Consciousness Science & The Emperor’s Arrival

Things have been hectic around here because I have been teaching 4 classes (4 preps) in our short 6-week winter session. It is almost over, just in time for our Spring semester to start! Even so February has been nice with a couple of publications coming out.

The first is Opportunities and Challenges for a Maturing Science of Consciousness. I was very happy to see this piece come out in Nature Human Behavior. Matthias Michel, Steve Flemming, and Hakwan Lau did a great job of co-ordinating the 50+ co-authors (Open access viewable pdf here). As someone who was around as an undergraduate towards the beginning of the current enthusiasm for the science of consciousness it was quite an honor to be included in this project!

In addition to that Blockheads! Essays on Ned Block’s Philosophy of Mind and Consciousness is out! This book has a lot of interesting papers (and replies from Ned) and I am really looking forward to reading it.

fullsizeoutput_62c0

 

Hakwan Lau and I wrote our contribution back in 2011-2012  and a lot has happened in the seven years since then! Of course I had to read Ned’s response to our paper first and I will have a lot to say in response (we actually have some things to say about it in our new paper together with Joe LeDoux) but for now I am just happy it is out!

Ian Phillips on Simple Seeing

A couple of weeks ago I attended Ian Phillips’ CogSci talk at CUNY. Things have been hectic but I wanted to get down a couple of notes before I forget.

He began by reviewing change blindness and inattentional blindness. In both of these phenomena subjects sometimes fail to recognize (or report) changes that occur right in front of their faces. These cases can be interpreted in two distinct ways. On one interpretation one is conscious only of what what is able to report on, or attend to. So if there is a doorway in the background that is flicking in and out of existence as one searches the two pictures looking for a difference and when one is asked one says that they see no difference between the two pictures one does not consciously experience the door way or its absence. This is often dubbed the ‘sparse’ view and it is interpreted as the claim that conscious perception contains a lot less detail in it than we naively assume.

Fred Dretske was a well known defender of a view on which distinguishes two components of seeing. There is what he called ‘epistemic seeing’ which, when a subject sees that p, “ascribes visually based knowledge (and so a belief) to [the subject]”. This was opposed to ‘simple seeing’ which “requires no knowledge or belief about the object seen” (all quoted material is from Phillips’ handout). This ‘simple seeing’ is phenomenally conscious but the subject fails to know that they have that conscious experience.

This debate is well known and been around for a while. In the form I am familiar with it it is a debate between first-order and higher-order theories of consciousness. If one is able to have a phenomenally conscious experience in the absence of any kind of belief about that state then the higher-order thought theory on which consciousness requires a kind of higher-order cognitive state about the first-order state for conscious perception to occur, is false. The response developed by Rosenthal, and that I find pretty plausible, is that in change blindness cases the subject may be consciously experiencing the changing element but not conceptualize it as the thing which is changing. This, to me, is just a higher-order version of the kinds of claims that Dretske is making, which is to say that this is not a ‘sparse’ view. Conscious perception can be as rich and detailed as one likes and this does not require ‘simple seeing’. Of course, the higher-order view is also compatible with the claim that conscious experience is sparse but that is another story.

At any rate, Phillips was not concerned with this debate. He was more concerned with the arguments that Dretske gave for simple seeing. He went through three of Dretske’s arguments and argued that each one had an easy rejoinder from the sparse camp (or the higher-order camp). The first he called ‘conditions’ and involved the claim that when someone looks at a (say) picture for 3-5 minutes scanning every detail to see if there is any difference between the two, we would ordinarily say that they have seen everything in the two pictures. I mean, they were looking right at it and their eyes are not defective! The problem with this line of argument is that it does not rule out the claim that they unconsciously saw the objects in question. The next argument, from blocking, meets the same objection. Dretske claims that if you are looking for your friend and no-one  is standing in front of them blocking them from your sight, then we can say that you did see your friend even if you deny it. The third argument involved that when searching the crowd for your friend you did saw no-one was naked. But this meets a similar objection to the previous two arguments. One could easily not have (consciously) seen one’s friend and just inferred that since you didn’t see anyone naked your friend was naked as well.

