On Fri, 02 May 2008 21:10:47 +0200, andrel wrote:

>> (She's got ocular albinism, which means the rods and cones aren't fully
>> developed, she lacks pigment in her iris, and the wiring to her brain
>> is different than everyone else's -
> 
> I always found it fascinating how two seemingly unrelated things as how
> the eyes connect to the left and right brain and pigmentation defects go
> hand in hand. But that is as a scientist with an interest in
> development. For the person involved it is probably slightly less
> fascinating.

Oh, we both have found it very fascinating - her ophthalmologist took 
pictures of her eyes - most people you get a bright center (from the 
reflection off the retina), but for those with this condition, it's not 
uncommon for the iris to "leak" light and for the photo to show a "spoke" 
pattern outside the pupil area.

>> what this means is that she has very
>> poor depth perception and the combination of the wiring problem and the
>> lack of pigment in her iris results in high contrast changes (usually
>> dark->light) will literally blind her for anywhere from 10 seconds to 2
>> minutes.
> 
> I think that is mainly the lack of pigment, that makes light enter the
> eye via other paths than the lens and not being able to regulate the
> amount of light. So she has to rely on slower chemical processes to
> adjust the rods and cones to the level of light.

That could well be the case.

>> Which makes driving at night a real pa in the ass for her.
> 
> So, just like me, you are the one that drives home after parties?

Pretty much, yeah.  She very occasionally will drive at night to pick our 
son up, but never on the freeway or unfamiliar roads.

>> Not to mention the nystagmus
> Wikitime

Rapid eye movement - a kind of spasm.  Essentially what it means is that 
her eyes "jump" randomly, which normally makes it difficult to read 
anything for an extended period of time.  I don't know for sure, but it's 
probably not uncommon for people who have nystagmus to be slower readers 
as a result.  My wife doesn't have that issue - she's managed to train 
herself to keep up - I don't think I've ever seen anyone read books as 
quickly as she does, and she definitely is taking in what she's reading.

>> - though for many this is a problem, my wife actually has managed to
>> harness this somehow and as a result reads very fast.  But she wonders
>> how other people actually see words on the page because she knows she's
>> not reading the text linearly.
> 
> Less serious a problem, but I always wondered how the world would look
> if it was out of focus. Whatever trick I used I was never able to not
> focus. Well, time solved this one. Now to find out how the world looks
> if you have a dominant eye. Possibly like walking with one eye closed,
> but I guess it may be subtly different.

Well, the thing is, even when using just one eye, if your brain has had 
practice at determining how far away stuff is, even with one eye you 
adjust and still have depth perception.  I asked my wife about this (my 
dad also had vision problems and I never understood the lack of depth 
perception) - she explained it as a calculation problem - she can tell 
how large something is compared to the surroundings, and if it's 
something she knows how large it is relative to, say, her hand, that 
helps - but her brain doesn't have enough practice at calculating the 
distance of an object moving based on those two reference points, and as 
a result, she has very poor eye-hand coordination when it comes to 
catching something thrown in her direction, because in order to figure 
out how far away something is, she actually has to think about it, while 
those who don't have the problem don't have to think about it.  According 
to her doctor, it comes back to things not being hooked up correctly 
between the optics and the brain.

Jim

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On Fri, 02 May 2008 20:46:52 +0200, andrel wrote:

>> [E.g., I've never been to one in my entire life.]
> 
> The fact that you don't do maintenance on your muscles and skeleton does
> not imply that it is not necessary. Some people don't maintain their
> cars and in general those cars don't live as long and healthy as other
> cars.

Absolutely true.  The only physical activity I used to get was walking to 
the car and back and the occasional bike ride.  Started going to the gym 
about 18 months ago (Andy, keep in mind that I'm 38 this year), and I've 
had much better energy levels, been able to walk further than before, and 
overall have felt better.

I could well have continued with no physical activity, and probably would 
have been fine, but I am - without a doubt - better off now that I'm 
getting regular exercise.

You want something that's good for stress management?  Go outside and go 
for a run or a bike ride.  Or get a gym membership and go down and lift 
weights for 30 minutes.  Physical activity is a *great* way to relieve 
stress - and if you'd have told me that 2 years ago, I'd have said you 
were nuts.

Before you say "but I don't know how to lift weights", I didn't either.  
That's one of the benefits of going to a gym; you can ask people who know 
these things for help.  That's what they get paid to do.  I've worked 
with trainers a couple of times (note that this isn't a cheap thing to do 
- working with a trainer, that is - the gym membership costs us about £10/
month, and gives us access 24x7 to one location.

