The manipulation part is what fascinates me. They didn't just correlate alpha wave frequency with ownership perception. They used transcranial stimulation to artificially speed up or slow down the waves, and the subjective experience changed accordingly.
That's a pretty direct causal link between a measurable brain state and something as fundamental as "where does my body end?"
I agree with you and I think we're changing at every moment, all the time, but it's usually gradual enough that most people don't notice or care until it manifests as new behavior.
My life is materially the same as it was on Friday but I definitely feel different after events this weekend.
I once read “The Joy of Living” by Yongey Mingyur Rinpoche. It should come with a warning. It broke me for a year. I’m actually grateful for the existential crisis it caused me. But it was a brutal experience at first.
I had a similar experience with Derek Parfit's "Reasons and Persons", but he offers some solace:
‘When I believed [that personal identity is what matters], I seemed imprisoned in myself. My life seemed like a glass tunnel, through which I was moving faster every year, and at the end of which there was darkness. When I changed my view, the walls of my glass tunnel disappeared. I now live in the open air. There is still a difference between my life and the lives of other people. But the difference is less. Other people are closer. I am less concerned about the rest of my own life, and more concerned about the lives of others.
When I believed [that personal identity is what matters], I also cared more about my inevitable death. After my death, there will be no one living who will be me. I can now redescribe this fact. Though there will later be many experiences, none of these experiences will be connected to my present experiences by chains of such direct connections as those involved in experience-memory, or in the carrying out of an earlier intention. Some of these future experiences may be related to my present experiences in less direct ways. There will later be some memories about my life. And there may later be thoughts that are influenced by mine, or things done as the result of my advice. My death will break the more direct relations between my present experiences and future experiences, but it will not break various other relations. This is all there is to the fact that there will be no one living who will be me. Now that I have seen this, my death seems to me less bad.’
I think we could summarize all as follows: _everything_ is inter-connected and hence influences its surroundings and hence everything, indirectly. Some connections (in-brain) are stronger/wider than others (human to human etc).
I read it last year, enjoyed the book, no existential crisis.
I already subscribed to the idea of the self and identity being independent and constructs. A lot of reflection around that and physics in younger years maybe helped.
This technique is likely to be utilized in some government interrogation methods now.
An excellent example of research that maybe shouldn't have been pursued, although it's possible that there are a large number of potential recuperative applications as well that I'm not aware of.
I don't think we should stop learning about ourselves out of paranoia. This sort of research could end up just like many powerful tech before (ex. nukes->green energy)
With those examples though, how would we know ahead of time that they "shouldn't be explored?" They sure looked interesting and maybe even potentially beneficial a couple decades ago.
Now, of course, we know those algorithms warp regular users (and by extension societies). Or... maybe they don't? Some research has suggested that just putting this many people in direct communication with each other is the root cause of the problems we see. There could be other ways to fix those without shutting down the internet. How would we know without more exploration?
What they seem to have identified isn't "the limits of you" so much as a timing parameter the brain uses to decide whether two sensory streams belong together
I think this is still important. How do you define a system? By boundary of communication, where inside system communication is fast, communication with outside is slow and limited. Think ( ( ((CPU) Memory) ((GPU) memory) PC ) Internet ). Your PC is a hierarchy of systems split on boundaries of communication speed. So, it would be proper that a brain identifies what's "inside" the brain in similar way.
> participants had a robotic arm tap the index finger of their real and fake hands, either at the exact same time or with a delay of up to 500 milliseconds between each tap. (...) Those with faster alpha waves appeared to rule out fake hands even with a tiny gap in taps, while those with slower waves were more likely to feel the fake hand as their own, even if the taps were farther apart.
That's the limit of "you"? Sounds more like a sampling rate/processing speed of the sense of touch.
> With a third group of participants, they used a non-invasive technique called transcranial alternating current stimulation to speed up or slow down the frequency of a person's alpha waves. And sure enough, this seemed to correlate with how real a fake hand felt.
I know this is largely orthogonal to the article, and I know what “non-invasive” means and why it’s used in this sentence, but it made me chuckle - “this technique that changed the subject’s brain waves sufficient to literally impact their sense of self - but don’t worry! It’s non-invasive!”
I wonder how those with multiple identities (DID), would affect this measurement. I know there are direct biomarkers in folk with it having to do with the frontal cortex and amygdala, and some neuroimaging being able to note vast differences in processing: https://pmc.ncbi.nlm.nih.gov/articles/PMC9045405/
I have DID and am also curious how it would affect the measurement. I'm just waking up so I've only skimmed the paper so far, but I suspect the results would differ depending on which of us was fronting.
