Reaction time

For a reflex, reaction time is the time from the onset of a stimulus until the organism responds.

Types

 * Simple reaction time is the time it takes to react to a simple stimuli- or small change in the enviorment.
 * Complex reaction time is the latency between a variable stimulus and a respectively variable response.
 * Go/NoGo (also called Recognition) reaction time task in which participants respond to one particular event but ignore other events
 * Choice reaction time task in which participants respond differentially to two stimuli by pressing one key for event A and a separate key for event B.

Extended reaction times as a possible contributing factor in falls of elderly humans has been studied extensively at the University of New South Wales. Refer to the author, Stephen Lord, pertaining to a book on reducing falls, which was published after the study of 80,000 older Australian citizens.

Factors
The major factors affecting reaction time are:
 * Recognition;
 * Choice;
 * Number of stimuli;
 * Type of stimulus;
 * Stimulus intensity;
 * Deseases, such as chicken pox;

There are many other factors that can also affect reaction time:
 * Practice and error
 * Fatigue
 * Sex
 * Age
 * Race (Jensen, 1993)
 * Distraction
 * Finger Tremors (Brebner and Welford, 1980)
 * Left vs. right hand (Dane and Erzurumluoğlu, 2003)
 * Vision (Direct vs. Peripheral) (Brebner and Welford, 1980)
 * Sobriety
 * Breathing Cycle (Buchsbaum and Calloway, 1965)
 * Stimulant Drugs (Caffeine) (Lorist and Snel, 1997)

History of the field
Physical scientists such as Archimedes and philosophers such as Aristotle conducted many observations involving aspects of chronometric measurement; however the tools or impetus to measure cognitive reaction time apparently was not developed, or simply has not left a significant traceable thread in the literature. The literature in other fields, e.g., epigraphical evidence, remnants of papyri, sherds, and other source material is uncertain and warrants additional investigation. An understanding of physical reaction time is critical for fields such as ballistics, archery, athletics and the physical sciences in order to estimate and measure.