Playing Ball in Space

oo7tushar writes "Although most experiments in space seem simple they have profound results. Take this for example, astronauts trying to catch a ball in space. What's so hard about that? Nothing much really, down here on Earth. In space it's a completely different story. Here on earth our eyes see the ball and our brain anticipates it's movement according to gravity. In space the brain continues to anticpate gravity but unlike motion sickness (which is adapted to within days), astronauts continue to anticipate the path of a ball for 15 days (after which they start to show progress). What are the ramifications? The brain must have some sort of internal gravitation model."

Comments

Encoding Specificity

[Transient0]

An internal gravitation model would be theorizing far more than is necesarry to account for the data. In cognitive science, there has long been an understanding of encoding specificity. This simply means that data, including skill knowledge, is best retrieved from human memory under the same conditions which it was learned.

An example from the real world is underwater welding. When underwater welders were first being trained, the companies tried to simply train professional welders in all the ways that underwater welding was different from normal welding. But, in diong this, they found that when they were underwater, the welders had serious trouble calling on those skills which supposedly transferred over unchanged. As a result, they had to be entirely retrained in skills they had apparently already learned.

Similarly, if you lose your keys while you're stoned and then can't find them the next day. Psychological evidence shows that your best chance to find them is to get stoned again and then look for them.

Any number of other controlled psychological experiments have been performed to domonstrate this same effect(memorizing words under different lighting conditions, etc.). I don't see why gravitation would be any different.

Re:Encoding Specificity

[hal9000(jr)]

Otherwise known to the common man as experience. Spend your life learning about what happens to a ball through on terra-firma and it doesn't seem too far fecthed to think that the prior learning would still be in force in space.

What is amazing is that it only took 15 days to adapt. Now that is incredble.

Re:Encoding Specificity

[sunhou]

Re: learning welding underwater -- when I visited Australia, driving was a somewhat similar experience (driving on the opposite side of the road from what I was used to).

At first, it was hard because everything was the opposite of what I knew. But within a few days, I simply learned to reverse my innate responses, since I knew that those responses were backwards, and so it got easier. But after a couple of weeks, I had started to get accustomed to the new configuration, and so some of my natural responses were correct. That meant I could no longer just "do the opposite of what felt natural", and it actually got harder again and took more thought; I always had to think "is my gut feeling about what to do an old gut feeling from the US, or a newly acquired gut feeling from the past couple of weeks in Australia?"

I was there for about 4 or 5 weeks. When I got back to the US, within a day, I promptly drove on the wrong side of the road. (It was a small road with no traffic, so fewer cues, and I did catch myself within a few seconds before causing any major havoc.)

Or...

[ruiner13]

It could be that a baby born in space would not have such models. I'm guessing that is a learned response of the brain, not an inherited one. I took a Psychology of learning class in college once, and i learned many interesting things. For one, spacial perceptions depend a lot on the environment in which you are raised. For instance, if you live in a rectangular type house, you can generally make good guesses as to the dimensions of other rectangular shaped rooms. If you bring that person into a round room, the estimations are way off. It works in reverse, too. If you live in a round hut your entire life, you won't be able to make good guesses about rectangular rooms. Seems kinda analogous to the gravity story. I say we get some randy astronauts to give birth on the space station, and kinda have a truman show in space. We'll see how that baby will catch a ball then.

Re:Or...

[Shalda]

There is really no question that this is a learned response. However the article belies a basic understanding of how atletic actions work. Most notably, when you catch a ball, you don't actually look at the ball as you catch it. You anticipate the path of the ball and keep your gaze steady.

This is further complicated by the lack of gravity. You move your arm and it torques the rest of your body out of position and throws off your reference frame too. I want to get paid to write stupid papers like that. Oh, wait, I'm getting paid right now...

Re:Or...

[Peyna]

Yeah, reminds me of "The Forest People", by Colin Turnbull. He took a pygmy out of the forest where he lived and up on this mountain, and the guy thought that everything he saw was miniature versions of what they really were. His eyes had never had to look at anything more than 15-20 feet in front of him in the forest, and he had no clue what things looked like when they were that far away.

LOL

[recursiv]

It takes 100 million years to learn to adapt to a new strength of gravity? I suppose that's why they can start to make progress in just 15 days.

And on top of all that, even if any of that was correct g hasn't changed that much. Can you explain why g isn't much different on the equator than at the poles?

Anyway, I know IHBT, but I just wanted to make sure no one else buys into this.

Isaac Asimov used this for a SF story

[Seth Finkelstein]

Isaac Asimov wrote a prescient short story "The Singing Bell", about this effect. The plot hinges on proving that a man has recently been to the moon, by catching him off-guard in catching something as if he was on the moon (i.e. he had adapted to the lunar gravity in terms of ball-catching). Absolutely great science-fiction story.

