How to Turn Five Discrete Streams of Consciousness into a Murky Commingling Bog

Here's something you might think you know about consciousness: It's unified and discrete.

When we think about the stream of conscious experience -- the series of conscious thoughts, perceptual experiences, felt emotions, images, etc., that runs through us -- we normally imagine that each person has exactly one such stream. I have my stream, you have yours. Even if we entertain very similar ideas ("the bus is late again!") each of those ideas belongs determinately to each of our streams of experience. We share ideas like we might share a personality trait (each having a full version of each idea or trait), not like we share a brownie (each taking half) or a load (each contributing to the mutual support of a single whole). Our streams of experience may be similar, and we may influence each other, but each stream runs separately without commingling.

Likewise, when we count streams of experience or conscious entities, we stick to whole numbers. It sounds like a joke to say that there are two and a half or 3.72 streams of conscious experience, or conscious entities, here in this room. If you and I are in the room with a snail and an anesthesized patient, there are either two conscious entities in the room with two streams of conscious experience (if neither snails nor people in that type of anesthesized state have conscious experiences), or there are three, or there are four. Even if the anethesized patient is "half-awake", being half-awake (or alternatively, dreaming) is to be fully possessed of a stream of experience -- though maybe a hazy stream with confused ideas. Even if the snail isn't capable of explicit self-representation of itself as a thinker, if there's anything it's like to be a snail, then it has a stream of experience of its own snailish sort, unlike a fern, which (we normally think) has no conscious experiences whatsoever.

I find it hard to imagine how this could be wrong. And yet I think it might be wrong.

To start, let's build a slippery slope. We'll need some science fiction, but nothing too implausible I hope.

At the top of the slope, we have five conscious human beings, or even better (if you'll allow it) five conscious robots. At the bottom of the slope we have a fully merged and unified entity with a single stream of conscious experience. At each step along the way from top to bottom, we integrate the original five entities just a little bit more. If they are humans, we might imagine growing neural connections, one at a time, between their brains, slowly building cross-connections until the final merged brain is as unified as one could wish. If necessary, we could slowly remove and reconfigure neurons during the process so that the final merged brain is exactly like a normal human brain.

Since the human brain is a delicate and bloody thing, it will be much more convenient to do this with robots or AI systems, made of silicon chips or some other digital technology, if we are willing to grant that under some conditions a well-designed robot or AI system could have a genuine stream of consciousness. (As intuitive examples, consider C3P0 from Star Wars or Data from Star Trek.) Such systems could be slowly linked up, with no messy neurosurgery required, and their bodies (if necessary) slowly joined together. On the top of the slope will be five conscious robots, on the bottom one conscious robot.

The tricky bit is in the middle, of course. Either there must be a sudden shift at exactly one point from five streams of experience to one (or four sudden shifts from exactly 5 to 4 to 3 to 2 to 1), as a result of ever so small a change (a single neural connection), or, alternatively, streams of experience must in some cases not be discretely countable.

To help consider which of these two possibilities is the more plausible, let's try some toy examples.

You and me and our friends are discretely different animals with discretely different brains in discretely different skulls, with only one mouth each. So we are used to thinking of the stream of conscious experience like this:

The red circles contain what is in our streams of conscious experience -- sometimes similar (A and A', which you and I share), sometimes different (C belongs only to you), all reportable out of our discrete mouths, and all available for the guidance of consciously chosen actions.

However, it seems to be only a contingent fact about the biology of Earthly animals that we are designed like this. An AI system, or an alien, might be designed more like this:

Imagine here a complex system with a large pool of representations. There are five distinct verbal output centers (mouths), or five distinct loci of conscious action (independent arms), each of which draws on some but not all of the pool of representations. I have included one redundant representation (F) and a pair of contradictory representations (B and -B) to illustrate some of the possible complexity.

In such a case, we might imagine that there are exactly five streams, though they overlap in some important way.

But this is still much simpler than it might be. Now imagine these further complications:

1. There is no fixed number of mouths or arms over time.
2. The region of the representational pool that a mouth or arm can access isn't fixed over time.
3. The region of the representational pool that a mouth or arm can access isn't sharp-boundaried but is instead a probability function, where representations functionally nearer to the mouth or arm are very likely to be accessible for reporting or action, and representations far from the mouth or arm are unlikely to be accessible, with a smooth gradation between.

This picture aims to capture some of the features described:

Think of each color as a functional subsystem. Each color's density outside the oval is that system's likelihood, at any particular time, of being available for speech or action in that direction. Each color's density inside the oval is the likelihood of representations in that region being available to that subsystem for speech or action guidance. With a rainbow of colors, we needn't limit ourselves to a discretely countable number of subsystems. The figure also might fluctuate over time, if the probabilities aren't static.

In at least the fluctuating rainbow case, I submit, countability and discreteness fail. Yet it is a conceivable architecture -- a possible instantiation of an intermediate case along our slippery slope. If such an entity could host consciousness, and if consciousness is closely related to its fluctuating rainbow a structural/functional features, then the entity's stream(s) of conscious experience cannot be effectively represented with whole numbers. (Maybe we could try with multidimensional vectors.)

Is this too wild? Well, it's not inconceivable that octopus consciousness has some features in this direction (if octopi are conscious), given the distribution of their cognition across their arms; or that some overlap occurs in unseparated craniopagus twins joined at the head and brain; or even -- reading Daniel Dennett in a certain way -- that we ourselves are structured not as differently from this as we normally suppose.

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Related:

A Two-Seater Homunculus (Apr 1, 2013);

How to Be a Part of God's Mind (Apr 23, 2014);

If Materialism Is True, the United States Is Probably Conscious (Philosophical Studies, 2015);

Are Garden Snails Conscious? Yes, No, or *Gong* (Sep 20, 2018).

Are Garden Snails Conscious? Yes, No, or *Gong*

If you grew up in a temperate climate, you probably spent some time bothering brown garden snails (Cornu aspersum, formerly known as Helix aspersa). I certainly did. Now, as a grown-up (supposedly) expert (supposedly) on the science and philosophy of consciousness, I've decided to seriously consider a question that didn't trouble me very much when I was seven: Are garden snails conscious?

Being an "experimental philosopher", I naturally started with a Facebook poll of my friends, who obligingly fulfilled my expectations by answering, variously, "yes" (here's why), "no" (here's why not), and "OMG that is the stupidest question". I'll call this last response "*gong*" after The Gong Show, an amateur talent contest in which performers whose acts were sufficiently horrid would be interrupted by a gong and ushered off the stage.

It turns out that garden snails are even cooler than I thought, now that I'm studying them more closely. Let me fill you in.

Garden Snail Cognition and Behavior

(Most of this material is drawn from Ronald Chase's 2002 book Behavior & Its Neural Control in Gastropod Molluscs.)

The central nervous system of the brown garden snail contains about 40,000 neurons. That's quite a few more neurons than the famously mapped 302 neurons of the Caenorhabditis elegans roundworm, but it's modest compared to the quarter million neurons of an ant or fruitfly. The snail's brain is organized into several clumps of ganglia, mostly in a ring around its esophagus. Gastropod neurons generally resemble vertebrate neurons, with a few notable exceptions. One exception is that gastropod neurons usually don't have a bipolar structure with axons on one side of the cell body and dendrites on the other side. Instead, input and output typically occurs on both sides without a clear differentiation between axon and dendrite. Another difference is that although gastropods' small-molecule neural transmitters are the same as in vertebrates (e.g., acetylcholine, serotonin), their larger-molecule neuropeptides are mostly different.

