Vision & Abstraction

[John Page]

Here's a link to an article on a unique case of eyesight restoration from the Washington Post (http://www.washingtonpost.com/wp-dyn/articles/A39676-2003Aug24.html) .

I'm interested in comments in this forum because of the comments regarding hard-wiring vs. plasticity of the mind/brain.

Clearly, the subject perceives objects and associated motion and reports this capability was immediate with sight restoration. However, after 3 years he is still learning how to see, cannot recognize his wife's face amongst others, sees only in 2D and cannot interpret facial expressions.

Seems to me that the sense data is coming in, hard wired aspects of perception make this data available to the rest of his mind but it has not been integrated into the subject's overall understanding of his world from his other senses.

Do you think that a (tentative) conclusion can be made that the more abstract (i.e. not direct sense data, but interpreted against experience) a notion is, the more likely it is acquired through a learning process than being an innate capability?

Cheers, John

[BDS]

In his book "Anthropologist on Mars" Oliver Sachs has a chapter on vision restoration. It's mainly a case history of one particular patient, but he also looks at other cases.

The patient in the case history had a lot of trouble learning to "see". After an operation, he could see perfectly but could not avoid bumping into the furniture, because he could not properly interpret the visual signals.

Strangely, this (like the Washington Post article John Post cites) mirrors the description in the Bible of Jesus restoring sight to the blind. In the Washington Post article, May, "....often can't tell shadows from trees."

Here's Mark's description of Jesus restoring sight to the blind: "“And Jesus took the blind man by the hand…and when He put His hands upon him, He asked him if he saw anything. And he looked up and said, “I see men looking like trees walking.” Mark, 8:24

Mark’s version of Jesus restoring the blind man’s sight is in remarkable agreement with the medical records. When Jesus first restores the man’s sight, the man can see, but cannot distinguish between men and trees. So Jesus, “put His hands on his eyes again… and he saw every man clearly.” The miracle (as reported in Mark, 8) was actually two-fold – restoring physical sight and providing enlightenment as to how to interpret it.

I have no idea what the perspicacity of Mark's version means, but it's impressive, at any rate.

[tronvillain]

The hard distinction between "hard wired in the brain" and "learned after birth" the article itself makes is a little ridiculous, but Ione Fine's quote seems reasonable enough:
The ability to process complex forms such as objects and faces may not fully develop until later and may require continual stimulation to function fully, because people need to be able to recognize new objects and changes in faces throughout their lives, she said. "We have to recognize new images throughout time. That system is much more plastic throughout our lives. The price for that is that if you switch the lights out, it kind of disintegrates over time. It's a system that needs stimulation.
I think it quite unlikely that "a (tentative) conclusion can be made that the more abstract (i.e. not direct sense data, but interpreted against experience) a notion is, the more likely it is acquired through a learning process than being an innate capability." A more reasonable conclusion is that various devoted brain mechanisms require stimulation to develop and to be maintained. It appear that "the sense data is coming in" but that he lacks the appropriate mechanisms to extract certain useful information from the relatively uninformative raw data. It does not seem likely that such mechanisms could simply be "learned" without some innate propensity.

[John Page]

Hi troff!
Originally posted by tronvillain
A more reasonable conclusion is that various devoted brain mechanisms require stimulation to develop and to be maintained.
Well, the article's detail got me thinking your conclusion is not always the case. The subject is reported as having sight restored pretty much instantantly after the stem-cell procedure. This would indicate that the visual cortex continues to develop even and remain functional after the stimulus of light (at age three in the subject) is completely removed.

What I am trying to home in on is that some of the "various devoted brain mechanisms" do not appear to require nurture (e.g. motion detection, color perception), whereas some definitely do (face recognition, hand-eye coordination).

My hypothesis remains that those functions requiring nurture deal with highly abstract analysis (say, intersubjective interpretation of feelings expressed by facial contortions), whereas less abstraction is required for such underlying functions as movement within the face itself.

In summary, it seems to me that the subject's brain could detect facial motion but lacked the ability to interpret it as body language.

Cheers, John

[BDS]

I'd have to get my copy of Sach's book, but I don't think that May's list of difficult cognitive visual functions is universal. Sachs (who, by the way, is a neurologist who also wrote the book "Awakenings" about how el dopa revived comatose Parkinson's patients, which was made into a Robin Williams movie) patient had a different list of difficulties, as I remember them.

