• Quick note - the problem with Youtube videos not embedding on the forum appears to have been fixed, thanks to ZiprHead. If you do still see problems let me know.

Visual reality: a new insight.

Re: Re: Re: Re: Re: Re: Visual reality: a new insight.

Upchurch said:
What do you mean by "we do not literally see at a distance"? How don't we?
Click to expand...

Lifegazer explained in his opening post. We learn to see at a distance by perceptual cues like Russdill mentioned. The point being is that when we see something at a certain distance, this is a learned ability rather than an innate one.
 
Interesting Ian said:
The point being that we do not literally see at a distance. Therefore our visual sensations cannot give any evidence for an "external world".

Is this what you meant Lifegazer?
Click to expand...
Yes. Incoming light (if there is any such thing), is distance-less.
It is upto the mind/brain to decide how far that light has travelled.
My argument was that there is no accurate way for the mind/brain to decide how far that light had travelled. Hence, I am puzzled as to the accuracy of our inner awareness of reality.

But I have seen responses to show how the mind could learn that some light-sources were closer than others, or longer than others. Hence, the situation has become too complex for me to argue. That's why I conceded. However, feel free to carry the argument for me.
 
Re: Re: Re: Re: Re: Visual reality: a new insight.

Interesting Ian said:


The trouble is that this is then a non-sequitur to Lifegazer's original point isn't it? :confused:

The point being that we do not literally see at a distance. Therefore our visual sensations cannot give any evidence for an "external world".

Is this what you meant Lifegazer?
Click to expand...
A quick experiment:

1. Close one eye, and look around at things for about 30 seconds just to get used to using one eye.

2. Pick an object relatively close to you, within arms distance.

3. Take your hand, and try to move your hand as close to the object as you can before touching it.


You'll notice that it is quite difficult to judge how close your hand is.

We do not see depth entirely indirectly, otherwise we would not be able to distinguish between a scene you view on your 2D television screen and the 3D scenes you view in real life.

The problem comes when the distance of an object is too great to be able to make distinctions between the closest and farthest parts of that object.

(I'm sure if we grew one more eye, which was between our two existing eyes and placed somewhere near the top of our forehead, we would have the ability to judge distances much much more accurately by sight alone.)
 
Re: Re: Re: Re: Visual reality: a new insight.

Interesting Ian said:
No no, it's more of a mental problem rather than a brain problem. You see we build up the hypothesis of a 3 D world from primarily our visual and tactile senses. Our vision can be absolutely perfect, but if we were blind from birth before acquiring this vision, then although we have perfect vision, we would not be able to see.

Why is this? Well it's because we haven't built up our implicit low level theory about how the world is. All we'd see is a chaos of differing colors. You wouldn't be able to make sense of your environment.
Click to expand...
It seems you have made the same point I made with fewer words. Occam would be proud :p

I do think the mental problem and the brain problem are causally related. Underdeveloped visual cognition due to an underdeveloped brain.
 
Re: Re: Re: Re: Re: Re: Visual reality: a new insight.

Yahweh said:

A quick experiment:

1. Close one eye, and look around at things for about 30 seconds just to get used to using one eye.

2. Pick an object relatively close to you, within arms distance.

3. Take your hand, and try to move your hand as close to the object as you can before touching it.


You'll notice that it is quite difficult to judge how close your hand is.

We do not see depth entirely indirectly, otherwise we would not be able to distinguish between a scene you view on your 2D television screen and the 3D scenes you view in real life.

The problem comes when the distance of an object is too great to be able to make distinctions between the closest and farthest parts of that object.

(I'm sure if we grew one more eye, which was between our two existing eyes and placed somewhere near the top of our forehead, we would have the ability to judge distances much much more accurately by sight alone.)
Click to expand...

I do not really want to get into an argument about this Yahwah.
 
Re: Re: Re: Re: Re: Re: Re: Visual reality: a new insight.

Interesting Ian said:
I do not really want to get into an argument about this Yahwah.
Click to expand...
Alrighty, I'll busy myself on PalTalk and finishing up homework, just give me a prayer if you need me...

