Cognitive Aspects of Normal and Delusional Belief Formations
References and Links
belief formation delusional disorder - Pubmed Search RSS
via pubmed: belief formation del... by Abdel-Hamid M, Brüne M on 4/26/12
Curr Psychiatry Rep. 2008 Jun;10(3):229-34
Authors: Abdel-Hamid M, Brüne M
Abstract
Delusional disorders (DDs) are clinically rare syndromes characterized by false beliefs that are held with firm conviction despite counterevidence. The neuropsychology of DDs is poorly understood. Two partially opposing models--a cognitive bias model and a cognitive deficit model--have received mixed empiric support, partly because most research has been carried out in patients with paranoid schizophrenia, with which the nosologic association of DDs is unknown. Based on these models, we review empiric findings concerning the neuropsychology of DDs (narrowly defined). We conclude that DDs can best be seen as extreme variations of cognitive mechanisms involved in rapid threat detection and defensive harm avoidance. From this viewpoint, the two models seem to be complementary in explanatory power rather than contradictory. Future research may help to clarify the question of gene-environment interaction involvement in the formation of delusional beliefs.
PMID: 18652791 [PubMed - indexed for MEDLINE]
via pubmed: belief formation del... by Coltheart M on 4/26/12
Q J Exp Psychol (Hove). 2007 Aug;60(8):1041-62
Authors: Coltheart M
Abstract
Cognitive neuropsychiatry is a new field of cognitive psychology which seeks to learn more about the normal operation of high-level aspects of cognition such as belief formation, reasoning, decision making, theory of mind, and pragmatics by studying people in whom such processes are abnormal. So far, the high-level cognitive process most widely studied in cognitive neuropsychiatry has been belief formation, investigated by examining people with delusional beliefs. This paper describes some of the forms of delusional belief that have been examined from this perspective and offers a general two-deficit cognitive-neuropsychiatric account of delusional belief.
PMID: 17654390 [PubMed - indexed for MEDLINE]
via pubmed: belief formation del... by Lawrence E, Peters E on 4/26/12
J Nerv Ment Dis. 2004 Nov;192(11):727-33
Authors: Lawrence E, Peters E
Abstract
Reasoning biases have been identified in deluded patients, delusion-prone individuals, and believers in the paranormal. This study examined content-specific reasoning and delusional ideation in believers in the paranormal. A total of 174 members of the Society for Psychical Research completed a delusional ideation questionnaire and a deductive reasoning task. The reasoning statements were manipulated for congruency with paranormal beliefs. As predicted, individuals who reported a strong belief in the paranormal made more errors and displayed more delusional ideation than skeptical individuals. However, no differences were found with statements that were congruent with their belief system, confirming the domain-specificity of reasoning. This reasoning bias was limited to people who reported a belief in, rather than experience of, paranormal phenomena. These results suggest that reasoning abnormalities may have a causal role in the formation of unusual beliefs. The dissociation between experiences and beliefs implies that such abnormalities operate at the evaluative, rather than the perceptual, stage of processing.
PMID: 15505516 [PubMed - indexed for MEDLINE]
via pubmed: belief formation del... by Stompe T, Ortwein-Swoboda G, Ritter K, Schanda H on 4/26/12
Psychopathology. 2003 Jan-Feb;36(1):6-12
Authors: Stompe T, Ortwein-Swoboda G, Ritter K, Schanda H
Abstract
A number of recent case reports published during the last 20 years described a quick inclusion of new technologies and cultural innovations into schizophrenic delusions which led many of the authors to the conclusion that the 'Zeitgeist' is creating new delusional contents. On the other hand, long-term comparisons and comparative transcultural studies on delusions showed, despite a certain degree of variability, a stability of delusional themes over longer periods of time. Combining anthropological and historical theories of the development of societies with a differentiated psychopathological approach (Klosterkötter's three-stage model of the formation of schizophrenic delusions), we were able to resolve the problem of the ostensibly divergent results: there are only a few themes of extraordinary anthropological importance for the organization of human relationships which can be found in every epoch and in different cultures (persecution, grandiosity, guilt, religion, hypochondria, jealousy, and love). With the exception of persecution and grandiosity, these themes showed a certain variability over time and between cultures. The 'new' themes, referring to the development of modern technology and the rapid changes of 'cultural patterns' turned out to be only the shaping of the basic delusional themes on the 3rd stage of Klosterkötter's phase model (concretization).
PMID: 12679586 [PubMed - indexed for MEDLINE]
via pubmed: belief formation del... by Garety PA, Hemsley DR, Wessely S on 4/26/12
J Nerv Ment Dis. 1991 Apr;179(4):194-201
Authors: Garety PA, Hemsley DR, Wessely S
Abstract
An experiment is described in which deluded subjects with a diagnosis of schizophrenia or of delusional disorder (paranoia) were compared with a nondeluded psychiatric control group and a normal control group on a probabilistic inference task. Factors relevant to belief formation and maintenance were investigated. Deluded subjects requested less information before reaching a decision and were more ready to change their estimates of the likelihood of an event when confronted with potentially disconfirmatory information. No differences were found between the two diagnostic groups of deluded subjects. The results are discussed in light of prevailing theories of the importance of abnormal experience rather than reasoning biases in the formation and maintenance of delusional beliefs. It is suggested that a reasoning abnormality is involved, which may coexist with perceptual abnormalities.
