SGU Episode 396

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SGU Episode 396
16th February 2013

Transcript Verified Transcript Verified

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SGU 395 SGU 397
Skeptical Rogues
S: Steven Novella
R: Rebecca Watson
B: Bob Novella
J: Jay Novella
E: Evan Bernstein
BW: Brian Wecht
Quote of the Week
Nothing is so firmly believed as what is least known.
Michel de Montaigne
Download Podcast
Show Notes
Forum Topic


You're listening to the Skeptics' Guide to the Universe, your escape to reality.

S: Hello and welcome to the Skeptics' Guide to the Universe. Today is Wednesday February 13th 2013 and this is your host Steven Novella. Joining me this week are Bob Novella.

B: Hey Everybody.

S: Rebecca Watson.

R: Hello Everyone.

S: Jay Novella.

J: Hot Damn!

S: And Evan Bernstein.

E: By the sweat of your face you shall eat bread till you return to the ground for out of it you were taken, for you are dust. Into dust you shall return.

R: That was weird and depressing. OK!

J: What's up with that?

E: Ash Wednesday.

S: Yeah it is Ash Wednesday.

R: Oooh.

B: Oh, it is?

E: Yeah.

S: Yeah, I was seeing a patient today and I thought they had some kind of dark and suspicious looking mole under their hair.


S: So even though I'm a neurologist I still examine the whole patient, and so I brushed their hair aside to see what it was, and it was... you know... they were Catholic.

E: You brushed their hair aside, you didn't just ask them?

R: You didn't lick your finger and rub it on their face did you?

S: No, I didn't wipe it off.

J: Guys! Guys!

E: Huh? Yeah? What? Oh hey, Jay.

J: I have a son. I have a baby boy. (laughs)

R: Yeah! Well done.

S: Is that where you were last week?

B: Why didn't you tell us?

R: Well done to Courtney I guess, you didn't really do much.

J: Uh, come on it was very hard to watch.

R: I bet.

J: That is serious stuff, man.

E: I know, you almost spilled your popcorn, I know.

J: It was epic. It was incredible, the whole experience was absolutely incredible. I don't recommend it, it's not for everybody.

R: You don't recommend it?

J: It's not for everyone I mean, it's not for everyone. It's absolutely fantastic if you want it and you're ready for it and I absolutely was ready for it.

S: Was that for the benefit of our younger listeners, Jay? The...

J: Absolutely, yeah I wasn't talking to Rebecca here, she already knows all of that.

R: Yeah, I know the birds and the bees.

J: You know, it's all the clichés, you know I wish I had a different profound thought to share other than when it happens and it's right it's the best thing in the world, it's fantastic.

S: The clichés are all true is what you're saying.

J: They are, and it's inexplicable, you have to experience this for yourself.

S: Well congratulations, brother.

J: Thanks, sorry I wasn't here for two weeks, guys. I didn't want it to be that way but you know.

R: Eh, what are you going to do?

S: Life intrudes on our little project here unfortunately.

J: You know, just so you know, babies make incredibly cute noises.

S: Yes, they do. The cooing noises?

R: Uh yeah, when it's yours. Before it starts that horrible screaming sound.

S: Well it gets cuter though Jay, when they start to form those noises into words, proto-language. It gets really cute.

J: I just want to share something.

R: Alright.

(cooing noises)

R: I'm pretty sure that was a seal.

J: (laughs) Come on that's adorable.

R: Yeah, it's alright, it's pretty cute.

This Day in Skepticism (3:02)[edit]

February 16, 1997 Physicist Chien-Shiung Wu died.

R: Hey, it's time for this day in whatever, are you ready?

S: Yeah.

B: Whatever.

R: It's exciting. I usually try to avoid "this is the day somebody died" events because you know, it's depressing. But in this case the person was so awesome that I wanted to talk about her. Today, February 16th in 1997, Chien-Shiung Wu died. So Chien-Shiung Wu was born in China in 1912 to a father who believed in the equality of the sexes, so much so that he started a vocational school for women. When she was 11, Wu left her home town to pursue her education which continued up through university where she studied physics, and upon graduation she became a researcher at the institute of physics at a Chinese academy. At the age of 24 she decided that she'd gone as far as she could possibly go in China, so she hopped a steam ship to the US and she landed in San Francisco and she enrolled at UC Berkley in grad school and she eventually finished here PhD there in 1940. Then she moved East. She became a faculty member at Smith, then Princeton, then finally at Columbia, where she did research for the Manhattan Project doing amazing things like helping to figure out how to separate uranium metal using gaseous diffusion. Also at Columbia, she hooked up with these two theoretical physicists who came up with an idea that the hypothetical law of conservation of parity was wrong when it came to the weak nuclear force. Wu was able to develop the experiment that proved them right. The theoretical physicists won the Nobel Prize for it and Wu won the first ever Wolf prize in physics for it in 1978. So she was a really amazing woman, she did tons of awesome stuff and I was very excited to note that we have something in common. She also has an asteroid named after her.

B: (laughs)

S: Cool.

R: So yeah. Chien-Shiung Wu. Awesome lady.

S: The Chinese Marie Curie, apparently.

R: Yeah.

E: Nice.

R: Although I like to think that Marie Curie is the European Chien-Shiung Wu.

E: Ah. Touché

S: Well that's what they say in China.

R: Right.

J: That is cool.

News Items[edit]

AI Doctor (5:23)[edit] Researchers Say AI Prescribes Better Treatment than Doctors

S: So Jay, you're going to start off the News Segment by telling us about computers practising medicine.

J: Right. But first.

Old Gray!

B: (laughs) Old Gray!

R: Why?

J: I'm just celebrating.

E: Should I know what that is?

Everyone: Old Gray.

B: Oh my god, Evan.

J: We need to talk after the show.

E: Now I remember you referencing that a long time ago, I never bothered to latch on.

J: You never bothered to watch like internet absolutely incredible?

B: You never bothered to laugh?

E: I was busy then.

R: Do you not have joy in your life, Evan?

E: Apparently not, apparently I am sorely lacking.

R: Why do you hate happiness?

J: OK so, two Indiana University researchers Casey Bennett and Kris Hauser have developed something called an expert machine. This is something we've talked about on the show before,[link needed] it's like IBM's Watson, remember that program they were using to play Jeopardy.

R: No relation.

B: Yep.

S: Oh yeah.

E: And it kicked ass.

J: This is something called, like I said, an expert machine, but this one is specialized in determining patient illness and treatments. Which I've been waiting for this, I've actually talked to Steve about this many times, I'm like 'Steve, why don't they have a computer to do all the heavy lifting and have the doctor do the fine tuning?' Well that's exactly what these guys did. The technology uses machine learning and is the same computer science discipline that in part supported some of these cool things that we all are getting to see now like voice recognition, we all have that on our cell phones, the self-driving cars, like the stuff, the work, that Google is doing with their cars, and credit card fraud detection systems which, I don't know if many people know about but that's a pretty significant system that they use, a very robust system that is in place to help prevent fraud and to capture people who are committing fraud. So at its core the new system uses a pair of predictive modelling techniques, one of them called the Markov Decision Process and the second one is Dynamic Decision Networks. These are two cool things that you should read about, each of them distinct; in conjunction, they are making something that was not too long ago impossible. The idea behind the research and eventual development is pretty straight forward. If doctors can stop relying in their intuition and instead focus on the known facts, they would be able to make better decisions. I know it sounds very simple, but in essence, that's what they set out to do. It uses sequential decision making where each decision opens up new pathways and those simulate alternative treatments and as new data becomes available it plans and re-plans its path and they say that, quote-unquote, "it can think like a doctor." So I know that that might sound like a contradiction, because I just said before that it could work better than doctors or doctors are using intuition to come to their decision. It's going to use the process that a doctor would use but on an amazingly huge scale, right? And this is where you need the huge processing power of computers to do it. The idea being that if they took say all of the medical records of the entire country, the entire United States, which as many of you know are rapidly becoming– our healthcare system is becoming electronic, and that all of our data is going online. Many of the people who have gone to the doctor over the past couple of years have noticed that they're using software now, they're asking you to restate all these questions so you can give them your information, they're plugging it into the system. Well that system's data very soon will become global and accessible, especially for research purposes, it would be an incredible win for everybody. Instead of a doctor seeing say a couple of thousand patients a year that have a similar illness, the software will look at hundreds of thousands of patients, take all that data, use it in a way, with their algorithms, use it so that it can determine what statistically is the best course of action, not just in the single doctor's experience or in a small practice's experience.