*Zooooom*

*Yahweh leaves the thread*
 
lifegazer said:

Yes. Incoming light (if there is any such thing), is distance-less.
It is upto the mind/brain to decide how far that light has travelled.
My argument was that there is no accurate way for the mind/brain to decide how far that light had travelled. Hence, I am puzzled as to the accuracy of our inner awareness of reality.

But I have seen responses to show how the mind could learn that some light-sources were closer than others, or longer than others. Hence, the situation has become too complex for me to argue. That's why I conceded. However, feel free to carry the argument for me.
Click to expand...

It seems to me that the argument you were making is that we are not a priori cognisant of distance from our visual sensations alone. Seeing is therefore a learnt ability, ultimately derived from the correlations between what we see and our sense of touch. Using visual sensations alone, visual cues thereafter give us the idea of how far away an object is.

How does this relate to an idea of a material world or an "external reality"? Well some people would say that they know there is an "external reality", or material reality, because they can immediately see it. They might claim that they can see a tree out there external to them residing at a certain distance. But, as has been pointed out, they do not literally see anything at a distance from them, and hence external to them. Normally all distance means is that if I make certain bodily movements (eg walk towards object in question), I will receive a certain tactile sensation. Hence one cannot justify the existence of a material world or "external reality" by saying one is immediately acquainted with such a reality.

On the other hand, only a philosophically naive person would maintain this, and if such a person were so disposed, they are unlikely to understand the argument that we do not literally see at a distance either!
 
Interesting Ian said:

Which are all irrelevant.



Yes! Good! But remember the real world need not be material, and indeed there are no good arguments to suppose it is.
Click to expand...
Or that it is not; such things rely on fundamental assumptions, rather than universal truths.

As for all those things being irrelevant...once you agreed that our depth perception knowledge must be built up with experience (you said tactile, in particular--I would broaden that a bit, but OK), I would have thought you would retract the "irrelevant" statement. Those cues are precisely the visual cues which we learn to pay attention to, based on their correspondence with that tactile experience. So, while they are not automatically developed as depth perception cues (I know you are familiar with the "carpenter-world hypothesis", for instance), they are used as depth perception cues. So...why irrelevant?
 
Mercutio said:
Or that it is not; such things rely on fundamental assumptions, rather than universal truths.

As for all those things being irrelevant...once you agreed that our depth perception knowledge must be built up with experience (you said tactile, in particular--I would broaden that a bit, but OK), I would have thought you would retract the "irrelevant" statement. Those cues are precisely the visual cues which we learn to pay attention to, based on their correspondence with that tactile experience. So, while they are not automatically developed as depth perception cues (I know you are familiar with the "carpenter-world hypothesis", for instance), they are used as depth perception cues. So...why irrelevant?
Click to expand...

Irrelevant to the issue I believe that Lifegazer was originally getting at.
 
lifegazer said:
I can see that the eye/brain could fathom that some objects were closer than others, and some further than others. But how does it get an accurate picture of events? None of the replies here have answered that question.
Click to expand...

As they say here in the STates "good enough for government work", the perception has to only approximate the external visual field, some organisms do very well with very simple perception.

And the answer is that it isn't accurate, just representational.

And learned.
 
Re: Re: Visual reality: a new insight.

Interesting Ian said:

This would mean therefore, for example, that a blind person from birth, but who suddenly could be made to see for the very first time, would not be able to tell a cube and sphere from the visual appearance of these objects alone.

Such considerations might be taken to be suggestive that there is no mind-independent reality.
Click to expand...

Or such considerations might suggest that there is no mind independant of body.

Ian hate to tell you this, and maybe I shouldn't, but the blind person is going to have to learn to see.
Thier brain is not wired to process visual information in the first place, so the nueral network is not going to make much sense of the visual sensation to begin with. I don't know how long it would take them to learn to see but they are not going to recognise any visual input at first. Their brain will have to go through the process that an infant goes through while the brain is growing.
 
Re: Re: Re: Re: Visual reality: a new insight.

Interesting Ian said:


Why is this? Well it's because we haven't built up our implicit low level theory about how the world is. All we'd see is a chaos of differing colors. You wouldn't be able to make sense of your environment.
Click to expand...

