Biological evidence that the cortex does not implement backpropagation
Sander de Haan, Pau Vilimelis Aceituno, Reinhard Loidl, Benjamin Grewe · Bernstein Conference 2024
The mammalian neocortex possesses the remarkable ability to translate complex sensory inputs into abstract representations through the coordinated activity of large neuronal ensembles across the sensory hierarchy. Theoretical works have proposed a variety of algorithms to coordinate learning across this hierarchy, including approximations of backpropagation of error as well as target-based methods such as predictive coding or control methods. In order to test the biological validity of these algorithms, we analyze the learning principles of the cortex, starting at the level of the synapse and