Title
Contrastive Hebbian Learning with Random Feedback Weights.
Abstract
Neural networks are commonly trained to make predictions through learning algorithms. Contrastive Hebbian learning, which is a powerful rule inspired by gradient backpropagation, is based on Hebb’s rule and the contrastive divergence algorithm. It operates in two phases, the free phase, where the data are fed to the network, and a clamped phase, where the target signals are clamped to the output layer of the network and the feedback signals are transformed through the transpose synaptic weight matrices. This implies symmetries at the synaptic level, for which there is no evidence in the brain so far. In this work, we propose a new variant of the algorithm, called random contrastive Hebbian learning, which does not rely on any synaptic weights symmetries. Instead, it uses random matrices to transform the feedback signals during the clamped phase, and the neural dynamics are described by first order non-linear differential equations. The algorithm is experimentally verified by solving a Boolean logic task, classification tasks (handwritten digits and letters), and an autoencoding task. This article also shows how the parameters affect learning, especially the random matrices. We use the pseudospectra analysis to investigate further how random matrices impact the learning process. Finally, we discuss the biological plausibility of the proposed algorithm, and how it can give rise to better computational models for learning.
Year
DOI
Venue
2018
10.1016/j.neunet.2019.01.008
Neural Networks
Keywords
Field
DocType
Random contrastive Hebbian learning,Supervised learning,Unsupervised learning,Random feedback
Matrix (mathematics),Algorithm,Hebbian theory,Computational model,Artificial intelligence,Boolean algebra,Artificial neural network,Backpropagation,Synaptic weight,Machine learning,Mathematics,Random matrix
Journal
Volume
Issue
ISSN
114
1
0893-6080
Citations 
PageRank 
References 
0
0.34
9
Authors
3
Name
Order
Citations
PageRank
Georgios Detorakis1284.19
Travis Bartley200.34
Emre Neftci318317.52