Wednesday, December 12, 2007

Perceptual Experience and Attention

I'm drafting an entry for Sage Press's forthcoming Encyclopedia of Perception. Since Sage seems to want a fairly relaxed, conversational style and the draft isn't much longer than a blog post, I thought I'd make it today's post.

Perceptual Experience and Attention

Do you have constant tactile experience of the shirt on your back? Constant auditory experience of the background rumble of traffic? Constant visual experience of the tip of your nose? Or, when you aren’t paying attention to such things, do they drop out of consciousness entirely, so that they form no part of your stream of experience – not even vaguely, peripherally, amorphously – no part of your phenomenology, no part of what it’s like to be you?

There is, of course, perceptual processing without attention. A gentle tug on the shirt or an unexpected movement in the visual periphery will generally call your attention, even if you are fully absorbed in other things. To call attention such events must register, first, pre-attentively. While your attention centers on one or a few things, you monitor many others inattentively, ready to redirect attention when an inattentional processes detects a large or important change. The interesting question is not whether there is perception without attention, but whether experience accompanies our inattentional perceptual processing or whether that processing is entirely nonconscious. We might think of consciousness as like a soup. Is it a rich soup, replete with experience across broad regions of several modalities simultaneously? Or is it a thin soup, limited to one or a few regions or objects or modalities at a time?

Ordinary people’s intuitions diverge considerably here. So also do the views of philosophers and psychologists. On intuitive or introspective grounds, William James and John Searle (among others) endorse the rich view, Julian Jaynes and David Armstrong the thin view. One widely discussed case is the absent-minded driver: You’ve driven to work a thousand times. Today you drive habitually, utterly absorbed in other thoughts. You arrive and seem suddenly to wake up: Ah, I’m here already! Now, did you actually visually experience the road – at all? very much? – on your way to work?

One might think the question easily settled. Simply introspect now. How much is going on in your consciousness? Unfortunately, the “refrigerator light phenomenon” frustrates any such straightforward test: The fact that you hear (or auditorially experience) the hum of traffic when you’re thinking about whether you hear the hum of traffic provides no evidence on the question of whether you hear the hum of traffic when you’re not considering the matter. Just as the act of checking the refrigerator light turns it on, so also might the act of checking for tactile experience of one’s shirt or visual experience of one’s nose produce those very experiences.

Often we fail to parse, respond to, or remember what might seem to be salient stimuli – a stream of speech we’ve decided to ignore, a woman in a gorilla suit walking through a fast-paced ballgame, substantial changes in a flickering picture, a geometric figure briefly presented in an unattended part of a visual display. Daniel Dennett and Arien Mack, among others, have interpreted such phenomena as evidence for the thin view. However, the conclusion does not follow. We may not parse unattended stimuli much or remember them well, but they may still be experienced in an inchoate or immemorable way, or the general gist may be remembered if not the details.

Ned Block has emphasized that it seems introspectively that we visually experience more of a visual display than we focally attend to. On the face of it, this fact (if it is a fact) seems to suggest that perceptual experience outruns attention. But might it, instead, be a matter of diffuse attention spreading more broadly than focal attention, perhaps along a gradient? Even if you visually experience this whole page while focally attending only to a few words at a time, it doesn’t follow that you also visually experience the wall in the far periphery when you’re not thinking about it, or the pressure of the shoes on your feet.

The issue of whether perceptual experience is, in general, rich or thin may also be addressed by gathering introspective or immediately retrospective reports about randomly sampled moments of experience. Eric Schwitzgebel, giving people beepers to wear during ordinary activities and asking them to reflect on the last undisturbed moment before each beep, found a majority of participants to report visual experience in 100% of sampled moments, tactile experience and peripheral visual experience somewhat less. However, as Schwitzgebel admits, it’s unclear how much credence to give such reports.

The rich and thin views draw radically different pictures of our experience. If the rich view is right, consciousness contains much more than adherents of the thin view suppose. Although there is room here for merely terminological confusion, it appears that there is also room for major substantive disagreement. Strange that this question, concerning an absolutely fundamental and pervasive aspect of human experience, is so poorly studied!

Suggested further readings:

Armstrong, D.M. (1981), The nature of mind. Ithaca, NY: Cornell.

Block, N. (forthcoming), Consciousness, accessibility, and the mesh between psychology and neuroscience. Behavioral and Brain Sciences.

Dennett, D.C. (1991), Consciousness explained. Boston: Little, Brown & Co.