Snails navigate primarily by chemoreception, or the sense of smell, and mechanoreception, or the sense of touch. They will move toward attractive odors, such as food or mates, and they will withdraw from noxious odors and tactile disturbance. Although garden snails have eyes on the tips of their posterior tentacles, their eyes seem to be sensitive only to light versus dark and the direction of light sources, rather than to the shapes of objects. The internal structure of snail tentacles shows much more specialization for chemoreception, with the higher-up posterior tentacles perhaps better for catching odors on the wind and the lower anterior tentacles better for odors closer to the ground. Garden snails can also sense the direction of gravity, righting themselves and moving toward higher ground to avoid puddles.

Snails can learn. Gastropods fed on a single type of plant will prefer to move toward that same plant type when offered the choice in a Y-shaped maze. They can also learn to avoid foods associated with noxious stimuli, in some cases even after only a single trial. Some species of gastropod will modify their degree of attraction to sunlight if sunlight is associated with tumbling inversion. In warm ocean Aplysia californica gastropods, the complex role of the central nervous system in governing reflex withdrawals has been extensively studied. Aplysia californica reflex withdrawals are centrally mediated, and can be inhibited, amplified, and coordinated, maintaining a singleness of action across the body and regulating withdrawal according to circumstances, with both habituation and sensitization possible. Garden snail nervous systems appear to be similarly complex, generating unified action that varies with circumstance.

Garden snails can coordinate their behavior in response to information from more than one modality at once. For example, as mentioned, when they detect that they are surrounded by water, they can seek higher ground. They will cease eating when satiated, withhold from mating while eating despite sexual arousal, and exhibit less withdrawal reflex while mating. Before egg laying, garden snails use their feet to excavate a shallow cavity in soft soil, then insert their head into the cavity for several hours while they ovulate.

Garden snail mating is famously complex. Cornu aspersum is a simultaneous hermaphrodite, playing both the male and female role simultaneously. Courtship and copulation requires several hours. Courtship begins with the snails touching heads and posterior antennae for tens of seconds, then withdrawing and circling to find each other again, often consuming each other's slime trails, or alternatively breaking courtship. They repeat this process several times. During mating, snails will sometimes bite each other, then withdraw and reconnect. Later in courtship, one snail will shoot a "love dart" consisting of calcium and mucus at the other, succeeding in penetrating the skin about one third of the time; tens of minutes later, the other snail will reciprocate. Courtship continues regardless of whether the darts successfully land. Sex culminates when the partners manage to simultaneously insert their penises into each other, which may require dozens of attempts.

Impressive accomplishments for creatures with brains of only 40,000 neurons! Of course, snail behavior is limited compared to the larger and more flexible behavioral repertoire of mammals and birds.

Garden Snail Consciousness: Three Possibilities

So, knowing all this... are garden snails conscious? Is there something it's like to be a garden snail? Do snails have, for example, sensory experiences?

Suppose you touch the tip of your finger to the tip of a snail's posterior tentacle, and the tentacle retracts. Does the snail have tactile experience of something touching its tentacle, a visual experience of a darkening as your finger approaches and occludes the eye, an olfactory or chematosensory experience of the smell or taste or chemical properties of your finger, a proprioceptive experience of the position of its now-withdrawn tentacle?

(1.) Yes. It seems like we can imagine that the answer is yes, the snail does have sensory experiences. Any specific experience we try to imagine from the snail's point of view, we will probably imagine too humanocentrically. Withdrawing a tentacle might not feel much like withdrawing an arm; and with 40,000 neurons total, presumably there won't be a wealth of detail in any sensory modality. Optical experience in particular might be so informationally poor that calling it "visual" is already misleading, inviting too much analogy with human vision. Nonetheless, I think we can conceive in a general way how it might be the case that garden snails have sensory experiences of some sort or other.

(2.) No. We can also imagine, I think, that the answer is no, snails entirely lack sensory experiences of any sort -- and thus, presumably, any consciousness at all, on the assumption that if snails are conscious they have at least sensory consciousness. If you have trouble conceiving of this possibility, consider dreamless sleep, toy robots, and the enteric nervous system. (The enteric nervous system is a collection of about half a billion neurons lining your gut, governing motor function and enzyme secretion.) In all three of these cases, most people think, there is no genuine stream of conscious experience, despite some organized behavior and environmental reactivity. It seems that we can coherently imagine snail behavior to be like that: no more conscious than turning over unconsciously in sleep, or than a toy robot, or than the neurons lining your intestines.

We can make sense of both of these possibilities, I think. Neither seems obviously false or obviously refuted by the empirical evidence. One possibility might strike you as intuitively much more likely than the other, but as I've learned from chatting with friends and acquaintances (and from my Facebook poll), people's intuitions vary -- and it's not clear, anyway, how much we ought to trust our intuitions in such matters. You might have a favorite scientific or philosophical theory from which it follows that garden snails are or are not conscious; but there is little consensus on general theories of consciousness and leading candidate theories yield divergent answers. (More on this, I hope, in a follow-up post.)

(3.) *Gong*. To these two possibilities, we can add a third, the one I am calling *gong*. Not all questions deserve a yes or a no. There might be a false presupposition in the question (maybe "consciousness" is an incoherent concept?), or the case might be vague or indeterminate such that neither "yes" nor "no" quite serves as an adequate answer. (Compare vague or indeterminate cases between "green" and "not green" or between "extraverted" and "not extraverted".)

Indeterminacy is perhaps especially tempting. Not everything in the world fits neatly into determinate, dichotomous yes-or-no categories. Consciousness might be one of those things that doesn't dichotomize well. And snails might be right there at the fuzzy border.

Although an indeterminate view has some merits, it is more difficult to sustain than you might think at first pass. To see why, it helps to clearly distinguish between being a little conscious and being in an indeterminate state between conscious and not-conscious. If one is a little conscious, one is conscious. Maybe snails just have the tiniest smear of consciousness -- that would still be consciousness! You might have only a little money. Your entire net worth is a nickel. Still, it is discretely and determinately the case that if you have a nickel, you have some money. If snail consciousness is a nickel to human millionaire consciousness, then snails are conscious.

To say that the dichotomous yes-or-no does not apply to snail consciousness is to say something very different than that snails have just a little smidgen of consciousness. It's to say... well, what exactly? As far as I'm aware (correct me if I'm wrong!), there's no well developed theory of kind-of-yes-kind-of-no consciousness. We can make sense of a vague kind-of-yes-kind-of-no for "green" and "extravert"; we know more or less what's involved in being a gray-area case of a color or personality trait. We can imagine gray-area cases with money too: Your last nickel is on the table over there, and here comes the creditor to collect it. Maybe that's a gray-area case of having money. But it's much more difficult to know how to think about gray-area cases of being somewhere between a little bit conscious and not at all conscious. So while in the abstract I feel the attraction of the idea that consciousness is not a dichotomous property and garden snails might occupy the blurry in-between region, the view requires entering a theoretical space that has not yet been well explored.

The Possibilities Remain Open

There is, I think, some antecedent plausibility to all three possibilities, yes, no, and *gong*. To really decide among them, to really figure out the answer to our question about snail consciousness, we need an epistemically well-grounded general theory of consciousness, which we can apply to the case.

Unfortunately, we have no such theory. The live possibilities appear to cover the entire spectrum from the panpsychism or near-panpsychism of Galen Strawson and of Integrated Information Theory to very restrictive views, like those of Daniel Dennett and Peter Carruthers, on which consciousness requires some fairly sophisticated self-representational capacities of the sort that well beyond the capacity of snails.

Actually, I think there's something wonderful about not knowing. There's something marvelous about the fact that I can go into my backyard, lift a snail, and gaze at it, unsure. Snail, you are a puzzle of the universe, right here in my garden, eating the daisies!

[image by Bryony Pierce]

Slippery Slope Arguments and Discretely Countable Subjects of Experience

I've become increasingly worried about slippery slope arguments concerning the presence or absence of (phenomenal) consciousness. Partly this is in response to Peter Carruthers' new draft article on animal consciousness, partly it's because I'm revisiting some of my thought experiments about group minds, and partly it's just something I've been worrying about for a while.

