Review of The Consciousness Instinct by Michael Gazzaniga

Summer is here and I have finally started on my summer reading list. First up was Michael Gazzaniga’s new book The Consciousness Instinct. Gazzaniga is of course we’ll known for his work on split brain patients and for helping to found the the discipline of cognitive neuroscience. I was very excited to read the book but after having done so I am very disappointed. There are some interesting ideas in the book but overall it does not strike me as a serious contribution to the study of consciousness.

The book begins with the standard potted history of the mind body problem with Descartes invoked as the primary villain. It was Descartes who initiated the-brain-is-a-machine ethos and Gazzaniga thinks that is a mistake. This part of the book was well written but could be found almost anywhere. He then goes completely off the rails and invokes quantum mechanics as a non-mechanical foundation for solving the mind-body problem. In particular he invokes the notion of complementarity as his solution. According to him Quantuum mechanics tells us that a physical system can be in two different states at once (p. 175). So the brain can be a mechanical system and also a mind at the same time. No problem.

I am of course no expert on quantuum mechanics (though I have put it in a fair amount of time trying to figure it out). But as far as I understand it this is a gross misuse of the idea of complimentary. Quantum mechanics does not say that a physical system can be in two contradictory states at the same time! Rather what it says is that the state of the system *before measurement* cannot be described by classical concepts  like ‘wave’ or ‘particle’ yet once a measurement is made (and depending on the type of measurement we make) we will find that it does have one of these properties (and had we done the measurement different we would have found that it had the other property). How, then, should we think of poor Schrodinger’s cat? Isn’t the poor cat both dead and alive (as Gazzaniga says on p. 181)? Not as I understand it! When we have a vector, represented by |A> and we add it to another vector |B> then, yes,  we do get a new vector that represents the state the system has entered but saying that 1/2|Alive> + 1/2|Dead> represents the cat’s state before measurement doesn’t mean it is both dead AND alive; it means that when we measure it it will EITHER be dead OR alive (with probabilities given by the 1/2).

But what about before we measure it? What state is the cat in then? As far as I understand it quantum mechanics (i.e. the mathematical formalism) is silent on that question but the reply I prefer is that the cat has no determinate properties before the measurement.

But all of this is highly controversial and does not help us at all with the mind-body problem! Suppose, as Gazzaniga assumes, that the mind and brain are two irreducible complimentary descriptions of the single system, then we would only be able to know (i.e. measure) one of the at a time, at the expense of the other. But that is manifestly not the situation. We can measure our own brain activity even as we are having conscious experiences produced by/identical with that neural activity.  No complementarity required.

I am leaving out a lot of the details, and as I said some of his views are interesting, but what is it about consciousness that drives people to these kinds of extreme intellectual gyrations? Why do people trust their intuitions so much that they are ready to jettison all of the progress made by psychology and neuroscience as wasted time?

Consciousness Online -10 Years Later

It was way back in May of 2008 that I finally decided to try to organize an online consciousness conference. Ten years later and the conference material from the resulting five online conferences is for the most part still there. There is the inevitable link rot that creeps in and I try to keep up with it but in some cases it is unavoidable. The first conference was hit the hardest because back then I used google video which went under (and somehow I lost all of the videos I had there) and hosted papers and related material on a server I can’t access anymore (I also let the custom url lapse a while back and it is now the original A lot survives, though, and I have been glad to see people linking to it in their courses and some of the discussion (all of which is still there) has been cited in scholarly papers!

I actually had the idea for a consciousness-specific online conference in the summer of 2007, and bothered a few people about trying to get something like this going over the next year or so (I vaguely remember pitching the idea of a Kripke & Consciousness online conference to the early Kripke Center in 2007).  My experience at the Tucson consciousness conference in April of 2008 finally goaded me to act. I had just recently started blogging (happy 11th birthday to this blog by the way!) and seen the Online Philosophy Conference so I thought that was an ideal format (but with more video). People warned me that it was too much work and that the previous online philosophy conferences had not really succeeded. I thought if it was kept small it could be done, and since I was tired of waiting for someone else to do it, I set out to do it myself. I spent the summer getting ready,  announced the conference in August of 2008 and held the conference in February of 2009 (papers published in April of 2010)…a lot of work but also a lot of fun!