R: Would that open up privacy concerns?

S: Well if you're going to use data, healthcare data, there are rules for that. It has to be scrubbed of any patient identifying information.

R: Mmm. OK.

J: Sure. Do you care if you're a number in some spreadsheet or some electronic process that says–

S: Well apparently people do care, because you've got to get permission from people to use it.

R: Yeah I mean I would care just because of the amount of times things go wrong.

J: Yeah but it's not like some person's going to be at the doctor in California, Rebecca, and your picture's not going to come up on their screen saying this person has this phenomenally awful disease. It's just data, it's just statistical data they're going to be using.

S: Yeah, you can ask systems like this, how many people who have this diagnosis are on this drug? Or how many people who are on this drug are also on this other one, and how many times did they get admitted to the hospital over the last three years. So it won't give you any specific information about any specific individuals, but you can ask statistical questions about the database.

R: Right.

S: Yep.

J: So Casey Bennett, one of the researchers, said:

"The Markov Decision Process and Dynamic Decision Networks enable the system to deliberate about the future, considering all the different possible sequences of actions and effects in advance even in cases where we are unsure of the effects."[1]

J: Their research tries to answer three issues concerning US healthcare. Steve, I'd like to know what you have about these three things. The rising cost, expected to reach 30% of the gross domestic product by 2050. A quality of care where patients receive correct diagnoses and treatment less than half the time on a first visit. And a lag time of 13 to 17 years between research and practice in clinical care.

B: Whoa.

S: Yeah, those are all correct.

B: 13 to 17 years?

J: Well sure, Bob, if you think about–

B: What kind of bullshit is that?

J: Well, no that's not bullshit.

S: Well it depends what kind of penetration you're talking about. I mean the younger doctors actually are a little bit better on that score, on incorporating the latest information. Academic physicians are better. But if you want to penetrate to the old guys out in the community, those are the hold outs, those are the people who are not necessarily getting all the critical updates that they should be in a timely fashion, and it takes a while to percolate through the culture of medicine. That is a significant problem. I think that the system of continuing medical education tries to address that, but it does so in my opinion in a very haphazard way, not in a systematic way. So there's still, I think, a lot of room for improvement there.

J: Well here are the facts guys. Bennett also said, that researcher also said later on that "the framework here easily outperforms the current treatment as usual, case rate fee-for-service models of healthcare." So listen to these statistics. With 500 real random patients, their software cost-per-patient difference was $495 down to $189, an improvement of 58.5% and the patient outcomes can be improved by, guys, a dramatic 41.9% at the peak performance of their system. That is huge, huge.

S: That's all a little theoretical though. It's not unreasonable, but it's also the system using its own criteria to assess itself, you know? So it would be nice to see how it works in the real world. Put it at the point of care in doctors' offices and then measure what effect it has, that would be more, I think, more of a meaningful measurement. But it shows that the potential is there, there's the potential for cost savings and improved outcomes. Essentially this is an expert system, these are nothing new, meaning that it's a system designed to be used by experts to give them– to augment their information, to give them the information they need when they need it. And I think that we have to go this way, it's just overwhelming, the amount of information, and new information that's being published. There's thousands and thousands of papers, even in a narrow area of expertise, that's being published every year. Plus, as Jay was saying, the number of permutations that physicians get presented with is staggering, every patient is unique in a way, in that they have their own medical history, they have a combination of medical problems, they're on a certain combination of medications, and then you're going to introduce a new element, a treatment or whatever, into that mix, and you could make only statistical statements about what's likely to happen but physicians are, by necessity, are using a simplified version of the data analysis. Even if we are trying to look it up at the time, how could I really know, for example what the interaction is going to be between a new medication and the five other medications that a patient is on? I know what the individual interactions are, but what are all the combinations? Where expert systems work well is in doing what humans don't do well, right? So they could do the heavy lifting, the number crunching, taking into consideration vast amounts of information that no human brain can hold, and then the physician can take that information, that recommendation: don't forget to do this, consider that, watch out for this interaction, this is the best evidence-based treatment right now, or here are the three options prioritized by the ones that are most likely to have the best outcome, and then the physician can individualize it for the patient a little bit more, taking into consideration some variables that maybe the system wasn't designed to take into consideration, not the least of which is patient preference, you know? There are some things where it's just patients care more about certain things than other things and you have to ask patients, what's more important, treating the symptom or avoiding the side effect? And you get different answers from different patients and that determines what treatment they might want. I think a good analogy is chess masters, right? If you think of physicians like chess-masters? They're very good at pattern recognition, they're very good at remembering the classic moves that really work, whereas a computer chess player can crunch hundreds of possible moves.

E: It'll play thousands of games in moments.

B: Brute force.

S: Yeah, you could brute force it in a way that a person can't. And for a while the human pattern recognition was better than computers, but now computers are better than the human. But imagine the two together. Imagine a chess master where the computer says I suggest you do this move, these are the things you've got to worry about and then he could use that in addition to his intuition and pattern recognition and then you get the best of both worlds.

R: Sounds like a great new buddy comedy.


E: Yeah

R: I got ya.

S: The odd couple?

E: You need to come up with a funny name for the computer of course, you know.

S: Hit it.

E: Felix?


S: Would the computer be Felix or Oscar? I guess Felix. One thing, a limiting factor here is that it takes a lot of time to create these algorithms and to feed it all the information. Keep in mind that this is just looking at treating one disease. All of the development is just coming up with: alright here's an algorithm to treat this one little thing, now we've got to build a thousand of these in order to really address the full breadth, and then keep them all of them updated as new information comes in. This is a massive project. That's really why these things aren't already in every doctor's office is because it's a massive project to create these things.

E: That's why I'm not so sure about the savings, the cost savings, maybe in the very long run you'll eventually see some cost savings, but I think there's still a lot of money that still needs to go into getting these things up to speed before you see the return on investment.

S: Yeah there are huge investments upfront, absolutely, but as the infrastructure becomes ubiquitous within medicine, the cost of adding some expert systems onto it will go down.

Ball and Cup Magic (17:16)[edit]

Scientific American: Magic Revealed: Cups Trick Found to Be More Effective Than Thought

S: Alright let's move on. Evan, you're going to tell us about the science of magic tricks.

E: Yes, I have some magic tricks, and specifically the cups-and-balls trick. Now 'cups and balls' is a culturally ubiquitous illusion by which the stage magician takes three cups and three balls, or what at least appears to the audience to be three balls, and with the magicians' sleight of hand, they're able to make the balls appear and disappear seemingly at will. I say it's culturally ubiquitous because stage magicians have been performing this illusion all over the world for reportedly thousands of years. Now, there are many variations to the trick but the general premise is the same, now you see the balls and with the help of the cups, now you don't. Youtube it, there are tons of examples to be seen. But scientists, they're analysing how magicians such as Penn and Teller, are performing this illusion, and they're now revealing that some aspects of the magic trick are even more effective at manipulating audiences than the magicians perceive or they predicted. Neuroscientists have increasingly been analyzing magicians' performances to gain insight into the human mind and if you remember back in Skeptics' Guide to the Universe episode 326, we presented an interview with Neuroscientists Stephen Macknik and Susana Martinez-Conde which was a really great interview, they talked with us about some of their work that they've done with Penn and Teller, among other professional tricksters, and how they studied their techniques for tricking the brain, and it was all put down in their book called Sleights of Mind - What the neuroscience of magic reveals about our everyday deceptions. I don't know if you read that book, Steve?

