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Percepts and Optical Illusions

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Amaroq
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I was on Second Life today, and through a group I was a member of, heard about this "intellectual discussion" that was being held at some spot, I forget where. The speaker gave a presentation about how our brain distorts and deletes most of the information that it doesn't deem worthy of paying attention to or something like that. Etc etc.

What really shocked me was that, on top of all this, the guy went on to shamelessly advocate what amounts to a primacy of consciousness view of reality, and that everyone there agreed with him. I was the only one there who believed that there really is an objective reality.

But anyway, even though I didn't believe any of it, one of the points he made stuck with me. I am extremely curious what Objectivism has to say about it.

Take a look at this picture. http://www.blifaloo.com/illusions/bumps.php

The argument used by the primacy-of-consciousness advocate was that you could alter your perception of these bumps and holes by thinking of the light source as coming from either the top or the bottom. I know that this has no primacy-of-consciousness implications, but I do think it may have implications on Objectivist epistemology.

Here's what I'm curious about.

Our senses give us raw data that come to us as percepts, right? We don't have a choice about this, we perceive the entities that we perceive whether we want to or not. (That's the main reason why we can trust our senses.) But if you look at the above optical illusion, it appears that we do have a choice about the entities in that picture. We can see them as either hills or holes. Doesn't this mean that percepts aren't as unyielding to conscious will as we think?

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I was on Second Life today, and through a group I was a member of, heard about this "intellectual discussion" that was being held at some spot, I forget where. The speaker gave a presentation about how our brain distorts and deletes most of the information that it doesn't deem worthy of paying attention to or something like that. Etc etc.

What really shocked me was that, on top of all this, the guy went on to shamelessly advocate what amounts to a primacy of consciousness view of reality, and that everyone there agreed with him. I was the only one there who believed that there really is an objective reality.

But anyway, even though I didn't believe any of it, one of the points he made stuck with me. I am extremely curious what Objectivism has to say about it.

Take a look at this picture. http://www.blifaloo.com/illusions/bumps.php

The argument used by the primacy-of-consciousness advocate was that you could alter your perception of these bumps and holes by thinking of the light source as coming from either the top or the bottom. I know that this has no primacy-of-consciousness implications, but I do think it may have implications on Objectivist epistemology.

Here's what I'm curious about.

Our senses give us raw data that come to us as percepts, right? We don't have a choice about this, we perceive the entities that we perceive whether we want to or not. (That's the main reason why we can trust our senses.) But if you look at the above optical illusion, it appears that we do have a choice about the entities in that picture. We can see them as either hills or holes. Doesn't this mean that percepts aren't as unyielding to conscious will as we think?

Since you know, in an entirely objective manner, what is happening and why, which you learned via your senses, it is a tribute to man's imagination, but has nothing to do with a test of reality or perception or objectivity. If anything, it is a support of the primacy of existence, as any perception is. The stolen concept is that the person who made up this image had to use their senses and imagination to create it, which they had to ignore or evade to make the assertion of the primacy of consciousness.

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We are looking at an illustration here. The illustration is 'exploiting' an aspect of vision (shading) to generate a picture that can have multiple interpretations. Just a some words have multiple meanings, the context (angle of the light source) needs to be maintained to ensure an accurate assessment. Not knowing the location of the light appears to me equivalent of a tree falling in the forest, does it make a sound analogy.

Edited by dream_weaver
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The advocate of primacy of consciousness didn't make the picture himself. But he did use a similar one to "prove" his point.

I don't understand how an optical illusion working on you is a reinforcement of primacy of existence. I do understand it's a stolen concept, because you had to be aware of objective reality in order to learn of and formulate an optical illusion in the first place. But I'm not sure how optical illusions aren't a test against percepts.

If our percepts are given to us without our choice in the matter, how is it that one can willingly see two different percepts in an optical illusion such as that?

One interesting thought I have on that specific image is that, in objective reality, you do know where the light source is coming from. The image is designed so that not only are you unsure of the light source, but it can look like it works when you imagine the light source coming from either direction.

EDIT: Dreamweaver, I hadn't seen you post before I responded. That is actually a very good answer, and a new way of thinking about it that I hadn't considered before. I didn't consider that visuals can have contexts and be taken out of context in the way that quotes and philosophical ideas could.

