By way of analogy, if a civilisation had found an antenna, but has not discovered radio they might think that the internet and it's content is coming from within the antenna, because that's all there is.
I was going to counter that we can circuit-bend humans enough to know that the processing is local, unless you're going to claim that every little piece of a human is connecting remotely to the magic-land - but then I remembered that this is exactly how "Internet of Things" starts to look like: tons of devices sitting next to each other, but for no fucking reason, talking through servers on the other side of the planet.
I suspect that if we stop and think about bandwith and transmission speed we likely find out that whatever might be transmitting information to our brains has to sit close to us, but I lack some data to actually do the computation.
If we jump this far off the beaten path we can probably stop assuming that whatever was transmitting the data would be limited to the 4 dimensional space we're trapped in and could in theory have causal connection via higher dimensions.
By way of analogy, if a civilisation had found an antenna, but has not discovered radio they might think that the internet and it's content is coming from within the antenna, because that's all there is.