The Arm That Wasn't Paralyzed

An intelligent, lucid 60 year old named Nora was interviewed by the neuroscientist V.S. Ramachandran.  Ramachandran tells the story in his book, the Tell-Tale Brain.

"Can you walk?"
"Yes." (Actually, she hadn't taken a single step in the last week.)
"Nora, can you use your hands, can you move them?"
"Yes."
"Both hands?"
"Yes."  (Nora hadn't used a fork for a week.)
[...]
"Touch my nose with your left hand."
Nora's hand reamins motionless.
"Are you touching my nose?"
"Yes."
"Can you see your hand touching my nose?"
"Yes, it's now almost touching your nose."

Nora's left side is paralyzed.  But she won't admit it.  This is a more common phenomena than you'd think.  After suffering a stroke in the right hemisphere of the brain, many people suffer paralysis of the left-hand side of their bodies.  About one in twenty of these people will insist that they are not in fact paralyzed.  This is called anosognosia, which is medical-speak for denial-of-illness.

Anosognosia does not necessarily go along with any other mental impairment.  A person can be psychologically completely normal in every respect--except when it comes to the inert mass of their paralyzed left half.

A notable sufferer of anosognosia was Woodrow Wilson who became paralyzed in 1919 after being smitten with a flu-related.  He was bedridden, blind in his left eye, and paralyzed on the left side of his body.  He remained in office, even as he was on the brink of death, mumbling limericks to himself, his wife serving as his 'steward' (read: regent).  He didn't attend any cabinet meetings for a full half year, and when he finally presented himself to his cabinet, his staff were shocked at the frail state of his heath, and at the secrecy which had covered it up.  But Wilson grew angry with any mention of his incapacities, and fired many functionaries who dared suggest that there was something wrong with him.  He even pondered running for a third term.

Anosognosia can come in many exotic flavors.  Some anosognosiacs will refuse to admit that other paralytics are paralyzed.  A syndrome called somatoparaphrenia often accompanies anosognosia, in which a person will deny all ownership of their paralyzed arm.  Nora, mentioned above, had somatoparaphrenia.  "Whose arm is this?" Dr. Ramachandran asked her.  "That's my mother's arm," she replied.  "Where's your mother?"  "She's under the table."

People can be anosognosiac about more than just paralysis.  Patients with Wernicke's aphasia--brain damage which limits their communication to a fluent stream of babble--are often anosognosiac about their condition, nodding and smiling and talking even though they have no content to their speech.



Sources today are V.S. Ramachandran's the Tell-Tale Brain, and Errol Morris' five-part blog post on anosognosia which is fun, philosophical, and exhaustive--not words you usually associate with five-part blog posts, I know.

What's The Deal With Airplane Food?

It is a question that has beguiled stand-up comedians for ages.  What's the deal with airplane food?  At best your in-flight meal tastes like styrofoam and gravy.  At worst it tastes like low-price cat food, styrofoam and gravy.  Do the airlines just hate us?

It turns out that it's not just the food that's the problem, but everything else on the airplane.

Flimsy Forks

The first culprit is the cutlery.  To save gas, airlines use light-weight cutlery.  But humans turn out to be very picky eaters, and we significantly prefer food that we shovel into our mouths with heavier cutlery.  Since airplanes serve us low-weight cutlery and trays, our meals end up tasting a little weird.

When the Concorde was still flying, British Airlines spent months developing the perfect lightweight cutlery set, one that would befit the clade of air passengers rich enough to afford a berth on the super-sonic luxury airline.  They made a fantastic set out of titanium.  Then they tired them out on the population.  People hated eating with them.  They were just too light.  It seems that when you spend a bundle on a plane ticket, you expect your knife and spoon to have a certain heft to it.

Dining High

The next problem is the air--specifically the low humidity, low air-pressure, recirculated, germ-laced miasma of an airplane cabin.  At ten-thousand feet about a third of our taste buds switch off.  At thirty-five thousand feet the humidity in the cabins is kept so low that our mouths start to dry out.  When we vainly chomp on our in-flight meals and taste styrofoam, it's more the fault of our mouths than our meals.

Man It's So Loud In Here

The final piece of the puzzle is the noise.  The airplane cabin is a hideously loud environment.  Not only do you have the ambient chatter of a few hundred people jammed into a small tin-can, but you also have the whine of the recirculating air, and the drone of the engines.

A noisy environment significantly effects our taste.  When it's noisy, salty and sweet tastes don't taste as salty and sweet.  So the taste of our in-flight meals have literally been droned out by the sound of our next-door neighbor snoring.

Because of these three reasons, airplane food tastes bland, limp, and lifeless.  Airlines try to remedy the problem by serving us flavorful, salt-bombed meals, but the problems of eating in an airplane environment are just too much for a glass of dry red wine to remedy.

The next time I hear someone complain, however, I'm going to remind them that for all the indignities of air travel, it remains a lot easier than the alternative--going by boat.

I learned about this from neuroscientist Charles Spence, a guest on Dr. Karl's call-in show

Why Is A Face So Fast?

It takes a little more than three days to get from the earth to the moon.

It takes between 24 and 72 hours to digest a meal.

Your Google search is retrieved in about 200 milliseconds.

In only 100 milliseconds your brain recognizes a given lump of color and shape as a face.  70 seconds more and your brain will tell you whether know that face or not.

The brain is really good at recognizing faces.  The question is--why?

A view of the mind has emerged in recent years that suggests the brain is less like a meat computer and more like a meat app-store.  We aren't born with some tabula rasa of grey and white matter that we can program any old way we want.  Instead, our brain comes pre-installed with a number of modules for stuff like learning language, analyzing visual inputs, and yes--identifying faces--modules that are mostly hard-wired.  And really good at what they do.

So why is one of our modules devoted merely to identifying faces?

Humans are a perversely social creature.  We are more likely to live and die because of another person than because of any other factor.  Out there on the red-in-tooth-and-claw ancestral veldt I know that if I see Bert he'll buy me a pizza because he's cool.  But if I see Bobby I should be wary because Bobby likes hitting my head with rocks.

So it's important that our brains devote a huge amount of care to figuring out whether that lump of pink over there is a pig or OH MY GOD ITS BOBBY RUN GUYS RUN!

Sorry.  False alarm.  Not actually Bobby.  You see, sometimes the machinery of the mind goes wrong.  Usually what happens is that our face-finding module is set a little bit too high, so we like to find faces in places where faces just aren't.  This is called pareidolia and it is awesome.

All evidence to the contrary, this is not a smile.

And this is not Marlon Brando.

This is not actually a creeper.

And this is not a real dog.  Turns out it's just some pixels.  I KNOW.  I WAS FOOLED TOO.

Sometimes our face-finding module is set too low, or even turned off entirely.  Some of Oliver Sacks' most evocative writing is about people who suffer from a disorder called prosopagnosia, the inability to distinguish a face from the other mass of color and angle that splatters the visual field.  For them, a face isn't a face, it's just a vaguely face-shaped object.

The more we understand the brain, the more amazing even our simplest actions become.  So this Friday night as you and your friends indulge in your post-employment toasts, remember that merely to recognize that your friends are your friends takes thousands of years of careful evolution.

And watch out for Bobby.  I don't trust that guy.

If you're curious about the modularity of the mind, here's a fun video explaining it all.