On the Underblog I've posted the text of the talk I gave this morning for the Toward a Science of Consciousness conference. Given that the title of the talk predicts the possible demise of consciousness studies, I thought it might be wise to check that the back door was unlocked in case I needed to make a quick escape! (Actually, everyone was very nice.)
The talk basically combined my reflections on the richness or thinness of experience from my 2007 article on the topic, "Do You Have Constant Tactile Experience of Your Feet in Your Shoes?" (advocates of a rich view say yes [and that we also constantly auditorially experience the hum of traffic in the background, etc.], while advocates of a thin view say no), with the pessimistic argument in a recent post that the question is unresolvable -- and, worse, that it's likely impossible to establish a general theory of consciousness without first settling the rich-vs-thin question. Grand conclusion: A general theory of consciousness may be beyond human reach.
The one new thing was this: Ned Block and Michael Tye have recently argued that experience outruns attention (and thus that the thin view can't be right) because one visually experiences at least the gist of the parts of a visual display (for example on a psychologist's computer) to which you don't focally attend -- for example in "change blindness" demonstrations. Or to put it another way: Your visual attention right now might be on a few of the words in this sentence, but surely you also visually experience more of what is before you than just those few words, so (they say) this shows that attention is not required for experience.
The problem with that argument, I think, is that it ignores the (quite reasonable) possibility that attention comes in degrees and can spread beyond just a narrow point. In some sense, one is attending to the whole computer display even if the finest, most focused point of attention is just a few words at a time. What remains open -- and what I'm pessimistic about resolving -- is whether you also simultaneously visually experience the picture on the wall behind the computer and the pressure of the chair against your back. (Of course you experience them now, but did you experience them ten minutes ago when you weren't thinking about it? I think neither objective nor subjective methods to address this question can yield a trustworthy answer.)
Anyway, I enjoyed having the chance to pontificate about this for a while for the people at this conference! With the new book and the plenary talk, people are starting to treat me almost like I'm an established philosopher. (Maybe it helps, too, that I'm going a bit gray at the temples.) I think it would be a good thing not to get too used to that.
Friday, April 11, 2008
Tucson Presentation
Posted by Eric Schwitzgebel at 3:47 PM
Labels: introspection, sense experience, stream of experience
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18 comments:
In thinking about thin or rich experience it helps to consider how the human brain might generate phenomenal experience. If you ignore the brain mechanisms underlying experience then the future of consciousness studies would, indeed, look bleak .
For a different perspective on the relative richness of phenomenal experience, you might reflect on the three levels of consciousness I've proposed in "Space, self, and the theater of consciousness", *Consciousness and Cognition (2007). C1 (the thinnest) is minimal awareness of a spatial surround, C2 is a minimal awareness of oneself at the origin of egocentric space, C3 is alert awareness including all of the sensory events that our attention captures within our occurrent representation of our phenomenal world.
Right, Arnold, but to which of the three does phenomenology attach? If you say all of them (though some in a less vivid or central way than others), then you're endorsing the rich view. I don't see how brain science can do this without the help of subjective report; yet I also think the subjective reports are fatally flawed. That's the problem, in my view.
Eric,
Yes, I endorse the rich view. But before I respond to your reason for chucking the investigation of consciousness based on brain science, I would like to know your reason for concluding that subjective reports are fatally flawed. This could be interesting.
I think they may be for this particular question. The short version is that concurrent reports are subject to the refrigerator light error and retrospective reports to stimulus error and memory error; for the full version see the presentation posted on the underblog.
A little bit of relax and non-seriousness.
Eric, you look great in David´s pics at Tucson!
Who´s sitting side by side with you?
It seems to me that we are really dealing with a terminological problem. The thickness or thinness of phenomenal experience depends on what we are willing to count as experience. Also the richness of occurrent experience depends on the particular sensory modality of experience. For example, visual experience would probably be the the richest for a sighted person (somasthetic, kinasthetic and acoustic for a blind person), with vestibular experience at the very thin end.
When I read what I have just typed on my computer screen, I am aware of roughly two kinds of visual experiences. One is a sharp visual and phonological experience of the word I have just typed (experience-1), and at the same time I have what might be called a rich but undifferentiated background experience of complex, space-filling shapes and colors that are in my visual field (experience-2). If a beep sounds, and I am required to tell you what I have detected, parsed, classified, and named within this rich experience, it would seem thin. But if I am also allowed to say that I had a complex visual experience full of shapes, colors, and words, as well as a phonological experience of inner language, it would be counted as a rich experience. And the latter subjective report would be a more accurate account of my phenomenal experience than a report of only the *particular* parts of my global experience.
I don't think that's just terminological. I think a lot of people disagree with your description of your experience, even though they mean the same thing by "experience" that you do. It's hard to show this conclusively, but one bit of evidence is this: People will shift their opinions on the question, and describe their shifts as substantive, not terminological.
Thanks Anibal. That's Par Sundstrom, a Swedish philosopher. I hadn't met him before or read any of his works, but we had some good conversations and I've put him on my reading list!
If people shift their opinion about their experience (rich or sparse) from probe to probe, doesn't this suggest that the thickness of experience can vary from thick/rich to thin/sparse from moment to moment? And why would this make it futile to look to brain science to explain this very phenomenon. In fact, if we have a good theory of the cognitive brain, we should be able to predict how specific experiences vary in phenomenal richness as a function of experimental manipulations. This is what I have been able to do, for example, with the seeing-more-than-is-there phenomenon.
Rather than undermining brain science as a way to understand phenomenal experience, the opportunity to probe the richness and other qualitative aspects of experience in relation to specific neuro-cognitive theories places brain science as a coequal part of the enterprise.
