Friday, 18 July 2014
Sketchy Fact #49: Small-Pox Won't Cause Pandamonium in Animals
Smallpox only infects humans and is not carried by any wild animals. It is the only natural biosafety level IV infectious disease (maximally dangerous) not to have an animal host.
Wednesday, 16 July 2014
Prosopagnosia: Facing the Facts About Face-Blindness
In 1976 NASA had their eyes on Mars. The Viking program was well underway and humans were at the cusp of getting up close and personal with the red planet. The plan was for the spacecraft Viking 1 to circle Mars and photograph possible landing sites for its sister ship Viking 2. After narrowing down possible landing sites, Viking 2 would be sent to the surface and the super-nerds in Houston could pop some bubbly. While doing its reconnaissance work however, Viking 1 snapped a picture that shocked not only the scientists at NASA, but the entire planet. The picture was of a human face staring up from the surface of Mars.
Conspiracy theorists and alien enthusiasts quickly began postulating the existence of subterranean Martian civilizations, touting the face as proof that humans are just transplanted people from our celestial neighbor. It wasn’t until 2001 when the Mars Global Surveyor spacecraft re-photographed the same geologic feature that the face controversy was put to bed. It was just a pretty distinct hill with some convenient shadows. In hindsight we should have known right away that it wasn’t actually a face, it isn’t entirely our faults though. It turns out our brains are wired to find faces everywhere they look.
If you’ve ever read a news story about a piece of toast that looks like Jesus or a bagel that looks like Elvis, you know what I’m talking about. One of the easiest things in the world is imagining a face where one doesn’t exist. We even have a specific chunk of our brains with the designated job of finding faces. It’s called the fusiform gyrus, but its function is so specific that most scientists just call it the fusiform face area. Under an fMRI scan if you show someone an apple the fusiform gyrus will stay as silent as a mouse, but show the same person a face and it will light up like the Fourth of July.
It makes a lot of sense when you think about it. We humans are some of nature’s most social creatures. We have large families, even larger circles of friends, and most of us live together in clusters with populations in the thousands or even millions. If your brain wasn’t insanely well-equipped to quickly sort out friends, enemies, and former employers from the crowd your life would be a lot tougher.
Unfortunately for some of us, this actually is the case. Recent research as begun to reveal that as many as one in every 50 people might suffer from at least mild face-blindness, known as prosopagnosia on more formal occasions. The term face-blindness likely gives you the wrong idea about the disorder. Someone with prosopagnosia doesn’t see a blank skin mask when they look at the front part of a person’s head. They can see eyes and noses and mouths and ears just like the rest of us. The problem is, that is all they see. The pieces don’t come together to form a single coherent picture that allows them to recognize the people they interact with. Imagine if I showed you a line up of noses, just noses, and asked you to identify one of them. Odds are you would have a tough time even if one of them belonged to your mother.
Prosopagnosia comes in a full spectrum of intensities. On the milder end, you might have a hard time recognizing when someone you saw in one movie appears in another. On the severe side, you might not be able to recognize yourself in a photograph. Famed psychiatrist and author Oliver Sacks didn’t realize that he was face-blind until he was well into middle-age, despite having a particularly severe case. Sacks has apparently failed to recognize his own therapist in encounters at the grocery store, missed his assistant of 6 years in a hotel lobby he went to specifically to meet up with her, and has over and over again “apologized for almost bumping into a large bearded man, only to realize that the large bearded man was myself in a mirror.”
Funny stories aside, prosopagnosia can be a source of immense frustration for the people it afflicts and the people they fail to recognize. Imagine if you had to convince your spouse that you were you every time to met them at the movies or the mall. The quirks would get old fast. That is why face-blind people often come up with other ways to recognize their close contacts. Someone who always wears pink shoes or has an affinity for large hats, for example, would make a great best friend for a prosopagnosia patient.
Face-blindness can either be lifelong or the result of brain trauma from an accident or a stroke. Regardless of how it is picked up or how severe it is, prosopagnosia makes a great get-out-of-jail free card for that guy at the office whose name you can never remember.
