SGU Episode 503
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| SGU Episode 503 |
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| February 28th 2015 |
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| (brief caption for the episode icon) |
| Skeptical Rogues |
| S: Steven Novella |
B: Bob Novella |
J: Jay Novella |
E: Evan Bernstein |
| Quote of the Week |
There is not a discovery in science, however revolutionary, however sparkling with insight, that does not arise out of what went before. |
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| Download Podcast |
| Show Notes |
| Forum Discussion |
Introduction
You're listening to the Skeptics' Guide to the Universe, your escape to reality.
Forgotten Superheroes of Science ()
- Mary Anning: Paleontologist who made significant early contributions to our understanding of prehistoric life and the history of the earth.
News Items
Marijuana Safety ()
Phantom Acupuncture (28:29)
S: OK let's move on. Have you guys heard of phantom acupuncture?
B: Yes, I have.
E: Is that a new play Andrew Lloyd Webber? That guy.
S: So, this is... I've heard of placebo acupuncture and sham acupuncture, now we have phantom acupuncture. So listen to this, this is what some researchers did.
E: OK, sounds redundant but alright.
S: Right? Well I think that was the point. You know that we can induce the experience of a phantom limb in a laboratory with pretty good reliability now.
B: Yeah, it's pretty cool.
E: It's remarkable.
S: The procedure is actually pretty simple. Let's say you're sitting in front of a table and one of your arms is on top of the table, the other one is under the table, and they're both sort of covered with a blanket and then there's a manikin or rubber arm on top of the table over your arm that's under the table. Right, you get that?
B: Yep.
S: So it looks like you have two arms on the table but one is rubber with your real arm being hidden under the table. And then, while you're looking at your arms, if somebody strokes the rubber arm in the same place and time that they stroke your real arm, you will feel and see the rubber arm being stroked. That's how your brain determines that you own the different parts of your body, right?
E: Steve, the brain overcomes the actual, I'm not sure what to call it, illusion that the rubber arm is made of rubber? It's able to sort of look past that?
S: The question has some assumptions in it that I think I need to address. Let me back up and just explain how the brain generates the sense of ownership in the first place. It's an active process and essentially what it's doing is comparing multiple different sensory streams at once: what you see, what you feel, what your motor planning is doing. Are the parts of your body doing what you want them to do? And then there are circuits that are comparing that information and they create the subjective sensation that we own the parts of our body and that we control the different parts of our body. There's actually a module in the brain called the ownership module that gives you the feedback that you own a part of your body. What happens in a phantom limb is that the ownership module still exists but even if you've had a limb amputated or it's dead, and so it's creating the sensation that you own this limb even if it's not there. And I know we've talked on the show about super-numinary phantom limbs where people have had, like after a stroke and part of their body is paralysed but their ownership module is still functioning, the ownership module may create a phantom limb because it's being deprived of the normal feed back that it gets, and so people have this hallucinatory limb, they think they have this extra arm that they feel like they own and can control.
J: Now Steve, also when someone loses a limb they could have phantom pain which is an odd phenomenon as well.
S: Right. One wrinkle to that is, like some people, their phantom sensation, like so they've had their arm amputated. They might feel like their fist is clenched and they're digging their fingernails into the palm of their hand and it's painful. One of the treatments for that is to put a mirror up so that they're looking at their intact limb but their brain sees it as their missing limb and then they open their hand so it's like visually signalling the brain that they're opening the phantom limb. And that often works. It takes the pain away.
B: Silly brain.
S: Yeah. So anyway, so now we'll get back to the acupuncture. If you do this with somebody and they successfully own the rubber hand, because of the tactile illusion, then they give acupuncture to the rubber arm. Right, so that's phantom acupuncture.
B: Wow.
S: What they found is that the brain...
E: The brain lights up.
S: The brain lights up in an fMRI scan, it responds in a way similar way to acupuncture of an actual limb.
J: Whoa.
E: Whaaaa...
S: When doing acupuncture of a phantom limb.
E: Oh my gosh, isn't that kind of a case closed kind of scenario. That's it?
S: Yeah.
B: Steve, are you saying that the rubber arms actually have meridians inside?
S: Yes, so obviously...
(laughter)
E: That's exactly what he's saying.
J: Yeah Bob, if you have a AAA battery in it, yes.