We've noticed that each of us integrates not just sensory information differently, but we also seem to be "wired" differently.
For instance, we are AuDHD, and I, the primary host, lean strongly to the autism behavioral side, my co-host is somewhere between, and a secondary host leans strongly to the ADHD behavioral side. Things that are easy for me can be hard for another.
We also experience senses very differently. There have been many times where one of us can smell something strongly, switch, and the other can't smell it at all.
This affects other senses as well. When I watch a 24 fps movie at a theater, for about the first 10 minutes, all I see is a strobing of still images before I finally adapt and see motion. My co-host sees continuous motion right from the start. This may relate to the temporal binding window discussed in the paper as a motivation for their research.
Our working hypothesis since we were finally diagnosed has been that identity is, at least in part, an integration of both sensory information as well as how strongly various brain regions are activated by whichever identity or identities are most active at a particular time.
Lastly, we have the ability to "take control" over just part of the body. For example, for whatever reason, the motion of stirring a sauce is difficult to me, but it's trivial for another, so sometimes they'll take control of our arms to stir the pot while cooking. To me it feels like my arms have disappeared and someone else's arms are now attached and stirring the pot. This may be temporal binding window related because we do seem to experience sensory information at different speeds and this might cause us to get that alien hand feeling, which is sort of opposite of the rubber hand illusion.
So, I suspect that each of us would react differently to the rubber hand illusion test.
Yes. My rifle feels like an "extension" of my body. Also, when I drive my car I will focus on how the car feels like an extension and the scale of objects feels different. Like if I am walking down a long street it feels big, in a car it feels small.
A cell phone vibrating in your pocket: in the first days, after some days of use, many people would feel it vibrating as a muscle sensation, not as external thing vibrating.
"The researchers say that the findings could lead to new understanding of or treatments for conditions where the brain's body maps have gone askew, such as schizophrenia or the sensation of 'phantom limbs' experienced by amputees."
I wonder if having a feel for musical timing works similarly where a brain wave frequency determines how 'thight' your sense of timing is. Would be sick if you could improve that aspect of musicality with stimulation
I do wonder how far they would get with the phantom limb stuff. We know phantom limb stuff is encoded before birth so would alpha waves adjust something so fundamential?
In college I tried to participate in a rubber-hand-illusion while wearing an EEG, but the stimulation was done by the researcher manually and I never felt the illusion. This does show an interesting twist, using a robot arm for repeated and accurate stimulation.
This is interesting but i find it strange than there is no tests with a controls groups with closed eyes. Maybe some of the observed effects are visual only or psychological and not tactile at all.
>are visual only or psychological and not tactile at all
I think for a visual only test you'd need something to the effect of a neuralink that gave control over the robot arm.
Otherwise we're dealing with a set of signal mixing where your brain is attempting to take the strongest/what it deems the most important signals and give an effect based on that. The eyes give us far more data than we can actually process so the has to filter down this data to a usable stream. This can also happen with tactile response, but the number of situations this occurs in is rather rare.
I guess what I'm trying to say, at the end of the day all observed effects (except maybe reflexes) are psychological as the brain is trying to create an accurate virtualization of the input data it's receiving and that more data doesn't necessarily mean better outcomes.
The idea of "ownership of a body" made me think about a quote I heard a long time ago, while talking amongst musicians while waiting to get up and perform. It felt like some secret knowledge that I gained privilege to, while somewhat inebriated and it hasn't left me since.
> I _have_ a body, I _am_ a soul.
Maybe what they're identifying is the first half of that statement, how we interpret the former, through the presence of the latter.
Dualism?! I believe the quote I referenced wasn't implying any sort of multiplicity...it's subordination of the lesser elements of a single entity and elevation of reverence for the ephemeral. Singularity, baby.
It doesn't have to be a reference to dualism. We can draw a distinction between specific patterns of brain activity and the body that realizes it. "I" exist only when the characteristic property of neural activity that realizes the self is present. I am the realization of this second-order property. Here the "soul" is this specific pattern of dynamics realized by my body's neurons.
You make it sound like we are flesh robots : sensors and motors, with a central "CPU" that channels between the two. But a robot has no first-person experience, it's just smart electron flows.
That we have first-person experiences shows the soul is definitely not "a process your body runs" : it's where your whole experience "registers".
That we are not flesh robots is also why we have free will. You could coherently argue that free-will is an illusion, but you can't argue that first-person experience is an illusion, as you need something to perceive the illusion.
Yes, with an advanced version on an LLM on top that makes it seem like you is you. As of so far we've found zero external magical devices that cause our body to act like it does other than the cells and electrical signals they produce.
