Predictive Coding System for Chronic Perceptual Disorders

Researchers

Dr. Anusha Yasoda-Mohan & Prof. Dr. Sven Vanneste
(BRAI3n/Trinity College Dublin)

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Background and goal

The project starts from the theory of predictive coding, which states that the brain constantly makes predictions about the outside world. When there is a difference between expectation and reality (a 'prediction error'), the brain adjusts its internal model.

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Chronic perceptual disorders — such as tinnitus and chronic pain — occur when this predictive system is disrupted and the brain continues to perceive the wrong signals even though the original stimulus has disappeared.

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The aim of this research was to understand how this predictive system develops throughout life, which neurological and biochemical factors contribute to the transition from an acute to a chronic condition, and which environmental, genetic and developmental factors make someone more vulnerable to such disorders.

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Operation

Analysis of existing literature and research data on tinnitus and chronic pain from a predictive coding perspective.

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Comparison of acute, transitional and chronic phases of these disorders using:

EEG and ERP measurements (such as mismatch negativity and P300)

Imaging (fMRI)

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Neurotransmitter analyses (GABA, glutamate, dopamine, norepinephrine)

Psychosocial factors (stress, anxiety, sleep, depression)

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Integrating clinical findings with a life-course approach to understand the development of the predictive system from childhood to adulthood.

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Results

The brain uses predictive coding as a basic mechanism for perception, but this system can be disrupted by stress, hearing loss, trauma, or genetic predisposition.

Both tinnitus and chronic pain appear to be based on a maladaptive form of prediction, in which the brain continues to experience erroneous stimuli as “normal”.

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Both disorders identified changes in the same brain networks, including the prefrontal cortex, cingulate cortex, and insular, suggesting a shared neurobiological mechanism.

Psychological factors such as depression, anxiety and sleep disorders play a key role in exacerbating and perpetuating these symptoms.

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These insights provide a new framework for identifying biomarkers and developing future preventive or neuromodulatory treatments.

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Conclusion

This project provided an innovative theoretical and clinical framework for understanding chronic tinnitus and pain from a predictive coding perspective. The results help to recognize early risk factors and contribute to the development of new, personalized neuromodulation therapies.