I can't remember the book now, I think one of Antonio Damasio's? He recounted an experiment with a patient that had a severed corpus callosum where they put a wall between the eyes and showed him two different pictures, asking him what he saw, and he wrote one answer and spoke another, without any indication either half of him was aware the other half was inconsistent.

It was terrifying 20 odd years ago to read this kind of thing, but it's amusing in light of all the obsession with productivity hacking in Silicon Valley that I could almost see someone with a YouTube channel doing this on purpose to try and be able to accomplish simultaneous tasks a normal person would be tripped up on by the need for a normal brain to produce a single consistent narrative.