To build a slippery slope argument concerning the presence of consciousness, do this:

* First, take some obviously conscious [or non-conscious] system as an anchor point -- such as an ordinary adult human being (clearly conscious) or an ordinary proton (obviously(?) non-conscious).

* Second, imagine a series of small changes at the far end of which is a case that some people might view as a case of the opposite sort. For example, subtract one molecule at a time from the human until you have only one proton left. (Note: This is a toy example; for more attractive versions of the argument, see below.)

* Third, highlight the implausibility of the idea that consciousness suddenly winks out [winks in] at any one of these little steps.

* Finally, conclude that the disputable system at the end of the series is also conscious [non-conscious].

Now slippery slope arguments are generally misleading for vague predicates like "red". Even if we can't finger an exact point of transition from red to non-red in a series of shades from red to blue, it doesn't follow that blue is red. Red is a vague predicate, so it ought to admit of vague, in-betweenish cases. (There are some fun logical puzzles about vague predicates, of course, but I trust that our community of capable logicians will eventually sort that stuff out.)

However, unlike redness, the presence or absence of consciousness seems to be a discrete all-or-nothing affair, which makes slippery-slope arguments more tempting. As John Searle says somewhere (hm... where?), having consciousness is like having money: You can have a little of it or a lot of it -- a penny or a million bucks -- but there's a discrete difference between having only a little and having not a single cent's worth. Consider sensory experience, for example. You can have a richly detailed visual field, or you can have an impoverished visual field, but there is, or at least seems to be, a discrete difference between having a tiny wisp of sensory experience (e.g., a brief gray dot, the sensory equivalent of a penny) and having no sensory experience at all. We normally think of subjects of experience as discrete, countable entities. Except as a joke, most of us wouldn't say that there are two-and-a-half conscious entities in the room or that an entity has 3/8 of a stream of experience. An entity either is a subject of conscious experience (however limited their experience is) or has no conscious experience at all.

Consider these three familiar slippery slopes.

(1.) Across the animal kingdom. We normally assume that humans, dogs, and apes are genuinely, richly phenomenally conscious. We can imagine a series of less and less sophisticated animals all the way down to the simplest animals or even down into unicellular life. It doesn't seem that there's a plausible place to draw a bright line, on one side of which the animals are conscious and on the other side of which they are not. (I did once hear an ethologist suggest that the line was exactly between toads (conscious) and frogs (non-conscious); but even if you accept that, we can construct a fine-grained toad-frog series.)

(2.) Across human development. The fertilized egg is presumably not conscious; the cute baby presumably is conscious. The moment of birth is important -- but it's not clear that it's so neurologically important that it is the bright line between an entirely non-conscious fetus and a conscious baby. Nor does there seem to be any other obvious sharp transition point.

(3.) Neural replacement. Tom Cuda and David Chalmers imagine replacing someone's biological neurons one by one with functionally equivalent artificial neurons. A sudden wink-out between N and N+1 replaced neurons doesn't seem intuitively plausible. (Nor does it seem intuitively plausible that there's a gradual fading away of consciousness while outward behavior, such as verbal reports, stays the same.) Cuda and Chalmers conclude that swapping out biological neurons for functionally similar artificial neurons would preserve consciousness.

Less familiar, but potentially just as troubling, are group consciousness cases. I've argued, for example, that Guilio Tononi's influential Integrated Information Theory of consciousness runs into trouble in employing a threshold across a slippery slope (e.g. here and Section 2 here). Here the slippery slope isn't between zero and one conscious subjects, but rather between one and N subjects (N > 1).

(4.) Group consciousness. At one end, anchor with N discretely distinct conscious entities and presumably no additional stream of consciousness at the group level. At the other end, anchor with a single conscious entity with parts none of which, presumably, is an individual subject of experience. Any particular way of making this more concrete will have some tricky assumptions, but we might suppose an Ann Leckie "ancillary" case with a hundred humanoid AIs in contact with a central computer on a ship. As the "distinct entities" anchor, imagine that the AIs are as independent as ordinary human beings are, and the central computer is just a communications relay. Intermediate steps involve more and more information transfer and central influence or control. The anchor case on the other end is one in which the humanoid AIs are just individually nonconscious limbs of a single fully integrated system (though spatially discontinuous). Alternatively, if you like your thought experiments brainy, anchor on one end with normally brained humans, then construct a series in which these brains are slowly neurally wired together and perhaps shrunk, until there's a single integrated brain again as the anchor on the other end.

Although the group consciousness cases are pretty high-flying as thought experiments, they render the countability issue wonderfully stark. If streams of consciousness really are countably discrete, then either you must:

(a.) Deny one of the anchors. There was group consciousness all along, perhaps!

(b.) Affirm that there's a sharp transition point at which adding just a single bit's worth of integration suddenly shifts the whole system from N distinct conscious entitites to only one conscious entity, despite the seemingly very minor structural difference (as on Tononi's view).

(c.) Try to wiggle out of the sharp transition with some intermediate number between N and 1. Maybe this humanoid winks out first while this other virtually identical humanoid still has a stream of consciousness -- though that's also rather strange and doesn't fully escape the problem.

(d.) Deny that conscious subjects, or streams of conscious experience, really must come in discretely countable packages.

I'm increasingly drawn to (d), though I'm not sure I can quite wrap my head around that possibility yet or fully appreciate its consequences.

[image adapted from Pixabay]

Help Me Choose Posts for My Next Book: Consciousness

As I've mentioned several times, my next book will consist of selected revised blog posts and op-eds. I've narrowed it down to about 150 posts, in seven broad categories. I'd really appreciate your help in narrowing it down more!

Categories:

moral psychology

technology

belief, desire, and self-knowledge

culture and humor

cosmology, skepticism, and weird minds

consciousness (live as of today)

metaphilosophy and sociology of philosophy

Every week or so I'm posting a poll with about twenty posts or op-eds to rate, on one of those seven themes. I've found the polls helpful in thinking about what has resonated with readers or been memorable for them. Many thanks to those of you who have responded!

Each poll will also contain links to the original posts and op-eds so you can refresh your memory if you want. But there's no need to rate all of the listed posts! Even if you just remember one or two that you like, it would be useful for me to know that.

Today's poll, 19 selected posts on consciousness.

(image from http://www.sandydan.com/photo/wide/fish/ftest5.jpg)

Why the Epistemology of Conscious Perception Needs a Theory of Consciousness

On a certain type of classical "foundationalist" view in epistemology, knowledge of your sensory experience grounds knowledge of the outside world: Your knowledge that you're seeing a tree, for example, is based on or derived from your knowledge that you're having sensory experiences of greens and browns in a certain configuration in a certain part of your visual field. In earlier work, I've argued that this can't be right because our knowledge of external things (like trees) is much more certain and secure than our knowledge of our sensory experiences.

Today I want to suggest that foundationalist or anti-foundationalist claims are difficult to evaluate without at least an implicit background theory of consciousness. Consider for example these three simple models of the relation between sensory experience, knowledge of sensory experience, and knowledge of external objects. The arrows below are intended to be simultaneously causal and epistemic, with the items on the left both causing and epistemically grounding the items on the right. (I've added small arrows to reflect that there are always also other causal processes that contribute to each phase.)

[apologies for blurry type: click to enlarge and clarify]

Model A is a type of classical foundationalist picture. In Model B, knowledge of external objects arises early in cognitive processing and informs our sensory experiences. In Model C, sensory experience and knowledge of external objects arise in parallel.