Phillips then when on to offer a different way of interpreting simple seeing based on signal detection theory. The basic intuition for simple seeing, as Phillips sees it, lies in the idea that the visual system delivers information to us and then there is what we do with the information. The basic metaphor was a letter being delivered. The delivery of the letter (the placing of it into the mailbox) is one thing, you getting the letter and understanding the contents, is another. Simple seeing can then be thought of as the informative part and the cognitive noticing, attending, higher-order thought, etc, can be thought of as a second independent stage. Signal detection theory, on his view, offers a way to capture this distinction.

Signal detection theory starts with treating the subject as an information channel. They then go on to quantify this, usually by having the subject perform a yes/no task and then looking at how many times they got it right (hits) versus how many times the got it wrong (false alarms). False alarms, specifically, involve the subject saying the see something but being wrong about it, because there was no visual stimulus. This is distinguished from ‘misses’ where there was a target but the subject did not report it. The ‘sensitivity to the world’ is called d’, pronounced “d prime”. On top of this there is another value which is computed called ‘c’. c, for criterion, is thought of as measuring a bias in the subjects response and is typically computed from the average of hits versus false alarms. One can think of the criterion as giving you a sense of how ‘liberal’ or ‘conservative’ the subjects’ response is. If they will say they saw something all the time then the seeming have a very liberal criterion for determine whether they saw something (that is to say they are biased towards saying ‘yes I saw it’ and is presumably mistaking noise for a signal). If they never say the say it then they are very conservative (they are biased towards saying ‘no I didn’t see it). This gives us a sense of how much of the noise in the system the subject treats as actually carrying information.

The suggestion made by Phillips was that this distinction could be used to save Dretske’s view if one took d’ to track simple seeing and c to track they subjects knowledge. He then went on to talk about empirical cases. The first involved memory across saccades and came from Hollingworth and Henderson, Accurate Visual Memory for Previously Attended Objects in Natural Scenes, the second f rom Mitroff and Levin Nothing Compares 2 Views: Change Blindness can occur despite preserved access to the changed information, and the third Ward and Scholl Inattentional blindness reflects limitation on perception, not memory. Each of these can be taken to suggest that there is “evidence of significant underlying sensitivity in [change blindness] and [inattentional blindness],”.

He concluded by talking about blindsight as a possible objection. Dretske wanted to avoid treating blindsight as a case of simple seeing (that is of there being phenomenal consciousness that the subject was unaware (in any cognitive sense) of having). Dretske proposed that what was missing was the availability of the relevant information to act as a justifying reason for their actions. He then went on to suggest various responses to this line of argument. Perhaps blindsight subjects who do not act on the relevant information (say by not grabbing the glass of water in the area of their scotoma) are having the relevant visual experience but are simply unwilling to move (how would we distinguish this from their not having the relevant visual experience)? Perhaps blindsight patients can be thought of as adjusting their criterion and so as choosing the interval with the strongest response and if so this can be thought of as reason responsive. Finally, perhaps, even though they are guessing, they really can be thought of as knowing that the stimulus is there?

In discussion afterwards I asked whether he though this line of argument was susceptible o the same criticism he had leveled against Dretske’s original arguments. One could interpret d’ as tracking conscious visual processing that the subject doesn’t know about, or one could interpret it as tracking the amount of information represented by the subjects mental states independently of what the subject was consciously experiencing (at leas to some extent). So, one might think, the d’ is good so the subject represents information about the stimulus that is able to guide its behavior, but that may be going on while the subject is conscious of some of it but not all of it, or different aspects of it, etc. So there is no real reason to think of d’ as tracking simple (i.e. unconceptualized, unnoticed, uncategorized, etc) content that is conscious as opposed to non-conscious. He responded that he did not think that this constituted an argument. Rather he was trying to offer a model that captured what he took to be Dretske’s basic intuition, which was that there was the information represented by the visual system, which was conscious, and then there was the way that we were aware of that information. This view was sometimes cast as unscientific and he thought of the signal detection material as proving a framework that, if interpreted in the way he suggested, could capture, and thus make scientifically acceptable, something like what Dretske (and other first-order theorists) want.