If you’ve ever read a news story about a piece of toast that looks like Jesus or a bagel that looks like Elvis, you know what I’m talking about. One of the easiest things in the world is imagining a face where one doesn’t exist. We even have a specific chunk of our brains with the designated job of finding faces. It’s called the fusiform gyrus, but its function is so specific that most scientists just call it the fusiform face area. Under an fMRI scan if you show someone an apple the fusiform gyrus will stay as silent as a mouse, but show the same person a face and it will light up like the Fourth of July.
It makes a lot of sense when you think about it. We humans are some of nature’s most social creatures. We have large families, even larger circles of friends, and most of us live together in clusters with populations in the thousands or even millions. If your brain wasn’t insanely well-equipped to quickly sort out friends, enemies, and former employers from the crowd your life would be a lot tougher.
Unfortunately for some of us, this actually is the case. Recent research as begun to reveal that as many as one in every 50 people might suffer from at least mild face-blindness, known as prosopagnosia on more formal occasions. The term face-blindness likely gives you the wrong idea about the disorder. Someone with prosopagnosia doesn’t see a blank skin mask when they look at the front part of a person’s head. They can see eyes and noses and mouths and ears just like the rest of us. The problem is, that is all they see. The pieces don’t come together to form a single coherent picture that allows them to recognize the people they interact with. Imagine if I showed you a line up of noses, just noses, and asked you to identify one of them. Odds are you would have a tough time even if one of them belonged to your mother.
Prosopagnosia comes in a full spectrum of intensities. On the milder end, you might have a hard time recognizing when someone you saw in one movie appears in another. On the severe side, you might not be able to recognize yourself in a photograph. Famed psychiatrist and author Oliver Sacks didn’t realize that he was face-blind until he was well into middle-age, despite having a particularly severe case. Sacks has apparently failed to recognize his own therapist in encounters at the grocery store, missed his assistant of 6 years in a hotel lobby he went to specifically to meet up with her, and has over and over again “apologized for almost bumping into a large bearded man, only to realize that the large bearded man was myself in a mirror.”
Funny stories aside, prosopagnosia can be a source of immense frustration for the people it afflicts and the people they fail to recognize. Imagine if you had to convince your spouse that you were you every time to met them at the movies or the mall. The quirks would get old fast. That is why face-blind people often come up with other ways to recognize their close contacts. Someone who always wears pink shoes or has an affinity for large hats, for example, would make a great best friend for a prosopagnosia patient.
Face-blindness can either be lifelong or the result of brain trauma from an accident or a stroke. Regardless of how it is picked up or how severe it is, prosopagnosia makes a great get-out-of-jail free card for that guy at the office whose name you can never remember.
Friday, 11 July 2014
Sketchy Fact #48: It's not moon, it's me.
The moon is drifting away from the Earth by about 1 cm each year. It’s like the longest, most dramatic break-up in the solar system.
Wednesday, 9 July 2014
Sugar-Loaded Surprises: Why We Need to Stop Ganging Up on High Fructose Corn Syrup
Here at Sketchy Science we publish a lot of articles about living a
healthy lifestyle. In particular we like to help people wade through the fact
and fiction that goes along with eating a nutritious diet. There is a lot of
misinformation floating around in the ether of western civilization and we like
to think that it helps to hear the truth about what we are putting in our bodies.
With that in mind, we decided to write about high fructose corn syrup (HFSC)
for this week’s post.
If you pay attention to the news at all, you have probably heard about
how evil HFSC is. It is making us fat, diabetic, and hopelessly addicted to
soda. No matter where you look, from articles written by doctors, to the Huffington Post, to one of my personal favourite websites HowStuffWorks.com the message is clear: “High fructose corn syrup will kill you.” That
is the apparent consensus and it is fully the message of the article that I expected
to write. I even thought I might throw in some jabs at the Corn Refiners
Association for ridiculous brainwashy ads like this one. However, when I hit up the scientific literature, what I actually read
shocked me.
The actual science on HFCS is a lot less doom and gloom than you would
expect. First off, HFCS is a processed form of corn syrup where some of the
glucose is turned into another sugar called fructose. Average, run-of-the-mill
table sugar (sucrose) contains both glucose and fructose at about a 50/50 ratio. HFCS has
slightly more fructose. Since fructose is sweeter than glucose, HFCS is
friggin’ delicious. It makes anything you put it into crazily sweet. Pretty much
to the point where you really don’t want to stop eating it.