Of course these models are far too simple! Possibly, the process looks more like this:

How do we know which of the three models is closest to correct? This is, I think, very difficult to assess without a general theory of consciousness. We know that there's sensory experience, and we know that there's knowledge of sensory experience, and we know that there's knowledge of external objects, and that all of these things happen at around the same time in our minds; but what exactly is the causal relation among them? Which happens first, which second, which third, and to what extent do they rely on each other? These fine-grained questions about temporal ordering and causal influence are, I think, difficult to discern from introspection and thought experiments.

Even if we allow that knowledge of external things informs our sense experience of those things, that can easily be incorporated in a version of the classical foundationalist model A, by allowing that the process is iterative: At time 1, input causes experience which causes knowledge of experience which causes knowledge of external things; then again at time 2; then again at time 3.... The outputs of earlier iterations could then be among the small-arrow inputs of later iterations, explaining whatever influence knowledge of outward things has on sensory experiences within a foundationalist picture.

On some theories, consciousness arises relatively early in sensory processing -- for example, in theories where sensory experiences are conscious by virtue of their information's being available for processing by downstream cognitive systems (even if that availability isn't much taken advantage of). On other theories, sensory consciousness arises much later in cognition, only after substantial downstream processing (as in some versions of Global Workspace theory and Higher-Order theories). Although the relationship needn't be strict, it's easy to see how views according to which consciousness arises relatively early fit more naturally with foundationalist models than views according to which consciousness arises much later.

The following magnificent work of art depicts me viewing a tree:

[as always, click to enlarge and clarify]

Light from the sun reflects off the tree, into my eye, back to primary visual cortex, then forward into associative cortex where it mixes with associative processes and other sensory processes. In my thought bubble you see my conscious experience of the tree. The question is, where in this process does this experience arise?

Here are three possibilities:

Until we know which of these approaches is closest to the truth, it's hard to see how we could be in a good position to settle questions about foundationalism or anti-foundationalism in the epistemology of conscious perception.

(Yes, I know I've ignored embodied cognition in this post. Of course, throwing that into the mix makes matters even more complicated!)

The Experience of Reading: Empirical Evidence

What do you experience while reading? Do you experience inner speech, as though you or the author are saying the words aloud? Do you experience visual imagery? Do you experience the black marks on the white page? All of these at once? Different ones at different times, depending on how you're engaging with the text?

Although educators, cognitive psychologists, and literary critics often make claims about readers' typical experience, few researchers have bothered to ask readers, in any systematic way, these basic questions about their experience. [Note 1] So Alan Tonnies Moore and I decided to try doing that. Alan's work on this topic became his 2016 dissertation, and we have now have a paper forthcoming in Consciousness and Cognition (final submitted manuscript available here).

In each of three experiments, we presented readers with several hundred words of text. In two of these experiments, a beep interrupted participants' reading. Immediately after the beep, readers were to report what was in their experience in the final split second before the beep. We collected both general free-response descriptions of their experience and yes/no/maybe reports about whether they were experiencing visual imagery, inner speech, and visual experience of the words on the page (all phrases defined beforehand). In all three experiments, we also collected readers' retrospective assessments of how frequently they experienced visual imagery, inner speech, and the words on the page while reading the passage we had presented.

At the end of each experiment, participants answered several questions about the text they had just finished reading. Some questions we thought might relate to visual imagery (such as memory for visual detail), other questions we thought might relate to inner speech (such as memory for rhyme), and still other questions we thought might relate to visual experience of words on the page (such as memory of the font). We were curious whether performance on those questions would correlate with reported experience. Do visual imagers, for example, remember more visual detail?

Here are the main things we found:

(1.) People differ immensely in what types of experiences they report while reading. Some people report visual imagery all the time; others report it rarely or never; and still others (the majority) report visual imagery fairly often but not all of the time. Similarly for inner speech and words on the page.

To see this, here are a couple of histograms [click to enlarge and clarify].

Readers' retrospective reports in Experiment 2 (Experiments 1 and 3 are similar):

Readers' yes/no/maybe reports immediately after the beep, also in Experiment 2:

(2.) Inner speech is less commonly reported than many researchers suppose. This has also been emphasized in Russ Hurlburt's related work on the topic. Although some researchers claim or implicitly assume that inner speech is normally present while reading, we found it in a little more than half of the samples (see the histograms above). Visual imagery was more commonly reported than inner speech.

(3.) Reported experience varies with passage type, but not by a lot. In Experiment 2, we presented readers with richly visually descriptive prose passages, rhyming poetry, and dramatic dialogue, thinking that readers might experience these types of passages differently. Differences were in the predicted directions, but weren't large. For example, visual imagery was reported in 78% of the beeped moments during richly descriptive prose passages vs 66% of the poetry passages and 69% of the dramatic dialogue (chi-square = 14.4, p = .006). Inner speech was reported in 65% of the beeped moments during dramatic dialogue passages vs 59% of the poetry passages and 53% of the descriptive prose (chi-square = 19.1, p = .001).

(4.) There was little or no relationship between reported experience and seemingly related comprehension or skill tasks. For example, people who reported seeing the words of text on the page were not detectably more likely to remember the font used. People who reported visual imagery were not detectably more likely to remember the color of objects described in passages. People who reported inner speech were not more likely to disambiguate difficult-to-pronounce words by reference to the rhyme scheme. Although all of this is possibly disappointing, it fits with some of my previous work on the poor relationship between self-reported experience and performance at behavioral tasks.

Alan and I believe that sampling studies will soon become an important tool in empirical aesthetics, and we hope that this study helps to lay some of the groundwork for that.

Full version of our paper available here.

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Note 1: One important exception to this generalization is Russ Hurlburt in his 2016 book with Marco Caracciolo and in his paper with several collaborators forthcoming in Journal of Consciousness Studies.)

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Related Posts:

What Do You Think About While Watching The Nutcracker? (Dec 17, 2007)

The Experience of Reading (Nov 25, 2009).

The Experience of Reading: Imagery, Inner Speech, and Seeing the Words on the Page (Aug 28, 2013).

Waves of Mind Wandering During Live Performances (Jan 15, 2014)

Is Consciousness Sparse or Abundant? Five Dimensions of Analysis

Consciousness -- that is, "phenomenal" consciousness, the stream of experience, subjective experience, "what-it's-like"-ness -- might be sparse, or it might be abundant. There might be lots of it, or there might be very little. This might be so along at least five different dimensions of analysis.

Entity sparseness vs. entity abundance. Consciousness might be sparse in the sense that few entities in the universe possess it, or it might be abundant in the sense that many entities in the universe possess it. Someone who thinks that consciousness is entity-abundant might think that insects are conscious, and snails, maybe earthworms -- all kinds of entities with sensory systems. They might also think that computers could soon have conscious experiences, if designed in the right way. At the extreme, they might accept panpsychism -- the view that every entity in the universe is conscious, even isolated hydrogen ions in outer space. In contrast, someone who thinks that consciousness is entity-sparse is much more conservative, seeing consciousness on Earth as limited, for example, only to cognitively sophisticated mammals and birds, or in the extreme only to adult human beings with sophisticated self-reflective powers.

State sparseness vs. state abundance. An entity who is conscious might be conscious all the time or only once in a while. Someone who thinks that consciousness is state abundant might think that even when we aren't in REM sleep we have dreams or dreamlike experiences or at least experiences of some sort. They might think that when we're driving absent-mindedly and can't remember a thing, we don't really blank out completely. In contrast, someone who thinks that consciousness is state sparse would hold that we are often not conscious at all. Consciousness might disappear entirely during long periods of dreamless sleep, or during habitual activity, or maybe during "flow" states of skillful activity. Someone who holds to extreme state sparseness might say that we are almost never actually phenomenally conscious, except in rare moments of explicit self-reflection.