I organized the last one in 2013 and the final special issue I edited as a result of that came out in 2015. All in all that is seven years I invested into that project! It was a shame that I had to stop because I really enjoyed working on it and was trying to grow it into something but as I was coming up for tenure it was communicated to me that my scholarly work was excellent and that I needed to focus on contributing something to the college. In other words, another conference, and another publication was not going to help me get tenure (this is how I interpreted it anyway). So I turned my focus to organizing things at LaGuardia and I just could not do both with my teaching load (5/4 plus extra classes). I was awarded tenure in the fall of 2015 and I briefly thought about trying to revive it but by then I had kids! Plus, I have been happy to see the Brains Blog, and their Minds Online Conference (and now Neural Mechanisms Online) spring up to fill the void (by the way, here is the excellent special session for CO5 organized by John Schwenkler).

One thing I have learned is that it is possible for one person/a small group of people to make an impact but what we really need is to ‘institutionalize’ online conferences, by which I mean have them sponsored by professional organizations like the APA or the Association for the Scientific Study of Consciousness  (or the Tucson Center for Consciousness Studies, etc) but it is not clear how to do that without money entering the picture (I footed the small bill for any costs related to running Consciousness Online and everyone else worked for free!).

The thing I am most proud of is that the conferences all resulted in publications (4 journal issues and one book). My basic idea was to have the conference itself count as part of the review process. The papers were usually rewritten after discussion and then sent out for a more traditional review before finally being published (and so the result was not just a conference proceedings but a new paper sharpened by the conference (remember I was still an idealistic graduate student at the time!)). I was very lucky to have the general editor from the Journal of Consciousness Studies initially approach me about editing a special issue and I ran with it from there. A quick check of Google Scholar shows that the six resulting papers from the first conference have (mostly) done pretty well since being published in 2010.

Prefrontal Cortex, Consciousness, and…the Central Sulcus?

The question of whether the prefrontal cortex (PFC) is crucially involved in conscious experience is one that I have been interested in for quite a while. The issue has flared up again recently, especially with the defenders of the Integrated Information Theory of Consciousness defending an anti-PFC account of consciousness (as in Christof Koch’s piece in Nature). I have talked about IIT before (here, here, and here) and I won’t revisit it but I did want to address one issue in Koch’s recent piece. He says,

A second source of insights are neurological patients from the first half of the 20th century. Surgeons sometimes had to excise a large belt of prefrontal cortex to remove tumors or to ameliorate epileptic seizures. What is remarkable is how unremarkable these patients appeared. The loss of a portion of the frontal lobe did have certain deleterious effects: the patients developed a lack of inhibition of inappropriate emotions or actions, motor deficits, or uncontrollable repetition of specific action or words. Following the operation, however, their personality and IQ improved, and they went on to live for many more years, with no evidence that the drastic removal of frontal tissue significantly affected their conscious experience. Conversely, removal of even small regions of the posterior cortex, where the hot zone resides, can lead to a loss of entire classes of conscious content: patients are unable to recognize faces or to see motion, color or space.

So it appears that the sights, sounds and other sensations of life as we experience it are generated by regions within the posterior cortex. As far as we can tell, almost all conscious experiences have their origin there. What is the crucial difference between these posterior regions and much of the prefrontal cortex, which does not directly contribute to subjective content?

The assertion that loss of the prefrontal cortex does not affect conscious experience is one that is often leveled at theories that invoke activity in the prefrontal cortex as a crucial element of conscious experience (like the Global Workspace Theory and the higher-order theory of consciousness in its neuronal interpretation by Hakwan Lau and Joe LeDoux (which I am happy to have helped out a bit in developing)). But this is a misnomer or at least is subject to important empirical objections. Koch does not say which cases he has in mind (and he does not include any references in the Nature paper) but we can get some ideas from a recent exchange in the Journal of Neuroscience.

One case in particular is often cited as evidence that consciousness survives extensive damage to the frontal lobe. In their recent paper Odegaard, Knight, and Lau have argued that this is incorrect. Below is figure 1 from their paper.

