@nierenstein @Insomnolant @HonkeyJustice @bleedingphoenix There's a fair amount of debate about this.

Imagine they build a perfect (really good) simulation of a neuron. Then one by one the neurons in your brain get replaced by their simulation. In the beginning you're obviously you. Where is the point where it's not you any more, just a simulation?

(basically Ship of Theseus for your brain)