Uh, Ian this isn't done at the cognitive level, it is done in the visual cortex and then presented to the frontal cortex. You could have all the theory you want, it is going to take the nueral network time to learn to process the signals. It is not a thought thing it is a perceptaul thing. Which occurs on the 'unconsious' level.

They aren't going to see anything, they will probably have synsthesia at first, if thier brain still has the potential to learn visual processing. If it is like language aquisition then they will never.
 
lifegazer said:

Yes. Incoming light (if there is any such thing), is distance-less.
It is upto the mind/brain to decide how far that light has travelled.
My argument was that there is no accurate way for the mind/brain to decide how far that light had travelled. Hence, I am puzzled as to the accuracy of our inner awareness of reality.

But I have seen responses to show how the mind could learn that some light-sources were closer than others, or longer than others. Hence, the situation has become too complex for me to argue. That's why I conceded. However, feel free to carry the argument for me.
Click to expand...

The point is that it is a learned sense. Micheal Jordan had to play a lot of basket ball to develop his skills. (Soory I couldn't name any fut-bol or cricket players.)

The brain learns the relationships through practise.
 
IIRC, some of the ancients proposed the eye "emits" a ray which reflects back into it.

Now, that's the Transactional interpretation's of QM advanced wave travelling backwards wrt (our) wall-clock time. What is the difference between zero+ and zero- for a wavicle whose own clock is moving -- so to speak -- at c.

A basic idea of TI is that no boson in the universe is ever emitted until it has an agreed-upon path that ends at a specific receptor.

lg, you give up too soon. ;)
 
lifegazer said:
Okay ladies and gents... I concede to your better knowledge.
I shall now acknowledge that it might be possible to construct an accurate picture of reality, given time and the numerous methods you've all mentioned. I'm not 100% convinced, but you have given me ample evidence to suggest I could be wrong.
I shall now retract my argument here.
Click to expand...
I hope you keep asking questions and presenting ideas. We learn most from those who don't know...
 
Re: Re: Re: Visual reality: a new insight.

Dancing David said:


Or such considerations might suggest that there is no mind independant of body.

Ian hate to tell you this, and maybe I shouldn't, but the blind person is going to have to learn to see.
Thier brain is not wired to process visual information in the first place, so the nueral network is not going to make much sense of the visual sensation to begin with. I don't know how long it would take them to learn to see but they are not going to recognise any visual input at first. Their brain will have to go through the process that an infant goes through while the brain is growing.
Click to expand...

If one has been blind throughout their lives due to some defect in their eyes, then this is cured, and then they have perfect vision (although they can't see very well) then clearly thier brain is "wired to process visual information in the first place".

It's not the brain, it's rather a psychological thing. They haven't had any opportuinity to build up a model/theory about the world to make sense of it.

Of course if you're a materialist you would insist that it is the brain. But then you would also say, for example, ones irrational behaviour is not due to anger (maybe because of things that have recently happened to you), but rather because of certain chemicals in the brain or neurons firing or whatever. In other words, even if you're a materialist, it's not very useful, and it is confusing to say that a person can't see because of the condition of their brain.

I see the brain as being crucial for vision, but the question of seeing (as opposed to vision) is a different matter. Given perfect vision, to also see perfectly is a psychological thing. That which enables us to see, to make sense of our vision, is an implicit theory about the world held by our minds.
 
Re: Re: Re: Re: Re: Visual reality: a new insight.

Dancing David said:
Originally posted by Interesting Ian

Why is this? Well it's because we haven't built up our implicit low level theory about how the world is. All we'd see is a chaos of differing colors. You wouldn't be able to make sense of your environment.

DD

Uh, Ian this isn't done at the cognitive level, it is done in the visual cortex and then presented to the frontal cortex.
Click to expand...

NO NO. Look at my previous post. You wouldn't say Einstein had certain processes occurring in his brain which accounts for how he came up with his idea that acceleration and gravitation are equivalent. Our theories about the world are described at the cognitive level even if such mental processes have neural correlates! Even materialists do this if only for the sake of convenience!

You could have all the theory you want, it is going to take the nueral network time to learn to process the signals. It is not a thought thing it is a perceptaul thing.
Click to expand...

NO NO NO. You just don't understand. It is ABSOLUTELY a "thought thing".
 
You must log in or register to reply here.

Back
Top Bottom