One important note, though - if you do start exercising, you need to be 
sure you're eating well as well.  Just like when you run out of petrol in 
the car, if you haven't taken in enough calories, you'll run out of gas.  
One thing that surprised me was that when working with a trainer, I was 
eating *5* times a day, but I was *losing* weight.  As one of my trainers 
put it to me "in order to burn fat, you've got to feed the engine".

Jim

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>> I was under the impression that your heart *can* recover from damage. 
>> Similarly, you can't regrow brain cells, but the brain has an impressive 
>> capacity to reassign functions and regain normal functioning after 
>> fairly serious injury.
>>
> Well, actually, the brain can grow new cells, it just doesn't do so 
> much, and it wouldn't help in some cases, since the *data* is encoded 
> into the existing cells. It might, in theory, repair itself with new 
> tissue, but the result would tend to be a blank slate, with no means to 
> relearn the correct responses. Its likely that there is some genetic 
> markers that strongly inhibit new growth, precisely due to how it could 
> destabilize the existing pattern.

I find it interesting that every single person's brain appears to be 
organised in roughly the same way. As in, there's a specific part of the 
brain that does function X, and it's in the same place in [almost] 
everybody's brain. Clearly much of the brain's structure must be 
hard-coded genetically or something.

Anyway, as I was saying, apparently the brain has the capacity to move 
those functions of other regions in case of damage. To an impressive 
degree...

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On Fri, 02 May 2008 09:19:43 +0100, Invisible wrote:

>>> - Central nervous system with cognative abilities unrivalled by any
>>> organism on Earth, as far as we know.
>> You forget the mice.
> 
> Is this a Douglas Adams reference?

Heh, you'd better believe it. ;-)

Best laid plans of mice....

Jim

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andrel wrote:

> The fact that you don't do maintenance on your muscles and skeleton does 
> not imply that it is not necessary. Some people don't maintain their 
> cars and in general those cars don't live as long and healthy as other 
> cars.

...or again, one could argue that humans are designed for a mode of 
living which happens to involve lots of moving around. The fact that 
people need to go to the gym at all is just an artifact of our modern 
lifestyle rather than a design flaw in our body plan.

> Skeletal muscle can also grow by increasing the size of the muscle cells 
> (as can the heart cells). I should know if skeletal muscle cells can 
> still divide in adults or not, but I don't. GIMF, but I don't feel like 
> meeting a friend now, perhaps later.

I was under the impression that you can basically grow (or catabolise) 
arbitrary amounts of muscle fiber as conditions necessitate...

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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>> Is this a Douglas Adams reference?
> 
> Heh, you'd better believe it. ;-)

May I have my geek license back now? :-P

> Best laid plans of mice....

I have never actually heard that figure of speech except in the book.

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On Fri, 02 May 2008 21:28:11 +0100, Orchid XP v8 wrote:

>>> Is this a Douglas Adams reference?
>> 
>> Heh, you'd better believe it. ;-)
> 
> May I have my geek license back now? :-P

I think we could arrange a provisional return. ;-)

>> Best laid plans of mice....
> 
> I have never actually heard that figure of speech except in the book.

http://en.wikipedia.org/wiki/Of_Mice_and_Men

and

http://en.wikipedia.org/wiki/To_a_Mouse

Honestly, I've never heard anyone say it either (that I can recall), but 
these are the origins. :)

Jim

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Jim Henderson wrote:
> On Fri, 02 May 2008 21:10:47 +0200, andrel wrote:
> 
>>> (She's got ocular albinism, which means the rods and cones aren't fully
>>> developed, she lacks pigment in her iris, and the wiring to her brain
>>> is different than everyone else's -
>> I always found it fascinating how two seemingly unrelated things as how
>> the eyes connect to the left and right brain and pigmentation defects go
>> hand in hand. But that is as a scientist with an interest in
>> development. For the person involved it is probably slightly less
>> fascinating.
> 
> Oh, we both have found it very fascinating - her ophthalmologist took 
> pictures of her eyes - most people you get a bright center (from the 
> reflection off the retina), but for those with this condition, it's not 
> uncommon for the iris to "leak" light and for the photo to show a "spoke" 
> pattern outside the pupil area.
I think that also the white of the eye may transmit more.
[..]