There was a lot of good discussion, a lot of which I don’t remember, but I do remember Ned Block asking about Phillips’ response to cases like the famous Dretske example of a wall, painted a certain color, having a piece of wallpaper in one spot. The little square of wallpaper has been painted and so is the same color as the wall. If one is looking at the wall and doesn’t see that there is a piece of wallpaper there, does one see (in the simple seeing kind of way) the wallpaper? Phillips seemed to be saying we did (but didn’t know it) and Block asked whether it wasn’t the case that when we se something we represent it visually and Phillips responded by saying that on the kind of view he was suggesting that wasn’t the case. Block didn’t follow up and didn’t come out after so I didn’t get the chance to follow up on that interesting change.

Afterwards I pressed him on the issue I raised. I wondered what he thought about the kinds of cases, discussed by Hakwan Lau (and myself) where the d’ is matched but subjects give differing answers to questions like ‘how confident are you that you saw it?’ or ‘rate the visibility of the thing seen’. In those cases we have, due to matched d’, the same information content (worldly sensitivity) and yet one subject says they are guessing while the other says they are confident they saw it (or rates its visibility lower while the other rates it higher (so as more visible)). Taking this seriously seems to suggest that there is a difference in what it is like for these subjects (a difference in phenomenal consciousness) while there is no difference in what they represent about the world (so at the first-order level). The difference in what it is like for them seems to track the way in which they are aware of the first-order information (as tracked by their visibility/confidence ratings). If so then this suggests that d’ doesn’t track phenomenal consciousness. Phillips responded by suggesting that there may be a way to talk about simple seeing involving differences in what it is like for the subject but didn’t elaborate.

I still am not sure how he responds to the argument Hakwan and I have given. If there is differing conscious experience with the same first-order states each in each case then the difference in conscious experience can only be captured (or is best captured) by some kind of difference in our (higher-order) awareness of those first-order states.

In addition, now that I have thought about it a bit, I wonder how he would respond to Hakwan’s argument (more stemming from his own version of higher-order thought theory) that the setting of the criterion in Phillips’ appeal to it in blindsight cases, depends on a higher-order process and so amounts to a cognitive state having a constitutive role in determining how the first-order state is experienced. This suggests that an ‘austere’ notion of simple seeing where there is no cognitive states involved in phenomenal consciousness is harder to find than Phillips originally thought.

Recent Events

Well, the semester at LaGuardia is finally coming to a close (our schedule is out of step with the rest of CUNY). A lot has been going on and I have barely had time to do anything but since today is our reading day and I have a brief break before final exams come in, I thought I would quickly talk about what has been going on.

My new course, Cosmology, Consciousness, and Computation was a huge success and the students really seemed to enjoy the chance to take these kinds of questions seriously. The basic idea behind the course is to explore issues related to physicalism but after a grounding in the actual physics. My experiment to use the Stanford Encyclopedia as a primary text seemed to work ok as well. Some of the readings are fairly technical but I gave students the choice of which to read and which to write a one page summary/reaction to. They also seemed to like the Terminator book, which was nice. This is the first time I have used it in a class. I am toying with the idea of maybe recording the lectures for this course over the summer as I prepare to teach it again next semester (but I am also teaching philosophy of religion and ethics over the summer and I am tempted to record my philosophy of religion as well…they do overlap a bit so maybe I’ll do both!). For those interested, here is the syllabus. As with any new class I expect to update a lot of it in light of what happened this semester and any feedback would be appreciated.

All of that will have to wait until later in July, though, since I am currently getting ready for my trip to San Diego for the 17th meeting of the Association for the Scientific Study of Consciousness (ASSC). This year I have organized a symposium on the Role of the Prefrontal Cortex in Conscious Experience. The speakers are Rafi Malach, Joe Levine, Doby Rahnev, and myself. I am really looking forward to it, as well as to the rest of the program! I am hoping to post a video of my talk in the nearish future.

