dutch ophthalmologist and medical scientist who did pioneering work on animal and vegetable heat, among many other things. ...

See also

Mental chronometry // Definition and history Psychologists have investigated mental chronometry for over 100 years. ...


  1. ^ Muhammad Iqbal, The Reconstruction of Religious Thought in Islam, "The Spirit of Muslim Culture" (cf. [1] and [2])

Sir Muhammad Iqbāl (Urdu/Persian: ‎ ) (November 9, 1877 – April 21, 1938) was an Indian Muslim poet, philosopher and politician, whose poetry in Persian and Urdu is regarded as among the greatest in modern times. ... The Reconstruction of Religious Thought in Islam is a book by Muhammad Iqbal on Islamic philosophy, which was published in 1930. ... Look up Cf. ...

External links

Simple Reaction Time:

Complex Reaction Time:

  Results from FactBites:
Reaction Time Clinic (1431 words)
You should be comfortable with the reaction times before you worry about Top-End Tactics.
We said that each light was a half-second apart, and thus a.500 light was a perfect reaction time.
Through experimentation, both in my college physics lab, and with the practice tree, I have determined that human reaction time is roughly.21 seconds, plus or minus several hundredths for individual differences, and human inconsistency.
Visual Expert Human Factors: Driver Reaction Time (3112 words)
Reaction time depends to some extent on the distance to the obstacle and whether it is approaching from the side and is first seen in peripheral vision.
The increased reaction time is due to several factors, including the need to interpret the novel situation and possibly to decide whether there is time to brake or whether steering is better response.
Perception times are presumably the same, but assuming the hands are on he steering wheel, the movement required to turn a wheel is performed much faster than that required to move the foot from accelerator to brake pedal.
  More results at FactBites »



Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m