> 
>>> - though for many this is a problem, my wife actually has managed to
>>> harness this somehow and as a result reads very fast.  But she wonders
>>> how other people actually see words on the page because she knows she's
>>> not reading the text linearly.
>> Less serious a problem, but I always wondered how the world would look
>> if it was out of focus. Whatever trick I used I was never able to not
>> focus. Well, time solved this one. Now to find out how the world looks
>> if you have a dominant eye. Possibly like walking with one eye closed,
>> but I guess it may be subtly different.
> 
> Well, the thing is, even when using just one eye, if your brain has had 
> practice at determining how far away stuff is, even with one eye you 
> adjust and still have depth perception.  I asked my wife about this (my 
> dad also had vision problems and I never understood the lack of depth 
> perception) - she explained it as a calculation problem - she can tell 
> how large something is compared to the surroundings, and if it's 
> something she knows how large it is relative to, say, her hand, that 
> helps - 
I'd imagine that all normal depth cues (you know, the ones we use when 
composing a good POV scene) should be available to her, some less 
because of the other visual problems.
> but her brain doesn't have enough practice at calculating the 
> distance of an object moving based on those two reference points, and as 
> a result, she has very poor eye-hand coordination when it comes to 
> catching something thrown in her direction, because in order to figure 
> out how far away something is, she actually has to think about it, while 
> those who don't have the problem don't have to think about it.  According 
> to her doctor, it comes back to things not being hooked up correctly 
> between the optics and the brain.

Makes sense. With the two images far away in disjoint parts of the 
visual cortex it would be hard to combine the information. Hmm, I wonder 
if the condition is more severe in man. IIRC the two halves of the brain 
do communicate more in women.

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On Fri, 02 May 2008 23:42:53 +0200, andrel wrote:

>> Oh, we both have found it very fascinating - her ophthalmologist took
>> pictures of her eyes - most people you get a bright center (from the
>> reflection off the retina), but for those with this condition, it's not
>> uncommon for the iris to "leak" light and for the photo to show a
>> "spoke" pattern outside the pupil area.
> I think that also the white of the eye may transmit more. [..]

Possibly.

>> Well, the thing is, even when using just one eye, if your brain has had
>> practice at determining how far away stuff is, even with one eye you
>> adjust and still have depth perception.  I asked my wife about this (my
>> dad also had vision problems and I never understood the lack of depth
>> perception) - she explained it as a calculation problem - she can tell
>> how large something is compared to the surroundings, and if it's
>> something she knows how large it is relative to, say, her hand, that
>> helps -
> I'd imagine that all normal depth cues (you know, the ones we use when
> composing a good POV scene) should be available to her, some less
> because of the other visual problems.

Oh, probably, relative size of an object to environment, shadows and such 
are all a factor in determining position; but as I said (below), 
processing that data properly is an issue.  This is why she'd never been 
good at team sports - it's hard to catch a softball if you can't tell 
where it is until after it's hit you in the head.

>> but her brain doesn't have enough practice at calculating the distance
>> of an object moving based on those two reference points, and as a
>> result, she has very poor eye-hand coordination when it comes to
>> catching something thrown in her direction, because in order to figure
>> out how far away something is, she actually has to think about it,
>> while those who don't have the problem don't have to think about it. 
>> According to her doctor, it comes back to things not being hooked up
>> correctly between the optics and the brain.
> 
> Makes sense. With the two images far away in disjoint parts of the
> visual cortex it would be hard to combine the information. Hmm, I wonder
> if the condition is more severe in man. IIRC the two halves of the brain
> do communicate more in women.

From the wikipedia article on OA, there are variants that affect men that 
don't affect women.  

Jim

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Jim Henderson wrote:
> On Fri, 02 May 2008 23:42:53 +0200, andrel wrote:
> 
>>> Oh, we both have found it very fascinating - her ophthalmologist took
>>> pictures of her eyes - most people you get a bright center (from the
>>> reflection off the retina), but for those with this condition, it's not
>>> uncommon for the iris to "leak" light and for the photo to show a
>>> "spoke" pattern outside the pupil area.
>> I think that also the white of the eye may transmit more. [..]
> 
> Possibly.
Drawing from what I heard from someone studying scattering of light in 
the eye. People with less pigment had more light coming in from all 
sides than people with more pigment. i.e. blue eyed people having more 
problems with headlight of cars approaching.
> 
> 
>>> but her brain doesn't have enough practice at calculating the distance
>>> of an object moving based on those two reference points, and as a
>>> result, she has very poor eye-hand coordination when it comes to
>>> catching something thrown in her direction, because in order to figure
>>> out how far away something is, she actually has to think about it,
>>> while those who don't have the problem don't have to think about it. 
>>> According to her doctor, it comes back to things not being hooked up
>>> correctly between the optics and the brain.
>> Makes sense. With the two images far away in disjoint parts of the
>> visual cortex it would be hard to combine the information. Hmm, I wonder
>> if the condition is more severe in man. IIRC the two halves of the brain
>> do communicate more in women.
> 
> From the wikipedia article on OA, there are variants that affect men that 
> don't affect women.  

That's not what I meant. I meant that if the image of the left eye ends 
up in the right visual cortex and vice versa, you need to communicate 
between the two brain halves to match them. BTW I see now that the 
problem with the optic nerve is only mentioned somewhere low on the 
page. For some reason I remembered it as being quite common.

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