S: Oh yeah.

E: A really good book and it was a great interview, now magic tricks work because humans have a hard-wired process of attention and awareness that is, well, for lack of a better term, hackable. And a good magician uses your mind's own intrinsic properties against you. By understanding how magicians can effectively hack our brain we can better understand how the sort of same cognitive tricks are at work in other ways, for example in business negotiations or how people are influenced by advertising strategies or other sorts of interpersonal relations. But while Macknik and Conde-Martinez were specifically studying the cups and balls trick as performed by Teller of Penn and Teller, they realized something rather astounding.[2] What they did is they had seven volunteers and they watched 10-12 second long video clips of Teller performing the cup and balls illusion. In the experiments, the volunteers reported when they saw balls get removed from or placed under cups by pressing buttons. The researchers at the same time used cameras pointed at the eyes of the volunteers to track their gazes. Now during the course of the illusion, the balls, one by one, are being placed atop the cups and then the cups at one point get tilted, they kind of tilt forward, and the ball rolls off the top of the cup and into the magician's hand. Now this action of the ball rolling off the cup is designed to focus the audience's attention on that ball rolling off the cup so that you're not watching the magician's other hand as he's palming another ball and placing it in the proper position for the next part of the trick. However, what the researchers found is that while the audience is watching the falling ball, and it definitely drew their attention, other aspects of the trick were actually stronger at making the illusion work, which were not the results that the performer was expecting to get, the magician was not expecting that, they expect people were looking at the ball rolling off, therefore they're free to do their other manipulations and stuff, but this research reveals it's really not working that way. It's not a knock against the performer right, it's just a more accurate understanding as to what's going on in the mind of the audience member.

R: There are two concepts here that the researchers claimed to have debunked in a way, that are standard things that magicians learn. One is the idea of social misdirection, the idea that the audience will look where the magician looks, so you always look at the hand that's, for instance, supposed to contain the coin. You know, if the coin is actually in your other hand, it doesn't matter, you look at your left hand, and the audience will look there as well. And the other thing being that the audience will follow motion. If you consider there's a very basic, like the first move that most magicians learn is the French Drop.

S: Yeah

R: and that's a method of making a coin disappear. And one of the first things you have to learn about that is that you don't move the hand that's doing the tricky stuff because the audience is going to look at the motion. You move the hand that is supposed to contain the coin that's not there because that's where the audience is going to look. So those are two really basic concepts that the researchers have claimed to show don't necessarily hold up. But that said, I read the study and I found it, I mean it's interesting, but at the same time it was a sample size of seven people, and I don't really feel like they did a very good job of proving this, even to the point where– like, I think it gets headlines because it's interesting, it's about magic, it's fun, it's got Penn and Teller, but I don't think that it's really worthy of much else. If anything it would be something that should encourage people to explore on a larger basis. But the thing is, this sort of stuff has been tested before, the researchers themselves cite a paper from 2011 that also showed that social misdirection doesn't work very well, this time using, I think, a coin trick instead of cups and balls.[3] But again, that study contained three different experiments that had nine people in the first, six people in the second, eight people in the third. So it's like these are such tiny studies, it would be really interesting to do this stuff on a larger scale. But as it is, I just don't find it terribly impressive, mostly because of the small sample size.

E: You know something else they talked a little bit about as sort of a tangent to this, is they're working on, Conde-Martinez and Macknik are working on a hypothesis that magic tricks which rely on social cues are less effective in people with autism.

S: Huh

E: They believe that autistics have a hard time paying attention to what other people are paying attention to and they give some examples of some people who were diagnosed with autism when they were young and they relayed their stories about how they would watch magic tricks, and like Rebecca you were describing how the magician looks this way and most everyone else in the audience looked that way but these people who had the autism were not influenced by the direction that the magician was looking in, instead they were looking at whatever little cups, ball and whatever other props were going on, much to the magicians' dismay, because... you know–

S: Yeah, they were harder to fool because they were harder to predict how they'd respond.

R: Another thing I'd be curious about with social misdirection would be both of these studies that claim to show that it doesn't work very well were done using video of the magicians, and so I'd be interested in seeing if there's a difference with in-person magicians because I feel like if a magician is standing right in front of you you're going to have a stronger reaction to those social cues, but I don't know.

Gorilla in the Bronchi (24:48)[edit]

Neurologica: Gorilla in the Bronchi

S: Rebecca, in I guess a somewhat related item, there was an interesting article that you found very intriguing, this actually combines the first two news items we were talking about, physician performance and misdirection.

R: Indeed. yeah this was a story that I laughed out loud when I first saw it and then got slightly scared. So you've all heard, I'm sure, of the invisible gorilla test by now. For those who haven't heard of it, I will ruin it for you now. You should pause the podcast now and look it up on YouTube first if you don't want it to be ruined. But the video is– basically the experiment is subjects watched a video of basketball players who were passing a basketball back and forth, and the subjects were told that they had to count the number of passes just between certain players. And throughout the video a gorilla walks into the frame, stands there, beats his chest and then slowly walks off to the other side, and it's really painfully obvious but half of the people, half of the subjects in the study missed him entirely, and this is sort of held up generally to find that you've got a 50:50 chance if you're showing somebody who's never seen it before, a 50:50 chance that they will miss him entirely. This is something called inattentional blindness, the idea is that when a person is consumed with one task, they become blind to looking at other things around them. So that study is pretty much always done on what we will call, and what the researchers of the upcoming study call, naïve: people who have no special training in spotting things. And certainly no special training in spotting gorillas that walk through basketball games. So psychology students at Brigham and Women's Hospital in Boston were curious to see whether or not professional anomaly hunters, basically, could perform any better.[4] So they showed 24 experienced radiologists the CT scans for 5 different patients, and each of those cases included hundreds of images of lung tissue. They asked the radiologists to sort through the images and find 10 nodules which were signs of lung cancer hidden throughout the scans. So the difference here is that these are trained professionals who are doing what they trained to do. So to test whether or not they would be subject to inattentional blindness, the researchers on the very last case they gave the radiologists, inserted a small, poorly photoshopped picture of a gorilla into the lung image. The gorilla was about the size of a matchbox or about 48 times the size of the nodules that the radiologists were looking for, so it was quite substantial, relatively speaking. The gorilla started out translucent in early images but then became more and more opaque until by the time the radiologists got to the final images, it was incredibly obviously staring out from the lung. So at the end of the trial, the researchers asked each radiologist if the last trial seemed any different, if the last case seemed different, and if they noticed anything unusual about it, and finally they just straight up asked, did you notice the gorilla? Of the 24 radiologists, only 4 of them noticed the gorilla. When the others who didn't see the gorilla were shown those last slides again, they all immediately saw it, and also eye tracking data suggested that they all had looked directly at it during their first pass.

B: Ha! They tracked their eyes, awesome.

R: Yeah, but they didn't even process it. So it's funny and it's especially funny if you see the image of this ridiculous gorilla in a CT scan of a lung, but also it's a little scary because radiologists aren't just looking for a specific thing when they view these CT scans, they're looking for a specific thing while also supposedly keeping a general eye out for anything else unusual like that gorilla could have just as easily have been a tumor, a gorilla tumor.

E: But they were told specifically to look for the nodules, right? I mean if they'd just been told, here's some images, tell me what you see.

R: Well that's, in a way, and maybe Steve can expand upon this in a second, but I think that the purpose of this was to mimic what they would actually do in their work. They would be looking for a very specific thing, like they know they have to look out for these nodules, but they are also going to be looking out for anything that might be wrong in these scans. I don't think they're generally just given scans and just told, find something. They're told what they're supposed to be looking for, is that right Steve?

