The doxastic shear pin: delusions as errors of learning and memory

Area of Science:

• Neuroscience
• Psychiatry
• Computational Psychiatry

Background:

• Delusions are often viewed as purely detrimental, lacking any functional benefit.
• Existing models struggle to explain the formation and persistence of delusional beliefs.

Purpose of the Study:

• To propose a new framework for understanding delusions using predictive coding principles.
• To re-evaluate the functional role of delusions in brain function and mental health.

Main Methods:

• Conceptual analysis integrating neuroscience and computational psychiatry.
• Application of predictive coding models to explain delusion formation and maintenance.
• Reinterpretation of "doxastic shear pin" hypothesis within a predictive coding framework.

Main Results:

• Delusions may function as a "doxastic shear pin," preventing cognitive collapse by disabling costly flexible inference.
• Delusions can arise from a lack of constraining top-down expectations, becoming new priors that shape perception and behavior.
• This mechanism allows for continued function in overwhelming situations, albeit in an attenuated capacity.

Conclusions:

• Delusions may serve a crucial, albeit maladaptive, role in maintaining cognitive and behavioral function.
• Understanding this protective function is essential for effective treatment strategies.
• Therapeutic approaches should consider the individual's capacity to function without the "shear pin" mechanism.