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.
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.
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
> 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.
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.
> 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!”
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.
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.
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.
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?
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
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.
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.
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 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".
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.
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?"
The self changes rapidly when dementia, alzheimers, a car crash, or a concussion which rocks someone's world the wrong way.
Who we are is incredibly fragile. You are just one bad infection away from being a different person.
My life is materially the same as it was on Friday but I definitely feel different after events this weekend.
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.
That's the limit of "you"? Sounds more like a sampling rate/processing speed of the sense of touch.
https://news.ki.se/how-brain-waves-shape-our-sense-of-self
I wonder if the brain can experience if clothing, tools, bikes are part of the body?
> 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!”
OTH nearly all brain experiments are non-invasive. Did they mean to use the word to downplay how seriously impacting the experiment was?
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.
You always hear about how something is an extension of the body to the best athletes.
> 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.
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.
I heard Michal Levin talk about dualism recently. He has an interesting point: https://youtube.com/watch?v=Qp0rCU49lMs&t=6210
Whether personality is entirely based on laws of physics or not - is a separate question.
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".
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).
https://pubmed.ncbi.nlm.nih.gov/20664147/
Meditation can alter a lot of “you” , and there is a reason you learn the advanced stuff under a guru (yoga mostly) or monk (buddhism).
>Recent health research has focused on subtle energy and vibrational frequency as key components of health and healing.
*ding ding, crackpot alert, ding ding*
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?
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.
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.
How about now?
Curses!