Experiments to identify potential neural mechanism in “feeling of presence” | Hacker News Reader

Experiments to identify potential neural mechanism in “feeling of presence”

newscientist.com

71 pointsrbanffy26 comments

I'm not sure that it makes sense to me that this explains the feeling a presence when no one's there since in this case there was someone behind them, its just happened to be a robot. Instead it seems to me that it just shows that the brain doesn't always realize that its actions caused an event if there is enough of a delay. This could be the explanation for feeling a presence if the person's own actions are causing the sensations that the brain is misinterpreting. However, the article doesn't seem to me to present evidence that that is necessarily the case.

Still an interesting finding though!

The difference was though that the participants didn't experience FoP when the robots were perfectly synched - even though the sensation that was caused was exactly the same.

I think the bigger point is the idea that FoP might be caused by the brain not correctly matching its own actions with sensations caused by those actions.

The example they chose to test that hypothesis might not have been the best, but it's certainly a good starting point to think up better experiments.

The sample size was also very small (12 people I think) - so I don't think they were planning to make any definite claims. This seems to me like a typical case of a "more research is needed" paper hyped up to "scientists discovered that..." by the press.

Nevertheless, I think it's an interesting direction to continue research in.

(Incidentally, it's amazing that the brain actually does attempt to match up actions and sensations - shows once again that biological mechanisms are a lot more sophisticated than one might think at first glance)

Scientists often hype the claims in their own papers, in this case:

"These data show that the illusion of feeling another person nearby is caused by misperceiving the source and identity of sensorimotor (tactile, proprioceptive, and motor) signals of one’s own body."

Which for a paper is quite a strong assertion (paper appears to be open access and is cited in the article by the way).

>> The difference was though that the participants didn't experience FoP when the robots were perfectly synched - even though the sensation that was caused was exactly the same.

If the back rub robot is in sync with your own hand movements, you can tell that the sensation is cause by yourself - because it IS. When they introduce the delay, they experience it as someone else because it IS. The difference is that the time delay prevents them from realizing they are controlling the other entity so they attribute it to someone else.

This offers no explanation for the feeling outside the context of the experiment.

...So people experienced a feeling of a presence behind them... when something behind them touched them?

That would seem to be pretty robust evidence of a presence behind someone, really.

(the bit with the sensorimotor lag is necessary for this, of course; it's pretty obvious that the brain accounts differently for sensory input that it can directly correlate with its own actions and that it can't. But I bet that you'd also get a feeling of presence if the robot was touching someone on an autonomous program, which would be just as completely unsurprising.)

I prefer 'Scientists latest understanding is' to 'Now we know why'

TL;DR: Ghostly presences – the feeling of someone near you when there’s no one there – could be down to your brain trying to make sense of conflicting information.

For all x -> y != For all y -> x

For all certain brain stimulations then ghostly feeling != for all ghostly feeling then certain brain stimulation

It's just matching a different expectation pattern when you add a delay.

After my white cat passed away any light change in the corner of my eye made me expect to see it crossing the door, even tho there wasn't anything there. It had nothing to do about motor signals, just a pattern that had become fixated enough over time. I'd assume people that fixate patterns too easily have a bad time with this.

So the experiment came down to experiencing a "Feeling of Presence" when a robot arm you are controlling touches your back out of sync. That almost feels expected, something is touching you and you didn't initiate it at that moment.

It would be great to see a follow on experiment where FoP is duplicated with direct stimulation of the associated brain regions.

It is dogmatic to insist that there is a single accurate interpretation of people's subjective sensory information.

I wonder if this this is the same area of the brain that causes the feeling of deja vu?

Didn't you just post this?

Isn’t déjà vu just your brain storing something in memory quicker than another part of your brain “looking it up”? In other words it’s a race condition on a dictionary insert.

That is a 100+ year old hypothesis. But as far as I know, there's no hard evidence to support it.

That doesn't explain predictive experiences - I've been here before, and I remember there being a drinking fountain over there [point's to far left at said drinking fountain]. Of course I can't rule out the possibility that it was seen on arrival but not consciously noted, but it was totally out of frame based on the way we got there and my friend whom I said that to was baffled as well.

So, it's lag, basically?

Yep, three years' worth apparently! (Would have been nice to have a [2014] tag in the original title.)

Because the FCC needs their help to defeat Net Neutrality! Jokes aside, no, I can't recall actually ever feeling a ghostly presence -- how many people here have?

God is dead and we have killed him.

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