> Real neurons don't use calculus and activation functions, nor back-propagation, etc in order to learn. All of those things in an ANN are just abstractions and

> Real neurons don't use calculus and activation functions, nor back-propagation, etc in order to learn. All of those things in an ANN are just abstractions and models around what occurs in nature. But do you think that real neurons are less complicated than artificial neurons? Look at the molecular structure of a single ion channel. It's crazy complicated! How do we know that neurons don't do calculus? Chemical gradients, summation, etc.