Reaction


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Related to Reaction: reaction time

reaction

1. opposition to change, esp political change, or a desire to return to a former condition or system
2. a response indicating a person's feelings or emotional attitude
3. Med
a. any effect produced by the action of a drug, esp an adverse effect
b. any effect produced by a substance (allergen) to which a person is allergic the simultaneous equal and opposite force that acts on a body whenever it exerts a force on another body
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Reaction

 

in the political sense, resistance to social progress; a political regime established to maintain and strengthen an outmoded social order. Reaction usually manifests itself in the struggle against the revolutionary movement, in the suppression of democratic rights and liberties, in the persecution of progressive political, public, and cultural figures, in mass terror and violence, in racial and national discrimination, and in an aggressive foreign policy. Reaction in its extreme form is fascism.

A reactionary is an adherent of political reaction, a retrograde person, an enemy of social, cultural, and scientific progress.


Reaction

 

in psychology, a behavioral act that takes place in response to a certain stimulus; a voluntary movement that takes place in response to a signal and is influenced by the subject’s idea of the task to be performed. It became necessary to investigate voluntary reaction after it was discovered that astronomers attempting to note the moment a star passed through a meridian were giving different figures. F. Bessel, who discovered this phenomenon, conducted an experiment in 1823 to measure reaction times of human beings to stimuli. The measurement of speed, intensity, and course of reactions created psychometrics as a branch of psychology with a special method of investigation—the method of reaction. Pioneers in this field included F. Donders of Denmark and W. Wundt, L. Lange, and N. N. Lange. Reaction was also studied by the Soviet psychologist K. N. Kornilov, the founder of reactology.

There are two basic types of reactions: simple and complex. In a simple reaction, a person quickly responds with a movement (motor and sensory reaction) to a single prearranged signal. In a complex reaction, when various signals are randomly given, a person responds to only one of them (discrimination reaction) or to all of them, but with various movements (choice reaction). The study of reaction has made it possible to formulate a number of principles of applied psychology, such as Hick’s law, which states that reaction time increases with an increase in the number of stimuli presented for discrimination.

REFERENCES

Wundt, W. Osnovy fiziologicheskoi psikhologii, fascs. 1–16. St. Petersburg, 1908–14.
Inzhenernaia psikhologiia za rubezhom. Moscow, 1967. Pages 408–24. (Collection of articles translated from English.)
See also references under .

V. I. MAKSIMENKO

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

reaction

[rē′ak·shən]
(control systems)
(mechanics)
The equal and opposite force which results when a force is exerted on a body, according to Newton's third law of motion.
(nuclear physics)
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
The study followed 512 children ages 3-15 months for an average of three years, documenting all allergic reactions to food.
Vegetable proteins such as Soy, wheat, peanuts, tree nuts are found to cause skin allergic reactions. [7] Reactions due to other uncommon foods like mustard, flavourings, and honey are comparatively rare, but it changes from country to county and people to people.
Deary & Der (2005) reported that from teens to middle age, reaction time slows and becomes more variable.
A deciding factor for many scientists investigating flow chemistry systems is the ability to rapidly optimize reaction conditions, reducing costs and saving valuable time.
At the time of ENL reaction, there is increase in serum transforming growth factor (TGF-[beta]), interferon gamma (INF-I3), interleukin-10 (IL-10), IL-6, IL-8 and IL-1B levels.
After multiple comparisons, results showed that the IgE specific activity was significantly higher in the systemic reaction group than the IgE specific activities in common localized reaction group ( Z = 4.907, P < 0.001), large localized reaction group ( Z = 2.643, P = 0.0082), and control group ( Z = 5.099, P < 0.001).
Conclusions: The first Leuckart reaction producing an amide, other than formamide, as the main product, was conducted.
Chapman and Lawson [12] conducted a study in which reaction time of 11 schizophrenic patients and 11 normal subjects after a series of regular pre-fitness was measured in which the research results confirms the slower reaction rate in schizophrenic people than the normal ones despite a pre-fitness period.
In the comparison of reaction time between the groups of national and international level athletes, the auditory reaction time of international level athletes were found shorter than national level athletes and the difference was statistically significant (p<0.05).
Caption: This image shows a few different reactions on a paragraph in a Fast Company Labs article.
- The time between administration of the drug and occurence of the reaction