Zimmer interviews Gary Marcus

NYU Psychology professor Gary Marcus has just released his latest book Kluge about how the human brain is the product of tinkering. It is really one of the best refutations of the argument from design. Here he is interviewed by Carl Zimmer.

Primates and stress

Yesterday I saw an interesting article at ScienceDaily titled Why Do Humans And Primates Get More Stress-related Diseases Than Other Animals?

Obviously the researchers don't write the headlines for these articles and press releases. (It's probably not the science reporters either. I'm guessing it's the editors.) News flash: Humans ARE primates; the headline is redundant. Had it said "Why do primates ..." or even "... humans and other primates ..." I wouldn't have twinged the way I did.

But to the article: Stanford University neuroscientist Robert Sapolsky claims that it's our higher intellect that causes our stress. He says that because we're super smart, we have all this extra time to make each other's lives miserable.

"Primates are super smart and organized just enough to devote their free time to being miserable to each other and stressing each other out," he said. "But if you get chronically, psychosocially stressed, you're going to compromise your health. So, essentially, we've evolved to be smart enough to make ourselves sick."

He backs up his assertions with baboon studies he's done. Why baboons you ask?

"The reason baboons are such good models is, like us, they don't have real stressors," he said. "If you live in a baboon troop in the Serengeti, you only have to work three hours a day for your calories, and predators don't mess with you much. What that means is you've got nine hours of free time every day to devote to generating psychological stress toward other animals in your troop. So the baboon is a wonderful model for living well enough and long enough to pay the price for all the social-stressor nonsense that they create for each other. They're just like us: They're not getting done in by predators and famines, they're getting done in by each other."

It turns out that unhealthy baboons, like unhealthy people, often have elevated resting levels of stress hormones. "Their reproductive system doesn't work as well, their wounds heal more slowly, they have elevated blood pressure and the anti-anxiety chemicals in their brain, which have a structural similarity to Valium, work differently," Sapolsky said. "So they're not in great shape."

Monkeys going around making each other's lives a living hell, where have I heard that before?



While he may sound like a fatalist, he's actually quite an optimist (at least for our species of primate).

"We are capable of social supports that no other primate can even dream of," he said. "For example, I might say, 'This job, where I'm a lowly mailroom clerk, really doesn't matter. What really matters is that I'm the captain of my softball team or deacon of my church'--that sort of thing. It's not just somebody sitting here, grooming you with their own hands. We can actually feel comfort from the discovery that somebody on the other side of the planet is going through the same experience we are and feel, I'm not alone. We can even take comfort reading about a fictional character, and there's no primate out there that can feel better in life just by listening to Beethoven. So the range of supports that we're capable of is extraordinary."

So primates are prone to life-shortening stress due to their superior intellect over other animals, while humans have the power to overcome this due to our superior intellect over other primates. I like that. Which reminds me: one more day of this self-imposed stress of "a new post every day for the month of February" even though I'm tired when I get home. I wonder if other primates bring stress upon themselves? I can't really complain though, I wouldn't have done this if it weren't fun.

Amazing Animal Human Tricks

One of the most popular types of tricks that people teach their pets is to "act human." It's amazing when animals do things that we only thought we could do. But what about the reverse? What about when people do what we thought only animals could do?

A while back, I saw this article in LiveScience called Top 10 Animal Senses Humans Don't Have. I say give humanity a chance. You might be surprised at what we can accomplish when we try.

For example, do you think people can sniff out a chocolate bar like some kind of hound? According to UC Berkeley researchers, yes.

To test Sobel and Porter's smell hypothesis, the UC Berkeley researchers soaked a 33-foot (10-meter) string in chocolate essence and laid it in the grass outside Barker Hall, located at the northwest corner of the UC Berkeley campus. They then garbed volunteers to block their senses of sight, hearing and touch, eliminating all clues other than smell to guide them along the trail. Sniffing like bloodhounds, two-thirds of 32 subjects were able to follow the chocolate scent to the end of the trail within three attempts. All volunteers zigzagged along the trail in the same way that tracking dogs follow a scent.



The researchers then trained four of these volunteers to see if they could improve. All were able to double their speed along the track within just a few days and deviated much less from the scent trail than on their first attempts. The researchers measured subjects' sniffs and noticed that the faster the subjects moved along the trail, the more rapid their sniffing - just as with dogs, though not as fast as the six sniffs per second rate exhibited by dogs.

I bet you didn't know that you could do that! You probably never realized that you were capable of echlocation. Check this kid out! (via)

Bug-brained chopper

Insects manage some pretty amazing aerial acrobatics for having a brain we humans can hardly see with the unaided eye. Yet even our best engineers and AI experts have trouble programming simple autonomous navigation. Just look at what it took to finish The Grand Challenge.

