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  • Perspective
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Biological underpinnings for lifelong learning machines

Abstract

Biological organisms learn from interactions with their environment throughout their lifetime. For artificial systems to successfully act and adapt in the real world, it is desirable to similarly be able to learn on a continual basis. This challenge is known as lifelong learning, and remains to a large extent unsolved. In this Perspective article, we identify a set of key capabilities that artificial systems will need to achieve lifelong learning. We describe a number of biological mechanisms, both neuronal and non-neuronal, that help explain how organisms solve these challenges, and present examples of biologically inspired models and biologically plausible mechanisms that have been applied to artificial systems in the quest towards development of lifelong learning machines. We discuss opportunities to further our understanding and advance the state of the art in lifelong learning, aiming to bridge the gap between natural and artificial intelligence.

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Fig. 1: Key features required to achieve lifelong learning.
Fig. 2: Biological mechanisms that support lifelong learning.
Fig. 3: Neurogenesis.
Fig. 4: Episodic replay in the hippocampus of a rodent.
Fig. 5: Neuromodulatory systems in the brain.
Fig. 6: Biological systems use multiple levels of dynamical interactions.
Fig. 7: BEN: a non-neural bioelectric network (a mechanism used for control of growth and form during regeneration and repair) that can learn.
Fig. 8: Biomolecular perceptron circuit.
Fig. 9: Lifelong learning in reconfigurable organisms.
Fig. 10: Application of biologically inspired models for L2.

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Acknowledgements

This work was partly supported by the DARPA Lifelong Learning Machines programme. We wish to express our thanks to the technical leadership team of DARPA L2M, specifically R. McFarland, B. Epstein, R. McFarland and T. Senator. R. McFarland and B. Epstein offered several insights on organization of the paper, contributed in brainstorming sessions, and provided graphics suggestions. T. Senator seeded the idea to develop a review article. R. McFarland and other members of the L2M team spurred insightful discussions and provided feedback on the Perspective. We thank G. Vallabha, E. Johnson, M. Peot, F. Sha for reviewing the manuscript.

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A brief explanation of the biologically inspired models mentioned in the article; and metrics that have been used to assess specific aspects of L2 performance.

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Kudithipudi, D., Aguilar-Simon, M., Babb, J. et al. Biological underpinnings for lifelong learning machines. Nat Mach Intell 4, 196–210 (2022). https://doi.org/10.1038/s42256-022-00452-0

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