I have also been working on a new paper, which came out of discussion at the 5th Online Consciousness Conference. It is entitled Consciousness is (Probably) a Biological Phenomenon. Those who know me know that I am attracted to an identity theory when it comes to consciousness and that I harbor the suspicion that consciousness is a uniquely biological phenomenon. This paper is my first attempt to spell out an answer to Chalmers’ fading and dancing qualia arguments using empirical results (in particular the partial report results that have figured in the overflow debate (see here and here)). It is extremely drafty (I have been working on it an hour here and hour there for the last few weeks) and any feedback would be much appreciated.

In addition to all of this I have just returned from my trip to the Omaha Kripke Conference (during which I was also on my first dissertation committee at the Grad Center, which was very much fun but then I also had to read and think about a dissertation!), which was a really rewarding experience. Omaha is a wonderful town and the conference itself was excellent, if exhausting. Three days of excellent papers and excellent discussion, and it was very cool to see Saul so active and engaging with the material. Unfortunately, due to bad weather, he came late and so he missed my talk but there was none the less a lot of very helpful discussion. The main objection was Dan Shargel’s ‘hierarchy objection’ which he presented at Tucson last year (the basic idea is that we can move the argument up to the level of appearance and imagine that we have that appearance without the neural state, etc). I have got to get better at explaining what my answer to that objection is. After the discussion at the conference I have come to think that the main problem is that we are using ‘how pain appears to me’ as a way to pick out two different states, one a psychological state and the other a neural state. On the one hand we use it to pick out the pain sensations, that is the first-order sensing of bodily damage. But we can also use it to pick out the neural state that the appearance is identical to (note: not the neural state that the sensation is identical to, but the neural state that is identical to the awful painfulness appearance. We can use the appearance property as a way to pick out that state itself). It is in that second sense that we avoid the charge of regress. This takes some spelling out to make sense of it and I am hoping to write something more detailed on it in the nearish future (hopefully before I head out to the ASSC).

During and after one of the other sessions I had the chance to talk to Saul about his 1963 paper Semantical Considerations on Modal Logic, which I have discussed previously on the blog. When I suggested that it was a cost to one’s theory to give up logical constants in your quantified modal logic he insisted that it was not. This was because for any sentence with a logical constant in it we could translate it into a sentence without the constant without loss of meaning using Quine’s trick of inventing a predicate. This led me to wonder whether this made it the case that we could reformulate the bothersome proofs using translated sentences. At the time I wasn’t able to come with a way to do this but once I got home I thought about it a bit more and came up with the following.

In the original reductio we used this sentences ☐∃x(x=k), where this is read as ‘there exists an x such that x is identical to Saul Kripke’. How would we translate this sentence to get rid of the constant? We would replace the constant with a predicate, say ‘K’ (‘the Kripisizer’) and thus we would get ☐∃x(x=Ky) but this has a free variable in it so we would have to take it as asserting the ‘closed’ version, so we get ∀y☐∃x(x=Ky). We can then proceed to prove this in the same way as before using a reductio

1. ~∀y☐∃x(x=Ky) -assumption for reductio
2. ∃y~☐∃x(x=Ky) -1, quantifier exchange
3. ∃y◊~∃x(x=Ky) -2, definition of ☐
4. ∃y◊∀x~(x=Ky) -3, quantifier exchange
5. ∃y◊~(Ky=Ky) -Universal instantiation on 4
6. ∀y☐(Ky=Ky) -instance of axiom of identity
7. ~∃y~☐(Ky=Ky) -6, quantifier exchange
8. ~∃y◊~(Ky=Ky) -7, definition of ☐
9. ∃y◊~(Ky=Ky) & ~∃y◊~(Ky=Ky) -4,8 -conjunction introduction
10. ∀y☐∃x(x=Ky) -1-9 reduction

I think the main issue with this reformulated proof is line 5 when I use ‘Ky’ as an instance of x in 4. It seems to me that this move should be allowed, though. This is because part of the whole point of the 1963 paper was that we could block these kinds of proofs and still keep our traditional quantification theory. So we should be able to use UI, but if we are not allowed the use of constants then we will have to use predicates, which is what I did. Also, the variable in 5 is not free and is bound by the existential quantifier. So all in all I think this reformulated proof works but I really haven’t had the time to think about it very carefully.

