"Content and Constancy"
February 24, 2008, 4-6PM
Note-taker: E. I.
Last Updated: April 18, 2008
[Q = Question, A = Answer, C = Comment, R = Response]
1:26:27
Q: What is it that we’re talking about? What are these things that shift? I want the fuller story.
A: I find this very hard. Here’s what I can say so far. The short version: I think that when we see the size of an object (e.g. size of blackboard) and we see it to remain constant throughout the variations of the distances at which it’s presented, but nevertheless, something in our experience of the size of the blackboard changes, the thing that changes is our sense of how far away the thing is. That’s a very preliminary account. The immediate question is, and for the phenomenologist what that means is something like I want to think of this as the horizon, or the visual background, some sort of background context that we are sensitive to, that’s a part of our experience but that’s not a part of our experience that we’re focused on. Now of course you could try to focus on the distance to the object, and I might look at how far away the thing is. And then maybe I can even make a judgment about how far that is (e.g. 12ft). But however the distance to the object is present in my experience of the size of the object it’s not that way. And again, I can switch to the attitude in which distance is presented that way. But I don’t think that’s the way it’s present in experience when I’m focused on the size. It’s present as a background phenomenon and then the question is, “what kind of presence is that?” And here’s where Merleau-Ponty is my guide.
C: Yes, not the virtual presence of Noe.
A: Yes, certainly not Alva’s virtual presence. Here’s where Merleau-Ponty is my true guide. This I think is his deepest insight and the one that I would like to try to develop. He says in various places things that suggest that the way I experience the distance to the object, or the angle of presentation of the object, or the lighting context when I’m focused on the color of the thing, is “as a tension around a norm”. He says “I don’t experience it as a determinate distance or a determinate angle of presentation, I experience it as a tension around a norm.” And he says in a very different place something that I think explains that. He gives an example where he says “there you are in a museum, you are walking close to the wall, you can hear and you can see the picture, and it pushes you back.” I think he really means that. I think he thinks it’s part of the experience that either you need to move back or you’re pushed to go back, or it would be better if you were back, and it pushes you back so that you can see it better. And so what I think he thinks, and what I think is the right thing to think is that: the way I experience the distance to the object while I’m focused on its size is in terms of how well that allows me to see the size of the object as it really is in my experience of it. So I experience the distance in terms of “needing to get a little closer” or “being pushed behind in order to see it a little better”. And this is really part of my visual experience of the thing and if that’s right that’s bizarre because what is means is that having a visual experience of even something as simple as the size/shape of an object, already involves a normative engagement with the world. It’s not a mere descriptive representation of the way the world is. In particular it’s not the case that what I’m representing is some apparent property that the object has. No, in order to see the size of the thing, I’m already involved in having a sense for how well the context it’s represented allows me to get a visual grip on it. And I think you can spell that out in more detail, but that’s roughly speaking what I think.
C: Yes, but part of the detail too, I think would be to cash out this notion of horizons. Both Husserl and Merleau-Ponty. So part of what could explain the fact that the identical sensation I have when I see this part of the table here is just what I would have if I were seeing a yellow sensation under different light, then how is it that the same sensations present different properties. And Husserl of course had this story, “well there’s hyletic data..” but he also has tools for a better theory which is it’s the presence of these horizons that describe what future experiences would be like were I to situate myself differently, were I to do this. That might be close to the virtual presence account standing on how you cash it out…
A: Yes, I think you have to be careful.
C: And I don’t know what to think of the virtual account—I haven’t paid a whole lot of attention to it.
A: Oh, I can make up your mind in three minutes. Let me try. I think this is deeply flawed. I think that a lot of the things Alva does are great, but the virtual thing I think is a real mistake and here’s how I think you can see that very quickly. Alva’s view is that in the case of seeing an object to be three dimensional, which is a case that he is very good at describing, it really is true that how I see this cup—it looks to me as it’s three dimensional and one way of saying that (Husserl said this already) it looks to me as though it goes beyond what I can see from here. It looks to me as though it’s got a back side. You might think, how could it possibly do that? But never mind how it does it, I think that’s a good preliminary characterization of the experience of something as three dimensional. The object looks as though (in Husserl’s terminology) it “transcends my experience of it”; goes beyond what I can see of it from here. I think that’s a good preliminary characterization of the experience of voluminousness (which is what Alva calls it), but Alva wants to give an explanation of that. And here’s how his explanation goes in terms of what he calls the virtual presence of the thing. He says, “what it is for me to experience the cup as voluminous, is for me in having the experience of it from here also to have a practical knowledge of the sensory motor contingencies”. What does that mean? It means something like: part of the experience of seeing the object from here is this practical knowledge that if I were over here, it would look like that, if I were here I would look like that…and so on. Now notice, this involves some weird commitment to the appearance properties too, because what you get is a sequence of appearances of the thing, all of which I have some sort of practical sense knowledge of when I see it from here. I think that’s like Husserl’s view (middle stage), and I think it’s kind of a phenomenalist view that you might find in someone like C. I. Lewis. Here’s what I think is wrong with that view. If that were the right way to characterize my experience of an object as three dimensional, then the world could be a very peculiar way and satisfy that experience. Namely, the world could be as follows: there could be before me, a two dimensional object that presents this image to me when I’m standing here, and goes out of existence but reappears in this two dimensional aspect when I’m here, and at this two dimensional aspect when I’m here…etc. In other words, the object that I experience to be voluminous could actually be a series of two dimensional appearances that come into or go out of existence depending upon where I am with respect to the thing. And that’s not the way my experience represents the world to me.
