Can the brain do backprop?

If you check out the “three visual streams” paper they have a good temporal predictive cells based on the brain wave timing principle.

They break the wave into PLUS and MINUS phases where the plus phase is the upper layers forming an opinion about the “ground truth” of sensation and the minus phase (at the end) comparing a prediction in the lower layers to this ground truth.

The plumbing involves a pass through part of the pulvinar but that does not materially affect the basic mechanism of using timing of the wave to do temporal prediction.

They do take the outcome of this test and fire it back to the pulvinar to be distributed to other maps that are processing this same stream.

Why am I going on about this?

This particular pulvinar based/predictive mechanism is part of the only plausible scheme that I have seen that accomplishes the long sought goal of a biologically plausible back-prop behavior. If you are interested in this topic you owe it to yourself to do the hard work of reading the paper and references. Some very good stuff going on there.