James, W. (1980/1981), The principles of psychology. Cambridge, MA: Harvard.

Jaynes, J. (1976), The origin of consciousness in the breakdown of the bicameral mind. Boston: Houghton Mifflin.

Mack, A., & Rock, I. (1998), Inattentional blindness. Cambridge, MA: MIT.

Reddy, L., Reddy, L., & Koch, C. (2006), Face identification in the near-absence of focal attention. Vision Research, 46, 2336-2343.

Rensink, R.A. (2000), When good observers go bad: Change blindness, inattentional blindness, and visual experience. Psyche, 6 (9).

Schwitzgebel, E. (2007), Do you have constant tactile experience of your feet in your shoes? Or is experience limited to what’s in attention? Journal of Consciousness Studies, 14 (3), 5-35.

Searle, J.R. (1992), The rediscovery of the mind. Cambridge, MA: MIT.

Simons, D.J. (2000), Attentional capture and inattentional blindness. Trends in Cognitive Sciences, 4, 147-155.

Note to blog visitors: One aspect of the question I've omitted is the old debate in introspective psychology about whether experiences of objects to which one is attending differ in some qualitative attribute like "clearness" or "attensity" from experiences of unattended objects. But this hasn't exactly been a hot topic in the last 100 years; and the more basic question of whether there even is experience outside of attention needs to be settled first.

12 comments:

Perlo said...

Interesting discussion. Do you have a paper on Jaynes' theory of the bicameral mind?

DrSteve said...

This may not be very deep philosophically-speaking, but bear with me. I guess it might be that part of the mind (brain?) is registering to everything all the time; now and then another part of the mind/brain attends to it.

The latter we call consciousness, the former what the psychologists call unconscious (psychoanalysts call it preconscious). This can be brought into consciousness with greater or lesser effect.
Some psychoanalysts (e.g. Ogden) believe that we are dreaming all the time but are unaware of it when awake. In the same way that we can't see the stars during the day - even though they're there influencing away.

For Ogden the goal of therapy is to help people to dream while awake - to make use of the irrational unconscious goings on behind the scenes. (But I digress - this is very different to the levels of consciousness you piece originally let me to contemplate.)

Anonymous said...

I wonder however if we are capable of recalling (even the very instant after experiencing it) somthing that we experienced in the vague way but did not 'record' and that that might easily be the majority of experiences. Of course maybe that is as close as we can get to answering the question.

GNZ

Eric Schwitzgebel said...

Thanks for the comments, folks!

Perlo: I'm afraid I haven't written on Jaynes, other than a brief discussion of his remarks on this topic in my 2007 essay (cited above). I do have trouble swallowing Jaynes's larger thesis that consciousness is really a relatively recent occurrence in human beings, though. I don't see how his arguments can even begin to show that sort of thing. That, in turn, makes me wonder whether he means the same thing by "consciousness" that I do; but it seems -- at the beginning of the book at least -- that he does, as best I can tell. Tricky stuff, though!

Dr. Steve: What you suggest here seems to me a version of the thin view, yes? (Though I wonder: Do you typically attend to what's going on in your mind/brain, or to the outside world?) Your comments about Ogden are interesting. I hadn't heard that theory! What sort of evidence might point one direction or the other...?

GNZ: I'm not sure I get your point. How can we recall something if we didn't record it? I do wonder, though -- and maybe this is in the vicinity of your comment -- whether we sometimes confuse our ability to recall a stimulus (e.g., the first few bongs of a clock, after we start paying attention at bong four) with previously having been conscious, without attention, of that stimulus.

Anonymous said...

Yes,
my point is that you might be 'aware of 4 bongs' but not really paying attention (remembering), so you experience it, but afterwards only remember 1 'bong'.

As a result any ‘after the fact’ question (even an instant afterwards) will have you report that you did not hear it. Your reflection is thus in error as is almost any other test you might contrive unfortunately.

the opposite could also be true which is that we dont actually experience it and yet because an automated part of our brain recorded it and later fed the information to 'our conciousness'
we might be able to recall it and thus seem as if we experienced it. (it might be possible to see thorugh that one)

GNZ ('Genius')

Perlo said...

Thanks for the prompt reply. The introductory chapter to Jaynes' book seems the best description of philosophy of mind around. I know he's been accused of committing the use/mention "fallacy" and that Dan Dennett has a paper defending Jaynes on that charge.

His theory is quite fascinating; though so far the only evidence is from literary sources and from persons with hallucinatory illnesses.

I wonder if you or your readers can imagine ways of testing the bicameral mind theory.

