When I first saw this video of Spaun and the tasks it can complete (solving the Towers of Hanoi problem, completing the Raven matrices), I was really impressed, but then I realized I didn't really know what other tasks were being completed by other neural architectures. Consequently, I almost asked a question here that was basically "How does Spaun compare in terms of task complexity to other neural architectures?". However, I realized that it would be better to if I could learn how to do this evaluation myself.
So, what metrics or heuristics can be used to evaluate the complexity of a task completed by a neural architecture? How can one evaluate the complexity of a problem/puzzle such at the Tower of Hanoi, to another problem, such as modelling how people solve algebraic equations, like ACT-R has accomplished?