Edited by Amaroq
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EDIT: Dreamweaver, I hadn't seen you post before I responded. That is actually a very good answer, and a new way of thinking about it that I hadn't considered before. I didn't consider that visuals can have contexts and be taken out of context in the way that quotes and philosophical ideas could.

It was off the cuff, and if there is veracity to it, I want CD rights, should I do an ARI speach on the topic <grin> . . .

Edited by dream_weaver
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Our senses give us raw data that come to us as percepts, right? We don't have a choice about this, we perceive the entities that we perceive whether we want to or not. (That's the main reason why we can trust our senses.) But if you look at the above optical illusion, it appears that we do have a choice about the entities in that picture. We can see them as either hills or holes. Doesn't this mean that percepts aren't as unyielding to conscious will as we think?

dream_weaver's observation that this is an optical equivalent of dropping context is a good insight. The only way to make sense of the image is to imagine light source, but two possible positions for a light source are plausible. The dropped context is that in the real world you know where the light source is, and there are other cues from other objects with different shapes.

The perceptual mechanisms work well within a range of conditions regarded as normal, and abnormal conditions can be a source of ambiguity. A conclusion based on unusual conditions says nothing about normal conditions.

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In addition to the fact that we could establish the light source from other objects as part of the greater context, these are also not real bumps or holes anyway, they're imitation bumps or holes. It doesn't matter which you deem are bumps and which are holes, you also have plenty of other information to tell you they are in fact flat and just colored in a way to imitate light on a 3d object, but done in a way that leaves the information not complete and consistent enough to establish exactly what kind of 3D object is being imitated. (Although, for the sake of argument, I'm going to say they are all holes and the lighting source is just inconsistent because bumps would leave some shadows on the flat surface too. >>) Real bumps or holes you could either see other stuff to tell where the light is coming from (and a cropped photo doesn't count either because it too falls into the same problem as the drawing, that it in fact is a flat image) or if you can't see it then you could feel it and tell. And if you can't see or feel it? Well then I don't think you have any information making you aware the bumps or holes exist anyway, so you can't make any mistakes about their nature. If you were to make a decision though not about the flat picture, but looking at a flat picture of bumps or holes and asked to say what you thought the photographed or illustrated objects actually were supposed to be, then if it was a cropped image all you have to say is you haven't been given sufficient perceptual data to say for sure about that other real or imagined object, but that if it and not just that limited picture was provided, then you could tell. Problem in that case wouldn't be percepts or reality but what question you were being asked to answer on what basis. You can't blame the senses as being flawed or inadequate because they can't always tell the exact nature of some object which isn't even there based on another object.

(not very relevant side note though, a similar optical illusion with the same kind of effect which can be interpreted different ways due to the same fact of lighting tricks, lack of further context, and actually being a flat image just imitating a 3D image which I like much better than these simple bumps or holes is this illusion where you are asked which way the lady is spinning: image I swear she always starts off spinning counterclockwise for me.)

Edited by bluecherry
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... Doesn't this mean that percepts aren't as unyielding to conscious will as we think?

To answer this question more directly, being able to shift between two perspectives is not the same as creating those perspectives. Those two perspectives exist because of what is perceived (the drawing) and the means of perception (visual system).

Edited by Grames
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To answer this question more directly, being able to shift between two perspectives is not the same as creating those perspectives. Those two perspectives exist because of what is perceived (the drawing) and the means of perception (visual system).

The stick appearing bent in a glass of water, eventually testified to the 'automaticness' of the senses to deliver the sense data. It led us to discover that light alters speed and direction in that medium.

In the observation of the optical illusion, some understanding of some geometric principles, selective application of shading are used to omit or augment the information to intentionally bring the phenomenon about.

Perhaps 'context dropping' is a bit strong or even misapplied here - perhaps more likely the mind is 'jumping to conclusions' based on a skillfull presentation of selective evidence (selective recreation of reality).

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  • 4 years later...

***** moderator note: merged & reformatted for BBS compliance. *****

 

This isn’t really an optical illusion: it’s just that the brain is aggregating the data about the moving dots in the way that would most make sense in the real world. In any case, it’s awesome!

https://www.youtube.com/watch?v=pNe6fsaCVtI

H/T: 22 Words

 

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Edited by dream_weaver
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