Figure 1a from Odegaard, Knight, and Lau

This is brain of Patient A, who was reportedly the first patient to undergo bi-lateral frontal lobectomy.  In it the central sulcus is labeled in red along with Brodman’s areas 4, 6, 9, and 46. Labled in this way it is clear that there is an extensive amount of (the right) prefrontal cortex that is intact (basically everything anterior to area 6 would be preserved PFC). If that were the case then this would hardly be a complete bi-lateral lobectomy! There is more than enough preserved PFC to account for the preserved conscious experience of Patient A.

Boly et al have a companion piece in the journal of neuroscience and a response to the Odegaard paper (Odegaard et al responded to Boly as well and made these same points). Below is figure R1C from the response by Boly et al.

Figure R1C from response by Melanie Boly, Marcello Massimini, Naotsugu Tsuchiya, Bradley R. Postle, Christof Koch, and Giulio Tononi

Close attention to figure R1C shows that Boly et al have placed the central sulcus in a different location than Odegaard et al did. In the Odegaard et al paper they mark the central sulcus behind where the 3,1,2 white numbers occur in the Boly et al image. If Boly et al were correct then, as they assert, pretty much the entire prefrontal cortex is removed in the case of patient A, and if that is the case then of course there is strong evidence that there can be conscious experience in the absence of prefrontal activity.

So here we have some experts in neuroscience, among them Robert T. Knight and Christof Koch, disagreeing about the location of the central sulcus in the Journal of Neuroscience –As someone who cares about neuroscience and consciousness (and has to teach it to undergraduates) this is distressing! And as someone who is not an expert on neurophysiology I tend to go with Knight (surprised? he is on my side, after all!) but even if you are not convinced you should at least be convinced of one thing: it is not clear that there is evidence from “neurological patients in the first half of the 20th century” which suggests that the prefrontal cortex is not crucially involved in conscious experience. What is clear is that is seems a bit odd to keep insisting that there is while ignoring the empirical arguments of experts in the field.

On a different note, I thought it was interesting that Koch made this point.

IIT also predicts that a sophisticated simulation of a human brain running on a digital computer cannot be conscious—even if it can speak in a manner indistinguishable from a human being. Just as simulating the massive gravitational attraction of a black hole does not actually deform spacetime around the computer implementing the astrophysical code, programming for consciousness will never create a conscious computer. Consciousness cannot be computed: it must be built into the structure of the system.

This is a topic for another day but I would have thought you could have integrated information in a simulated system.

Back on the Clock

I have been on parental leave for the past eight weeks but now I am officially back to work! Since there are only four weeks left of the semester I am returning to Administrative Assignment (don’t worry, I’ll be back to teaching in the summer!). I have a lot of stuff to do and I hope to be able to write about some of it here. Updates (hopefully) to follow.

Mary, Subliminal Priming, and Phenomenological Overflow

Consider Mary, the super-scientist of Knowledge Argument fame. She has never seen red and yet knows everything there is to know about the physical nature of red and the brain processing related to color experience. Now, as a twist, suppose we show her red subliminally (say with backward masking or something). She sees a red fire hydrant and yet denies that she saw anything except the mask (say). Yet we can say that she is primed from this exposure (say quicker to identify a fire truck than a duck subsequently or something). Does she learn what it is like to see red from this? Does she know what it is like to see red and yet not know that she knows this?

It seems to me that views which accept phenomenological overflow, and allow that there is phenomenal consciousness in the absence of any kind of cognitive access, have to say that the subliminal exposure to red does let Mary learn what it is like for her to see red (without her knowing that she has learned this). But this seems very odd to me and thus seems to me that this is a kind of a priori consideration that suggests there is no overflow.

Of course I have had about 8 hours of sleep in the last week so maybe I am missing something?


Gottlieb and D’Aloisio-Montilla on Brown on Phenomenological Overflow

Last year I started to try to take note of papers that engage with my work in some way (previous posts here, here, here, here, here, here, and here). The hope was to get some thoughts down as a reference point for future paper writing. So far not much in that department has been happening; with a 3 year old and a 1 month old it is tough to find time to write (understatement!) but I am hoping I can “normalize” my schedule in the next few weeks and try to get some projects off of the back burner. At any rate I have belatedly noticed a couple of papers that came out and thought I woud quickly jot down some notes.