Modality sparseness vs. modality abundance. An entity who is currently state conscious might be conscious in lots of modalities at once or in only one or few modalities at a time. For example, a minute ago, as you were reading the previous paragraph, did you have visual experience of the computer screen? Did you also have auditory experience of the hum of the fan in your room (to which I assume you weren't attending)? Did you have tactile experience of your feet in your shoes? Did you hear the words of that paragraph in inner speech? Did you have relevant visual imagery? Were you also simultaneously having emotional experience, a lingering feeling of hunger, etc., etc.? Someone who accepts modality abundance thinks that we have many types or modalities of experience ongoing most of the time when we are conscious. In contrast, someone who accepts modality sparseness thinks that we have only one or a few modalities of experience at any one time -- for example, no experience at all of the feeling of your feet in your shoes when your attention is elsewhere.

Modality width. Within a modality that is currently conscious in an entity at a time, the stream of experience might be broad or it might be narrow. Consider visual experience as you are reading. Do you have visual experience only of a few degrees of visual arc, whatever is near the center of your attention? Or do you have visual experience all the way out to the edge, including the rim of your computer screen, the rims of your glasses, the tip of your nose, almost 180 degrees of arc? Or somewhere in between -- maybe the whole computer screen and its rim, but little beyond that? Someone with a sparse view about visual modal width thinks that visual experience is usually (maybe until you think to attend to the periphery) only of a few degrees of arc. Someone with an abundant view might think that we basically experience the full 180 degrees of the visual field all the time when we have any visual experience at all. Analogous issues arise for other modalities. Do you have auditory experience only of the conversation to which you are attending, or also of the background noise? Is your visual imagery sketchily minimal or full of detail? Is your emotional experience a minimal valence and label or is it a very specifically embodied feeling?

Property sparseness vs. property abundance. Consider visual experience again. You are looking at a tree. According to one view, all you visually experience are low-level properties like color, shape, and orientation. You know it's a tree, but the "treeness" of it isn't part of your visual experience. (Maybe you have a cognitive experience of thinking "tree!" but that's a different modality.) According to another view, your visual experience is not just of simple low-level properties but instead of a wealth of properties. It's part of your visual experience, for example, that it's a tree, and that it looks ancient, and that it invites climbing, and that the leaves look about ready to fall.

Philosophers and consciousness scientists have recently been arguing in all kinds of interesting ways about various of these issues in isolation, but I can't recall seeing a good structuring of the landscape of options here which both captures the many different mix-and-match possibilities here, while also recognizing that all of the "abundant" views have something in common (consciousness is widespread and multifarious; it's easy to generate lots of types of it) and all of the "sparse" views have something in common (consciousness is rare and limited in its forms).

[image source]

Am I a Type or a Token? (guest post by Henry Shevlin)

guest post by Henry Shevlin

Eric has previously argued that almost any answer to the problem of consciousness involves “crazyism” – that is, a commitment to one or another hypotheses that might reasonably be considered bizarre. So it’s in this spirit of openness to wild ideas I’d like to throw out one of my own longstanding “crazy” ideas concerning our identity as conscious subjects.

To set the scene, imagine that we have one hundred supercomputers, each separately running a conscious simulation of the same human life. We’re also going to assume that these simulations are all causally coupled together so that they’re in identical functional states at any one time – if a particular mental state type is being realized in one at a given time, it’s also being realized in all the others.

The question I want to ask now is: how many conscious subjects – subjective points of view – exist in this setup? A natural response is “one hundred, obviously!” After all, there are one hundred computers all running their own simulations. But the alternate crazy hypothesis I’d like to suggest is that there’s just one subject in this scenario. Specifically, I want to claim that insofar as two physical realizations of consciousness give rise to a qualitatively identical sequence of experiences, they give rise to a single numerically identical subject of experience.

Call this hypothesis the Identity of Phenomenal Duplicates, or IPD for short. Why would anyone think such a crazy thing? In short, I’m attracted by the idea that the only factors relevant to the identity and individuation of a conscious subject are subjective: crudely, what makes me me is just the way the world seems to me and my conscious reactions to it. As a subject of phenomenal experience, in other words, my numerical identity is fixed just by those factors that are part of my experience, and factors that lie outside my phenomenal awareness (for example, which of many possible computers are running the simulation that underpins my consciousness) are thus irrelevant to my identity.

Putting things another way, I’d suggest that maybe my identity qua conscious subject is more like a type than a token, meaning that a single conscious subject could be multiply instantiated. As a helpful analogy, think about the ontology of something like a song, a novel, or a movie. The Empire Strikes Back has been screened billions of times over the years, but all of these were instantiations of one individual thing, namely the movie itself. If the IPD thesis is correct, then the same might be true for a conscious subject – that I myself (not merely duplicates of me!) could be multiply instantiated across a host of different biological or artificial bodies, even at a single moment. What *I* am, then, on this view, is a kind of subjective pattern or concatenation of such patterns, rather than a single spatiotemporally located object.

Here’s an example that might make the view seem (marginally!) more plausible. Thinking back to the one hundred simulations scenario above, imagine that we pick one simulation at random to be hooked up to a robot body, so that it can send motor outputs to the body and receive its sensory inputs. (Note that because we’re keeping all the simulations coupled together, they’ll remain in ‘phenomenal sync’ with whichever sim we choose to be embodied as a robot). The robot wakes up, looks around, and is fascinated to learn it’s suddenly in the real world, having previously spent its life in a simulation. But now it asks us: which of the Sims am I? Am I the Sim running on the mainframe in Tokyo, or the one in London, or the one in Sao Paolo?

One natural response would be that it was identical to whichever Sim we uploaded the relevant data from. But I think this neglects the fact that all one hundred Sims are causally coupled with one another, so in a sense, we uploaded the data from all of them – we just used one specific access point to get to it. To illustrate this, note that in transferring the relevant information from our Sims to the robot, we might wish (perhaps for reasons of efficiency) to grab the data from all over the place – there’s no reason we’d have to confine ourselves to copying the data over from just one Sim. So here’s an alternate hypothesis: the robot was identical to all of them, because they were all identical to one another – there was just one conscious subject all along! (Readers familiar with Dennett’s Where Am I? may see clear parallels here.)

I find something very intuitive about the response IPD provides in this case. I realize, though, that what I’ve provided here isn’t much of an argument, and invites a slew of questions and objections. For example, even if you’re sympathetic to the reading of the example above, I haven’t established the stronger claim of IPD, which makes no reference to causal coupling. This leaves it open to say, for example, that had the simulations been qualitatively identical by coincidence (for example, via being a cluster of Boltzmann brains) rather than being causally coupled, their subjects wouldn’t have been numerically identical. We might also wonder about beings whose lives are subjectively identical up to a particular point in time, and afterwards diverge. Are they the same conscious subject up until the point of divergence, or were they distinct all along? Finally, there’s also some tricky issues concerning what it means for me to survive in this framework – if I’m a phenomenal type rather than a particular token instantiation of that type, it might seem like I could still exist in some sense even if all my token instances were destroyed (although would Star Wars still exist in some relevant sense if every copy of it was lost?).

Setting aside these worries for now, I’d like to quickly explore how the truth or falsity of IPD might actually matter – in fact, might matter a great deal! Consider a scenario in which some future utilitarian society decides that the best way to maximize happiness in the universe is by running a bunch of simulations of perfectly happy lives. Further, let’s imagine that their strategy for doing this involves simulating the same single exquisitely happy life a billion times over.

If IPD is right, then they’ve just made a terrible mistake: rather than creating a billion happy conscious subjects, they’ve just made one exquisitely happy subject with a billion (hedonically redundant) instantiations! To rectify this situation, however, all they’d need to do would be to introduce an element of variation into their Sims – some small phenomenal or psychological difference that meant that each of the billion simulations was subjectively unique. If IPD is right, this simple change would increase the happiness in the universe a billion-fold.