S: Yeah, it's beyond absurd to think that there's chi and meridians, life force, flowing through this rubber arm but it emphasises the fact that, how subjective these sensations are, and that even just visually tricking the brain is enough to get it to respond in a way that it thinks that it should be responding, it's sort of generating the expected experience even when nothing is actually physically happening, in this case, this is a pretty darn good control. The acupuncture is happening to a rubber arm so it can't be doing anything physiologically. The only real thing that's happening is that you're seeing it happen to an arm that your brain has been tricked into thinking is part of you. So yeah, isn't that fascinating? Now I always have to throw in the normal caveats here, this is one study, fMRI studies are really tricky to do, it would be interesting to see this replicated and to see how far we can take this but yeah, I found this very interesting. Now of course, some people will say, OK well acupuncture works by tricking the brain into thinking you're not having pain. So what? You're still not having pain. But that still gets you back to it's just an elaborate placebo, do you know what I mean? It doesn't mean you can treat cancer with acupuncture, that's always the problem I have is that they're using how easily our perception can be manipulated to say that there is something specific about acupuncture that has a specific effect and that the underlying philosophy is correct and all of that stuff and therefore I'm going to use it to treat high blood pressure and cancer and mumps and all of this other nonsense. But meanwhile studies show that just pain is incredibly distractable. You know, if you just look at the other arm while a procedure is being done on one of your arms, your perception of pain will be less, for example.
E: I do that when I get a shot in the arm, I turn away and concentrate on some other part of my body or something and I don't feel it.
S: Yeah exactly. Whereas if your attention were focussed on it it might be incredibly painful, but this pretty much undercuts the notion that therefore it must have a specific physiological effect or that chi is real or meridians are real, there's no support for that in any evidence.
E: So what's left? I mean the whole acupuncture paradigm falls entirely apart as far as I'm concerned.
J: Oh it won't do anything. Evan, nothing is going to change.
E: Oh I understand that, it's not going to convince the true believers, but that part of their argument is now entirely gone. It's over.
S: Yeah. So this wasn't looking at a clinical response, this was just looking at the brain response on an fMRI scan. The researchers said that they want to do follow up studies looking to see if there's a clinical response and that will be interesting as well. Other research already has shown that the only thing that really matters to the effect of acupuncture right, it doesn't matter where you stick the needles, it doesn't matter if you stick the needles, it doesn't matter if it's a trained acupuncturist or somebody who was just told ten minutes ago how to fake their way through it, none of that matters. The only thing that matters is the interaction between the acupuncturist and the patient. And the more supportive they are, the more positive they are, the better the outcome, and that's it. You could be randomly poking them with toothpicks but if you're nice and positive and confident they'll have a placebo effect. That's it.
E: What's next, virtual acupuncture in which you don't even have to touch the patient?
S: Well you don't, right? Therapeutic touch is virtual acupuncture, basically. Just waving your hands over somebody, literally there's nothing physical happening.
E: But they didn't call it something cool like virtual acupuncture.
S: There you go Evan, that's going to be your pseudoscience, you could do that, make a million bucks.
E: Alright! I'm getting the t-shirts made now.
S: Virtual acupuncture.
B: I'd go for multi-dimensional acupuncture.
S: Guys, quantum acupuncture.
B: Oh, there you go.
E: Oh, gosh.
J: That's good.
E: Wait, Deepak might already own the rights to that, we're going to have to check on that, yeah.
S: Yeah, that one's probably out there already.
Liberal and Conservative Biases (26:54)
Bladderwort Genome ()
Who's That Noisy ()
- Answer to last week: Shepard's Tone
Dumbest Thing of the Week ()
Interview with Timothy Caulfield ()
Science or Fiction ()
Item #1: In Stockholm, wild rabbits are being culled and their corpses are being burned in a heating plant in central Sweden. Item #2: A Beverly Hills plastic surgeon used the waste from his patient’s liposuction to create biodiesel to fuel his SUV. Item #3: On the International Space Station, human waste is dried to reclaim moister, and the remains are burned to produce power for the station.
Skeptical Quote of the Week ()
'There is not a discovery in science, however revolutionary, however sparkling with insight, that does not arise out of what went before.' - Isaac Asimov
S: The Skeptics' Guide to the Universe is produced by SGU Productions, dedicated to promoting science and critical thinking. For more information on this and other episodes, please visit our website at theskepticsguide.org, where you will find the show notes as well as links to our blogs, videos, online forum, and other content. You can send us feedback or questions to info@theskepticsguide.org. Also, please consider supporting the SGU by visiting the store page on our website, where you will find merchandise, premium content, and subscription information. Our listeners are what make SGU possible.
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