Gravity Hard-Coded Into The Brain 49
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."
Re:Rut Row (Score:2)
Re:Rut Row (Score:1)
But still its not a design flaw, merely further proof that evolution does not do prediction, e.g., for space travel, but is merely a random mutation survival of the fittest method.
t.
So you mean... (Score:3, Funny)
Oh please (Score:2)
Read about this in 98 (Score:1)
Useless article, lack of credibility and rigor (Score:2, Insightful)
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.
Re:Useless article, lack of credibility and rigor (Score:1, Funny)
Re:Useless article, lack of credibility and rigor (Score:2)
In addition, the astronauts in the study had not managed to fully adapt even at the end of the time period, and were also able to readapt to Earth-normal gravity rather more quickly than to the zero-g environment.
Re:Useless article, lack of credibility and rigor (Score:1)
Re:Useless article, lack of credibility and rigor (Score:1)
Re:Useless article, lack of credibility and rigor (Score:2)
I'm in agreement with most of what you say, but ...
That's a pretty ambitious statement, and one that strikes me as more dogmatic than scientific. The human brain is the product of millions of years of evolution to fit a specific (Terrestrial) environment -- isn't it reasonable to believe that some of the necessary responses to that environment might be built in?
Tangentially, I'll note that in general, psychologists and anthropologists have for some years now been moving away from the old dogma of "humans don't have any instincts" toward a more balanced acknowledgement that yes, humans do have instincts, but the way we express those instincts is determined by learned behavior.
Re:Useless article, lack of credibility and rigor (Score:1)
Re:Useless article, lack of credibility and rigor (Score:1)
The point of the article wasn't that the astronauts were off. Like you said, duh, that is going to be a given.
The point I came away with was "Why did it take so long to adapt?"
Before you go off and say "duh!" again, think about it. Given a balance beam, how tries do you think it would take you before you could walk on it without having any balance problems? Once? Twice? Three times? Maybe zero?
So why did it take the astronauts FIFTEEN DAYS before they even STARTED adapting to catching the ball in zero g?
Unless the experiment consisted of only "thowing" the ball one time in each day of the expriment, the outcome is contrary to normal human adaption.
Just my two cents.....
think video games (Score:2, Interesting)
Okay, so that wasn't a scientific experiment, I just find that there reasoning is quite poor, baby's on a glass table are scared, ya, that is really good scientific proof.
One way to figure this one is to test one of those dudes whose been in space for months, and then test him just as he get's back to earth, I bet for at least a few hours he would be on "space gravity".
just my $.02
Good scientific proof (Score:2, Informative)
But what irks me about your post is the comment, "baby's on a glass table are scared, ya, that is really good scientific proof." Do you even know what that experiment [hbcollege.com] is, who conducted it, and what were the follow-up studies? It's one of the classics of developmental psychology. And they were careful not to draw too many conclusions from it. But it does support (not prove, nor does it claim to) the notion that our sense of gravity is innate.
juggling (Score:4, Insightful)
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.
Re:juggling (Score:2)
--Ender (Orson Scott Card)
Re:juggling (Score:1)
t.
Minor correction with G: (Score:1)
must
const float G = 6.68 * 10^-11 Nm^2 / (kilogram)^2
float g = 9.81 m / s^2
thanks for the great info!
Er, uh.. (Score:2, Funny)
Like multiple hardware profiles? I don't know about this, my brain couldn't even switch back over to the "short hair profile" of my past when I went back to having short hair.
Seems to me... (Score:2)
Think of it this way: A little kid can't just start catching a ball naturally. It takes a while for it to click. It just so happens that, by the time someone is a teen-ager, they've had to catch things so often that they do it without thinking about it. That's not hard wiring, it's conditioning. Of course, when you've been conditioned to do something over a long period of time, it takes a little while to unlearn it.
Anyway, I just don't see any solid evidence from the material presented that predicting gravitational acceleration is hard-wired into the brain. Take some kids who haven't yet learned to catch into a zero-G environment (Vomit Comet, anyone?) and do the experiment with them. That way, conditioning won't contaminate the results.
Re:Seems to me... (Score:2, Insightful)
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.
Learning with and without gravity (Score:3, Insightful)
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 (Score:1, Funny)
Re:Learning with and without gravity (Score:3, Insightful)
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.
Re:Learning with and without gravity (Score:1)
Are you sure that's not "foot-eye" coordination?
