Maybe I need to look more closely at EcoPsych literature, but it seems to me that there is not that much that tries to explain the putatively difficult visual phenomena, rather than simply dismiss them as superficial.
I think you're right, we don't really engage with these topics as they're the wrong questions from our perspective; ambiguous lab stimuli aren't what vision is about, after all. Still, there's no reason in principle we couldn't do it, I guess; and in fairness, Runeson has engaged with this kind of thing in some detail, eg his analysis of the Ames Room. Is that the kind of thing you have in mind?
Yes, there is Runeson's analysis of the Ames room and also the TSRM treatment of the Muller-Lyer. I think there are a few others that do not come to mind right now. So, roughly four papers seem to me to be the difference between EcoPsych doing nothing about the visual illusions and not doing much about visual illusions.
But, I could be wrong. There could be other EP tries at the visual illusions. Happy to hear of more EP papers that are not dismissive, as I am interested in this Orlandi paper.
I do wonder, though, why EP is apparently happy to study the size-weight illusion, but not visual illusions. Why is one illusion of interest, but most of the others not?
In Geoff's case, because the illusion pattern matched the throwability judgments so clearly; that's what made him look into it.
As for the earlier work, perhaps because size and weight are so straightforwardly action relevant properties of objects, and relate so obviously to the inertia tensor work, that the fit made sense? Misjudging length in a Muller Lyer setup or perceiving motion in the snake illusion where there isn't any don't have any obvious connection to perception-for-action and are more obviously examples of restricting the exploration to produce the effect. That's all just a guess, but it seems the obvious place to look.
In general, of course, illusions are just side effects of restricting information in weird ways, and so aren't that interesting ecologically. The other thing, actually, about the size-weight illusion is that it's damned robust and additional exploration doesn't help. Finding a functional account for what people were actually perceiving when asked to judge weight was therefore quite important.
The task is 'judge the length of this line'; it's 2D, it's just a line and not an object, etc. It's a little interesting that you can push the length judgment around in the way that you can, but only a little interesting. Do you get Muller-Lyer in reaching? Actions tend to resist illusions, hinting that they are a side effect of the judgment task.
When in doubt, pull Gibson 66 off the shelf (pg 313)
"[Length, angles etc] are variables of optical structure,... but they are variables of relatively low order. They come from plane geometry, not from the relational invariants of perspective or projective geometry, which, I argue, carry most of the information about the world." ... "But the information for length of line, I have argued, is not simply length of line. To suppose so is to confuse the picture considered as a surface with the optical information to the eye. A line drawn on paper is not a stimulus. The stimulus information for the length of a line is altered by combining it with other lines." ... "The answer depends on discovering the combinations of information in line drawings....the apparent sizes of the two ridge lines depend on their apparent distances in accordance with the general principle of perception of size-at-a-distance illustrated in Fig 14.9 (a photo of said figure).
"If this hypothesis is valid, the geometrical illusions are not subjective phenomena as they have always been taken to be, but instead are special cases of the information in variables of optical structure as displayed in drawings."
So, Gibson is suggesting that the lines on the end of the lines in the Muller Lyer create a context in which the line to be judged is seen as being at different distances. Same length seen further away is perceived as longer.
"Gibson is suggesting that the lines on the end of the lines in the Muller Lyer create a context in which the line to be judged is seen as being at different distances. " I think everyone thinks this.
But, this is still not an answer to the question, "How does the Muller-Lyer arise from "restricting information in weird ways"?" There is nothing at all in which you just cited that mentions restricting information, much less restricting it in weird ways.
How does the Muller-Lyer arise from "restricting information in weird ways"?
One way you typically know that two objects at different distances are in fact the same size is the horizon ratio; objects are cut by the horizon in the same proportions regardless of distance. The Muller Lyer presents two lines in contexts that suggest different distances but no horizon. The two lines are optically the same size but are different distances 'in the world' and are therefore perceived as different actual sizes.
Replace or expand on horizon ratio to include other information for size invariance as you see fit.
The horizon was just one example; but the point is that asking people to judge the size of lines that are at different distances (according to some context) without information supporting size constancy is a restriction.
If the task requires size constancy, viewing without a horizon is an example of restricting information. Note the Muller Lyer doesn't have any size constancy information; it's not just the horizon it doesn't have.
