Hacker News Reader

Comment by raldi | Hacker News Reader

This fails the brain-in-vat test. Put mine in one, give it the exact same signals, and I’m still sentient and will experience hunger even without a stomach.

Or even without the science fiction: people with amputated limbs frequently report phantom itches on them.

View on HN

I would disagree with the experience hunger without a stomach part, based on my empirical experiences with remembering being under general anesthesia. I didn't even feel my heartbeat and calmly wondered if I was dead until I came to. Phantom limbs are a thing certainly, but there seems to be a certain amount of dependence upon bodily inputs.

In the scenario I'm describing, the brain inputs would remain the same.

I don't think you can generalize it like that. Hunger comes from signals originating in your stomach. Without a stomach, you're brain would lose energy -- and I'd wager the symptoms would be more like oxygen deprivation than "hunger".

Why would the symptoms feel any different if my brain were receiving the exact same signals?

How can you possibly know this? Has your brain been in a vat?

We don't know, maybe it has.

With reasoning, and logic. Phantom limb syndrome is a real thing. Extending that to a 'phantom stomach' that always reports that it is empty (missing) is not far fetched...

So 'know': no, no one knows what it's actually like to be a brain in the vat... but it's a reasonably good guess that you might experience something like this.

If my brain were receiving exactly the same signals, why would my experience feel any different?

Reply on news.ycombinator.com