Benchmarking Predictive Coding Networks -- Made Simple
Luca Pinchetti, Chang Qi, Oleh Lokshyn, Gaspard Olivers and, Cornelius Emde, Mufeng Tang, Amine M'Charrak, Simon Frieder and, Bayar Menzat, Rafal Bogacz, Thomas Lukasiewicz, Tommaso Salvatori

TL;DR
This paper introduces PCX, a simple and efficient library for benchmarking predictive coding networks (PCNs), enabling large-scale experiments, achieving new state-of-the-art results, and identifying current limitations to guide future research.
Contribution
The authors present PCX, an open-source library that standardizes benchmarks for PCNs, facilitating scalable experiments and advancing the state-of-the-art in the field.
Findings
Achieved state-of-the-art results on multiple datasets.
Enabled testing of larger architectures on complex data.
Identified key limitations and future directions for PCNs.
Abstract
In this work, we tackle the problems of efficiency and scalability for predictive coding networks (PCNs) in machine learning. To do so, we propose a library, called PCX, that focuses on performance and simplicity, and use it to implement a large set of standard benchmarks for the community to use for their experiments. As most works in the field propose their own tasks and architectures, do not compare one against each other, and focus on small-scale tasks, a simple and fast open-source library and a comprehensive set of benchmarks would address all these concerns. Then, we perform extensive tests on such benchmarks using both existing algorithms for PCNs, as well as adaptations of other methods popular in the bio-plausible deep learning community. All this has allowed us to (i) test architectures much larger than commonly used in the literature, on more complex datasets; (ii)~reach new…
Peer Reviews
Decision·ICLR 2025 Spotlight
- Addresses Core Issues in PC Research: The paper tackles fundamental shortcomings in the subfield, such as inconsistent comparisons, overly simple benchmarks, and a lack of rigorous, standardized practices. - Unified Benchmarking Framework: Introduces a comprehensive and standardized benchmark for PCN models, incorporating major datasets like CIFAR-100, Tiny ImageNet, FashionMNIST, and MNIST to ensure consistent and meaningful comparisons. - Implementation of Open-Source Tool (PCX): Offers a
Weaknesses of the Paper: - Writing and Terminology: The paper has inconsistencies in terminology and occasional grammar and spelling issues, along with unclear phrasing that affects readability and comprehension. - Comparative Analysis Limitations: The paper could be strengthened by including more comparisons with other biologically inspired approaches and better situating its findings within the broader machine learning context. - Practical Implications: The paper lacks a thorough exploration o
1. The benchmark results included in this work is very extensive which includes most of the popular baselines. 2. The design and usage of the contributed library are well documented with provided repos (I didn't run the code in this repo). 3. The analysis provided in the paper is well explained such as showing different results from different methods which makes the paper easy to read 4. With the contributed library, the paper is able to scale up the field to larger datasets which greatly improv
1. Some figures can be improved, e.g. for figure 2, the method name can be draw above the images for better representation. 2. The main models used in the paper is MLP and VGG, since the library has been developed, we should probably test a few more model types such as resnet (shallow is OK if deep ones cannot be test) or vit. This could probably real more insights on the overall states of PCN algorithms.
### Originality The main contribution of the paper is the PCX library which can be used to implement predictive coding networks, and the proposed benchmarks, which can be used to evaluate the scalability of new predictive coding networks. ### Quality The PCX library, owing to Just-In-Time compilation, is much faster than the baseline library. The reported performance (training times) of the PCX library shines against the baseline by Song et al. ### Clartity The tutorials are of good quality.
I gave a score of 3 for Contribution but only 1 for Soundness. This is because I believe the PCX library is a valuable contribution to the community; however, I have reservations about some of the conclusions and claims made in the paper. Consider the Energy propagation subsection of Section 5.1 (Energy and Stability). L377 says, “Note that the decay in performance as function of increasing γ is stronger for Adam despite being the overall better optimizer in our experiments. This suggests that
Code & Models
Videos
Taxonomy
TopicsNeural Networks and Applications
MethodsSparse Evolutionary Training · Focus · Lib
