I was just reading about a hypothesis that quantum search might be common in nature. If it is leveraged in the brain, perhaps that might increase the biological plausibility of Hinton’s capsules. In particular I’m wondering if EM routing between capsules might be implemented as quantum search.

Another possibility is a quantum search encompassing multiple layers of neurons to find weights that minimize the cost function, without the need for back-propagation. But unless nature has some secret for maintaining quantum coherence over large structures, it seems more likely that quantum search would operate more locally.