There are other potential interesting applications of IPD. For example, coupled with a multiverse theory, it might have the consequence that you currently inhabit multiple distinct worlds, namely all those in which there exist entities that realize subjectively and psychologically identical mental states. Similarly, it might mean that you straddle multiple non-continuous areas of space and time: if the same identical simulation is run at time t1 and time t2 a billion years apart, then IPD would suggest that a single subject cohabits both instantiations.

Anyway, while I doubt I’ve convinced anyone (yet!) of this particular crazyism of mine, I hope at least it might provide the basis for some interesting metaphysical arguments and speculations.

[Image credit: Paolo Tonon]

Is Consciousness an Illusion?

In the current issue of the Journal of Consciousness Studies, Keith Frankish argues that consciousness is an illusion -- or at least that "phenomenal consciousness" is an illusion. It doesn't exist.

Now I think there are basically two different things that one could mean in saying "consciousness doesn't exist".

(A.) One is something that seems to be patently absurd and decisively refuted by every moment of lived experience: that there is no such thing as lived experience. If it sounds preposterous to deny that anyone ever has conscious experience, then you're probably understanding the claim correctly. It is a radically strange claim. Of course philosophers do sometimes defend radically strange, preposterous-sounding positions. Among them, this would be a doozy.

(B.) Alternatively, you might think that when a philosopher says that consciousness exists (or "phenomenal consciousness" or "lived, subjective experience" or whatever) she's usually not just saying the almost undeniably obvious thing. You might think that she's probably also regarding certain disputable properties as definitionally essential to consciousness. You might hear her as saying not only that there is lived experience in the almost undeniable sense but also that the target phenomenon is irreducible to the merely physical, or is infallibly knowable through introspection, or is constantly accompanied by a self-representational element, or something like that. Someone who hears the claim that "consciousness exists" in this stronger, more commissive sense might then deny that consciousness does exist, if they think that nothing exists that has those disputable properties. This might be an unintuitive claim, if it's intuitively plausible that consciousness does have those properties. But it's not a jaw dropper.

Admittedly, there has been some unclarity in how philosophers define "consciousness". It's not entirely clear on the face of it what Frankish means to deny the existence of in the article linked above. Is he going for the totally absurd sounding claim, or only the more moderate claim? (Or maybe something somehow in between or slightly to the side of either of these?)

In my view, the best and most helpful definitions of "consciousness" are the less commissive ones. The usual approach is to point to some examples of conscious experiences, while also mentioning some synonyms or evocative phrases. Examples include sensory experiences, dreams, vivid surges of emotion, and sentences spoken silently to oneself. Near synonyms or evocative phrases include "subjective quality", "stream of experience", "that in virtue of which it's like something to be a person". While you might quibble about any particular example or phrase, it is in this sense of "consciousness" that it seems to be undeniable or absurd to deny that consciousness exists. It is in this sense that the existence of consciousness is, as David Chalmers says, a "datum" that philosophers and psychologists need to accept.

Still, we might be dissatisfied with evocative phrases and pointing to examples. For one thing, such a definition doesn't seem very rigorous, compared to an analytic definition. For another thing, you can't do very much a priori with such a thin definition, if you want to build an argument from the existence of consciousness to some bold philosophical conclusion (like the incompleteness of physical science or the existence of an immaterial soul). So philosophers are understandably tempted to add more to the definition -- whatever further claims about consciousness seem plausible to them. But then, of course, they risk adding too much and losing the undeniability of the claim that consciousness exists.

When I read Frankish's article in preprint, I wasn't sure how radical a claim he meant to defend, in denying the existence of phenomenal consciousness. Was he going for the seemingly absurd claim? Or only for the possibly-unintuitive-but-much-less-radical claim?

So I wrote a commentary in which I tried to define "phenomenal consciousness" as innocently as possible, simply by appealing to what I hoped would be uncontroversial examples of it, while explicitly disavowing any definitional commitment to immateriality, introspective infallibility, irreducibility, etc. (final MS version). Did Frankish mean to deny the existence of phenomenal consciousness in that sense?

In one important respect, I should say, definition by example is necessarily substantive or commissive: Definition by example cannot succeed if the examples are a mere hodgepodge without any important commonalities. Even if there isn't a single unifying essence among the examples, there must at least be some sort of "family resemblance" that ordinary people can latch on to, more or less.

For instance, the following would fail as an attempted definition: By "blickets" I mean things like: this cup on my desk, my right shoe, the Eiffel tower, Mickey Mouse, and other things like those; but not this stapler on my desk, my left shoe, the Taj Mahal, Donald Duck, or other things like those. What property could the first group possibly possess, that the second group lacks, which ordinary people could latch onto by means of contemplating these examples? None, presumably (even if a clever philosopher or AI could find some such property). Defining "consciousness" by example requires there to be some shared property or family resemblance among the examples, which is not present in things we normally regard as "nonconscious" (early visual processing, memories stored but not presently considered, and growth hormone release). The putative examples cannot be a mere hodge-podge.

Definition by example can be silent about what descriptive features all these conscious experiences share, just as a definition by example of "furniture" or "games" might be silent about what ties those concepts together. Maybe all conscious experiences are in principle introspectively reportable, or nonphysical, or instantiated by 40 hertz neuronal oscillations. Grant first that consciousness exists. Argue about these other things later.

In his reply to my commentary, Frankish accepts the existence of "phenomenal consciousness" as I have defined it -- which is really (I think) more or less how it is already defined and ought to be defined in the recent Anglophone "phenomenal realist" tradition. (The "phenomenal" in "phenomenal consciousness", I think, serves as a usually unnecessary disambiguator, to prevent interpreting "consciousness" as some other less obvious but related thing like explicit self-consciousness or functional accessibility to cognition.) If so, then Frankish is saying something less radical than it might at first seem when he rejects the existence of "phenomenal consciousness".

So is consciousness an illusion? No, not if you define "consciousness" as you ought to.

Maybe my dispute with Frankish is mainly terminological. But it's a pretty important piece of terminology!

[image source, Pinna et al 2002, The Pinna Illusion]

Paraphenomenal Experience: Conscious Experience Uncorrelated with Cognition and Behavior

My student Alan T. Moore defends his dissertation today. (Good thing we proved he exists!) One striking idea from his dissertation is that much of our consciousness might be, in his terminology, paraphenomenal. A conscious experience is paraphenomenal to the extent it is uncorrelated with cognitive and behavioral processes. (That's my own tweaking of his formulation, not quite how Alan phrases it himself.)

Complete paraphenomenality is a possibility so bizarre and skeptical that I'm unaware of any philosopher who has seriously contemplated it. (It seems likely, though, that someone has, so I welcome references!) Complete paraphenomenality would mean having a stream of experience that was entirely uncorrelated with any functional, cognitive, or sensory input and entirely uncorrelated with any functional, cognitive, or behavioral output (including introspective self-report). Imagine laying the stream of William James's conscious experience atop the behavior and cognitive life of Moctezuma II, or atop a stone -- simply no relationship between the non-phenomenal aspects of one's cognitive life and one's outward behavior (or lack of it) and the stream of lived experience. Or imagine taking the philosophical zombie scenario and instead of denying the zombies any experience, randomly scramble which body has which set of experiences, while holding all the physical and behavioral stuff constant in each body.

Paraphenomenal is not the same as epiphenomenal. Epiphenomenalism about consciousness is the view that conscious experience has no causal influence, the view that consciousness is a causal dead-end. But most epiphenomenalists believe, indeed emphasize, that conscious experience still correlates with causally efficacious brain processes. On paraphenomenalism, in contrast, there aren't even correlations.

