Beliefs are firm beliefs about reality that we accept as true. They provide us with the basic mental framework for understanding our world and engaging meaningfully in it. Beliefs remain fundamental to our behavior and identity, but are not well understood.
Delusions, on the other hand, are stable, usually false beliefs that are strongly held, but not widely shared. In previous work, we proposed that the study of delusions provides unique insights into the cognitive nature of belief and its dysfunction.
Based on evidence from delusions and other psychological disciplines, we present a tentative five-stage cognitive model of belief formation.
When faced with an unexpected sensory input or social communication, we seek to account for it based on existing beliefs, memories, and other social information. We then evaluate our account based on how well it explains our experiences and how consistent it is with our prior beliefs. If it meets these criteria, the belief is accepted. This then guides what we pay attention to and what other ideas we can consider.
We propose that illusions can arise at different stages in this model. Our approach highlights the importance of the individual’s search for meaning and social context in shaping delusions. It also draws attention to the impact an illusion has on subsequent perceptions and thinking once it is formed.
This model linking delusions and beliefs differs from earlier accounts, which suggested that delusions were separate from beliefs or arise as a largely passive response to abnormal sensory input, such as hallucinations. For example, previous research has found that some people who believed that family members had been replaced by impostors (known as the Capgras illusion) had deficits in processing familiar faces, leading to This idea could have arisen.
Based on this, some have suggested that other illusions arise similarly, but in combination with as-yet-undiscovered deficits in the cognitive process of evaluating our beliefs.
But these accounts did not fully consider other contributing factors, such as the individual’s prior beliefs, social context, and their personal efforts to explain their experiences.
informative case studies
The study of illusion is informed by selected informative case studies. Unlike large group studies, case studies allow researchers to more detailed exploration of the origins and course of clinical features not explained by current theories.
We recently published a paper in the international journal Cortex describing a unique case study of a woman who experienced temporarily hypertonic delusions, which were accompanied by hallucinations, during a brief admission to hospital for postpartum psychosis. Confusion can lead to mood changes and hallucinations. It is a rare complication of pregnancy, affecting approximately 1–2 women in 1,000, thought to be caused by hormonal changes or immunological factors.
Natalie (pseudonym) had no previous medical or psychiatric history. She developed postpartum psychosis during a hospital stay after the birth of her second child.
As part of her condition, Natalie reported several delusions, including the belief that the strangers were her in-laws in disguise (known as the Fregoli delusion). Natalie recovered quickly with treatment. The combination of interviews and observations while she was experiencing delusions and subsequent retrospective descriptions provided a unique window into the onset and experience of her delusions.
After a full recovery, Natalie confirmed that she considered her delusions to be strongly held beliefs. She compared them to her belief that her husband was her husband. This contrasts with some views that suggest delusions are distinct from normal beliefs.
Natalie was able to identify specific characteristics that contributed to her delusions. In the case of believing that the strangers were her in-laws, Natalie identified the strangers’ mannerisms, behavior, and speech patterns that reminded her of her in-laws. This showed that the illusion may arise from inappropriate activation of memory representations of familiar people based on these cues and other factors.
Natalie also recalled having other beliefs, including that she was dead (known as the Cotard delusion), which she did not share with physicians at the time. He said he considered the idea because of his strange experiences and the failure of other explanations for the idea of ​​a television show.
Natalie said she ultimately dismissed the idea as unbelievable, while still retaining other delusional ideas. This suggests that belief assessment may include different thresholds for different illusions. It also highlights the personal nature of some illusions.
In addition to all her delusions, Natalie described her active involvement in trying to explain and manage her experiences. They reported considering different explanations and testing them by asking for additional information. For example, she asked questions of people she thought were her in-laws. This suggests a surprisingly similar approach to how we generally form beliefs.
Natalie recalled the influence of television and movies on her thoughts. He also recalled how he elaborated on his delusions based on information around him.
These characteristics challenge theories that illusions arise only from abnormal sensory data. Instead they highlight the role of the individual’s search for meaning and social context, as well as the subsequent impact of illusion on perception and thinking.
intent
As a case study, Natalie’s experiences are not necessarily representative of all people who experience delusions or postpartum psychosis. However, Natalie’s case presents informative features that theories of delusion need to take into account.
In particular, Natalie’s personal insights highlight the important role of the individual in actively trying to understand and provide meaning to their experiences. This contrasts with simply passively accepting beliefs in response to abnormal sensory data or neuropsychological deficiencies. This suggests that in some cases, psychological treatments in combination with other treatments may be useful in treating psychosis.
More generally, Natalie’s description reveals parallels between delusions and normal beliefs and supports the view that delusions can be understood in terms of the cognitive processes at the stages of normal belief formation that we have identified.
Although challenges remain in investigating delusions, further study may provide insight into the basis of everyday belief and, in turn, the self.
,Author: Michael Connors, Joint Senior Lecturer in Psychiatry, UNSW Sydney and Peter W Halligan, Honorary Professor of Neuropsychology, Cardiff University)
,disclosure statement: The authors do not work for, consult, own shares in, or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment. have done)
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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