The Ecclesia

Predictive Coding and Free Energy Principle

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Predictive Coding and Free Energy Principle

Source: Karl Friston, Nature Reviews Neuroscience, 2010; Rao & Ballard, Nature Neuroscience, 1999 Institution: UCL

Finding

Friston’s free energy principle proposes that the brain minimizes variational free energy — the discrepancy between predictions and sensory data. Prediction errors propagate upward; predictions propagate downward. The framework unifies earlier predictive coding models. When the generative model produces percepts that override sensory evidence, hallucinations result. The brain maintains alignment between its internal model and external reality through continuous error correction.

Pattern Mapping

Alignment — The brain maintains alignment between model and reality. When prediction matches sensation, free energy is minimized. Misalignment is registered as prediction error and triggers updating.

Honesty — Prediction error is structurally honest. The system cannot suppress the discrepancy between what it predicted and what it received. The error signal is not optional.

Non-fabrication — Hallucinations occur when the generative model produces percepts that override sensory evidence. This is fabrication: internally generated structure treated as external reality.

Connections

  • Default Mode Network — DMN generates narrative at rest; predictive coding explains why: the generative model runs continuously
  • Heart and Cardiac Valves — both use pressure/prediction gradients to detect and correct misalignment
  • Kidney and Nephron Filtration — tubuloglomerular feedback parallels prediction error: both detect deviation and correct
  • Narcissus — Narcissus’s perceptual error (reflection = other) is a failure of predictive coding: the model overrides the evidence
  • Bone Remodeling — both continuously restructure to match actual conditions rather than theoretical ones

Status

Influential but debated (Colombo & Series 2012; Bowers & Davis 2012). The property mapping is this project’s structural interpretation.

The mapping to the five properties is this project’s structural interpretation.

Graph View

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