I think you're right, we don't really engage with these topics as they're the wrong questions from our perspective; ambiguous lab stimuli aren't what vision is about, after all. Still, there's no reason in principle we couldn't do it, I guess; and in fairness, Runeson has engaged with this kind of thing in some detail, eg his analysis of the Ames Room. Is that the kind of thing you have in mind?
ReplyDeleteYes, there is Runeson's analysis of the Ames room and also the TSRM treatment of the Muller-Lyer. I think there are a few others that do not come to mind right now. So, roughly four papers seem to me to be the difference between EcoPsych doing nothing about the visual illusions and not doing much about visual illusions.
ReplyDeleteBut, I could be wrong. There could be other EP tries at the visual illusions. Happy to hear of more EP papers that are not dismissive, as I am interested in this Orlandi paper.
I do wonder, though, why EP is apparently happy to study the size-weight illusion, but not visual illusions. Why is one illusion of interest, but most of the others not?
In Geoff's case, because the illusion pattern matched the throwability judgments so clearly; that's what made him look into it.
DeleteAs for the earlier work, perhaps because size and weight are so straightforwardly action relevant properties of objects, and relate so obviously to the inertia tensor work, that the fit made sense? Misjudging length in a Muller Lyer setup or perceiving motion in the snake illusion where there isn't any don't have any obvious connection to perception-for-action and are more obviously examples of restricting the exploration to produce the effect. That's all just a guess, but it seems the obvious place to look.
In general, of course, illusions are just side effects of restricting information in weird ways, and so aren't that interesting ecologically. The other thing, actually, about the size-weight illusion is that it's damned robust and additional exploration doesn't help. Finding a functional account for what people were actually perceiving when asked to judge weight was therefore quite important.
How does the Muller-Lyer arise from "restricting information in weird ways"?
DeleteThe task is 'judge the length of this line'; it's 2D, it's just a line and not an object, etc. It's a little interesting that you can push the length judgment around in the way that you can, but only a little interesting. Do you get Muller-Lyer in reaching? Actions tend to resist illusions, hinting that they are a side effect of the judgment task.
DeleteThat's not an answer to my question. How does the Muller-Lyer arise from "restricting information in weird ways"?
DeleteWhen in doubt, pull Gibson 66 off the shelf (pg 313)
Delete"[Length, angles etc] are variables of optical structure,... but they are variables of relatively low order. They come from plane geometry, not from the relational invariants of perspective or projective geometry, which, I argue, carry most of the information about the world."
...
"But the information for length of line, I have argued, is not simply length of line. To suppose so is to confuse the picture considered as a surface with the optical information to the eye. A line drawn on paper is not a stimulus. The stimulus information for the length of a line is altered by combining it with other lines."
...
"The answer depends on discovering the combinations of information in line drawings....the apparent sizes of the two ridge lines depend on their apparent distances in accordance with the general principle of perception of size-at-a-distance illustrated in Fig 14.9 (a photo of said figure).
"If this hypothesis is valid, the geometrical illusions are not subjective phenomena as they have always been taken to be, but instead are special cases of the information in variables of optical structure as displayed in drawings."
So, Gibson is suggesting that the lines on the end of the lines in the Muller Lyer create a context in which the line to be judged is seen as being at different distances. Same length seen further away is perceived as longer.
"Gibson is suggesting that the lines on the end of the lines in the Muller Lyer create a context in which the line to be judged is seen as being at different distances. " I think everyone thinks this.
ReplyDeleteBut, this is still not an answer to the question, "How does the Muller-Lyer arise from "restricting information in weird ways"?" There is nothing at all in which you just cited that mentions restricting information, much less restricting it in weird ways.
How does the Muller-Lyer arise from "restricting information in weird ways"?
One way you typically know that two objects at different distances are in fact the same size is the horizon ratio; objects are cut by the horizon in the same proportions regardless of distance. The Muller Lyer presents two lines in contexts that suggest different distances but no horizon. The two lines are optically the same size but are different distances 'in the world' and are therefore perceived as different actual sizes.
DeleteReplace or expand on horizon ratio to include other information for size invariance as you see fit.
So, you want to say that viewing without a horizon is "restricting information in weird a way"?
DeleteThe horizon was just one example; but the point is that asking people to judge the size of lines that are at different distances (according to some context) without information supporting size constancy is a restriction.
DeleteSo, you do want to say that viewing without a horizon is "restricting information in a weird way"?
DeleteIf the task requires size constancy, viewing without a horizon is an example of restricting information. Note the Muller Lyer doesn't have any size constancy information; it's not just the horizon it doesn't have.
Delete