Well I like to think of it this way. We know that the brain is at least a Turing machine since we can perform the same calculations. If the brain is more powerf

Well I like to think of it this way. We know that the brain is at least a Turing machine since we can perform the same calculations. If the brain is more powerful than a Turing machine than any attempts to replicate it in a general sense will not work. A pushdown automaton can solve certain problems that a finite state machine can't. Finite state machines can't solve the general palindrome problem, but they can be designed to solve palindromes of a bounded length / alphabet. The complexity explodes with the length of the string and number of characters, but it can be done. To me our attempts at creating a general AI with a turing machine is starting to take a similar shape. We know we can generate an algorithm (machine learning) that can solve a contained problem.