In
psychiatryPsychiatry is the medical specialty devoted to the study and treatment of mental disorders. These mental disorders include various affective, behavioural, cognitive and perceptual abnormalities...
,
derailment (also
loosening of association,
asyndesis,
asyndetic thinking,
knight's move thinking, or
entgleisen) refers to a pattern of discourse (in speech or writing) that is a sequence of unrelated or only remotely related
ideaIn the most narrow sense, an idea is just whatever is before the mind when one thinks. Very often, ideas are construed as representational images; i.e. images of some object. In other contexts, ideas are taken to be concepts, although abstract concepts do not necessarily appear as images...
s. The frame of reference often changes from one sentence to the next. Examples:
- "The next day when I'd be going out you know, I took control, like uh, I put bleach on my hair in California."—given by Nancy C. Andreasen
Nancy Coover Andreasen is an American neuroscientist and neuropsychiatrist. She currently holds the Andrew H. Woods Chair of Psychiatry at the University of Iowa Roy J. and Lucille A. Carver College of Medicine.-Early life:...
- "The traffic is rumbling along the main road. They are going to the north. Why do girls always play pantomime heroes."—given by Carl Schneider
Carl Schneider , professor at Heidelberg University, chairman of its department of Psychiatry, director of its clinic, was a senior researcher for the Action T4 Euthanasia program....
In a mild manifestation, this
thought disorderIn psychiatry, thought disorder or formal thought disorder is a term used to describe incomprehensible language, either speech or writing, that is presumed to reflect thinking. There are different types...
is characterized by slippage of ideas further and further from the point of a discussion. Some of the synonyms given above (
loosening of association,
asyndetic thinking) are used by some authors to refer just to a
loss of goal: discourse that sets off on a particular idea, wanders off and never returns to it. A related term is
tangentialityIn psychiatry, thought disorder or formal thought disorder is a term used to describe incomprehensible language, either speech or writing, that is presumed to reflect thinking. There are different types...
—it refers to off-the-point, oblique or irrelevant answers given to questions.
Entgleisen (
derailmentA derailment is an accident on a railway or tramway in which a rail vehicle, or part or all of a train, leaves the tracks on which it is travelling, with consequent damage and in many cases injury and/or death....
in
GermanGerman is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....
) was first used with this meaning by
Carl SchneiderCarl Schneider , professor at Heidelberg University, chairman of its department of Psychiatry, director of its clinic, was a senior researcher for the Action T4 Euthanasia program....
in 1930. The term
asyndesis was introduced by N. Cameron in 1938, while
loosening of association was introduced by A. Bleuler in 1950. The phrase
knight's move thinking was first used in the context of pathological thinking by the psychologist Peter McKellar in 1957, who hypothesized that schizophrenics fail to suppress divergent associations. In some studies on
creativityCreativity refers to the phenomenon whereby a person creates something new that has some kind of value. What counts as "new" may be in reference to the individual creator, or to the society or domain within which the novelty occurs...
,
knight's move thinking, while it describes a similarly loose association of ideas, it is not considered a mental disorder or the hallmark of one; it is sometimes used as a synonym for
lateral thinkingLateral thinking is solving problems through an indirect and creative approach, using reasoning that is not immediately obvious and involving ideas that may not be obtainable by using only traditional step-by-step logic...
.
Derailment was used with this meaning by
Kurt SchneiderKurt Schneider was a German psychiatrist known largely for his writing on the diagnosis and understanding of schizophrenia.-Biography:...
in 1959.
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See also
- Train of thought
The train of thought, stream of thought, trail of thought, or chain of thought refers to the interconnection in the sequence of ideas expressed during a connected discourse or thought, as well as the sequence itself, especially in discussion how this sequence leads from one idea to another.When a...
- Non sequitur (logic)
Non sequitur , in formal logic, is an argument in which its conclusion does not follow from its premises. In a non sequitur, the conclusion could be either true or false, but the argument is fallacious because there is a disconnection between the premise and the conclusion. All formal fallacies...
and Non sequitur (literary device)
- Nonsense
Nonsense is a communication, via speech, writing, or any other symbolic system, that lacks any coherent meaning. Sometimes in ordinary usage, nonsense is synonymous with absurdity or the ridiculous...
- SCIgen
SCIgen is a program created by scientists at the Massachusetts Institute of Technology that randomly generates nonsense in the form of computer science research papers, including graphs, diagrams, and citations...
, a program that generates nonsense research papers by grammatically combining snippets; many of the sentences generated are individually plausible
- Relevance logic
Relevance logic, also called relevant logic, is a kind of non-classical logic requiring the antecedent and consequent of implications be relevantly related. They may be viewed as a family of substructural or modal logics...
- Tip-of-the-tongue