C: If you had that view that’s right, if you had that experience that would be an illusional experience
A: That’s exactly right. So there’s an important distinction. If the world were that way, it would trick me into having an experience as of there being a voluminous entity there. But what’s important is that we’re trying to characterize the conditions of satisfactions of experience per say, we’re try to characterize how the world would have to be in order for this experience to be satisfied. And it’s an indication that you got the wrong conditions if it turns out that the experience can be satisfied in a very unusual way like this.
C: I wonder if someone can say something like this: When you’re talking just about visual phenomena you’re talking about visual schemata. We don’t have the full constitution of the thing until you integrate the ?? which you already did, and also the tangle and all sorts of other things… To really flesh out the experience, it’ll also have to be true that I can put my hand on it. That’s also prescribed in horizon of my visual experience is that I’ll have a certain handle and that changes the condition of satisfaction, and then I can ….way
1:37:56
A: But you could be tricked in a similar way. I mean, it could be that the part of the object that comes to existence is the part that is in contact with my hand. Something of a relevant weight, or something like that. It looks like what it fails to do is to make the object look like it has the features independent of my experience of having those features. And that’s what you need to take into account of. It’s got a Berkeley sort of thing built into it, and that’s what it means to say it’s virtual. That’s how Alva defines virtual—remember he says it’s virtual just in the sense that the stuff in my computer desk top is available whenever I go to get it. It looks like it’s really there, but it’s not. It only comes to existence when I need it. He has this account because of the way he thinks certain kinds of change blindness experiments work and other kinds of things, but I just think it’s misapplied in this kind of context because it gives rise to this pretty immediate kind of counter example.
1:39:00
Q: It’s pretty well known in memory that we make associations and we generalize many many things. You might make a mistake in memory, but Moshe Bar a former speaker says that’s when memory is working properly, when it makes these mistakes and generalizes. So how would you know that the priming effect in case of a penny is not just a fault of memory being due to the priming effect. Because in subliminal priming it’s not available but if you’re doing conscious priming it’s possible that the priming effect is coming from memory. Thus the reason we would be primed for a circle would because our memory, not our experience, generalizes the shape to the standard view of the penny.
A: Let me try this. Some people complain that the weakness in our experiment is that we used a picture of the actual penny, and since people know that pennies are round, they might have a certain association “roundness” with the image, and it’s that association that’s giving rise to the differential priming effect. There are two things. One thing you could do is to redo the experiment not with a picture of a penny but with a 3-D disk at an angle. But somehow it seems you’re pushing on something different.
C: Yes. Because memory in general extracts information when it can. It can’t do that for a complicated shape, it would have to remember the exact shape, maybe. And it might be that in the initial eight shapes that you gave, if there was one that was very different it may have primed for that one too, I don’t know. But my point is, whereas for abstract shapes maybe memory doesn’t abstract information away as you get priming that doesn’t have anything to do with memory, maybe in your case because these are things that fairly common. Even a disk would be something that we would be able to…
A: This sounds like something that is a kind of criticism not in my experiment in particular, but on the shape priming paradigm in general.
C: Well, I’ve always understood it as the subliminal, so I’m not really aware of the conscious priming. Subliminal would never have those problems because it’s never going through working memory.
A: Subliminal things could go through working memory.
C: If it doesn’t go through the prefrontal, it doesn’t go through the working memory. So anything that’s definitely unconscious, lets say, wouldn’t be going through hippocampus. I don’t even know if the hippocampus is really necessary for what I’m talking about.
C2: I guess the question is, as soon as you have conscious priming, you cannot exclude the possibility that the effect you are getting is due to something more than just the bare experience. There could be some kind of a process. A filter, a memory of some kind, that is giving you the effect. That doesn’t tell you anything about how you experience the thing.