Complete paraphenomenalism is about as implausible a philosophical view as one is likely to find. However, partial paraphenomenalism has some plausibility as an interpretation of recent empirical evidence, from Moore and others. Partial paraphenomenalism is the view that the correlations between conscious experiences and cognitive processes are weaker and more limited than one might otherwise expect -- that, for example, presence or absence of the conscious experience of visual imagery is largely irrelevant to performance on the types of cognitive tasks that are ordinarily thought to be aided by imagery. If so, this would be one way to explain empirical results suggesting that self-reported visual imagery abilities are largely uncorrelated with performance on "imagery" tasks like mental rotation and mental folding. (See my discussion here and in Ch. 3 of my 2011 book.)

Especially strikingly to me are the vast differences in the experiences that people report in Russell T. Hurlburt's Descriptive Experience Sampling (e.g., here, here, here, here). Hurlburt "beeps" people at random moments throughout their day. When the beep sounds, their task is to recall their last moment of experience immediately before the beep. Hurlburt then later interviews them about details of the targeted experience. Some of Hurlburt's participants report conscious sensory experiences in almost all of their samples, while others almost never report sensory experiences. Some of Hurlburt's participants report inner speech in almost all of their samples, while others almost never report inner speech. Similarly for emotional feelings, imageless or "unsymbolized" thinking, and visual imagery -- some participants report these things in almost every sample, others never or almost never. Huge, huge differences in the general reported arc of experience! When functional cognitive capacities vary that much between people, it's immediately obvious (e.g., blind people vs. sighted people). But no such radical differences are evident among most of Hurlburt's participants. Participants often even surprise themselves. For example, it's not uncommon for people to initially say, before starting the sampling process, that they experience a stream of constant inner speech, but then report few or no instances of it when actually sampled.

In his dissertation, Moore finds very large differences in people's reported experiences while reading (some of the preliminary data were reported here), but those reported experiential differences don't seem to predict performance in plausibly related cognitive tasks like recall of visual details from the story (for people reporting high visual imagery), rhyme disambiguation (for people reporting hearing the text in inner speech), or recall of details of the visual layout of the text (for people reporting visually experiencing the words on the page in front of them).

When faced with radical differences in experiential report that are largely uncorrelated with the expected outward behavior or cognitive skills, we seem to have three interpretative choices:

1. We could decide that the assumed functional relationship shouldn't have been expected in the first place. For example, in the imagery literature, some researchers decided that it was a mistake to have expected mental rotation ability to correlate with conscious visual imagery. Conscious visual imagery plays an important causal functional role in cognition, just not that role.

2. We could challenge the accuracy of the subjective reports. This has tended to be my approach in the past. Maybe people who deny having visual sensory experience of the scene before them in Hurlburt's and Moore's data really do have sensory experience but either forget that experience or fail to understand exactly what is being asked.

3. We could adopt partial paraphenomenalism about the experience. Maybe people really are radically different in their streams of experience while reading, or while going about their daily life, but those differences have little systematic relationship to the remainder of their cognition or behavior (apart from their ability to generate reports). I wouldn't initially have been much attracted to this idea, but I now think it's an important option to keep explicitly on the table. Alan Moore's dissertation builds an interesting case!

[image source]

Introspective Attention as Perception with a Twist

Tomorrow I'm off to the Pacific APA in San Francisco. Thursday 4-6 I'm commenting on Wayne Wu's "Introspection as Attention and Action". This post is adapted from those comments.

(Also Wed 6 pm I'm presenting my paper "A Pragmatic Approach to the Metaphysics of Belief" and Sat 6-9 I'm critic in an author-meets-critics on Jay Garfield's Engaging Buddhism. Feel free to stop by!)

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What does introspective attention to one's perceptual experiences amount to? As I look at my desk, I can attend to or think about my ongoing sensory experiences, reaching judgments about their quality or character. For example, I'm visually experiencing a brownish, slightly complicated oblong shape in my visual periphery (which I know to be my hat). I'm having auditory experience of my coffee-maker spitting and bubbling as it brews the pot. What exactly am I doing, in the process of reaching these judgments?

One thing that I'm not doing, according to Wayne Wu, is launching a new process, distinct from the perceptual processes of seeing the hat and hearing the coffee-maker, which turns an "attentional spotlight" upon those perceptual processes. Introspective attention, Wu argues -- and I agree -- is a matter of applying phenomenal concepts in the course of ordinary perceiving, with the goal of arriving at a judgment about your perceptual experience -- doing so in a way that isn't radically different from the way in which, according to your goals, you can aim to categorize the things you perceive along any of several different dimensions.

I hope the following is a Wu-friendly way of developing the idea. Suppose you're looking at a coffee mug. You can do so with any of a variety of perceptual goals in mind. You can look at it with the aim of noticing details about its color -- its precise shade and how consistent or variable its color is across its face. You can look at it with the aim of noticing details of its shape. You can look at it with the aim of thinking about how it could effectively be used as a weapon. You can look at it with a critical aesthetic eye. Each of these aims is a way of attending differently to the mug, resulting in judgments that employ different conceptual categories.

You can also look at the mug with an introspective aim, or rather with one of several introspective aims. You can look at the mug with the aim of reaching conclusions about what your visual experience is as you look at the mug rather than with the aim of reaching conclusions about the physical mug itself. You might be interested in noticing your experience of the mug's color, possibly distinct from mug's real color. According to Wu, this is not a process radically different from ordinary acts of perception. Introspection your visual experience of the color or shape of the mug is not a two-stage process that consists of first perceiving the mug and then second of introspecting the experiences that arise in the course of that perceptual act.

The approach Wu and I favor is especially attractive in thinking about what the early introspective psychologists E.B. Titchener and E.G. Boring called "R-error" or "stimulus error". Imagine that you're lying on your stomach and an experimenter is gently poking the bare skin of your back with either one or two toothpicks. You might have one of two different tasks. An objective task would be to guess whether you are being poked by only one toothpick or instead by both toothpicks at once. You answer with either "one" or "two". It's easy to tell that you're being poked by two if the toothpicks are several centimeters apart, but once they are brought close enough together, the task becomes difficult. Two toothpicks placed within a centimeter of each other on your back are likely to feel like only a single toothpick. The objective task would be to guess how many toothpicks you are being poked with in reality.

An introspective task might be very similar but with a crucial difference: You are asked to report whether you have tactile experience of two separate regions of pressure or only one region. Again you might answer "one" or "two". This is of course not the same as the objective task. You're reporting not on facts about the toothpicks but rather on facts about your experience of the toothpicks. The objective task and the introspective task have different truth conditions. For example if two toothpicks are pressed to your back only 6 millimeters apart and you say "one" you've given the wrong answer if your task is objective but quite possibly the right answer if your task is introspective.

[Edwin G. Boring in 1961]

Here's the thing that Titchener and Boring noticed, which they repeatedly warn against in their discussions of introspective methodology: People very easily slide back and forth between the introspective task and the objective task. It's not entirely natural to keep them distinct in your mind over the course of a long series of stimuli. You might be assigned the introspective task, for example, and start saying "one", "one", "two", "one", "two", "two", "two" -- at first your intentions are clearly introspective, but then by the thirtieth trial you have slipped into the more familiar objective way of responding and you're just guessing how many toothpicks there actually are, rather than reporting introspectively. If you've slipped from the introspective to the objective mode of reporting, you've committed what Titchener and Boring call stimulus error.

For Wu's and my view, the crucial point is this: It's very easy to shift unintentionally between the two ways of deploying your perceptual faculties. In fact I'm inclined to think -- I don't know if Wu would agree with me about this -- that for substantial stretches of the experiment your intentions might be vague enough that there's no determinate fact about the content of your utterances. Is your "one" really a report about your experience or a report about the world outside? It might be kind of muddy, kind of in-between. You're just rolling along not very thoughtful of the distinction. What distinguishes the introspective judgment from the perceptual judgment in this case is a kind of minor thing about your background intentions in making your report.