Now researcher Nicolas Franceschini, a neurophysiologist and engineer at France’s National Center for Scientific Research and at the University of the Mediterranean in France has decided to emulate those little bug brains in his newest project.

The simple principles that Franceschini and his colleagues think underlie insect flight have to do with visual cues. As insects fly, their ground view changes depending upon their height above the ground and their speed relative to the ground. Essentially, the higher the insect, the slower the ground will appear to sweep below it.

The changing view that insects have of the ground, known as "optic flow," thus encodes details on both an insect's height and velocity. Franceschini and his colleagues speculated that insects rely on simple relationships between their height and velocity to keep flying. Basically, the idea is that if they slow down, they will begin descent, and if they speed up, they will begin climbing. By the same token, if they are descending, they will slow down, and if they are climbing, they will speed up.

"They don't need a speedometer or altimeter. They just need to use their eyes," said Franceschini, whose latest work on this topic is detailed online in the Feb. 8 issue of the journal Current Biology.

That's pretty cool stuff. A simple feedback system controls both speed and altitude--ain't evolution grand? Of course, such a simple system can sometimes trip up.

Their findings also help illuminate the basis for a number of previously unexplained observations regarding insect flight. For instance, honeybees often drown when flying over very still water. "There are no contrasting features in their field of view then, so they have no visual cues to go by," Franceschini said.

Franceschini's helicopter is equiped with a 200 mg. electronic brain, is tethered to a maypole, and free to fly around. At least under these simple circumstances, it seems to behave just like a fly.

The phenomenal power of the human mind

The phenomenal power of the human mind

I cdnuolt blveiee taht I cluod aulaclty uesdnatnrd waht I was rdanieg The phaonmneal pweor of the hmuan mnid! Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer inwaht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Amzanig huh? Yaeh, and I awlyas thought slpeling was ipmorantt.

I received the above paragraph in an email today and was quite surprised at how easily I was able to read it. Whole words indeed. While the explanation may seem counter-intuitive, it actually fits well with my experience. As a crossword puzzle afficionado, I oftentimes find myself stuck for the longest time, only to realize that I had been misreading the clue. (“Imitate friendship?” What was I thinking?) Looking back, I’m sure that every time, I’ve always confounded the clue for another word with the same first and last letters. I’ll have to pay closer attention the next time it happens to me.

That mixed-up paragraph also reminded me of an article in Scientific American on the Expert Mind. The author, Philip Ross, discusses a study done by Dutch psychologist Adriaan de Groot that demonstrated that chess grandmasters could recall chessboard positions much better than novices.

De Groot also had his subjects examine a position for a limited period and then try to reconstruct it from memory. Performance at this task tracked game-playing strength all the way from novice to grandmaster. Beginners could not recall more than a very few details of the position, even after having examined it for 30 seconds, whereas grandmasters could usually get it perfectly, even if they had perused it for only a few seconds. This difference tracks a particular form of memory, specific to the kind of chess positions that commonly occur in play. The specific memory must be the result of training, because grandmasters do no better than others in general tests of memory.

While that may not seem at all surprising, the following study might. It starts to get to the heart of why grandmasters have such superior recall.

In the 1960s Herbert A. Simon and William Chase, both at Carnegie Mellon University, tried to get a better understanding of expert memory by studying its limitations. Picking up where de Groot left off, they asked players of various strengths to reconstruct chess positions that had been artificially devised--that is, with the pieces placed randomly on the board--rather than reached as the result of master play. The correlation between game-playing strength and the accuracy of the players' recall was much weaker with the random positions than with the authentic ones.

If this sounds confusing, or if you’re wondering what this all has to do with the shuffled-up words, perhaps this will explain.

Psychologist George Miller of Princeton University famously estimated the limits of working memory--the scratch pad of the mind--in a 1956 paper entitled "The Magical Number Seven, Plus or Minus Two." Miller showed that people can contemplate only five to nine items at a time. By packing hierarchies of information into chunks, Simon argued, chess masters could get around this limitation, because by using this method, they could access five to nine chunks rather than the same number of smaller details.

Take the sentence "Mary had a little lamb." The number of information chunks in this sentence depends on one's knowledge of the poem and the English language. For most native speakers of English, the sentence is part of a much larger chunk, the familiar poem. For someone who knows English but not the poem, the sentence is a single, self-contained chunk. For someone who has memorized the words but not their meaning, the sentence is five chunks, and it is 18 chunks for someone who knows the letters but not the words.

In other words, our brains are constantly using our experiences to create short cuts. We learn to recognize familiar patterns. When we later encounter the familiar pattern, our brains process it as a single bit of information, allowing us to streamline our thinking and be more efficient.

Hvae a wedrnoufl day!
—Jveiar