I stumbled upon this nice discussion about the human brain with UChicago neuroscientist Bobby Kasthuri. People like commenter RR have argued that the human mind is too miraculous to be explained by biology but it’s more likely that the biology is just incredibly complex. For example, let’s say the average human brain has 86 billion neurons, and each neuron might be connected to 10,000 other neurons. That’s 860000000000000 connections! The reason brain size is moderately correlated with IQ is perhaps because the bigger the brain, the more room there is for more neurons and more connections. In addition, smart brains have more fatty substance surrounding the connections to make them transmit information faster which also takes up space.

But the larger point is if we could map all these 860000000000000 connections we could capture not only your intelligence, but your hopes, dreams, memories, fears, anxieties, passions, sexual fantasies…your very soul, and maybe one day we could upload your consciousness, your “soul” on a computer. An interesting philosophical question is whether we’re uploading you; in my opinion it would not be you because in theory, this could even be done while you’re still alive without you knowing it, which makes it a separate entity.

Anyway, the interview doesn’t go into all that sci-fi stuff but it does discuss the practical problems of mapping brains. You can listen here.