S: Yeah, basically. So radiologists are often given a history, like this is a patient with this history and I'm ordering this CT scan because I'm concerned about X. So they are going to pay particular attention to whatever it is the ordering physician is interested in. But they're also trained to read the whole scan, not just focus on the one thing that they're interested in. I did wonder myself though, whether or not there was an artefact in the study in that they knew they were being challenged, they knew they were being studied and they were specifically told, find the cancer nodules. And essentially that was meant, that was a test of inattentional blindness. They were given a task, and looking for something different than the gorilla and so they were processing information, filtering it in a way to look for the nodules, and they didn't process the gorilla, that's the whole point of inattentional blindness. I looked at– so when I first came across the study, I looked at the scan, I didn't see the gorilla either.

R: Yeah.

S: Because I was looking for pathology, not that I'm a radiologist, and I've read scans, so I was looking for stuff I was familiar with, but it was completely unfamiliar. It's also black on black, I mean let's point that out.

R: With a white border around it.

S: Yeah, but it's a black gorilla on the black lung, and it was just easy for me to completely filter it out.

J: Ah, here come the excuses. Come on, you missed it.

S: I missed it. It was inattentional blindness.

B: Steve, I just looked at the image that's on your blog right now, I mean a few minutes ago. And it took, I didn't see it immediately, I saw an alien head in this image, but I did not see the gorilla until I really started looking around.

S: Yeah.

R: Well it's worth noting again though, after they were told there is a gorilla in this picture, they all immediately saw it. Immediately.

S: Yes. And now I can't not see it, looking at the scan. It's blaring out at me. But first time I looked at it, I didn't see it.

R: There's a bit of reassurance here because in addition to showing the radiologists these CT scans, the researchers had a control group of the average naïve observer, so somebody who was not trained to look for any of this. And in the control group, not a single one of them saw the gorilla, so it's possible that the radiologists are so good at looking for things like these nodules that they have a bit more ability to look for general problems and so they are actually better than the average person at inattentional blindness, at least when it comes to CT scans. The headlines on this, I've noticed, have been really grim, like ‘83% of radiologists miss a gorilla in a CT scan’. But I think it's actually reassuring that they’re doing–

S: It misses the point, yeah.

R: Yeah, they're doing quite a bit better than the average person, which to me suggests that this could be something that radiologists and others in similar positions can learn from and they can actually work to develop their skills at spotting these things.

S: Well let me tie this into the news item that Jay talked about, about the artificial intelligence. There are software programs that analyse images and highlight anything unusual. And again, it's a perfect combination of the pattern recognition of a radiologist with the lack of inattentional blindness, lack of all the cognitive biases that we have, information processing that a computer has, the combination of those two is much better than either one alone, and this is just an example of that, you know a computer wouldn't be fooled by that because it doesn't suffer inattentional blindness. Let me give one other aside. I wrote about this, when I was doing some further background research on it I came across a very interesting bit. Do you know when the first study was published that demonstrated the phenomenon of inattentional blindness was?

E: Uh, 1959?

S: (laughs) Cheater. Yes, 1959.[5] But this is fascinating, this was a researcher, was a ghost researcher publishing in the journal of the society for psychical research and they were, they did an interesting study where the guy draped himself in a white sheet and strolled down the middle of a campus, and nobody reported noticing anything unusual.

J: What, that is so– did they see him and fear to do the report? Or did they not see the guy?

S: Well hang on. So then he did a follow-up study where, during a movie trailer, he walked out onto the stage, you know all theaters have, like they had a screen on a stage, you know what I mean? So you could walk on the stage. So he walked across the stage in the ghost costume, in the sheet, and only 50% of the audience noticed anything unusual. So he inadvertently did the first experiment demonstrating inattentional blindness, even came up with the 50% figure, the same thing as the invisible gorilla. Although he interpreted it differently, he said, ‘ah, there must be something psychic and different about genuine ghost encounters’.

B: Ugh.

S: Because people notice them.

R: I don't think he had any figures on what percentage of people noticed an actual ghost.

S: No, still that was his conclusion. He also, in discussing it, was perplexed by the peoples' inability to notice the ghost and couldn't understand it. But of course now we know it's inattentional blindness. Isn't that interesting?

B: Yeah, it's cool.

E: Very.

Feathered Dino Follow Up (35:34)[edit]

Neurologica: Transition Denial and Feathered Dinosaurs

S: Alright well let's move on. I'm going to do a quick follow-up to the feathered dinosaur piece that I talked about last week. If you recall, scientists have discovered yet another feathered dinosaur in China, Eosinopteryx brevipenna. It's a small feathered Theropod dinosaur, stubby wings, couldn't fly, with teeth, a bony tail, fingers and toes, lack of a lot of bird features, but it does have a lot of other features that are similar to birds so it puts it in that middle-zone between theropod dinosaurs and full birds. A beautiful transitional fossil, I wrote about the fact that Ken Ham and the Answers in Genesis creationists were denying that this is a transitional fossil, they said it was just a bird. So this is on the Answers in Genesis website, this is now their response to criticism, including from some of their own people, that how could you call this just a bird? This is by Dr. Elizabeth Mitchell, and let me just read you the money quote. She goes on and on quoting nonsense, then she says, "apart from those evolutionary pre-suppositions though, extinct birds that happen to have feathers, teeth, wings, claws and no bony keel remain just another kind of bird."[6]

B: Oh god.

S: So she's like, she's saying that, ok so in the past there are extinct species of birds that happened to have teeth and bony tails and winged claws and couldn't fly because they had stubby wings, but they're just another kind of bird. Allrighty.

J: That's like saying. 'That's not a dinosaur, that's just a huge gecko with big sharp teeth that likes to eat flesh'. Please.


S: Right. So it's just defining out of existence transitional species, just calling it "just a bird". Calling it "just a bird" doesn't mean that in the past there were birds that looked awfully a lot like theropod dinosaurs and it's just a massive coincidence. Right. Pure, mindless denialism, I don't know what else to say about that. But I just thought that that follow up was interesting.

Who's That Noisy? (37:54)[edit]

S: Evan

E: Doctor?

S: Tell us about Who's That Noisy.

E: I'll play for you last week's Who's that Noisy.

B: You do that.

E: Here we go.

I love oxygen because it plays such an important role in keeping alive the terrestrial animals on this planet.

E: So, who was that?

R: She makes a lot of sense.

E: (laughs) Yes, a lot of sense.

R: I'll say that much. I agree with her.

E: A lot of correct answers. A lot of people are very familiar with the one and only {{w|Jane Goodall|Dr. Jane Goodall].

S: Jane Goodall.

R: Ah.

E: Talking about the importance of oxygen. From a segment from something called the RI channel called My Favourite Element in which they– this particular segment of this show goes around, and they talk to scientists and other famous personalities about, well, their favorite element and they give a little brief explanation as to why. So that was Jane Goodall's take on that. For those of you who don't know, Jane Goodall is a British primatologist, ethologist, anthropologist and a UN messenger of peace. She said in an interview once with Ira Flatow that she believes Bigfoot exists, I don't know if she retracted that since, this was many years ago, but you know...

R: Didn't she just say that she was hopeful or something? I don't think she came out and said he exists, did she?

E: Uh, here's what she said:

"I've talked to so many native Americans who all describe the same sounds, who have seen them, I've probably got about oh 30 books that have come from different parts of the world, from China, all over the place, and there's a little tiny snippet in the newspaper just last week which says that the British scientists have found what they believe to be Yeti hair, and the scientists in the Natural History Museum in London couldn't identify it as any known animal."[7]

R: It's the worst.

E: "You'll be amazed when I tell you that I'm sure they exist." That's her quote.

R: Ah.

S: Although she does also say, "it's strange that there's never been a single authentic hide or hair of the bigfoot." So still she's...

E: So she's...

