Photons guided by axons may enable backpropagation-based learning in the brain

" Despite great advances in explaining synaptic plasticity and neuron function, a complete understanding of the brain’s learning algorithms is still missing. Artificial neural networks provide a powerful learning paradigm through the backpropagation algorithm which modifies synaptic weights by using feedback connections. Backpropagation requires extensive communication of information back through the layers of a network. This has been argued to be biologically implausible and it is not clear whether backpropagation can be realized in the brain. Here we suggest that biophotons guided by axons provide a potential channel for backward transmission of information in the brain. Biophotons have been experimentally shown to be produced in the brain, yet their purpose is not understood. We propose that biophotons can propagate from each post-synaptic neuron to its pre-synaptic one to carry the required information backward. To reflect the stochastic character of biophoton emissions, our model includes the stochastic backward transmission of teaching signals." {Credits 1}

{Credits 1} 🎪 Zarkeshian, P., Kergan, T., Ghobadi, R. et al. Photons guided by axons may enable backpropagation-based learning in the brain. Sci Rep 12, 20720 (2022). https://doi.org/10.1038/s41598-022-24871-6. © 2022 Author(s). This is an open access article distributed under the terms of the Creative Creative Commons Attribution 4.0 International License.