>we have first-person experiences
Do you? You say you do, much like an LLM says it knows things. But all these things you say about you are actually effects many orders separated from the cause. Your idea of first-person is something you're experiencing many filters later. Which is what the article is somewhat about. Messing with the input signals to your brain via physical mechanism changes what you feel about who you are. There is not magic, just electron flows.
>but you can't argue that first-person experience is an illusion, as you need something to perceive the illusion.
A computer can generate and play it's own video game. This can be entirely virtualized like a dream, or it could be more like AR where it's getting inputs from the world around us. "But, but, but, that's totally different in ways I cannot explain nor do I want to because I'm special"
Our improvements in AI will never lead to AI being proven smart. It will just lead to humans being proven dumb.
You can do that with mental phenomenon too - eg, having memories, feelings, consciousness, thoughts. All aspects of "I" that might be present or not - so they can't really be said to be you as much as possessed by you for a moment. Insofar as a soul exists for you to be ... it is quite small.
> You can do that with mental phenomenon too - eg, having memories, feelings, consciousness, thoughts.
But once you carry that reasoning to its full conclusion, the original argument for a "soul" or "self" that can even be meaningfully called "I" vanishes entirely. There still is some sort of underlying "true" subjective awareness that's felt to be ontologically basic in some sense (just like the "soul") but now it's entirely impersonal (the traditional term is "spirit", or "the absolute") since anything that's still personal is no longer comprised in it: an ongoing phenomenon and perhaps an inherent feature of existence itself, not a "thing".
although our internet is whitelist-blocked and I can only read the comments here, this reminds me of something my friend said some years ago, he said my car is the extension of my limbs and I can feel the limits of my car similar to my hands and feet
So, how far does the human electric field extend outside the body? May be only picovolts or in that range... But can we measure that? Does the field exist past our skin?
Can things like meditation modify that? Or how about stuff like OOBE's like what some folks call astral projection? What do those practices to to the body's electric field?
There are some capacitive sensors (Electric Potential Integrated Circuit or EPIC) that can work through clothing fabric (which is a resistor). Within a few millimeters they are good enough for a diagnostic EKG. It's also used for stress monitoring, and can be embedded in a mattress or seat back.
There are also magnetoencephalography, magnetocardiography, magnetogastrography, and magnetomyography systems in use, which use superconducting quantum interference devices (SQUID). Those are orders of magnitude sensitive enough (10^-18 T sensitivity vs 10^-6 T to 10^-9 T for some body processes or 10^-15 T for neural activity).
"Subtle energy" and "vibrational frequency" are dead giveaways of metaphysics instead of science.
I'm not adverse to that, as I do believe that much of metaphysics does have real physical backing that we haven't uncovered yet.
But I also asked a strong scientific question. First, with the human electric field, how far does it extend outside the body and at what strength? Secondly, can drugs or practices modify this, and how so?
>So, how far does the human electric field extend outside the body?
Electromagnetic fields extend infinitely.
>Can things like meditation modify that?
Anything you do with your brain changes the electric field. Reading this comment changed the electric field generated by your brain by some tiny amount.
Wow, that’s really interesting! It seems like alpha waves are the ‘tick rate’ of this system, and some set number of ticks are required to update the body model?
I don’t think the study claims alpha waves are literally the body model’s clock. What they show is that the speed of alpha cycles influences how precisely the brain binds sensory signals to generate the feeling of body ownership.
Very interesting, and I suspect somewhat related to the phenomenon in high-performance sports and music where the player or athlete feels they have become one with the instrument or equipment. It happens after a certain level of expertise, and when everything is tuned just right, and often with the flow state.
The perception goes beyond feeling fine sensations in the interface to the instrument/equipment, but literally feeling like it is a part of your body. I've gotten it in both alpine ski racing and sportscar racing. When it is ON, moving a ski or wheel to a particular spot feels the same as when I'd put my foot on a particular rock where running in rough terrain, and often even more part of me than when kicking a soccer ball with my real foot. Both the sensitivity of the feel (feedback) and the precision with which I could execute was just an entire other level, and it is still weird to think of how it was often better feedback & precision than my own foot in a less-skilled situation.
Now run the same kinds of tests while listening to music, meditation, sleep, orgasm, psychoactive substances (including caffeine/alcohol/nicotine), during simulated stress event (hard slap in the face?), on different age groups, genders, races. Perhaps there are more than one version or definition of "You" that arises in certain circumstances.
Like the large scale, nearly speed-of-light continuous electrical field fluctuations that influence long-distance discrete neural firing and may be the basis for conscious experience?
That's a pretty direct causal link between a measurable brain state and something as fundamental as "where does my body end?"
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