Well that is enough for now…time to head over to Brains to read some of the commentaries in the Symposium on Louise Richardson’s “Flavor, Taste and Smell”.

Zombies vs Shombies

Richard Marshall, a writer for 3am Magazine, has been interviewing philosophers. After interviewing a long list of distinguished philosophers, including Peter Carruthers, Josh Knobe, Brian Leiter, Alex Rosenberg, Eric Schwitzgebel, Jason Stanley, Alfred Mele, Graham Priest, Kit Fine, Patricia Churchland, Eric Olson, Michael Lynch, Pete Mandik, Eddy Nahmais, J.C. Beal, Sarah Sawyer, Gila Sher, Cecile Fabre, Christine Korsgaard, among others, they seem to be scraping the bottom of the barrel, since they just published my interview. I had a great time engaging in some Existential Psychoanalysis of myself!

The Brain and its States

Some time ago I was invited to contribute a paper to a forthcoming volume entitled Being in Time: Dynamical Models of Phenomenal Experience. I was pleasantly surprised to find out that I was invited because of my paper “What is a Brain State?” Looking back at that paper, which I was writing in 2004-2005, I was interested in questions about the Identity Theory and not so much about consciousness per se and I wished I had said something relating the thesis there to various notions of consciousness. So I was happy to take this opportunity to put together a general statement of my current views on this stuff as well as a chance to develop some of my recent views about higher-order theories. Overall I think it is a fairly decent statement of my considered opinion on the home of consciousness in the brain. Any comments or feedback is greatly appreciated!

The Overflow Cup Runneth Over

There has been a lot of action on the overflow front lately! It started with papers by Ned Block and Dennett and Cohen in Trends in Cognitive Science (Block’s paper criticized, among others, my recent paper on this stuff). These articles spawned a response by me here and here, which I still stand by.

But now, having read the response from Kouider (which echoes his response given at his CUNY Cogsci talk) as well as the response from Overgaard and Block’s response to both of them in addition to Lamme’s response to Cohen and Dennett and their response in turn, it seems a couple points should be emphasized.

Accessed vs. Accessible
Block again and again says that his argument does not depend on inaccessible consciousness but rather on it being necessary that at any given moment there is some consciousness that is not accessed (but could be accessed at a different moment and so is not inaccessible tout court). There seem to me to be several issues worth considering here.

First is that there is a conceptual question about what it means to say that something is accessible but not accessed. One might think that you cannot know that something is accessible without it actually being accessed. Block and others respond that something is accessible when, roughly, it is globally broadcast. But then we might wonder why we ought to think that being globally broadcast is equivalent to being accessible. Aren’t their mental contents/states that are globally broadcast but which are not accessible? David Rosenthal has pressed this kind of question in conversation and I am not exactly sure what the neuropsychological answer is in this case. Is there any serious neuropsychological reason to think that global broadcasting is equivalent to being accessible?

Second one might worry about the ‘thin edge of the wedge’ implications of Block’s argument. If we can show that there is consciousness that is not accessed then it seems a short step to consciousness that is inaccessible in principle. And if it is true that there is a principled connection between the two then though it would be strictly speaking true that Block’s argument did not rely on inaccessible consciousness it would none the less still be appropriate to give a reductio of his argued for view in terms of absurdities in the view it leads to.

Finally, it does seem as though there is a principled connection between the two notions. Block argues that it is inappropriate to argue against the claim that there is inaccessible consciousness because he only requires that some consciousness not be accessed not inaccessible. But if one thinks just of a particular moment in consciousness leaving aside the next moment it is of course true that some consciousness is inaccessible. It is inaccessible at that moment. Block’s view is that at any given moment in your daily conscious experience there is, necessarily, some parts of your conscious experience that are inaccessible at that moment. Because of this his view really does have all of the problems associated with in principle inaccessible consciousness.

Given these considerations I don’t think that the appeal to the distinction between not accessed and inaccessible helps make Block’s case.

