Gradient Expectations

An insightful investigation into the mechanisms underlying the predictive functions of neural networks—and their ability to chart a new path for AI.

Prediction is a cognitive advantage like few others, inherently linked to our ability to survive and thrive. Our brains are awash in signals that embody prediction. Can we extend this capability more explicitly into synthetic neural networks to improve the function of AI and enhance its place in our world? Gradient Expectations is a bold effort by Keith L. Downing to map the origins and anatomy of natural and artificial neural networks to explore how, when designed as predictive modules, their components might serve as the basis for the simulated evolution of advanced neural network systems.

Downing delves into the known neural architecture of the mammalian brain to illuminate the structure of predictive networks and determine more precisely how the ability to predict might have evolved from more primitive neural circuits. He then surveys past and present computational neural models that leverage predictive mechanisms with biological plausibility, identifying elements, such as gradients, that natural and artificial networks share. Behind well-founded predictions lie gradients, Downing finds, but of a different scope than those that belong to today’s deep learning. Digging into the connections between predictions and gradients, and their manifestation in the brain and neural networks, is one compelling example of how Downing enriches both our understanding of such relationships and their role in strengthening AI tools.  

Synthesizing critical research in neuroscience, cognitive science, and connectionism, Gradient Expectations offers unique depth and breadth of perspective on predictive neural-network models, including a grasp of predictive neural circuits that enables the integration of computational models of prediction with evolutionary algorithms.Preface xi
Acknowledgments xv
1 Introduction 1
2 Conceptual Foundation of Prediction 11
3 Biological Foundations of Prediction 29
4 Neural Energy Networks 61
5 Predictive Coding 93
6 Emergence of Predictive Networks 117
7 Evolving Artificial Predictive Networks 149
8 Conclusion 187
Notes 195
References 197
Index 205“Charting a path from early artificial neural networks to the contemporary vision of the predictive brain, with rich forays into biology and evolution, this book explains the buzz about brains as engines of prediction.”
—Andy Clark, Professor of Cognitive Philosophy, University of Sussex; author of Surfing Uncertainty: Prediction, Action, and the Embodied Mind and The Experience Machine: How Our Minds Predict and Shape Reality
 
 
“Downing’s reach is omnidirectional. He connects the roots and new growth of deep learning with math, neuroscience, evolutionary biology, ethology, and computer science to show how intelligence emerged in animals and is emerging in machines.”
—Josh Bongard, Veinott Professor of Computer Science, University of VermontKeith L. Downing is Professor of Artificial Intelligence and Artificial Life at the Norwegian University of Science and Technology and the author of Intelligence Emerging: Adaptivity and Search in Evolving Neural Systems (MIT Press).