Not from probe to probe but slowly over the course of several days of probing.
I think we just disagree about brain science, Arnold. I don't think brain science can get a grip on phenomenology until we have at least a rough sense of what brain states are conscious and what the consciousness is like. Only then can we start to correlate consciousness with brain processes. And until we solve the rich/thin question we don't have even a rough sense of what brain states are conscious.
We seem to agree that this is an important issue, Eric. And I agree that brain science can't ".. get a grip on phenomenology until we have at least a rough sense of what brain states are conscious and what the consciousness is like." But it seems to me that we *do* have a good idea of what consciousness is like, and what brain states are required to realize consciousness. Revonsuo (2006) deals with this question in considerable detail. He relates the phenomenal level of experience to some kind of brain system that can model the world from an egocentric perspective and can represent its semantic properties. See for example:
http://www.people.umass.edu/trehub/Revonsuo.pdf
If you disagree with Revonsuo, I would be very much interested in your reasons for disagreeing.
Isn't Gopnik saying that baby consciousness in effect is "fat," and that thinning or "focusing" is attention?
Separately, this thick/thin "problem" sounds secondary to the questions of what of the self and "now" is, and the "problem" that they aren't so simple as we (perhaps reasonably must) insist on thinking they are. As I compartmentalize my own beliefs and epistemological proclivities, I don't see a problem. (Granted, I haven't read your essay yet).
Hypothesizing off the top of my head, I'd guess we have several short temporal segments of candidate self narrative running in parallel, which we can swap or splice into, as circumstances cause our consciousness generating machinery to change its best guess of what's actually going on. It takes time to cognize a visual stimulus, so I would think our experience of "now," while perhaps often anticipated or existing already in a tentative form, typically at least is issued if not produced after the happening, and either way is just a theory of the happening. (I say "typically" because there can be a selective advantage in responding to tigers even before you know they're tigers--by leaping sideways at the first visual suggestion of striations)
Thanks, Arnold. Revonsuo is interesting, but I would still argue that on many key questions (including rich vs thin) we don't have a good enough sense of the rough phenomenology to correlate to brain processes. My presentation on the Underblog details the case. Also see my just-appeared Phil Review paper "The Unreliability of Naive Introspection" for a broader argument.
MT, that's a pretty cool theory. Of course, if those few processes running in parallel are the only candidates for consciousness at the time, then that's a version of the "thin" view. Maybe the thin view is right, but I don't see how we can know whether it is.
On Gopnik: In earlier versions, she was basically saying that baby experience was rich and adult experience thin. She has moderated that somewhat, but it does still have that general tenor.
Thanks, Eric. I imagine that hypothesis is at least partially "osmosed" from ideas in the scholarly mix, although I can't think where. Regarding "how we can know whether it is," you make me think of the testimonies that Ramachandran talks and writes about from people who are in denial about the paralysis of an arm, for example, and spontaneously concoct stories in which they have consciously decided not to move it, or assert that they did and accuse the experimenter of lying. I may be conflating these studies with Ramachandran's trick for "rehabilitating" phantom limbs (and maybe split brain studies as well), but I think he might have been able to induce this "false consciousness"/"false memory" with mirrors that make the subject think he or she is moving both hands while actually moving one. Anyway, I'm thinking the different testimony under the two experimental conditions (mirror/no-mirror or same subject during/after temporary paralysis) might be a kind of evidence. On the other hand, I think Kuhn would red-flag the suggestion that we must answer thick vs. thin to progress scientifically past this conundrum or to do so on the basis of good evidence. I'm betting on a paradigm shift, which I think is already well underway. I just think we might be forever stuck with a foot in each paradigm, because we're all conscious and beholden to the highly adaptive misconceptions that go with the circumstance. My bias is that worrying over thick/thin is to allow one foot to sink in that "old"/adaptive/phenomenological paradigm. (I still haven't read the essay.)
I'm a fan of Kuhn and one of the more interesting discussions I had after my talk was with someone pressing a Kuhnian criticism like yours. Maybe I put the point too apocalyptically, and psychological or sociological pressures will force a resolution. But I'm not sure that one paradigm will prove more productive than the other, since both the rich and the thin view can tap into crucial functional correlates of what they're thinking of as consciousness, allowing their research approaches to continue to produce useful results on what the other side would call functional, psychological (as opposed to consciousness-involving) issues.
And sometimes sciences are overthrown because of central conundra and irresolvabilities in favor of something radically different. In fact it has already happened once to consciousness studies, in the early 20th century.
Science Friday's reminded me of the famous line of evidence that I probably ought to have cited--the delay between pressing a button and the experience of consciously deciding to press it: People consciously deciding to press could not simultaneously be aware that they have already pressed it. To me, that's thinner than thin. It suggests the deeper issues are our concept of "now" and what/who we are.
MT, your idea of consciousness being created on the fly out of semi-conscious parallel background processes is similar to that of Susan Blackmore's. http://www.susanblackmore.co.uk/ . She goes so far as to say that our concept of time is flawed - we don't experience a real now, but create it after the fact.
It seems to me the thin or rich question about experience is overly concerned with making a clear demarcation between conscious and unconscious experience. It seems the demarcation is not clear - it is a rainbow of gradation. Most of the processes that can be conscious can also be unconscious, and we always have unconscious and semi-conscious processes to draw on.
The 5th century Chinese Buddhist patriarch Hui Neng was fond of explaining his theory of mind with the story of not knowing that we heard the crow caw until after someone asked us if we did. His point is that awareness and consciousness are distinct - we can be aware without being conscious. I think he advocated making experience less thin, by blurring the distinction between conscious and unconscious processes, through mind training.
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