R: It's like she has the facts. Not using them the way they're meant to be used.

E: She just has to implement them. Come on doctor, just take the next step, you know what to do. But otherwise, you know, very famous.

S: Let's not focus on that, she's an awesome primatologist.

E: Yes, I agree.

S: An incredible legacy, great scientist.

E: And she loves oxygen, like so many others.

S: Yes, very fond of oxygen.

E: No doubt. Danny H is this week's winner.

S: Danny.

E: From alllll the people who guessed correctly, and there were a lot of you, thank you all for playing, but Danny from the message board.

S: Danny. I've got a Prescott(?).


E: Oh my gosh. Wonderful. Well done. Well played.

S: All right, so what have you got for this week?

E: This week, here we go. We have a puzzle this week because we know how much people love puzzles and there's never any controversy.

S: They're so puzzling.

E: Alright, here we go, this week's puzzle. "There are three switches downstairs."

S: These are light switches?

E: Light switches, thank you.

S: OK.

E: "There are three light switches downstairs."

J: (shouting) There are four lights!


R: I knew it was coming, I knew it was coming.

B: Oh, I didn't.

E: Wow. "There are three light switches downstairs. Each corresponds to one of three incandescent light bulbs up in the attic. You cannot see the lights in the attic from where the switches are located. You can turn the switches on and off and leave them in any position. How would you identify which switch corresponds to which light bulb, if you are only allowed one trip upstairs? You got that?

S: Very tricky.

B: Yep, it's a good one.

E: Go ahead and give us your answer to that. wtn at is the official email address for your answers, or post them on our forums, and as I like to say every week, good luck everyone.

S: Thank you Evan.

E: Thank you.

Name That Logical Fallacy (41:57)[edit]

S: We're going to do a Name That Logical Fallacy this week this email comes from Paul.

(baby sounds)

S: From Lynwood, Washington.

E: You OK, Jay?

S: (laughs) And he writes:

Radiohalos proves young earth. By the way, where is the missing link? Still missing? Have a blessed day, and know that GOD still holds you in his heart. Enjoy your show very much, always amused when man tries to disprove the glory of GODS [sic] creation. Take care.

S: Well thank you Paul, we appreciate your kind words.

E: And for listening.

R: Argument from ridiculous nonsense.

S: (laughs)

B: Yep, that's about it.

S: There might be some problems with the arguments. So there are, can we get the factual problems out of the way first? We actually did a segment, Bob I think you did this on the radio halos[8], these are the polonium halos, just refer you to that previous segment on the Sketpics' Guide, we went into that in detail. But no, it doesn't prove a young Earth, that has completely scientifically been demolished. The polonium halos are perfectly consistent with a 4 billion year old Earth, thank you. And we've talked about the missing link more than once on the show. There's no such thing as the missing link. There are of course gaps in the fossil record, but you'll never fill in all the gaps to an arbitrary level of detail. We have found connections between many major groups including, I don't know if he's specifically referring to a human-ape missing link, but you know we have– we find and keep finding more examples of hominids filling out the space between humans and our closest ape ancestors, so this is not– this is evidence for evolution, this is not a problem for evolution. But what do you think about his other sentiments here?

E: Well having a blessed day, I've got a big problem with that.


R: He's offered no evidence that the day is blessed.

J: You have no joy in your life Evan.

R: We've already established&ndash,

E: Apparently not, because I don't know that clip that you played earlier, but–

S: But he is amused when man tries to disprove the glory of God's creation.

J: Everything is the glory of God in his paradigm, so there's no way to prove or disprove anything.

S: Well I mean I think the main thing, to me, is that he's assuming his conclusion, he's making a circular argument here. He's assuming that God created the Earth and we're trying to disprove something that he knows to be true, the glory of God's creation. The question is, did God create the Earth, is the Earth the product of creation or of Evolution? That is a question we can address scientifically. He's stating his amusement in such a fashion where he's assuming his conclusion. Now I don't know if Paul is sincere in saying that he enjoys our show, and he may be listening to our show, if for no other reason than to hear what the quote-unquote "other side" has to say and we been emailed by other people who said that they started listening to our show to hear what the skeptics had to say, and that over time we slowly won them over, and in fact there's a couple who were creationists who listed to our show to mock us, and then now they're staunch skeptics who reject creationism.

B: Yeah, that was awesome.

E: Yeah, that was very satisfying.

S: We should not give up hope that Paul will eventually come around if he is listening to our show and absorbing much of it. So Paul, this is my challenge to you: you brought up two challenges to evolutionary theory, the missing link and radio halos. Investigate them, honestly. Take a look at those, we talked about it, you can do the same research that we did, and then come back to us. Email us back if you're listening to this, and tell us what you think about those arguments after doing some actual research and looking into what the scientists have to say about these two points, because what we're saying is that you're just completely factually wrong on these two points about radio halos and the missing link. You got it wrong, in my opinion, because you're listening to propaganda, to secondary hostile sources, you are not listening to what scientists are actually saying. If you do, you'll see that we are completely right on those two points, and you're completely wrong. And if you think that that's incorrect, please explain to me in detail, without gratuitous reference to your conclusions, explain to me why those arguments debunk evolution. We'd be happy to go around with you on that. That was the real reason why I wanted to talk about this news item.

R: So you could throw down the gauntlet.

S: Yes.

E: Yeah.

J: (laughs) Steve. The poor guy.

E: Throw down with Steven Novella.

S: Alright, guys

R: You're just trash talking him.

Interview with Brian Wecht[edit]

Propellantless Space Drive "EmDrive" Made in China (46:56)[edit] Propellantless Space Drive Called "EmDrive" Made in China

S: Alright guys, let's go on to our interview. Joining us now is Brian Wecht. Brian, welcome back to the Skeptics' Guide.

BW: Hey, thanks so much for having me.

B: Hey, Brian.

S: Brian is a theoretical physicist, a musician and a comedian.

BW: Mm-hmm.

S: Your physics work is on string theory. so basically you're Sheldon Cooper.

BW: I am Sheldon Cooper.


S: So Brian, we're bringing you on tonight mainly to talk about this one news item that has been making the rounds. Now I found this really fascinating. So tell us about this, this is a Chinese researcher claims he's actually produced a propellantless drive, or a so-called EM or electromagnetic drive. This is based upon some work that a British researcher has done. So get us up to speed, what is this all about.

BW: So based on, and I should say this is, it's a bit outside of my field, but based on what I've been reading, the idea is they create a cavity, so they have some metal plates that are arranged in a particular shape which is a cone here, and they put some electromagnetic radiation in, in this case it's microwaves. And the claim is that by doing that, and by having the cavity be shaped a particular way, effectively the waves can exert a pressure on one side of the cavity more than they can on the other, and make the thing move.

S: So there's a net force in one direction.

BW: That's the claim.

S: But that's supposed to be impossible.

BW: It is supposed to be impossible and I have to say that in reading this, everything in my gut as a physicist said that this should not be allowed to happen.

B: Primarily wouldn't that be for a couple of things, like Newton's third law, and the conservation of momentum, those are the two that I keep seeing and it kind of makes sense. The idea with Newton's Third Law is that every action has an equal an opposite reaction clearly isn't really happening here. And then there's conservation of momentum, you've got this closed system, momentum has got to be constant, and this kind of ties back into Newton's third law, so if a rocket moves in one direction without something moving in the opposite direction, how is it going to, it can't really go.

BW: The big one is especially the conservation of momentum. So unless you're exerting a net force on something from the outside, then momentum should be conserved, and here it's a closed system, momentum should be conserved. I mean it's not like anyone is pushing it from the outside, so it appears to violate conservation of momentum. Now if you read the papers, what they claim, and I don't really buy this claim, the claim is that because the electromagnetic field has some momentum in it, so this is something that I think may or may not be widely appreciated, but an electromagnetic wave actually carries momentum.

B: Right.