Anonymous said...

Perlo,
what do you want us to test?

The historical accuracy of his theory (recent emergence)? or if people's minds are bicameral when halucinating? Or something else?

Anyway like eric I find it very hard to swallow the first of those, it rings all sorts of alarm bells as a theory.

GNZ

Eric Schwitzgebel said...

Ah, Genius=GNZ -- didn't make the connection!

Yes, I agree completely about the two possibilities you mention. An advocate of a rich view might say that reports of no experience might be due to memory failure. On the other side, an advocate of a thin view might say that reports of past, unattended experience (such as of the unattended bongs) might be due to drawing non-consciously processed information into consciousness only after the fact. Tough issue, methodologically!

Eric Schwitzgebel said...

I find the introductory chapter of Jaynes fun and engaging. It's certainly written in a lively style! But of course its treatments of the opposing views are too brief to be very persuasive as counterarguments to anyone not antecedently convinced!

How to test the bicameral mind theory? Well, one approach is to look at the connection between speech and consciousness, since Jaynes thinks speech is central. In this connection -- possibly against Jaynes (but I haven't refreshed myself on the details) I remember reading about a case of a French monk who had epileptic seizures that when under medication caused severe aphasia but little other debility. The case study describes an extended episode, recalled by him, that involved getting off a train, reserving a room in a hotel, and ordering a restaurant meal -- all without (evidently) any inner or outer speech production or comprehension.

Now was this monk *conscious*? The authors don't raise the question explicitly (that I recall), but it seems natural to suppose he probably was....

DuMaurier-Smith said...

I started with your home page. Anyone taught piano by Matt Dennis is okay with me. What a musician!

I think these issues are better addressed as modes of information processing rather than ontologically as states or kinds of mind. Walter Ong and Jaynes take similar approaches to a very old phenomenological recognition: the human processes information in at least two modes. Structurally, left and right brain hemisphere "styles" may represent the modes, but they probably also involve the shorter neural pathways to the cortex versus longer pathways through reticular activating system, enabling us to process meaning (relevance) prior to differentiation--identification or attention behvior. Thus in the more "primary" mode, we deal with relevance or action potentials whereas in the more "secondary" mode we deal with representation and the slower processes involved in processes of attention to identity features, cognition, etc.

Gregory Bateson modeled such a process in his essay on codification of information in the book Communication: the Social Matrix of Psychiatry. (Ironically, he and Jurgen Ruesch, the co-author, communicated so well they discovered their differences, and each signed his own chapters.) As I recall, he described the two modes of codification progressive and selective modes of information integration.

Anonymous said...

yes GNZ/GeniusNZ/Genius,

depending on if I have my blogger ID signed in. apologies for any confusion.

The bicameral mind seems like a hard one to test but your story seems to be the story as remembered by the monk - so we at least do not appear to have the alternative where there is no continuality between 'the monk' without language and 'the monk' with language.

I was wondering if there might be similar examples with deaf people who may not have been taught a language – or the fact that they might (I don’t know if this is the case) process that language in a distinct part of the brain. However I admit I haven't read his book - just "out-takes".

GNZ

Eric Schwitzgebel said...

Thanks for the comments, D-S and GNZ!

D-S, you know the real shame about Matt Dennis? He had a truly *amazing* talent for written solo piano arrangements of jazz standards that never really saw the light of day. I don't think he himself fully saw it. When he finally put together a book of arrangements he published only his more far-out arrangements. But what he was best at -- and what I have still probably a dozen or two handwritten (photo-)copies of -- were relatively straight arrangements, with just a little variation in the melody and rich chords underneath. [sigh.] He could make the funkiest chords sound perfectly natural -- not at all discordant or challenging. I guess that's what I mean by "rich"!

Well, um, philosophy! I do like your suggestion that what's going on here should be thought of as modes of processing, deeper and more intellectual vs. faster and more automatic. Yet I still feel that the basic question about consciousness remains -- a fact that needs to be addressed about how much of the shallow, quick processing is really conscious. How to settle that? (This is not to say that deeper processing is always conscious.) Unfortunately, I don't know the Bateson/Ruesch. Sounds interesting, though!

GNZ: Nice point about the monk! I've thought about working a bit on the languageless deaf (those without ASL or any other signed language) and consciousness, but it has always been on the back burner. There are only so many things one can do with any intellectual responsibility -- and I'm pushing it as it is! Sacks' Seeing Voices is delightful (as Sacks always is). Is that the book you have in mind?