[thaumasiotes]

> We can estimate the amount of information processed.

I'm not sure this makes sense. Here is a simple dynamic programming problem from Project Euler: https://projecteuler.net/problem=67

You can estimate the amount of information being processed in a few different ways. But that's not really relevant; the whole point of solving this problem is that you can do the same job with less computation than it looks like you need.

There is no particular connection between "amount of information processed" and "amount of computation performed".

[rini17]

There is a connection. How can any computation be done without moving information around? In absence of better measure, we can roughly estimate the computational complexity of a black box from looking on the input and output.

If the brain's job could be hypothetically done by some optimized system using an picowatt is irrelevant. We don't have such a system.