Some seemed similar, however. Depth perceptions is apparently difficult to learn. One patient reported being unable to comprehend that there were objects outside of the window of his hospital room -- they looked to him like they were ON the window. I'll look at my book when I go home tonight and report back.

Very interesting topic.

[BDS]

By the way, the Sachs' book has a number of chapters about interesting visual impairments. One guy was a painter and lost all color vision (and began painting in black and white); another had a gunshot wound which gave him "super vision" -- he could read license plate two blocks away -- but negatively affected his vision in other ways. One chapter was about an autistic kid who couldn't even talk, but could remember and draw precise and incredibly acurate recreations of things he had seen. Another was about an artist who painted only paintinings of his childhood home in Italy, which he hadn't seen for 40 years, but remembered in precise visual detail.

[John Page]

Originally posted by BDS
Depth perceptions is apparently difficult to learn. One patient reported being unable to comprehend that there were objects outside of the window of his hospital room -- they looked to him like they were ON the window.
BDS:

Cool! In another thread the 3d phenomena has been discussed as the effect created by triangulating the 2D (space) information received against the movement away and towards the observer (muscular/nerve feedback) against the object getting larger and smaller. Sorry about this poor explanation, but an inability to integrate/analyze the sense data concerned would roughly tally with your example.

Cheers, John

[tribalbeeyatch]

Originally posted by BDS
el dopaEl Dopa? Is he that vato down the block that deals Thai stick out of his El Camino?:D

[tribalbeeyatch]

Originally posted by John Page
BDS:

Cool! In another thread the 3d phenomena has been discussed as the effect created by triangulating the 2D (space) information received against the movement away and towards the observer (muscular/nerve feedback) against the object getting larger and smaller. Sorry about this poor explanation, but an inability to integrate/analyze the sense data concerned would roughly tally with your example.

Cheers, John Do you have a link for that thread, John? It sounds interesting. You're saying that depth perception is only provided in instances where the object in view is moving towards or away from the viewer? That's clearly not true, so I guess I'm not quite following. Could you expand a bit?

[John Page]

Originally posted by tribalbeeyatch
Do you have a link for that thread, John? It sounds interesting. You're saying that depth perception is only provided in instances where the object in view is moving towards or away from the viewer? That's clearly not true, so I guess I'm not quite following. Could you expand a bit?
Tribal:

I'll look for the thread, I'm trying to remember what the OP was.

On depth perception, I'm not suggesting that we only know about a specific objects depth only when it moves. I'm suggesting that we learn about depth through trial and error experimentation as kids (building blocks in mouth, mom's head getting bigger as her voice gets louder etc.) and this experience is how come we know/intuit the thickness of an object before us. Hence 3D optical illusions such as the 2D ever-climbing stairs picture which fools our learned expectation of an actual 3D staircase.

Cheers, John

[John Page]

Tribal:

Thanks to wordfailure for remembering the thread referenced above. (http://www.iidb.org/vbb/showthread.php?s=&threadid=54543&perpage=25&pagenumber=1) ,

Cheers, John

[BDS]

El dopa should have been written "l dopa". It's a drug for Parkinson's disease. When it was first discovered, it was used on patients who had been in comas due to severe Parkinsons, some for ten years an more. They snapped out of their comas, had incredible bursts of creativity, and then slipped back into having problems from both the disease and the side effects of the drug.

I glanced through Sachs' book last night. Some other interesting observations from people who had recovered sight: one patient had trouble moving from one object to another. He couldn't count how many fingers he had without touching them. he could see each finger, but when he moved from one to another in the counting process he would become confused. An other patient who couldn't tell the difference between a dog and a cat would grab the animal and feel it to discover which species it was, and then stare at it for minutes, saying to himself, "I will remember you are a cat." Sometimes he WOULD remember, but sometimes he'd forget.

[tribalbeeyatch]

Originally posted by John Page
Tribal:

I'll look for the thread, I'm trying to remember what the OP was.

On depth perception, I'm not suggesting that we only know about a specific objects depth only when it moves. I'm suggesting that we learn about depth through trial and error experimentation as kids (building blocks in mouth, mom's head getting bigger as her voice gets louder etc.) and this experience is how come we know/intuit the thickness of an object before us. Hence 3D optical illusions such as the 2D ever-climbing stairs picture which fools our learned expectation of an actual 3D staircase.

