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Author Topic: The nature of sensing touch !  (Read 2626 times)

Offline neilep

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The nature of sensing touch !
« on: 17/04/2007 20:39:52 »
I am debating as to whether I should get some sleep before asking another question cos I'm having trouble explaining things today !!...and this is sort of complicated for me to convey !

Anyway..I'll give it a try.




You touch a part of your body and you can ' feel ' where the touch is yes ?..eg: if I pinch myself an inch below my belly button I can feel that that is where the pinch is !!..with me so far ?

Say, I undergo one of those big ops where they cut off a huge amount of body fat plus the skin and then eveything moves round a bit yes ?..are you still with me ?

So, lets say that piece of skin that I pinched an inch below my belly button is now moved elsewhere or is cut off and another piece of body is stretched to replace it...then...............will the pinch feel if it's in the same location if I pinch the same inch below my belly button ?...even though it's a different piece of skin I'm pinching ?

Are you kind of understanding this ?


should I just give up and go to bed ?



 

Offline Seany

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The nature of sensing touch !
« Reply #1 on: 17/04/2007 21:08:30 »
Nah Neil it makes sense. And its only 9pm ya dummy!

So let's think of it this way.

I chop off one of my toes. And one of my fingers.

I chuck the toe away. And with surgery, stick my finger in replacement of the toe.

Now, if I pinch the finger/toe which is on my toe, will it feel like if it hurts on the foot or the hand?

Definitely the foot, because it is no longer part of your hand anymore, even though it was. It now shares the same nerves as your old toe had, because when you had a surgery or something, the nerves are joined. So you wouldn't feel pain on your hand, but still on your toe, even though it was originally a finger.
 

another_someone

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The nature of sensing touch !
« Reply #2 on: 17/04/2007 21:26:49 »
There are two different issues.

Firstly, there is, as Sean mentioned, then issue of where are the nerves connected.

Secondly, there is the adaptability of the brain.  After all, my brain is perfectly aware that the relationship of my belly button and various other parts of me has shifted over my lifetime - bits have drifted further away from each other totally without the surgeons knife to help.

An indication of how adaptable the brain is can be seen with that oft recounted experiment where people were given prisms to wear that made the world look upside; and after an initial confusion, the brain quickly compensated for the prisms, so the subjects could still tell exactly where things were without even being aware of the distorting effects of the prism (and in fact, when the prisms were removed, they were initially confused and thought the world to be upside down, until they had acclimatised to the world without the prisms).

Thus, even if the nerves were wired up differently, the brain will begin to rewire itself to compensate for changes in external wiring.
 

Offline neilep

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The nature of sensing touch !
« Reply #3 on: 17/04/2007 22:08:29 »
Nah Neil it makes sense. And its only 9pm ya dummy!

So let's think of it this way.

I chop off one of my toes. And one of my fingers.

I chuck the toe away. And with surgery, stick my finger in replacement of the toe.

Now, if I pinch the finger/toe which is on my toe, will it feel like if it hurts on the foot or the hand?

Definitely the foot, because it is no longer part of your hand anymore, even though it was. It now shares the same nerves as your old toe had, because when you had a surgery or something, the nerves are joined. So you wouldn't feel pain on your hand, but still on your toe, even though it was originally a finger.


Gosh !!..ewe are a clever lad aren't ewe ?....and to think...you're only gonna get clevererereererer !!..LOL

Thanks sean
 

Offline neilep

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The nature of sensing touch !
« Reply #4 on: 17/04/2007 22:12:20 »
There are two different issues.

Firstly, there is, as Sean mentioned, then issue of where are the nerves connected.

Secondly, there is the adaptability of the brain.  After all, my brain is perfectly aware that the relationship of my belly button and various other parts of me has shifted over my lifetime - bits have drifted further away from each other totally without the surgeons knife to help.

An indication of how adaptable the brain is can be seen with that oft recounted experiment where people were given prisms to wear that made the world look upside; and after an initial confusion, the brain quickly compensated for the prisms, so the subjects could still tell exactly where things were without even being aware of the distorting effects of the prism (and in fact, when the prisms were removed, they were initially confused and thought the world to be upside down, until they had acclimatised to the world without the prisms).

Thus, even if the nerves were wired up differently, the brain will begin to rewire itself to compensate for changes in external wiring.


Gosh !!..you're a clever lad too !!

THANK YOU GEORGE,

I am just glad that there was a semblance of coherence in my question because you have answered it perfectly.

I find it extraordinary that the brain will adapt to make me feel that my skin is being touched at a spot on my body that I can see  despite the fact that perhaps the nerves are routed elsewhere.

is this brain adaptability  a similar thing to the fact that we really see things upside down and the brain turns it around for us ?
 

another_someone

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The nature of sensing touch !
« Reply #5 on: 17/04/2007 22:28:37 »
The brain is just a machine for making decisions - sometimes right decisions, and sometimes wrong decisions - when it gets it wrong, it changes the decision to make a better one next time.

When the brain senses something (touch of the skin, image from the eye, etc.), it makes judgements as to how it should react to that.  If that reaction leads to a painful result, it rewires itself to make a different judgment next time, until it finds that the judgements it makes are not painful, bring it food, or achieve whatever it was it was trying to achieve.

If you rewire or change part of the body, so it sends different signals; the brain will ask the body to respond to those signals in the way it was used to doing - but soon finds that response does not have the desired result, so it changes its internal model so that next time it will ask for a slightly different response to the stimuli, until it starts getting the response it wants.
 

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The nature of sensing touch !
« Reply #5 on: 17/04/2007 22:28:37 »

 

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