Re:What a ridiculous notion (Score:2)
I not trying to troll or flame you or anything, but could you please tell me where you get the 100 million BP? Also, just because a perception of gravity may have evolved 100 million BP doesn't mean that it can't be "updated" through time to incorporate the new values of g. It seems that the astronaughts adapted in as much as 15 days. Not perfectly, but who knows what 30 day could do; or a year; or a century; or 100 millino years. In addition, it seems to me that the study does not determine that gravity is genetic or in the brain from birth, but that by the time someone is old enough to get on a space shuttle and play around in zero-G, they have some kind of subconscious understanding of gravity.
Re:What a ridiculous notion (Score:3, Informative)
First, your figure of "100 million years" seems to have been completely fabricated. Care to back that up?
Your number for day length of 100 MYA is also rather off. Day length change is approximately 2 milliseconds per century [tudelft.nl], meaning that even 100 MYA, the day could not have been more than 2000 seconds (considerably less than 6 hours) shorter than it is currently. The actual day length was actually longer than what these quick calculations indicate, given changing rates, but your numbers are completely out of the ballpark.
In addition, your very concept of gravity seems to be off. Gravity is the attraction of two bodies with definite mass, and is equal to G_c*m_1/d^2. Rotational speed doesn't affect gravity at all -- only mass does.
Heck, you even contradict yourself, not to mention practically all scientific knowledge we have. A weaker gravitational force means a lower gravitational acceleration constant, which is rather inconsistent with your figure of 15.2 m/s^2, which is rather more than the 9.8 m/s^2 we have now!
Re:What a ridiculous notion (Score:1)
Considerably less than _one_ hour, in fact. 34 minutes, to be almost exact.
Re:TROLL! (Score:4, Informative)
Of course, this has no grounding in fact, as gravitational force relates only to the masses of the objects in question and the distance separating them, and neither the mass of the Earth nor its radius has changed significantly enough to change the value of g to only one decimal place.
Presumably, the original poster was referencing the apparent force felt by objects on the Earth. Assuming the presumed increased centrifugal force to be significant, that would mean that g would instead be less than its current value --- the exact opposite of the larger value of g that the post gives.
Now then, if we wish to calculate the effect of centrifugal force... F_c = mv^2/r, so a_c = v^2/r, where v is the velocity, and r is the distance from the centre of the circle. v is proportional to 1/t, so using 86400 s and 84400 s, we get a change of less than 5% as a rough figure.
Now, calculating a_c, we use the Earth's rotational velocity and the radius for v and r. At the equator, these are approximately 460 m/s and 6378.1 km, respectively. Using the formula for a_c, we obtain a figure of approximately 0.03 m/s^2 at the equator, and values that decrease the further we get from the equation. A 5% change on 0.03 m/s^2 gives us less than 0.002 m/s^2, which is hardly even detectable without highly sensitive instruments!
The estimated change in centrifugal force at the equator from 100 MYA is less than 0.02% of g --- which is hardly even noticeable!
Article says it is NOT hardwired (Score:5, Insightful)
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.
The problem is with the assumptions... (Score:2)
The problem with this article is, not that they assume that gravity is hardwired, the article actually states that they are not sure, but rather that there assumptions are off base.
They say that it takes about 2-3 days before you get over the (lack of) motion sickness. That is, it takes the human body roughly 48-72 hours of doing something that it considers really wrong before it gets used to it.
Now consider the throwing, they say that after 15 days the astronaughts were getting used to it. Lets assume (for sake of argument) that they were throwing the ball 3 hours a day. It might seem unlikely given the cost of putting someone in space that we would give them them such a task, but even if we did, then we are saying that after roughly 45 hours of practice the body is getting used to something that it considers really wrong.
Am I really the only one that sees the parallel here?
Story about experiencing zero-g (Score:2)
Kittens (Score:2)
What about catching a frisbee on the ground? (Score:3, Interesting)
I think a more valid conclusion from that experiment might be that free fall makes you clumsy.
Everything is hardwired... (Score:1)
Second, we are poorly adapted to weightless environments (if you look at things from the anatomy point of view). Attempting to say "oh look how we do poorly there than on earth" is much like saying "oh, look how lousy a whale walks on land".
Finally, if you view it from an objective point of view (which I always do [grin]), what would be the point of hardwiring gravity in the brain? We didn't evolve catching baseballs! This is just plain silly.
And while we're at it, why are you banging those two halves of coconuts together?
Just like... (Score:1)