Wednesday, January 30, 2008

The Richness of Experience and the Collapse of Consciousness Studies

Many people have looked foolish by claiming a scientific question insoluble that was not so. Yet I wonder if the following question will prove ultimately intractible: Is conscious experience rich or thin?

To say that consciousness is rich is to say that our phenomenology or stream of experience contains many things at once, in different modalities -- that as I sit here typing for example, I consciously experience not just what I'm attending to most focally, but also much else in a peripheral way: the sound of traffic in the background and of click of the keys on the keyboard, the feeling of my fingers typing and of my feet in my shoes and of my back against the seat, a whole broad visual field fuzzy outside the focal region, and possibly also feelings, images, inner speech, and the like. To say that consciousness is thin is to say that most of what we don't attend to we don't experience. The feeling of my feet in my shoes and the sound of traffic in the backgroud are not actually experienced by me, not even in a peripheral way, when I'm not thinking about such matters.

Philosophers' and ordinary folks' intuitions on this question appear to be divided; and I also got mixed results when I gave people random beepers set at long intervals and asked them to go about their ordinary day, noticing when the beep went off whether they had (for example) tactile experience in their left foot in the last undisturbed moment before the beep.

The refrigerator light illusion frustrates any attempt to address this question through concurrent introspection: Thinking about whether you have conscious experience of your feet in your shoes will normally create that experience whether it was there before the question occurred to you or not.

So it seems that the question must be studied retrospectively (as I attempted with the help of the beeper). But any retrospective study will raise the issue of memory error. Change blindness studies, for example, suggest that we retain very little memory of what we're not attending to, even over the tiniest intervals. Experience could be massively rich but all that detail might be instantly forgotten. (Why, after all, would we retain it?) Some people may still recall a general impression of richness; but evidently others do not. Who's to say which of them is right? Furthermore, someone might mistakenly report sensory details as experienced that were not experienced, but only called to mind as a result of the beep, details brought into awareness as a result of the person's focus a moment later, though not experienced at the targeted time -- a kind of retrospective refrigerator light error. I worry that such introspective difficulties are intractable.

So could we do without introspective report? Could we just look at the brain, for example? No, not that either. We have no good theory right now of what makes a brain state conscious; and we never will have a good theory until we know, broadly speaking, which brain states are the conscious ones; and we will never know, not even broadly speaking, which brain states are the conscious ones until we figure out whether that hum of traffic processed ever so lightly in the auditory cortex is consciously experienced.

So is the question simply intractible? If so, that could lead to the collapse of consciousness studies. The question is so central and important to our understanding of consciousness that it's not clear how much progress we can make on any general account of consciousness without resolving it.


Kerry said...

This topic reminds me of a common thread in many anecdotal descriptions of psychedelic experiences. Some people describe one of the primary effects as a dampening of their internal sensory filters. All of that ordinary experience of feeling the shoe on your left foot and hearing the traffic outside passes through to primary consciousness, giving the mind all sorts of unusual and novel input to process. This can lead to a feeling of seeing the ordinary world anew, but for some people it can also overload the conscious experience with too much information to comfortably process.

From my own experience I think the "richness" of consciousness varies greatly with how hard I am concentrating on my current task and how comfortable I am in my environment. When I moved to a new neighborhood near an airport I was always aware of the sound of airplanes for the first few weeks. Over time, though, the loud noises stopped intruding on my conscious experience because it became part of the normal, safe environment. And even at the height of adjusting to the noise, if I became really engrossed in reading or writing I would stop registering the plane traffic for a while.

I think this is why it's so much fun to visit new places. A new environment means the brain doesn't recognize as much sensory input as routine. This makes the conscious experience much richer and more interesting.

KenF said...

Just as an analogy, a cardiologist will ask a patient how they are feeling, and note the self-report, but that is just one small piece of the puzzle of how they are going to treat the heart condition. The more they learn about brain science, the more this analogy will hold.

One interesting question is once we have a perfect brain science, how much of philosophy will just dissolve away. What will be left?

Josh Weisberg said...


I feel this way quite often--and doesn't this drive Dennett to his first-person operationalism? Is that what collapse looks like?

But in response, it may be that we can find a good theory for the clear cases of experience and nonexperience, and use that to make brain-based third-person claims about the hard cases. So if one or another of the going theories begins to look well-confirmed, then we might use it to judge these sorts of cases. The global workspace hypothesis makes a clear claim about these things, as does the HOR and FOR theory. If we have good reason to accept on of these views, then we might look into the brain and see if the content of the global workspace is rich or poor, or if the HOR represents a rich or thin experience.

Of course, it may be that no theory can gain prior acceptance without first deciding on these cases. And then we've got trouble. Most likely, it will be a reflective equilibrium type deal, with evidence from neuroscience, psychological models, and folk intuitions balanced in the best way we can. It wont satisfy everyone, no doubt, but it may be better than imminent collapse.

Eric Schwitzgebel said...

Thanks for the comments, folks!

Kerry: Interesting connection to reports about psychedelic experiences. I've heard similar things, but hadn't thought much about the connection.

It's certainly possible that the richness does vary depending on level of absorption in a task and/or on the familiarity/comfort of the environment. Some of the responses of the subjects in my experiments seemed to suggest this very thing.

Alison Gopnik in her new work on baby consciousness (see an earlier post) says something very similar to what you've just said about travel -- and gives some neuroscientific theory to back it up!

Kenf: Of course even if introspective reports were absolutely accurate, the connection to physiological conditions outside the brain might be pretty shaky. Good question how much philosophy will be left after another century or so of neuroscience! I'm inclined to think that there is no threat to philosophy here, but that's in part because of my particular conception of philosophy as inquiriy into the most general, theoretical, conceptual, and normative questions about things. There is no conflict between the advance of science and interest in these questions and no distinctively philosophical method in competition with the methods of science.

Eric Schwitzgebel said...

That's a very helpful comment, Josh!

What does collapse look like? Yes, it might look a bit like Dennett -- but not entirely like Dennett, because Dennettian operationalism doesn't conceive of itself as mere operationalism that sets aside intractable questions about consciousness. (And Dennett explicitly embraces the thin view.)

Your suggestions about how progress might be achieved are certainly plausible. I'm not so optimistic myself, though, that enough progress can be made on global workspace theory, HOR, or FOR without an independent understanding of whether experience is rich or thin to get traction with those theories to use them to illuminate the rich/thin debate. And furthermore the content of those theories remains radically unclear without prior or simultaneous clarification of the rich/thin issue.

It is perhaps possible that neuroscience could show that uncontroversially nonconscious events have property A and uncontroversially conscious ones have property B, then use this fact to assign consciousness or nonconsciousness to the less clear cases. However, I'm not optimistic. The only uncontroversially conscious events are ones that (in some appropriate sense of "attention") involve attention. An advocate of a rich view might then slough off the lack of B-ishness in the processing of the unattended traffic hum to a lack of attention rather than a lack of consciousness. (And similar complementary moves will be available to the advocate of the thin view.)

I don't want to be dogmatic on this point. The cleverness of science sometimes seems boundless! But I remain convinced that the worry is very serious.

MT said...

Check out Alison Gopnik. She says consciousness in babies is huge and that it becomes focused as we mature. But I'm disinclined to think that in adulthood the focus is fixed under all circumstances (e.g. floating in an isolation tank?) or the same in everybody.

MT said...

Doh! I see now Gopnik's come up already in the comments.

Eric Schwitzgebel said...

Alison Gopnik is a font of interesting ideas. I love her work. She was one of my advisors in grad school.

Look for a book from her before too long called The Philosophical Baby.