PMID: 2007889 [PubMed - indexed for MEDLINE]
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belief formation neuropsychiatry - pubmed search RSS
via pubmed: belief formation neu... by Gerrans P on 4/26/12
Cogn Neuropsychiatry. 2001 Aug;6(3):161-73
Authors: Gerrans P
Abstract
UNLABELLED: Delusions are explanations of anomalous experiences. A theory of delusion requires an explanation of both the anomalous experience and the apparently irrational explanation generated by the delusional subject. Hence, we require a model of rational belief formation against which the belief formation of delusional subjects can be evaluated.
METHOD: I first describe such a model, distinguishing procedural from pragmatic rationality. Procedural rationality is the use of rules or procedures, deductive or inductive, that produce an inferentially coherent set of propositions. Pragmatic rationality is the use of procedural rationality in context. I then apply the distinction to the explanation of the Capgras and the Cotard delusions. I then argue that delusions are failures of pragmatic rationality. I examine the nature of these failures employing the distinction between performance and competence familiar from Chomskian linguistics.
RESULTS: This approach to the irrationality of delusions reconciles accounts in which the explanation of the anomalous experience exhausts the explanation of delusion, accounts that appeal to further deficits within the reasoning processes of delusional subjects, and accounts that argue that delusions are not beliefs at all. (Respectively, one-stage, two-stage, and expressive accounts.)
CONCLUSION: In paradigm cases that concern cognitive neuropsychiatry the irrationality of delusional subjects should be thought of as a performance deficit in pragmatic rationality.
PMID: 16571516 [PubMed]
via pubmed: belief formation neu... by Coltheart M on 4/26/12
Q J Exp Psychol (Hove). 2007 Aug;60(8):1041-62
Authors: Coltheart M
Abstract
Cognitive neuropsychiatry is a new field of cognitive psychology which seeks to learn more about the normal operation of high-level aspects of cognition such as belief formation, reasoning, decision making, theory of mind, and pragmatics by studying people in whom such processes are abnormal. So far, the high-level cognitive process most widely studied in cognitive neuropsychiatry has been belief formation, investigated by examining people with delusional beliefs. This paper describes some of the forms of delusional belief that have been examined from this perspective and offers a general two-deficit cognitive-neuropsychiatric account of delusional belief.
PMID: 17654390 [PubMed - indexed for MEDLINE]
Flaskerud JH.
Issues Ment Health Nurs. 2000 Jan-Feb;21(1):5-29. Review.
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via pubmed: belief formation neu... by Ladowsky-Brooks R, Alcock JE on 4/26/12
Cogn Neuropsychiatry. 2007 Mar;12(2):97-111
Authors: Ladowsky-Brooks R, Alcock JE
Abstract
INTRODUCTION: The purpose of this paper is to outline ways in which characteristics of memory functioning determine truth judgements regarding verbally transmitted information.
METHOD: Findings on belief formation from several areas of psychology were reviewed in order to identify general principles that appear to underlie the designation of information in memory as "true" or "false".
RESULTS: Studies on belief formation have demonstrated that individuals have a tendency to encode information as "true" and that an additional encoding step is required to tag information as "false". This additional step can involve acquisition and later recall of semantic-episodic associations between message content and contextual cues that signal that information is "false". Semantic-episodic interactions also appear to prevent new information from being accepted as "true" through encoding bias or the assignment of a "false" tag to data that is incompatible with prior knowledge.
CONCLUSIONS: It is proposed that truth judgements are made through a combined weighting of the reliability of the information source and the compatibility of this information with already stored data. This requires interactions in memory. Failure to integrate different types of memories, such as semantic and episodic memories, can arise from mild hippocampal dysfunction and might result in delusions.
PMID: 17453893 [PubMed - indexed for MEDLINE]
via pubmed: belief formation neu... by Cashmore AR on 4/26/12
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Proc Natl Acad Sci U S A. 2010 Mar 9;107(10):4499-504
Authors: Cashmore AR
Abstract
It is widely believed, at least in scientific circles, that living systems, including mankind, obey the natural physical laws. However, it is also commonly accepted that man has the capacity to make "free" conscious decisions that do not simply reflect the chemical makeup of the individual at the time of decision--this chemical makeup reflecting both the genetic and environmental history and a degree of stochasticism. Whereas philosophers have discussed for centuries the apparent lack of a causal component for free will, many biologists still seem to be remarkably at ease with this notion of free will; and furthermore, our judicial system is based on such a belief. It is the author's contention that a belief in free will is nothing other than a continuing belief in vitalism--something biologists proudly believe they discarded well over 100 years ago.