BW: I don't know if you guys, do you guys know what optical tweezers are?

B: Oh yeah, they're cool.

BW: They're the best things ever, basically you use little lasers to push beads or random objects around. You can finely tune these lasers to actually move objects. So electromagnetic radiation certainly can exert a force on things, so I think from what I've been reading, the scientists' claim is that ok, so you're taking momentum out of the radiation inside the cavity but still momentum should be conserved, so I don't understand how the thing can actually move.

S: Yeah so here Roger Sawyer is the British researcher who has been pushing this for a while and/ he wrote a reply to a New Scientist article about this and this is what he says. He says:

As the engine accelerates, momentum is lost by the electromagnetic wave, and gained by the spacecraft, thus satisfying the conservation of momentum. In this process energy is lost within the resonator, thus satisfying the conservation of energy.[9]

S: So that seems to be the crux of the claim, that they're transferring momentum from the electromagnetic wave to the spacecraft itself. To me, as a non-theoretical physicist, it kind of seems reasonable. To me, so here's the analogy that came to my mind, you tell me if this is apt. There's a conservation of energy, energy can't be created or destroyed, but it can change forms, you could essentially do E=mc2, matter could be converted into energy, and that could superficially seem as if you're creating energy until you account for the fact that mass, matter, is energy, just another form of it. So does the same apply to conservation of momentum where momentum is conserved, but you're converting from one form, in this case electromagnetic wave, to another form, the spacecraft. Could that hold? Could that make sense?

BW: I mean you can, you can use an electromagnetic wave to push things, like the optical tweezers, but at the end of the day, if it's a closed system, the net momentum of the thing– you know what the momentum is because you can measure the center of mass and there's no radiation outside that thing either, it's all contained inside. So I don't understand how you can actually get a net momentum of the thing if it really is an honestly closed system. Because you can actually set– the average momentum is the mass times the velocity of the thing, very roughly speaking. So OK, maybe there's some momentum, there certainly is momentum in the electromagnetic wave, but at the end of the day the thing either has a momentum or it doesn't, and if there's no external force there shouldn't be any change in the momentum, momentum must be conserved.

B: Yeah Steve, I think the fact that it's a closed system is one of the things that is most against this. The only thing that I've come across that even makes remote sense to me is that you could have some sort of asymmetric thermal glow around the box but that would be so tiny and that kind of reminds me of the... what was it?

S: The Pioneer?

B: The Pioneer probes, but that would be negligible and ridiculous, as low as even what they're claiming, it would be smaller than that I think. But it's the closed system I think that really is the nasty part of this that won't go away. And I mean if he's got this, great, send it to us, have somebody look at it. Send it to some university or some government agency and have them check this and just prove it, it shouldn't be hard to prove that you can do this, it's like a perpetual motion machine.

BW: The thing I love is, like you said I'm a string theorist, so when I see something with data, I'm like "Oh my god, that's real science." So yeah, that's exactly my reaction too is that if this really happens, it shouldn't be– you know it may be very sensitive, but it should not be impossible to duplicate.

B: Guys real quick, don't forget, Boeing's Phantom Works actually looked at one of this guy's prototypes and they didn't pursue it. So to me, I mean, that's not evidence that this is baloney, but to me this is just another little thing that you've got to consider.

S: But that's where we are now, so the Chinese say that they've built one, it's producing this tiny amount of acceleration, and this is like the perpetual motion machines where they say 'OK I've built one and it's producing this tiny amount of energy, but we can scale it up'. But of course, it never scales up–

B: (laughs)

S: –because the tiny amount of energy, or in this case the tiny amount of momentum, is probably a round-off error that they're then multiplying by 50,000 and producing an apparent effect. Or they're just– their measurements are off by a teeny tiny, itsy bitsy amount, right?

BW: That's the big question, right. Is the effect they're claiming, how does that compare to their error? Their ability to detect. And that's something I certainly don't know the answer to, but if they can't convincingly say that the effect they're measuring is much larger than their precision it doesn't matter, that's not a result.

S: Yeah now some people are saying, 'yeah start pushing satellites around, and then we'll believe you'. That's like, you know, run your house off your perpetual motion machine and then I'll pay attention. You know, your free energy device or whatever it is. But it never scales up to anything practical because they're all living in the world below the threshold of noise, where it's just all in the errors whether it's mathematical or tiny measurement errors or whatever, and it never does scale up. But, we'll see, I mean this one is interesting, it seems that the consensus is that this is the equivalent of perpetual motion, you can't violate conservation of momentum. His hand-waving explanation of transferring electromagnetic momentum from the electromagnetic wave to the spacecraft superficially sounds OK, but I guess it doesn't really solve the problem of the conservation of momentum. It's also called the reactionless dive because it's not reacting with the outside world in any way, so if you were sending electromagnetic waves off in one direction then sure, that would produce thrust, but that's not a reactionless drive.

B: Yeah, the other aspect of that is some people kind of confuse it and they say, oh it's a rocket engine with no fuel, and that's really not true, it's without reaction mass.

S: Without propellant.

B: Right, or propellant. The fuel is whatever you would use to power the reactor that generates the electricity.

BW: Do you guys know the article about this, this has appeared in a journal or not? I don't remember offhand.

S: Well the Chinese are not disclosing their information because they're saying oh we have to make sure we have all the patents and we don't get scooped, so they're saying it's going to take them a year before they're actually going to have transparency with their data. So that's fishy, right?

BW: Yeah. Super fishy.

B: Alright. See you in a year.

S: That's super fishy. Shawyer, he wrote the theoretical papers and they're online, you can get them on the New Scientist website that I'll link to, or at

BW: Yeah, he has a website with a FAQ and all these, you know the answers to every objection that you could possibly raise to his device, right.

S: Right. And reading the comments is funny because the cold fusion people have jumped on board with this.

B: Oh boy. Yeah, yeah.

BW: Yeah.

S: And all the conspiracy theories about you know, the scientific priesthood says it's impossible so they don't want to research it.

E: Scientific priesthood, yep.

S: Well what we need to do is hook up a cold fusion reactor to an EM drive, then we basically have anti-gravity, man.

BW: Unlimited power.

E: Mwa-ha-ha.

S: It would be super cool if this worked.

BW: If this somehow works, it's cool from any number of perspectives, right? It's cool from any number of perspectives, it's cool from a practical perspective, like we might actually be able to use this thing for thrust. But then it also says that clearly a lot of people maybe don't really understand physics as well as they thought.

S: Yeah

BW: So anytime you have to go back and reevaluate your assumptions, that's great.

S: Yeah I mean it's worth saying, we would love for this to work.

B: Oh my god. Some people were predicting that if you had a superconducting cavity, something like an EM drive, you could eventually lift 3 tons with just 1 kW of input power, I mean, can you imagine? Three tons.

S: That sounds crazy.

B: Yeah, it would be amazing.

S: Even if what they're claiming now is the limit of it, which is a tiny amount of propulsion, that is a very effective way of moving ships around the solar system because you won't have to carry propellant with you and you won't have to accelerate the propellant, and therefore the rocket equation is off the table and this would be massively efficient, even with its tiny acceleration.

B: It's actually even more efficient than an ion thruster, it's like four times as much thrust, half as much power, with no propellant needed to be carried on.

BW: Certainly the effects that they're describing right now are really, really tiny.

B: Yeah, 72 grams of thrust with 2,500 watts of electricity

S: Right, well you just need a lot of them. So it would be cool, but don't hold your breath is the bottom line.

BW: Yes, that's right. I'm... doubtful.

S: You're skeptical, right.

BW: Actually I was going to say skeptical, then stopped.


J: Hey but there's something cool that you don't have to hold your breath for that's coming up.

BW: Amazing segue.

R: Yeah, we're really good at those.

BW: Yeah, I know.

S: We've been getting better, we've been practising.

R: Yeah, you should have heard us seven years ago.

