Investigating the generative dynamics of energy-based neural networks

Fuente: arXiv
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Autori principali: Tausani, Lorenzo, Testolin, Alberto, Zorzi, Marco
Natura: Preprint
Pubblicazione: 2023
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author Tausani, Lorenzo
Testolin, Alberto
Zorzi, Marco
author_facet Tausani, Lorenzo
Testolin, Alberto
Zorzi, Marco
contents Generative neural networks can produce data samples according to the statistical properties of their training distribution. This feature can be used to test modern computational neuroscience hypotheses suggesting that spontaneous brain activity is partially supported by top-down generative processing. A widely studied class of generative models is that of Restricted Boltzmann Machines (RBMs), which can be used as building blocks for unsupervised deep learning architectures. In this work, we systematically explore the generative dynamics of RBMs, characterizing the number of states visited during top-down sampling and investigating whether the heterogeneity of visited attractors could be increased by starting the generation process from biased hidden states. By considering an RBM trained on a classic dataset of handwritten digits, we show that the capacity to produce diverse data prototypes can be increased by initiating top-down sampling from chimera states, which encode high-level visual features of multiple digits. We also found that the model is not capable of transitioning between all possible digit states within a single generation trajectory, suggesting that the top-down dynamics is heavily constrained by the shape of the energy function.
format Preprint
id arxiv_https___arxiv_org_abs_2305_06745
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Investigating the generative dynamics of energy-based neural networks
Tausani, Lorenzo
Testolin, Alberto
Zorzi, Marco
Neural and Evolutionary Computing
Machine Learning
Generative neural networks can produce data samples according to the statistical properties of their training distribution. This feature can be used to test modern computational neuroscience hypotheses suggesting that spontaneous brain activity is partially supported by top-down generative processing. A widely studied class of generative models is that of Restricted Boltzmann Machines (RBMs), which can be used as building blocks for unsupervised deep learning architectures. In this work, we systematically explore the generative dynamics of RBMs, characterizing the number of states visited during top-down sampling and investigating whether the heterogeneity of visited attractors could be increased by starting the generation process from biased hidden states. By considering an RBM trained on a classic dataset of handwritten digits, we show that the capacity to produce diverse data prototypes can be increased by initiating top-down sampling from chimera states, which encode high-level visual features of multiple digits. We also found that the model is not capable of transitioning between all possible digit states within a single generation trajectory, suggesting that the top-down dynamics is heavily constrained by the shape of the energy function.
title Investigating the generative dynamics of energy-based neural networks
topic Neural and Evolutionary Computing
Machine Learning
url https://arxiv.org/abs/2305.06745