Cheers, John I think that I agree with you, but I'm not sure. It sounds like you are talking about monocular depth cues being learned at a young age. That aligns well with my intuition. After all, larger size or greater brightness and contrast, etc. are all subject to interpretation. Without experiencing these attributes dynamically (i.e. while they are in motion), an infant wouldn't necessarily understand that the large mommy was the same as the small mommy, just closer. By that I mean, if we flashed two different visual scenes to them, one with a smaller, dimmer, less-contrasty mommy and one with a larger, brighter, contrasty one, they might not be able to connect the two. If we instead showed them a moving scene in which the mommy walked right up to them, then the small and large mommies have been connected, and with them the accompanying change in those monocular visual cues.

I still wonder if binocular depth perception is a learned skill, though. By that I mean only the perception itself and not the motor coordination of eye convergence and accomodation, for example. Given that it relies so much more on "hardwired" features of the nervous system than in the case of monocular depth cues, it seems to be much less abstract. I would be curious to hear other's thoughts.

[tribalbeeyatch]

Originally posted by BDS
El dopa should have been written "l dopa". It's a drug for Parkinson's disease. When it was first discovered, it was used on patients who had been in comas due to severe Parkinsons, some for ten years an more. They snapped out of their comas, had incredible bursts of creativity, and then slipped back into having problems from both the disease and the side effects of the drug. I know, I was just funnin' ya.

FYI: L-DOPA is the natural precursor to dopamine in the brain. Tyrosine is converted to L-DOPA by tyrosine hydroxylase, then L-DOPA is converted to dopamine by DOPA decarboxylase.

[BDS]

So far, nobody has commented on the most interesting part of my posts, the scene in Mark.

I think it's fascinatiing that the Biblical sight restoration story is so accurate, based on modern, scientific accounts.

Of course I'm fully aware this doesn't prove anything -- a brilliant and empathetic writer of fiction could describe something like this just as accurately as an eye witness. But it certainly highlights the genius of myth -- sort of like the Old Testament's "All rivers floweth unto the sea, and yet the sea is not full. for unto that place from whence the rivers came, thither they return again....."


Did Ecclesiastes know about evaporation?

[John Page]

Originally posted by BDS
So far, nobody has commented on the most interesting part of my posts, the scene in Mark.
I held back given your invitation for comments from others. Miracles cease to be miracles given a believable cause....

I wonder if the story was borrowed from yore.

Cheers, John

[BDS]

"Miracles cease to be miracles given a believable cause.... "

Well, I don't know about that.

Miracles cease to be miracles given a cause that is conjunction with natural law or agency. Plenty of people believe in, say, the divine power of Jesus to cure the blind. The fact that, to them, this "cause" is "believable" doesn't make the miracle less miraculous.

I don't know if the "curing the blind" story has ancient counterparts. Quite possibly. Still, the biblical version is very well done. I recognize that this is an atheist message board, but I think it's a mistake to fail to see the virtues of and the values of myth. It's sort of like rejecting novels because "none of it is even true."

[John Page]

Originally posted by BDS
"Miracles cease to be miracles given a believable cause.... "

Well, I don't know about that.

Miracles cease to be miracles given a cause that is conjunction with natural law or agency. Plenty of people believe in, say, the divine power of Jesus to cure the blind. The fact that, to them, this "cause" is "believable" doesn't make the miracle less miraculous.
Disagree, miracles cease to be miracles when people cease to believe they are miracles. The phenomenal event that occured is unaffected.

From Mirriam-Webster - miracle - "1 : an extraordinary event manifesting divine intervention in human affairs"

No dib=vine intervention, no miracle. No divine being to do the intervention, no miracles are possible.

Cheers, John

[BDS]

We're not that far apart.

Although I said "natural laws" in my definition, the laws of nature are of course created by us. Nature has no laws, simply events that happen. We invent the "laws" to describe and predict the events.

So, yes, if an event happens, and we (correctly) change the "laws of nature" so that the event fits in, then it is no longer a miracle.

My dictionary didn't use the word "divine".

Still, shouldn't we let the evidence speak for itself? If we posit that since there are no divinities, so there are no miracles, aren't we in danger of having God speak to us out of a burning bush, and then sticking our fingers in our ears and chanting, "I can't hear you! I can't hear you!"

Surely we disbelieve in God because we haven't seen proof of miracles, not the other way around?

[Keith Russell]

BDS, what would constitute 'proof' of a miracle?

Isn't a 'miracle' supposed to be an event which cannot happen, yet happens anyway? (Bushes which burn, but are not consumed; water which becomes wine; the firstborn sons of the Egyptians die in their sleep; a staff becomes a snake, and then a staff again; a man forsees a flood in time to build a boat and gather together a mating pair of ever species of plant and animal; a man is crucified, dies, and lives again?)