C: Exactly. And because we know in particular that memory does this, that would be grounds for…
A: So let me show you another version of this experiment and see if you think it’s a problem for this version too. Because this is a pretty well known version in the literature. Yes, it was in the paper—here is the picture. I wanted to use this in the context of temporal primacy. The prime is this complicated image. You have four different pairings (circle & pac-man, circle & circle, pac-man & circle, pac-man & pac-man). You’re asked to attend to the lower image in the prime, and the question is, what gets primed? In this case what gets primed is similarity judgments in circles, in this case what gets primed is similarity judgments in pac-man, and the question is what happens in this case. And the answer is it depends on how long the prime is presented for. Short presentation (75msec or so), then the pacman gets primed, with longer presentation (200msec) the circles get primed. So this is a sort of standard thing in the literature. These of course are all conscious presentations not subliminal.
C: That seems to be more of gist perception—the 75 msec could just be gist perception.
C2: Wouldn’t that support an opposite conclusion? Because in that case, the apparent property is the one where you have the pacman. Whereas the real property so-to-speak, ..
If it is true that for the short presentation the priming that occurs is the pac-man, it would seem that the apparent property is what’s caused temporally.
A: Good. You are reproducing the part of the talk that I skipped. Prima facie, that’s what it seems. But I don’t think we’re justified in drawing that conclusion. During the short presentation, (we haven’t done it yet, but if we do) I think what we’ll find is that the subject reports seeing an ellipse. And you’ll get differential priming for ellipses. So doesn’t that just show that during the first 75msec, you experience the apparent property, and only later in time do you experience the real property? And the answer is, no, I don’t think it shows that because: What we wanted to know was the during the longer presentation, you first experience the apparent property, and then the real property. The fact that when the thing is presented for only 75msec you experience the apparent property is no indication that during the first 75msec of the longer presentation you experience the apparent property. Because there’s a crucial difference. Namely, in the shorter presentation, at 75msec the image is turned off. And it could be, and I think it is, that the turning off of the image is what gives rise to the apparent property, and in the longer presentation you don’t get that.
C2: But the alternative explanation could be that in the 200msec presentation, the initial image is overridden.
A: Yes that is correct. The date does not suggest which of the two interpretations is correct.
C: I’m not even sure if you did interpret it to be in favor of Noe’s hypothesis that it would work even then because if it were just phenomenon. Because what he means by apparent properties, I’m assuming, are not just phenomenon. If you look at Ode Oliva’s work at MIT, she basically shows two pictures of a hallway and a building overlapping each other, and has found out that the duration of presentation changes which image you see. So again, this could be just gist phenomena, not a perceptual phenomena. Like something that has to do with apparent properties in general. To be able to test that you would have to have a more refined experiment. Gist phenomenon is known to pick up strong black and white properties in very short amounts of time. So that all that this would have shown is that the gist perception in the 75msec, not that an apparent property has been picked up. Because apparent properties, I’m hoping, are not just gist properties.
A: How do you define gist?
C: Gist is not well defined, but Ode Oliva and other people who work on it claim that it’s the short wave properties of what we experience. Long wave being subtle grays. So the shape of something, say a ball is coming at your head, you would experience that in gist perception, but those are not the apparent subtle properties. Because the subtle properties are what the exactly how the world looks. Gist properties are the course grain properties.
A: So would it make a difference if instead of being black and white, these were red and green?
C: I’m not sure because I think that gist could also pick up on strong color distinctions. I’m not even sure how you would even make sure that it was apparent and not gist.
A: What my experiment shows is that somehow during the short presentation the pacman is what does the priming. You’re idea is that there are two different ways to describe the pacman. It could be the short wave stuff in the image or it could be the stuff of a certain shape. And of course the short wave stuff is of a stuff of a certain shape. I guess the way to distinguish it would be to ask whether…
C: So if you did this Ode Oliva test where you overlaid the hallway with the building, the apparent property would be this entire picture. But the gist property would only be the black and white building and not the gray hallway. And that would be a problem, because then you would find a split in these experiments. Although this experiment is picking up on gist perception, it’s not picking up on what Alva Noe would call apparent.
A: I think it’s unlikely that there is a confound here, but I think the way to tell, if I understand what a gist is, to do the experiment with shades of different color patches. And I bet that if you do that, you’ll priming both for green shades and for red shades.
C: Or even see if it primes for that exact shape. (the two shapes together).
A: Well, what you’re supposed to attend to is the lower shape. I’ll have to think more about this.