Therein lies the problem with HFCS. Its tastiness, combined with the fact that
food manufacturers understandably put it in everything (their goal, after all,
is to sell a lot of Oreos), makes HFCS dangerous. The poison is in the dose, as
the old saying goes; and we are happily dosing ourselves at off-the-charts
levels. An American study recently found that a full one-third of the calories
consumed by middle school students was in the form of added sugars.
However, just because gorging ourselves on something is bad for us
doesn’t make it fair to point the finger in one direction if the thing we are
pointing at isn’t especially harmful. When you look at research comparing HFCS
to sucrose (table sugar) you end up reading the same thing over and over
again: HFCS isn’t really any worse. If you don’t believe me (and I completely
understand being surprised by this) read some of the studies I’ve linked to at
the bottom of this post. Over and over again, the effects of HFCS and sucrose
are the same. While scientists agree that pure fructose has terrible consequences for your body, there is actually little evidence to support the idea that the combination of fructose and glucose in HFCS is any worse than classic sugar.
I did manage to find one study about how HFCS led to greater weight gain
over the long-term in mice, but researchers only compared mice eating HFCS to
controls who weren’t getting any extra sugar. When you stack the deck against something like that, you are not
conducting good science. Admittedly the same study also found differences in
short-term weight gain with HFCS causing more flub than sucrose, but I
haven’t found any other research to support that.
The lesson here is not to go out and inhale a gallon of orange soda, it
is actually pretty much the opposite. Obviously there is a problem with the way
companies make and sell food. They put sugar in things that have no business
having sugar. Read the ingredients list on a box of crackers next time you’re
at the grocery store if you have any doubts. However, the problem is not with
the substance itself. It is with the people who are making and marketing the food and, ultimately, with the people who are consuming it. Clearly we can’t rely on big companies to only
provide us with healthy foods, so we need to take some responsibility for our own
actions.
Read labels and make smart choices. Maybe somewhere down the line enough
people will get upset about the amount of sugar in food that we can pass a law
limiting it, but until then companies will continue to sell sugar loaded snacks for as long as we keep buying them. HFCS is really cheap to produce and it makes you drink
more juice. If I wanted to sell you a lot of lemonade, I would keep
making the kind you like the most. Capitalism isn’t rocket science.
The other lesson here is not to believe everything you hear. Just
because some doctor on the internet tells you something is good or bad, doesn’t
mean anything. When it comes down to it, you are trusting strangers to tell you
how the world works. Read different sources, make use of Google Scholar and
read some published science, make up your own mind. Sometimes what seems like
an issue of nutrition is really one of psychology.
References by findings:
No difference between HFCS and
sucrose:
Maybe a difference:
Pure Fructose is bad:
Friday, 4 July 2014
Sketchy Fact #47: World's Deadliest Virus
Until 2004 when an experimental treatment saved the life of Jeanna Geise, rabies had a 100% fatality rate. It remains the deadliest known virus on the planet once an infected person shows symptoms.
Wednesday, 2 July 2014
Bad to the Bone: Are men’s faces evolved for fist fights?
Look in the mirror. What do you see? If you’re a man, you might be looking at the consequences of thousands of years of fist fights. It might not be the most flattering thing to consider but a new theory suggests that the features of men’s faces are more strongly built than those of women so that we are better able to take a punch.
Researchers from the University of Utah have studied the differences in the facial structure of men and women going back millions of years and concluded that the differences we see may be indicative of a violent past. Biologist David Carrier is a firm believer that the ancestors of humans relied on fist fights to sort out who got to mate with who on the African plains.
These ideas fly in the face of conventional wisdom on how the face evolved. People have long assumed that the robust jaws and cheekbones of ancient apes in the genus Australopithecus were the product of tough, plant-based diets. Much like modern gorillas whose diet is made up almost entirely of vegetation that requires a lot of chewing, it was thought that the predecessors of modern humans had strong facial bones to support strong facial muscles needed to grind up leaves and the like. Not so, according to Carrier who after looking at wear patterns on the teeth of Australopithecines concluded that they were likely eating soft fruit, rather than hard nuts.