Introspection of perceptual experience is perception with a twist, with an aim slightly different from the usual aim of reporting on the outside world. That's the idea. It's not a distinct cognitive process that begins after the perceptual act ends, ontologically distinct from the perceptual act and taking the perceptual act as its target.

When you know that your experience might be misleading, the difference can matter to your reporting. For example, if you know that you're pretty bad at detecting two toothpicks when they're close together and you have reason to think that lots of the trials will have toothpicks close together, and if your focus is on objective reporting, you might say: "Well, 50-50% -- might be one, might be two for all I know". For introspective reporting, in contrast, you might say something like "Sure feels like one, though I know you might well actually be touching me with two".

In visual experience, noticing blurriness is similar. Take off your glasses or cross your eyes. You know enough about the world to know that your coffee mug hasn't become objectively vague-edged and blurry. So you attribute the blurriness to your experience. This is a matter of seeing the world and reaching judgments about your experience in the process. You reach an experiential judgment rather than or in addition to an objective judgment just because of certain background facts about your cognition. Imagine someone so naive and benighted as to think that maybe actual real-world coffee mugs do in fact become vague bordered and blurry edged when she takes off her glasses. It seems conceivable that we could so bizarrely structure someone's environment that she actually came to adulthood thinking this. That person might then not know whether to apply blurriness to the outward object or to her experience of the object. It's a similar perceptual act of looking at the mug, but given different background concepts and assumptions in one case she reaches an introspective attribution while in the other case she reaches an objective attribution.

[image source]

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Related:

"Introspection, What?" (2012), in D. Smithies and D. Stoljar, eds., Introspection and Consciousness (Oxford). My own positive account of the nature of introspection.

"Introspection". My Stanford Encyclopedia review article on theories of introspection.

"The Problem of Known Illusion and the Resemblance of Experience to Reality" (2014), Philosophy of Science 81, 954-960. Puzzlement and possible metaphysical juice, arising from reflections on the weird relation between objective and introspective reporting.

Phenomenal Consciousness, Conceptualized as Innocently as I Can Manage

I've been reading Keith Frankish recently. For example, this. Frankish appears to deny the reality of phenomenal consciousness, a.k.a. "qualia" or "what-it's-like-ness".

"Phenomenal consciousness" does sound like a bit of a suspicious concept. The terminology is technical and recent, for one thing. That invites the idea that phenomenal consciousness is a new concept invented by philosophers, and culturally specific. And that in turn invites the idea that in talking about it, we're talking about some odd sort of theoretical concoction, not a foundationally important aspect of human life.

Furthermore, philosophers wax oddly mysterious when they talk about it. Sometimes they say that it can't be defined, only gestured at or expressed via synonyms. Ned Block, borrowing a phrase about jazz from Louis Armstrong, tells us ("only half in jest"): "If you got to ask, you ain't never gonna get to know" (1978/1983, p. 241).

Despite all this air of mystery, I think the idea of phenomenal consciousness is simple and obvious, once you stop to think about it -- and probably would be so across cultures (though I'll admit that's speculative).

You have sensory experiences. Of course you do. Maybe you have the experience of seeing a computer screen. Maybe you have the experience of hearing someone making noise down the hall. Maybe you have the experience of the taste of coffee lingering in your mouth. Consider some vivid and obvious ones.

You have imagery experiences too. Imagine your house, as viewed from the street, if you can. Or think of the melody of Beethoven's Fifth ("da da da DA, da da da DA"). Or say this very sentence silently to yourself in inner speech.

You've had emotional experience also, I'm sure -- panics of fear, thrills of joy, the quiet pleasure of mellow contentment.

This isn't necessarily an exhaustive list of types of experience, but I think this is enough to give you the idea. There's something that sensory experiences, imagery experiences, and emotional experiences have in common. They're experiences. Dream experiences have this too (even though in some sense you're not "conscious"). At the same time, there are other things going on inside of you that you don't in the same way experience -- immune system response, for example, or the processes by which your fingernails grow. There are also other facts about your mind which you don't normally experience, such as your propensity to say "blue" when asked your favorite color (and let's assume that you aren't being asked right now), or your general, not-currently-relevant preference for vanilla over chocolate. Sensory, imagery, and emotional experiences have something obvious in common, which makes them different from all these other things. The term "phenomenally conscious" refers to that obvious feature they have in common. When you try to describe these experiences to someone else, there are facts about what those experiences are, facts that you are trying to get right -- facts that you might feel like you are struggling to put into words.

Neologism is helpful here not, I think, because the concept is new or strange but rather because folk usage is messy. "Experience" can mean that you've acquired some skills or undergone some events in the past, as in the phrase "I have some teaching experience". The words "consciousness" and "awareness" invite trouble if we hear too much of an epistemic dimension in them: To say that one is conscious of something or aware of something seems to imply that you know something about it, but we might not want to build any suggestions of transitive knowledge into our concept of consciousness. Personally, I like the phrases "conscious experience" and "stream of experience". I think those phrases convey the idea well enough. But for extra clarity, among those philosophers who like to make fine distinctions, the phrase "phenomenal consciousness" also serves.

Frankish suggests, in his 2012 article linked above (I'm not sure he's still committed to this), that demonstrative definitions of phenomenal consciousness by means of example -- that is, definitions of the sort I've just tried -- must fail because philosophers have different accounts of the underlying nature of such things (for example, some philosophers think we are directly aware of properties of our experiences, while others think that at least in sensory experience we are instead directly aware only of the properties of outward objects); but as Frankish acknowledges, disagreement about the fundamental nature of things is compatible with referring to them in common -- as for example ancient people and modern astronomers were both able to refer to "stars". Pushing farther, Frankish endorses Gareth Evans's view that identification of spatio-temporal particulars requires being able to track them in egocentric space; but that's quite a dubious commitment to take on board, especially in this context.

Frankish suggests -- and also Jay Garfield, in his recent book on Buddhist philosophy -- that the modern philosophical concept of phenomenal consciousness imports dubious notions, such as ineffability or infallible knowability or immateriality, which make it fail as a concept. But I don't see how a bare demonstrative account of the sort I've given, in terms of positive and negative examples, involves any such dubious philosophical commitments. Of course, one could define "qualia" or "phenomenal properties" in a way that commits to such matters, and sometimes philosophers do so, but my own aim is to avoid such commitments, keeping open as much as possible, while still pointing at the obvious thing that all conscious experiences have in common that makes us want to classify them together as "conscious experiences".

There are, I think, two main issues that I do not keep open. One is that there is some obvious common feature of most or all of the intended positive examples have (the various sensory experiences, imagery experiences, and emotional experiences) and which the negative examples lack, which we can take to be the target of the phrase "phenomenal consciousness". The other is that there are facts about what these experiences are, which in our introspective reports we are trying to get at. These assumptions are not entirely philosophically innocent; but I hope they are plausible enough. I can't make do with fewer.

There is one further thing that I will commit to here, of some philosophical significance. It's kind of the flip side of openness. If I have succeeded in conceiving of phenomenal consciousness with a high degree of metaphysical innocence, then there ought to be nothing built into the notion of phenomenal consciousness that rules out various wild metaphysical views such as idealism (the view that only mental things exist, and not anything material) or even radical solipsism (the view that the only thing that exists in the universe is my own mind). And indeed, I do think that there's nothing incoherent in the supposition that there might only be phenomenal consciousness and nothing else. Some philosophers -- maybe Frankish and Garfield among them? -- would like to rule out idealism from square one, would like to say that the very idea of mentality already presupposes the idea of something beyond the mental, so that idealism, and maybe also less radical views like dualism, are conceptually incoherent. If my minimalist conception of phenomenal consciousness is correct, however, there is no such easy path to the rejection of those metaphysical positions.

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