PMID: 20142481 [PubMed - indexed for MEDLINE]
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Monothematic delusion
From Wikipedia, the free encyclopedia
(Redirected from Monothematic delusions)
A monothematic delusion is a delusional state that only concerns one particular topic. This is contrasted by what is sometimes called multi-thematic or polythematic delusions where the person has a range of delusions (typically the case of schizophrenia). These disorders can occur within the context of schizophrenia or dementia or they can occur without any other signs of mental illness. When these disorders are found outside the context of mental illness, they are often caused by organic disfunction as a result of traumatic brain injury, stroke, or neurological illness.
People who suffer from these delusions as a result of organic dysfunction often do not suffer from any obvious intellectual deficiency nor do they have any other symptoms. Additionally, a few of these people even have some awareness that their beliefs are bizarre, yet they cannot be persuaded that their beliefs are false.[citation needed]
Contents[hide] |
[edit] Types
The delusions that fall under this category are:
- Capgras delusion: the belief that (usually) a close relative or spouse has been replaced by an identical-looking impostor.
- Fregoli delusion: the belief that various people who the believer meets are actually the same person in disguise.
- Intermetamorphosis: the belief that people in one's environment swap identities with each other whilst maintaining the same appearance.
- Subjective doubles: a person believes there is a doppelgänger or double of him or herself carrying out independent actions.
- Cotard delusion: the belief that oneself is dead or does not exist; sometimes coupled with the belief that one is putrifying or missing internal organs.
- Mirrored-self misidentification: the belief that one's reflection in a mirror is some other person.
- Reduplicative paramnesia: the belief that a familiar person, place, object or body part has been duplicated. For example, a person may believe that they are in fact not in the hospital to which they were admitted, but in an identical-looking hospital in a different part of the country.
- Somatoparaphrenia: the delusion where one denies ownership of a limb or an entire side of one's body (often connected with stroke).
Note that some of these delusions are sometimes grouped under the umbrella term of delusional misidentification syndrome.
[edit] Causes
Current cognitive neuropsychology research points toward a two-factor approach to the cause of monothematic delusions.[1] The first factor being the anomalous experience—often a neurological defect—which leads to the delusion and the second factor being an impairment of the belief formation cognitive process.
For example of one of these first factors, several studies point toward Capgras delusion being the result of a disorder of the affect component of face perception. As a result, while the person can recognize their spouse (or other close relation) they do not feel the typical emotional reaction and thus the spouse does not seem like the person they once knew.
As studies have shown, these neurological defects are not enough on their own to cause delusional thinking. An additional second factor, a bias or impairment of the belief formation cognitive process is required to solidify and maintain the delusion. Since we do not currently have a solid cognitive model of the belief formation process, this second factor is still somewhat of an unknown.
Some research has shown that delusional people are more prone to jumping to conclusions[2][3][4] and thus they would be more likely to take their anomalous experience as veridical and make snap judgments based on these experiences. Additionally, studies[4] have shown that they are more prone to making errors due to matching bias—indicative of a tendency to try and confirm the rule. These two judgment biases help explain how delusion prone people could grasp onto extreme delusions and be very resistant to change.
Researchers claim this is enough to explain the delusional thinking. However other researchers still argue that these biases are not enough to explain why they remain completely impervious to evidence over time. They believe that there must be some additional unknown neurological defect in the patient's belief system (probably in the right hemisphere).
[edit] See also
[edit] References
- ^ Davies, M., Coltheart, M., Langdon, R., Breen, N. (2001). "Monothematic delusions: Towards a two-factor account" (PDF). Philosophy, Psychiatry and Psychology 8: 133–158. doi:10.1353/ppp.2001.0007. http://philrsss.anu.edu.au/~mdavies/papers/mono.pdf.
- ^ Sellen, J., Oaksford, M., Langdon, R., Gray, N. (2005). "Schizotypy and Conditional Reasoning". Schizophrenia Bulletin 31 (1): 105–116. doi:10.1093/schbul/sbi012. http://schizophreniabulletin.oxfordjournals.org/cgi/content/full/31/1/105.
- ^ Dudley RE, John CH, Young AW, Over DE (May 1997). "Normal and abnormal reasoning in people with delusions". Br J Clin Psychol 36 (Pt 2): 243–58. PMID 9167864.
- ^ a b Stone, T. (2005). "Delusions and Belief Formation" (Powerpoint). http://www.lsbu.ac.uk/psycho/teaching/ppfiles/cicp-l5.ppt.
- Stone, T. (2005). "Face Recognition and Delusions" (Powerpoint). http://www.lsbu.ac.uk/psycho/teaching/ppfiles/cicp-l4.ppt.
[edit] External links
- The Belief Formation Project a project of the Macquarie Centre for Cognitive Science, which uses research on delusions with the aim of developing a cognitive model of beliefs
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