It’s easy to think yourself a mere brain within a human body -- a cognitive machine making sense out of all the incoming sense data from outside world. But what if other parts of the body and even objects beyond the body serve a vital role in our cognition? In this episode of the Stuff to Blow Your Mind podcast, Robert and Joe discuss the concept of extended cognition and how it relates to the human condition, number systems, spider webs, octopuses, mantises and even a fictional alien brain monster.