Gravity Hard-Coded Into The Brain

guiding_knight writes: "A study by French scientists suggests that gravity is imprinted in the human brain. Interesting article, tells of human ability to calculate effects of Earth-normal gravity and how difficult it is to adapt to another model."

Comments

Useless article, lack of credibility and rigor

[billcopc]

Anyone reading this article will see a big red "DUH!" in their mind. They're taking astronauts, presumable 30+ years old, and having them perform various experiments in alternate gravity situations. 30 years of experience on earth with 9.8m/s^2 gravity will surely look like hard-coded parameters when you try tossing a ball in zero-g for 5 minutes. Now if they could bear a child up in weightlessness, and raise that kid in space, teaching him to play catch without gravity, then that kid would be just as messed up once he'd return home and tried to play his game.

Brains do not store any hard-coded information, they just adapt; once they've adapted to something, it takes an equal amount of effort to change that knowledge. Say you've been playing Pacman for the last 20 years, and can pull a perfect game up to the 112th level. Then you play Virtual Fighter for the first time in your life, and get your ass savagely beat within 4 seconds. DUH! Your knowledge of Pacman's rules and strategies means nothing once you move to a new game. Same thing applies here.

juggling

[DeadSea]

As a juggler, I would be very suprised if the earth's gravitational constant was totally pre-implanted in your brain. One way to teach people to juggle is to use handkercheifs or some other object that falls slowly due to air resistance. Learning to juggle when stuff moves more slowly is much easier, and people have no trouble catching handkerchiefs.

Also look at computer games which can have arbitrary G constants. People playing video games can get very very good at predicting when their character hits the ground no matter what G is thrown in.

Upon reading the article, it looks as though they have found evidence that we are attuned to normal earth gravity but they have proven nothing. Their experiments are all done with people who, after having grown up in normal gravity, are thrown off by less gravity. I don't think they have much in the way of nature/nurture on this. Better experiments would involve raising a kid in space and seeing how he could catch a ball.

I would not be suprised if we somewhat expect earth's gravity after years of evolution (the same way we are easily get phobias of snakes but not much more dangerous things like cars and electricity), but humans obviously have wide skills with other acceleration constants. This study is hardly conclusive from the summary of it in the news article.

Learning with and without gravity

[martyb]

It's one thing to try and do something WITHOUT gravity, that I had originally learned how to do WITH gravity. That's what this experiment was attempting to do.

I'd be more interested in how well they did learning, for example, to play hacky sack (passing a small, bean-filled leather bag using only your feet). if they had no prior experience with the game, I'd be interested in seeing how well they did, learning it in zero-G; compared to others learning how to do it with normal gravity. That would be a more valid experiment in my book.

Re:Learning with and without gravity

[martyb]

It's a bit hard to play it at all in zero-G

Though I have no first-hand experience in zero-G (man, don't I wish!), I would expect it would be difficult to play hacky sack there. Then again, It was hard for me to learn how to play hacky sack in normal gravity. ;^)

But, that was not the point. The article contended that gravity may be hard-coded into the brain. My concern is that the experiment they used does not clearly test that hypothosis. This could simply be a learned response, that happened to have been learned under the influence of gravity.

The point is to have people learn a skill which they had never done before, some under the influence of gravity, and others in zero-G. I just used hacky sack as an example that did not require the individuals to UNLEARN something they already had gained some measure of expertise while in earth gravity. Feel free to use some other coordination challenging task that could involve gravity. Hacky sack involves hand-to-FOOT coordination which I discovered was much more difficult than I thought it would be. Not because it is that difficult, but because I was that inexperienced.

So, whether or not it's hacky sack, pick some coordination activity other than one in which the participants are already well-versed. Use the same instrumentation as was used in the article's experiment to monitor muscles, timing, feedback, and the like. Then, compare the results between the zero-G participants and the earth-bound participants. If the brain were really wired for gravity, then I would expect there would be clearly perceptible differences in the abilities, and the learning curves, of the two groups.

Article says it is NOT hardwired

[m_evanchik]

Despite its title, the article states the scientists are unsure of how "hard-coded" gravity is in the brain:

It's possible that the astronauts did adapt to 0-g, and then readapted back to 1-g again. It's also possible that the brain is able to learn and retain multiple models of acceleration. In different situations, it might simply choose which one to apply. That, in fact, is what McIntyre and his colleagues believe is going on.

In other words, like on Slashdot and other publications, the headline writers didn't read the article, or deliberately misstated its conclusion in the interest of an exciting headline.

Re:Seems to me...

[Paradise Pete]

A little kid can't just start catching a ball naturally. It takes a while for it to click.

And here in Costa Rica, where soccer is the national sport and nobody plays baseball, even the teenagers and adults can't catch anything. Toss something to a Tico and nine times out of ten it goes ricocheting off his hand.