What happens when the brain can no longer filter reality?

In this interlude of The Observable Unknown, Dr. Juan Carlos Rey examines the neuroscience of psychosis, predictive processing, and the breakdown of perceptual stability. This episode focuses on how excessive prediction error destabilizes the brain’s internal model of reality and alters the way meaning is constructed.

Drawing on the work of Chris Frith at University College London, this episode explores how the brain distinguishes between internal and external signals through prediction and error correction. Perception is not passive. It is an active process of generating expectations and updating them through incoming sensory data. Prediction error signals indicate when reality does not match expectation, allowing the brain to refine its model.

The discussion extends through the research of Philip Corlett at Yale University, whose work on psychosis demonstrates what occurs when prediction error becomes overweighted. In these states, signals that would normally be ignored are treated as significant. The brain assigns meaning where it would typically filter, resulting in heightened pattern detection, increased salience, and the formation of beliefs that attempt to stabilize overwhelming input.

This episode examines the difference between altered perception and psychotic destabilization, emphasizing that psychosis is not defined by a lack of meaning but by an excess of meaning. When the brain cannot reduce or discard incoming signals, it compensates by generating explanations at every point of discrepancy. The result is a form of over-interpretation in which every detail appears relevant.

Additional insights are drawn from Dr. Rey’s work in A Simplified Neuroscience of Intuition: How the Brain Learns Before the Mind Speaks, highlighting the role of selective processing under uncertainty. Intuition functions through constraint and weighting, allowing the mind to navigate incomplete information without assigning significance to every signal.

Key topics include predictive processing theory, prediction error weighting, psychosis and delusion formation, salience misattribution, cognitive filtering, perception vs reality, neuroscience of belief formation, and the stability of the brain’s internal model.

This interlude challenges the assumption that reality is simply perceived. It presents a more precise view: reality is constructed through a balance of prediction, filtering, and error correction. When that balance fails, perception becomes unstable, and meaning becomes excessive.

The Observable Unknown continues its exploration at the intersection of neuroscience, psychology, and philosophy, examining not only how reality is constructed, but how it can destabilize when the brain loses its ability to ignore.

The Observable Unknown is a podcast exploring consciousness at the intersection of neuroscience, culture, and lived experience. It is written and hosted by Dr. Juan Carlos Rey of drjuancarlosrey.com and crowscupboard.com, an interdisciplinary scholar whose work bridges neuroscience, philosophy, and the interior dimensions of human experience. https://squareup.com/outreach/nyD7vi/subscribe