S: So what are you talking about, Jay?

R: Get to the point, Jay.

Stimulus, Response - NECSS of science and improvisation (59:15)[edit]

J: Brian and George Hrab were tasked with coming up with a new event for NECSS that's unique to NECSS that's going to be a unique event. Brian, why don't you tell us what you guys came up with?

BW: So the idea, what George and I came up with, we're both super psyched about it. It's called Stimulus, Response - NECSS of science and improvisation and the idea is that we wanted to create an event which was really particularly unique, and also unique to NECSS so the idea is that we're going to have two improvised performances, so the evening is going to start out with George and his cousin, is that right? Roman?

J: That's right, yep.

BW: Yep. So George of course is an incredible musician, and his cousin Roman is an artist and they're going to spontaneously create a simultaneous work of music and art at the same time and draw inspiration off of each other. So that'll be the first act. After that we're going to get a panel together of George and Roman, we're going to have Steve, and Steve will talk about the neuroscience of improvisation, we'll get to hear his scientific input on how exactly you're able to create these events, how you're able to spontaneously come up with the kind of stuff that people have seen. Also Heather Berlin, who is a phenomenal scientist, will be on the panel as well. I'll be moderating. And then we're also going to get some improv comedians, the second act is this panel discussion of the nature of improvisation and in part, the sort of like'what the hell were you thinking when you did this?', and then go to the scientists, Steve and Heather, for their scientific input. Then also talk to some people who improvise comedy on a regular basis, and then they're going to take over in act three and then do a whole improvised set, basically a comedy set based on an interview with some prominent NECSS attendee, which we're not announcing yet because we have yet to confirm, but some really awesome person who will talk about their life or talk about some particularly interesting thing that they've done. The comedians are then going to draw inspiration from him or her and then create a 20-25 minute set based on that.

B: Awesome.

J: I can't wait to see this thing, man.

S: All right Brian, thanks for coming on the show with us and helping us debunk this latest bit of pseudoscience.

E: Yep

BW: (laughs) Well great, thanks.

S: And I'll really look forward to NECSS, and seeing you there and to what you guys put together on Friday night.

BW: Yeah thanks so much for having me and I can't wait to see you guys in April.

S: Alright take care.

BW: You too.

B: Thanks, Brian.

R: Thanks, Brian.

E: See ya, Brian.

Science or Fiction (1:01:44)[edit]

S: Each week, I come up with three science news items or facts, two real and one fake. I challenge my panel of skeptics to tell me which one is the fake.

E: You almost yelled the work fake at us.

R: Yeah. There's a lot of anger there.

S: Fake stuff gets me mad, what can I tell you? Are you guys ready for this week.

B: Then why are you making it up? Yes!

E: Sure.

R: Mm-hmm.

S: I know, I hate myself when I do it. Here we go. Item #1: A new review concludes that Vitamin C supplementation halves the incidence of the common cold. Item #2: New research finds that decision making continues subconsciously even when we have turned our attention to a new task. And item #3: A recent study finds that African American women require twice the supplemental doses of vitamin D as do Caucasian women. Jay, go first.

J: The one about the vitamin C, I would be shocked if that's true, right out of the gate. Just because I've read so many times that vitamin C does not have an effect on that. I'm assuming here, by the way it's written down, you say vitamin C supplementation, that it's not just that they take it when you have a cold, that over a long period of time. Because we know that if you take it when you get a cold that it does absolutely nothing, or so I think. But OK, alright that one's on the back burner. The second one about decision making continuing even after you've turned your attention to a new task, I think that's true, of course it's true, your brain isn't just thinking or working on what's in the front of your mind, what's in the front of your mind, what's in your conscious mind, it's constantly, constantly pulling apart things and analyzing things, so that one to me 100% fact, without a question of a doubt. And the third one about African American women requiring twice the supplemental doses of vitamin D as Caucasian women, that's interesting. It's interesting, you know maybe in a low-sun situation under normal living conditions, people are indoors more than outdoors and maybe because of the color of their skin they don't absorb as much vitamin D somehow? Meaning they need longer exposure to sunlight to absorb the same amount of vitamin D for their skin to produce as much vitamin D as a Caucasian person. Huh. That's OK, so I could make an argument either way for that. So now it's the vitamin C one which we already know for years and years we've all heard that vitamin C does not help with the common cold mow this is a reverse on that. Interesting. Or the third one. I'm going against my gut and I'm going to select the third one, the vitamin D one as the fake. And the die roll is... number 1.

S: OK, Rebecca.

R: Alright, this is tough because I had an immediate reaction to these in that vitamin C, the vitamin C one immediately sounded wrong and the other two immediately sounded right to me. And in fact African American women requiring twice as much vitamin D, in my head that's obvious and solved and done. I was already under the impression that African Americans required more vitamin D and that vitamin D deficiency led to a higher incidence of certain diseases and maybe even cancers in African Americans compared to in Caucasians. But I don't know, so that one immediately sounded right, and the idea that your decision making continues subconsciously, that immediately seems right not because I've seen any studies on it but just because I've always felt like that's what works for me, like I input things in my brain before I go to bed and then I wake up with the answer, things like that. Or if I'm working on something creative and I'm hitting a roadblock I just go play video games or I do something else or I work out or something and then when I come back I've got it, you know. So that seems obvious to me too, and like Jay said, everything I thought I knew about vitamin C is that it was ineffective. But I'm always suspicious when things seem that obvious that means that something's screwy.

B: Or maybe that's what he wants you to think!

R: I know! Maybe it's the old double cross! I'm going to go with the vitamin C one being wrong, because I fell for it I guess, I don't know. That one.

S: OK. Evan.

E: Vitamin C supplementation halves the incidence of the common cold. I think we've talked about vitamin C before in this regard, Jay some of the things you were talking about ring bells. If you were to build it up in your body ahead of time and maintain a higher than average level of vitamin C then perhaps that could work. Decision making continues subconsciously even when we've turned our attention to a new task. Sure, I don't see why that couldn't be the case, which makes me suspicious. Continues subconsciously, boy we do so many things subconsciously, I'm probably doing a whole bunch of things subconsciously right now and I couldn't describe them because they are, what? Subconscious. And I'm already on to a new task because I'm on to the third one. African American women require twice the supplemental doses of vitamin D as do Caucasian women. Would that be because the African American women have a harder time absorbing the vitamin D from the sun, from sunlight? That would seem to make sense on some level, but I've not heard vitamin D being part of the need for women, as opposed to men, so I don't know about this one, I'm kind of thinking that this one's wrong because twice the supplemental doses of vitamin D, yeah I don't think that's right at all actually, I don't think that Caucasian women need supplements of vitamin D at all and therefore African American women would not require twice the supplemental dose so I'll say that one's the fiction.

S: And Bob.

B: I had a similar reaction to Rebecca. Seemed pretty straightforward. I'll start with three. African Americans requiring more vitamin D, yeah it made total sense, you've got more melanin, you absorb less sun, therefore you make less vitamin D. Twice as much may sound like a lot but you don't necessarily need a lot anyway, so twice of a little is still not that big. The subconscious decision making yeah, I mean my go-to example for that is I'm trying to think of a word, can't think of it, and then almost invariably, 10, 15 minutes, an hour later, bam! It just totally pops right into my head, clearly something was looking for it without my conscious control. And then the vitamin C, yeah I mean how long have we heard that it's not dramatic, you don't really need to go crazy with vitamin C, it's not going to have that much of an effect on the common cold. So what the hell, I know it's... I'm just going to go with the common cold and say that one is fiction.

R: You and me, Bob. You and me.

S: OK, interesting. So you all agree on the middle one that new research finds that decision making continues subconsciously even when we have turned our attention to a new task, you all think that one is science, and that one is... science. Yep, that was the easy one this week. But what new researchers found is they did actual brain studies where they imaged the different parts of the brain functioning and they had subjects, they gave them a task, then they had them move on to a different task and they found that the decision making parts of the brain were still active even when they had moved on to a distracting task.