Kouider’s Data Count Against His Own View?
Block has said several times that Kouider’s own data counts against the no-overflow view. He says in his latest response,

According to the hypothesis Kouider et al. put forward, what is in consciousness before the cue are generic representations plus specific representations that are too sparse to provide the information necessary to explain partial report superiority. However, on their hypothesis one would expect a substantial error rate concerning the uncued items. However, Kouider et al. found the error rate to be small: their own evidence counts against them.

It really is not clear to me why Block thinks that one would expect a substantial error rate concerning the uncued items. He seems to be thinking that the no-overflow view is committed to only generic phenomenology before the cue but this is clearly not the case. It is compatible with the no overflow view that there is some specific phenomenology before the cue (just not all of the items as per overflow).

But even if one is not moved by this there is an obvious problem with the argument. The no overflow position maintains that there is enough information unconsciously processed to do the task. Subjects don’t make a lot of errors because that information was there whether consciously or not.

Falsifiability vs. Support by the Evidence
I think that Block is right that we do not want falsifiability as a=our standard here and that we need to evaluate theories holistically based on the widest swath of available evidence and theories available to us. Block thinks that there is some evidence that the kinds of unconscious processes necessary to sustain the no overflow view aren’t there. But this evidence is very weak and the jury is still out on this issue. In general the science is all over the place on this issue. There is partial evidence on both sides and no theory comes out on top on the basis of current scientific evidence alone. Hopefully this will change in the nearish future but at this point this is where it is.

Given this one might think that we should be agnostic about whether overflow is true or not but this doesn’t seem right to me. The overflow hypothesis is radical in that it postulates a kind of consciousness that cannot in principle be accessed (at that moment) and yet which is also for me in the way that normal accessed consciousness is for me. That is, I experience the unaccessed consciousness as mine without being aware that I do. How this could be so is deeply mysterious and perhaps in principle untestable with any known scientific methods. Barring prejudice in its favor we would need strong evidence indeed to accept such a notion.

Clip Show ‘011

It’s that time of year again! Here are the top posts of 2011 (see last year’s clip show and the best of all time)

–Runner Up– News Flash: Philosophy Sucks!

Philosophy is unavoidable; that is part of why it sucks!

10. Epiphenomenalism and Russellian Monism

Is Russellian Monism committed to epiphenomenalism about consciousness? Dave Chalmers argues that it is not.

9. Bennett on Non-Reductive Physicalism

Karen Bennett argues that the causal exclusion argument provides an argument for physicalism and that non-reductive physicalism is not ruled out by it. I argue that she is wrong and that the causal exclusion argument does cut against non-reductive physicalism.

8. The Zombie Argument Requires Phenomenal Transparency

Chalmers argues that the zombie argument goes through even without an appeal to the claim that the primary and secondary intension of ‘consciousness’ coincide. I argue that it doesn’t. Without an appeal to transparency we cannot secure the first premise of the zombie argument.

7. The Problem of Zombie Minds

Does conceiving of zombies require that we be able to know that zombies lack consciousness? It seems like we can’t know this so there may be a problem conceiving of zombies. I came to be convinced that this isn’t quite right, but still a good post (plus I think we can use the response here in a way that helps the physicalist who wants to say that the truth of physicalism is conceivable…more on that later, though)

6. Stazicker on Attention and Mental Paint

Can we have phenomenology that is indeterminate? James Stazicker thinks so.

5. Consciousness Studies in 1000 words (more) or less

I was asked to write a short piece highlighting some of the major figures and debates in the philosophical study of consciousness for an intro textbook. This is what I came up with

4. Cohen and Dennett’s Perfect Experiment

Dennett’s response to the overflow argument and why I think it isn’t very good

3. My Musical Autobiography

This was big year for me in that I came into possession of some long-lost recordings of my death metal band from the 1990’s as well as some pictures. This prompted me to write up a brief autobiography of my musical ‘career’

2. You might be a Philosopher

A collection of philosophical jokes that I wrote plus some others that were prompted by mine.

1. Phenomenally HOT

Some reflections on Ned Block and Jake Berger’s response to my claim that higher-order thoughts just are phenomenal consciousness