Sig: What Happened To The Censorware Project (censorware.org)

Re:Nothing special...

[evilrunner]

I would think that the reactions would be based more off of observed behavior and experience than a "hard wired" instinct. It would be interesting to do the test on young children who have the motor skills but do not have the experience level of the adult participants.

Re:What a bunch of crap

[rmayes100]

Exactly. I doubt the brain is doing any complex calculations simply just taking into account the thousands of other times it's seen projectiles and guessing based on that data where this one is going to go. I've been trying to teach my young children to catch for years and they still have trouble figuring out where the ball's going to go every time. They simply don't have the experience to pull from in every case yet.

our brain learns for us.

[joopsTao]

The article does seem incredibly counter intuitive. The human brain learns through experiance, when learning to play badminton or tennis your brain builds a mental model of how the ball will travel to you.

IT also builds a mental model of how the ball will travel away from you when struck.

This just takes exposure and practice. (However I could believe that the brain has developed the ability to learn patterns of motion)

During our lives we watch leaves fall, we play ball games, we do the thing out of aliens with the knife. All of this allows our brain to predict how things will happen around us.

Maybe the scientists are right (I really have no educational basis for what I say) but I feel that too often people have a theory, they do an experiment and then merrily claim that the experiment proves the theory. Without exploring the alternatives. (I apologise to scientist types, I do not meen to generalise and I only refer to the "weird" experiments that make it into the main stream press) Cheers.

rat

[Toshito]

I saw a documentary where there was a rat (I think, or another small furry ball of some sort) that was given a small piece of food. This piece of food was dropped in a hole in front of the animal's eyes and was exiting on the bottom. There was several holes on the top of the box and another row of holes in the bottom.

The experiment was to drop the piece and see where the animal would expect it to fall. Well, it seems that the animal always expected it to fall from the hole directly under the one it was dropped into, and when it wasn't the case the animal was confused.

So they found that this animal was expecting the piece of food to follow the law of gravity.

Re:Constants

[xonker]

The brain may have a pre-programmed response to gravity on earth

I doubt that it's pre-programmed. We learn to respond to gravity the same way that we learn to walk, talk or catch a ball on Earth. If you took an infant to a zero-gravity environment (ignoring any other potential ill-effects like bone-density loss...) they would simply grow up used to that gravity. If you brought them back to Earth (again, ignoring the fact that an infant raised in zero-gravity would be a helpless whelp if brought to Earth later in life) they wouldn't automagically be able to adapt to the cause and effect of the stronger gravity. It's not innate, it's learned.

bees, parachutes, & linear thinking

[hawk]

From other seminars I've attended in the past:

there's a certain amount of linear modeling the brain can do. Note that, for a small enough interval, a linear model can be made "good enough".

The interesting examples:

1. Move a beehive by a fixed amount each day while they're out gathering. The bees adjust to this (e.g., 10feet/day), and head to where they know it *will be*. Increase this amount by a fixed amount (10, 11, 12, etc.) and they can't do it.

2. Parachute landing. Don't look at the ground. You're falling at a rate the brain can't handle; if you watch, you compensate incorrectly, and often hurt yourself. (so hear the brain seems to expect the gravity induced quadratic, whereas you're moving at a linear rate?).

hawk

Re:You can simulate this

[mikewas]

This is a different effect.

Humans' 3d vision is effective over a very short range. the spacing of our eyes is optimized for accurate depth perception at arm length. It is still usable to several feet -- maybe 10s of feet, but with ever reduced accuracy until it fails us entirely.

Beyond this limited range, we rely on a number of other cues -- comparing an object with nearby objects of known size, reduced detail at distance, and observed change of anglular direction to a moving object.

Humans use the latter -- observation of the angle to a moving object, to catch a ball. The effect is easily visible when driving down a road at constant speed. Watch the telephone poles by the side of the road -- they appear to "speed up" as they get closer. It's because they're off to the side, as they get closer even though the car's speed hasn't changed, the rate that the angle to a given pole changes more rapidly until it is exactly opposite you. You could also plot it. If you drive straight at a pole (don't try this at home), this cue doesn't exist, and bifocal vision doesn't help until possibly too late.

We use this to determine a moving ball's distance. Watch a baseball outfielder. if the ball is coming straight overhead, as he runs back to get the ball he'll actually run to the side, then veer back in to meet the ball. I suspect that when you were throwing a ball up & catching it, you were subconsiously learning how long it takes for a ball to come down for a given force of throw. Had you had the ball dropped from straight above, from a random height, you'd still be unable to accuratly time the ball's arrival & miss the catch.