B: That's cool.

S: Something that didn't involve decision making, that was something like doing math, you know just something specific but not involved in the decision-making process. They also said this is consistent with research that shows that decision making is improved when– well this is actually a follow-up to that research, so prior research showed that if you take a break from a decision making task, that it may actually improve the quality of the decisions that you make. Now the question was, is that because your brain is still working on the problem or is it because you take a break from the problem and then you come back with a fresh look, fresh outlook? You know does it sort of recharge your batteries? So this study gave the subjects the task, then gave them a distracting task and it showed that the brain is still working in the background, subconsciously, same parts of the brain are active, the decision-making, you know the parts that were active during the active decision-making. So that, pretty strong evidence that that is the case. Not surprising, I agree with Bob, I think most people probably have a similar experience of trying to think of something and then you move on and then the boom! The information pops into your head. What's going on there? Obviously it seems like it was, the solution was derived subconsciously and then presented to your conscious self and that does seem to be what the neuroscience shows. Well let's go back to number one, a new review concludes that vitamin C supplementation halves the incidence of the common cold. Bob and Rebecca think this one is the fiction. Jay and Evan think this one is science. And this one is... science.

J: Aha.

E: Oooh.

R: Aaargh.

B: Shit.

R: Damn you, Novella!

S: A little surprising. This is a {{w|Cochrane Library|Cochrane Library review. Now there's some details in here that are worth pointing out.

B: I'm sure there are.

S: The improvement in the– the reduction I should say, the reduction in the incidence of contracting the common cold was only in those studies that showed– that involved people that were under some kind of physical activity, like engaging in a sport or in the military or essentially they were under some physical stress. If you weren't under physical stress that 50% figure does not hold.

B: Under physical stress or do you mean generally fit?

S: No no, under physical stress, yeah not just in good shape, but you had to be, at the time you were supplementing, were subjected to some kind of physical stress. So the thinking there is that the vitamin C is helping you somehow compensate for that physical stress. The review identified 5 double blind placebo controlled trials which showed that. Jay, you pointed out something that was very important though. These were supplementation trials meaning that you're taking it all the time. Treatment trials where you give vitamin C once you contract the cold generally show no effect. The review did note that in adults, the duration of the cold is reduced by about 8% with vitamin C supplementation and in children by about 14%. These have generally been considered to be clinically insignificant, what are you going to have your cold lessened by a few hours, you know? This is 1 to 2 grams a day. The effects of vitamin C are pretty modest outside of this one parameter. I have to say, personally I'm not 100% convinced of this, I have to like really dissect the quality of the trials that they're citing.

R: Then maybe it shouldn't have been in Science or Fiction, I'm just saying, Steve. Just saying.

S: Well that's why I said "a study concludes".

R: Just saying.

S: A review concludes that.

R: I don't like your weasel language.

S: I'm not concluding that.

R: Yeah, weasel.

S: I didn't say "demonstrates", I just said that a review concludes.

R: The used car sales man of self-lies.

E: You called him a whistle-pig

S: The whistle-pig? I picked that wording very deliberately. But it is what it is. I mean it's a Cochrane Review, it seems pretty up and up, but I'm just a little suspicious of it. The conclusion, I don't agree with the authors' recommendations based upon this because they say that regular supplementation is inexpensive and low risk so why not do it even if you're not sure if it's worthwhile or not. And they eventually said, as an individual you could try it out and see if it works for you, which I think is kind of a worthless recommendation. You're not going to be able to tell if it works for you, its all going to be placebo effect and anecdote. But the other thing is given the number of colds that the average person has a year, it's really not worth, in my opinion, taking a gram or two of vitamin C all year round just to prevent one cold, even if this data is consistent, or shorten the duration by a tiny amount.

R: Maybe spend that money on hand soap, or one of those face masks.

S: Yeah right. It's probably, yeah probably better off just having good hand hygiene. And I'm not so convinced that high doses of vitamin C are benign. It could be associated with a higher risk of heart disease, for example. So I would not give the same bottom line recommendation as this study. I think that the only thing that this really adds that you could really make a case for is if you are going to be under extreme physical stress, then supplementing with vitamin C may help your body deal with that stress. A general recommendation for supplementation I think is not warranted by this data. All of this means that "a recent study finds that African American women require twice the supplemental doses of vitamin D as do Caucasian women" is the fiction and Bob and Rebecca, you engaged in exactly the reasoning I was hoping that you would because that certainly was my thought.

B: Screw you.

S: And it's plausible, this is why it was studied, because people with dark skin absorb less vitamin D from the sun and so you might think they might need more supplementation. But what they found, what the study found was that African American women and Caucasian women required the exact same amount of vitamin D supplementation, that their base levels that they're getting from the sun didn't really have an effect on how much oral supplementation they needed, that the same recommendations would suffice for both groups.

B: I disagree with that conclusion.

S: (laughs)

E: So women do need additional vitamin D?

S: Well it depends, I think that the best recommendation right now is just to get your vitamin D levels checked with your primary care doctor, and then if it's on the low side then it's reasonable to supplement. If you're not under the regular care of a physician, then it's a little hard to say because there's so many variables, where do you live, how much sun exposure do you get, how dark is your skin. Combine all those, and also the time of year. You know your needs in January are going to be different than your needs in July, but if you really want to know just get your levels checked.

R: What about men?

S: The study only involved women so I don't know, I'm assuming it's the same.

R: What about men?

S: I don't know, this study...

R: I'm not assuming does(?).

S: Yeah I know. I would suspect that it would not be dramatically different but this study only involved women for whatever reason. So good work, Jay and Evan.

J: Thank you.

E: Yeah.

S: And the die went with Bob and Rebecca this time and failed. So we should note that

J: The die died.

Skeptical Quote of the Week (1:17:24)[edit]

S: Well Jay, do you have a quote for us this week?

J: I sure do. This is a quote sent in by my friend Craig Good over at Pixar. Craig wanted to congratulate me about my son and also sent a pretty cool quote. The quote is:

Nothing is so firmly believed as what is least known.

J: That quote was penned by Michel de Montaigne. Montiag-ne. Montiai. Taig.

S: Montaigne.

J: Montaigne (shouting) Michael de Montaigne yeah!

S: Alright, thanks Jay. And thanks for joining me this week everyone.

B: You're welcome, Steve.

R: Thank you, Steve.

E: It was good to be joined to you.

J: Thanks Stevie!

S: And until next week, this is your Skeptics' Guide to the Universe.

Voiceover: 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 You can also check out our other podcast the SGU 5x5 as well as find links to our blogs and the SGU forums. For questions, suggestions and other feedback please use the contact us form on the website or send an email to If you enjoyed this episode then please help us spread the word by leaving us a review on iTunes, Zune or your portal of choice.


  1. Indiana University press release - Can computers save health care? IU research shows lower costs, better outcomes
  2. Rieiro, H, Martinez-Conde, S & Macknik, S.L (2013), Perceptual elements in Penn & Teller’s “Cups and Balls” magic trick, PeerJ
  3. Cui et al.(2011), Social misdirection fails to enhance a magic illusion, Frontiers in Human Neuroscience [Note: Macknik & Martinez-Conde are also authors of this paper
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  5. Cornell, A. D. (1959). An experiment in apparitional observation and findings Journal of the Society for Psychical Research, 40 (701), 120-124
    See Simons (2011), Ghost busters, parapsychology, and the first study of inattentional blindness on
  6. Mitchell (2013), How can we say it’s a bird?,
  7. Jane Goodall, Friday, September 27, 2002, during National Public Radio's (NPR) Talk of the Nation: Science Friday with Ira Flatow (YouTube clip)
  8. Episode 201: Polonium Halos
  9. New Scientist blog: Em drive on trial (Oct 3 2006)
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