
Experiments to identify potential neural mechanism in “feeling of presence” - rbanffy
https://www.newscientist.com/article/dn26516-ever-felt-a-ghostly-presence-now-we-know-why/?utm_campaign=Echobox&utm_medium=Social&utm_source=Twitter&cmpid=SOC|NSNS|2017-Echobox#link_time=1509532068
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harimau777
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!

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xg15
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)

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new299
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).

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alethiophile
...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.)

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

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sharmanaetor
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.

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

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

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FranOntanaya
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.

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zspade
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.

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

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

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pixel_fcker
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.

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

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OtterCoder
So, it's lag, basically?

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

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thefalcon
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?

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tzakrajs
God is dead and we have killed him.