This presented something of a problem for explaining heavy facial bones. Fortunately Carrier had an idea. As it turns out, in 2012 he co-authored another paper published in the Journal of Experimental Biology explaining how the proportions of the human hand are ideal for making fists. It doesn’t take much of a leap for a fist expert to conclude that apes with thick cheek bones might have used them to better handle frequent punches to the face.
Dr. Carrier’s ideas have been met with a lot of skepticism on the part of other scientists. Just because a fist makes a good weapon doesn’t mean that a fist evolved to be a weapon. It’s a perfect case study in one of the great challenges that scientists face. At the end of the day, you may have used perfectly objective and defensible methods to collect your data; but the tool you use to interpret that data is a human brain... And human brains have biases and preconceived notions. It is one thing to say that men have more robust faces than women, but it’s another to say that you know the reason why.
The key to good science is critical thinking. Look at what is in front of you and question it. That is not to say that Dr. Carrier is wrong, it’s just important to consider alternative explanations. Maybe human faces and hands are designed to help us beat the tar out of each other; but maybe men’s faces are tougher because they got injured more often than women while hunting big game. Maybe our hands evolved to help us manipulate tools and the design just so happened to work as a fist. Or maybe using tools and punching people in the face were equally important in shaping our hands.
In truth, that last explanation is probably a bit closer to the truth. The tricky thing about evolution is that there are so many variables acting on every single trait in an animal’s body or brain at the same time that it should raise flags whenever we read that “The reason for x is y!” Things in the real world are usually in shades of grey, regardless of our ancestors’ black eyes.
Researchers from the University of Utah have studied the differences in the facial structure of men and women going back millions of years and concluded that the differences we see may be indicative of a violent past. Biologist David Carrier is a firm believer that the ancestors of humans relied on fist fights to sort out who got to mate with who on the African plains.
These ideas fly in the face of conventional wisdom on how the face evolved. People have long assumed that the robust jaws and cheekbones of ancient apes in the genus Australopithecus were the product of tough, plant-based diets. Much like modern gorillas whose diet is made up almost entirely of vegetation that requires a lot of chewing, it was thought that the predecessors of modern humans had strong facial bones to support strong facial muscles needed to grind up leaves and the like. Not so, according to Carrier who after looking at wear patterns on the teeth of Australopithecines concluded that they were likely eating soft fruit, rather than hard nuts.
This presented something of a problem for explaining heavy facial bones. Fortunately Carrier had an idea. As it turns out, in 2012 he co-authored another paper published in the Journal of Experimental Biology explaining how the proportions of the human hand are ideal for making fists. It doesn’t take much of a leap for a fist expert to conclude that apes with thick cheek bones might have used them to better handle frequent punches to the face.
Dr. Carrier’s ideas have been met with a lot of skepticism on the part of other scientists. Just because a fist makes a good weapon doesn’t mean that a fist evolved to be a weapon. It’s a perfect case study in one of the great challenges that scientists face. At the end of the day, you may have used perfectly objective and defensible methods to collect your data; but the tool you use to interpret that data is a human brain... And human brains have biases and preconceived notions. It is one thing to say that men have more robust faces than women, but it’s another to say that you know the reason why.
The key to good science is critical thinking. Look at what is in front of you and question it. That is not to say that Dr. Carrier is wrong, it’s just important to consider alternative explanations. Maybe human faces and hands are designed to help us beat the tar out of each other; but maybe men’s faces are tougher because they got injured more often than women while hunting big game. Maybe our hands evolved to help us manipulate tools and the design just so happened to work as a fist. Or maybe using tools and punching people in the face were equally important in shaping our hands.
In truth, that last explanation is probably a bit closer to the truth. The tricky thing about evolution is that there are so many variables acting on every single trait in an animal’s body or brain at the same time that it should raise flags whenever we read that “The reason for x is y!” Things in the real world are usually in shades of grey, regardless of our ancestors’ black eyes.
Friday, 27 June 2014
Sketchy Fact #46: Stale Clams
In 2006 a clam from the species Arctica islandica was collected and killed for climate change research of the coast of Ireland. Researchers studying the clam felt surprised and probably a little guilty when they discovered the clam was 507 years old. The oldest complex animal ever found.
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