Skip to content

Canalization and plasticity in psychopathology

Robin Carhart‐Harris, Shamil Chandaria, David Erritzøe, Adam Gazzaley, Manesh Girn, Hannes Kettner, Pedro A. M. Mediano, David Nutt, Fernando E. Rosas, Leor Roseman, Christopher Timmermann, Brandon Weiss, Richard J. Zeifman, Karl Friston

Neuropharmacology December 27, 2022 DOI: 10.1016/j.neuropharm.2022.109398

Summary

A new Psychology model suggests psychopathology entrenches through "canalization," a brain plasticity akin to Hebbian theory. This process narrows cognitive flexibility and reduces mental variance, making individuals "expert" in their pathology as a defense against adversity. Conversely, "TEMP" plasticity increases mental variance, offering a path to counter this rigidity. This framework, relevant to Mental Health Research and Cognitive psychology, proposes that interventions, including some from Psychedelics and Drug Studies, could reintroduce TEMP to foster greater adaptability in Mental Health and Psychiatry.

Abstract

This theoretical article revives a classical bridging construct, canalization, to describe a new model of a general factor of psychopathology. To achieve this, we have distinguished between two types of plasticity, an early one that we call 'TEMP' for 'Temperature or Entropy Mediated Plasticity', and another, we call 'canalization', which is close to Hebbian plasticity. These two forms of plasticity can be most easily distinguished by their relationship to 'precision' or inverse variance; TEMP relates to increased model variance or decreased precision, whereas the opposite is true for canalization. TEMP also subsumes increased learning rate, (Ising) temperature and entropy. Dictionary definitions of 'plasticity' describe it as the property of being easily shaped or molded; TEMP is the better match for this. Importantly, we propose that 'pathological' phenotypes develop via mechanisms of canalization or increased model precision, as a defensive response to adversity and associated distress or dysphoria. Our model states that canalization entrenches in psychopathology, narrowing the phenotypic state-space as the agent develops expertise in their pathology. We suggest that TEMP - combined with gently guiding psychological support - can counter canalization. We address questions of whether and when canalization is adaptive versus maladaptive, furnish our model with references to basic and human neuroscience, and offer concrete experiments and measures to test its main hypotheses and implications. This article is part of the Special Issue on "National Institutes of Health Psilocybin Research Speaker Series".

Tags

Comments

No comments yet.

Log in to comment