1–5 Sept 2026
University of Sussex
Europe/London timezone

Spatial Coarse-Graining Impedes the Ability to Classify Message-Passing Algorithms

1 Sept 2026, 15:43
1m
Large Lecture Theatre (Jubilee Building)

Large Lecture Theatre

Jubilee Building

Speaker

Carter Goldman (University of Sussex)

Description

Supporters of the Bayesian Brain Hypothesis argue that the brain maintains a generative model of the environment and inverts this model to infer the states of the world. Message-passing is one class of algorithms that performs this computation tractably. While there is some evidence that the brain uses specific forms of message-passing, such as mean-field variational inference, other algorithms, such as Thouless-Anderson-Palmer message-passing, remain plausible candidates but have yet to be thoroughly considered. In this study, we investigate the measurement requirements for comparing message-passing algorithms as alternative explanations of data. We examine how the spatial precision of neural recordings would affect the ability to determine which message-passing algorithm the brain implements. Even with exact coarse-graining procedures using the renormalization group, we were not able to identify the ground-truth implemented by individual neurons. Thus, fine-grained measurements may be necessary to draw conclusions about how the brain could implement Bayesian inference through message-passing.

Affiliation University of Sussex
Career status PhD student

Authors

Carter Goldman (University of Sussex) Dr Christopher Buckley (University of Sussex) Mr Ryan Singh (University of Sussex)

Presentation materials