Each of these things violates the laws of causality and identity. They contradict 'A is A', and thus there can be no physical explanation for them....no evidence as to why they happened, and thus no 'proof'.

So, if one is rational, and bases one's beliefs only on evidence, one the basis of what, would one believe in such things?

K

[BDS]

The laws of causality and identity (as I explaned above) aren't REAL laws. They are simply laws that have been made up by humans. If a bush were to burn without being consumed, we'd have to take that into account, and create new laws.

My point is: if we think the LAWS are the reality, then we disbelieve anything that doesn't conform to the laws. That's just as bad as a fundamentalist disbelieving everything that doesn't conform to the bible.

The laws are simply stories which we make up to predict reality. They are usually either wrong, or at least incomplete, as the history of science has demonstrated. It is up to us to make the laws conform to events, not up to the events to conform to the laws.

You are confused about what constitutes "evidence". Evidence is the actual event.

[John Page]

Originally posted by BDS
If we posit that since there are no divinities, so there are no miracles, aren't we in danger of having God speak to us out of a burning bush, and then sticking our fingers in our ears and chanting, "I can't hear you! I can't hear you!"

Surely we disbelieve in God because we haven't seen proof of miracles, not the other way around?
Yes, I think we aren't too far apart. However I'm not saying that if there are no divinities there are no miracles. I'm effectively saying that if one does not believe in divinities one will not believe in miracles. Hence my question about how a materialist (no believing in a dualistic universe) could appreciate the spiritual.

Cheers, John

[BDS]

Agreed.

We tend to look at the evidence, and fit it into the paradigm to which we are accustomed.

Only when the evidence is dramatically revolutionary do we make what Thomas Kuhn, in Scientific Revolutions, called a "paradigm shift".

[student738]

Being as this detour is already well underway, I shall plead not guilty to "hijacking" your thread! Consistent with this, I have started a "Natural and Supernatural" thread, which I hope might be a precursor to a thread on Miracles. Perhaps we can move this discussion there, or perhaps we can start a new thread on "justified belief or knowledge concerning miracles and violations of natural law". A thread on "natural laws" alone might also prove interesting!

"Disagree, miracles cease to be miracles when people cease to believe they are miracles. The phenomenal event that occured is unaffected."
In the literature by the traditional definition, it seems, minimally a miracle involves a violation of a natural law. By "a natural law" I mean not merely "a scientific law", but more, "a scientific law that is true" (similar to the difference between knowledge and justified/warranted belief). Our belief concerning whether or not a happening involves a violation of a natural law does not (usually) affect whether or not this happening involves a violation of a natural law.

"I'm effectively saying that if one does not believe in divinities one will not believe in miracles."
True perhaps, but by the definition above, if one believes that a miracle (a violation of a natural law) has occurred, and one follows through consistently with his or her beliefs, he or she will believe that "divinities" (which as a term perhaps carries with it some bias) exist.

"Each of these things violates the laws of causality and identity. They contradict 'A is A', and thus there can be no physical explanation for them....no evidence as to why they happened, and thus no 'proof'."
So far as I am aware, while "the law of causality" may be a scientific law, it is at least not provably true by any attempts thus far. Neither is any "principle of sufficient reason".

Consider some set, S. Proving that some x is not an element of S if in fact it is not, is trivial. I need merely examine every element of S and confirm for each element that this element is not x.

Suppose that we -- all of us -- are in a box of some sort. We know nothing concerning what is outside the box. In fact, we do not know whether there is anything outside the box at all. Suppose that some happening, x comes about. Proving that x did not came about due to any cause or for any reason within the box if in fact it did not, is trivial. I must merely examine every possible cause or reason for x within the box, and confirm that each is not a cause or reason for x.

Having done so, I may conclude that either there was no cause or reason whatsoever for its coming about that x, or that the cause or reason of its coming about that x is outside the box.

Additionally, if induction is viable, as we suppose it is, I will need to examine only some "sufficient" subset of possible causes and reasons within the box to arrive at my conclusion.

The only significant remaining step is further arriving at the conclusion that its coming about that x has a cause or reason outside of the box, as opposed to that it has no cause or reason whatsoever.

I believe that one approach which may lead to this conclusion is considerrations of repeatability or explanatory power.

There also remains, independent of any of these considerations, the possibility of a direct transfer or implantation of knowledge from a supernatural being.