The first paper is one by Joseph Gottlieb and came out in Philosophical Studies in October of 2017. It is called The Collapse Argument and makes the argument that all of the currently available mentalistic first-order theories of consciousness turn out to really be versions of the higher-order theory of consciousness. I don’t know Joseph IRL (haha) but we have emailed about his papers several times, though I usually get back him too late for it to matter on account of the 16 classes a year I have been teaching since 2015 (for anyone who cares: I am contractually obligated to teach 9 a year and  in addition I teach another 7 as an adjunct (the maximum allowed by my contract)…sadly this is what is required in order for my family to live in New York! ) and I have blogged about his work here before (linked to above) but I really, really like this paper of his. First, I obviously agree with his conclusion and it is nice to see some discussion of this issue. I took some loose steps in this direction myself in the talk I gave at the Graduate Center’s Cognitive Science Speaker Series back in 2015. I thought about writing it up but then had my first son and then found out about Joseph’s paper, which is better than what I could have come up with anyway! I suppose the only place we might disagree is that I think this applies to Block’s first-order theory as well.

But even though I really like the paper there is a bit I would quibble about (but not very much). Gottlieb seems to take seriously my argument that higher-order theories are in principle compatible with phenomenological overflow but I am not sure I agree with how he puts it. He says,

As Richard Brown (2014) points out, HO theorists don’t need to claim that we are aware of our conscious states in all their respects. I might be aware that I am seeing letters (a fairly generic property) but not the identity of every letter I am seeing. In other words, I can be unaware of some of the information represented by the first- order state without the state itself being unconscious (ibid). What happens, then, is: I am phenomenally conscious of the entire 3 X  4 array, with representations of the identities of all the letters available prior to cuing. But only a small number (usually around four) ever get through, accessed by working memory. That’s overflow, and perfectly consistent with HO theory.

In the paper he is citing I was trying to make the point that the higher-order theories which deny overflow do not thereby also commit themselves to the existence of unconscious *states* which are doing heavy lifting. If the states are targeted by the appropriate higher-order representation then those states are conscious. Yet one may not represent all of the properties of the state and so, even though the state is conscious, there is information encoded in the state which you are not aware of (and so is unconscious). That unconscious information (that is to say, that aspect of the conscious state)  is (presumably) what you come to be aware of when you get the cue in the relevant experiments. So it is a bit strange to see this part of the paper cited as supporting overflow (though I do think the position is compatible with overflow I wasn’t thinking of it in this way). But I think I see his point. On the higher-order view it will true to say that one has a phenomenally conscious experience of all of the letters and the details but only access a few (even though what it is like for one may not have all of the details, which is really what I think the overflow people mean to be saying).

This point, though, is I think they key difference between higher-order theories and Global Workspace theories (which is what Block is really targeting with his argument). The basic idea behind the higher-order approach is this. When one is presented with the stimulus all or most of the details of the stimulus are encoded in first-order visual states (that is, states which represent the details of the visual scene). Let’s call the sum-total representational state S. S represents all (or most) of the letters and their specific identifies. One can have S without being aware that one is in S. In this case S is unconscious. Now suppose that one comes to have a (suitable) higher-order awareness that one is in S. According to the higher-order theory of consciousness one thereby comes to have a phenomenally conscious experience of S and becomes consciously aware of what S represents. But since one’s higher-order awareness is (on the theory) a cognitive thought-like state, it will describe its target. Thus one can be aware of S in different ways. Suppose that one is aware of S merely as a clock-like formation of rectangles. Then what it is like for one will be like seeing a clock-like formation of rectangles. Being aware of S seems to keep S online and as one is cued one may come to have a different higher-order awareness of S. One may become aware of some of the details already encoded in S. One was already aware of them, in a generic way, but now one comes to be aware of the same details but just in more detail. Put more in terms of the higher-order theory, one’s higher-order thought(s) come to have a different content than they previously did. The first higher-order state represented you as merely seeing a bunch of rectangles and now you have a state that represents you as seeing a bunch of rectangles where the five-o’clock position is occupied by a horizontal bar (or whatever). Notice that in this way of thinking about the case there are no unconscious states (except the higher-order ones). S is conscious throughout (just in different respects) and it will be true that subjects consciously see all of the letters (just not all of the details).

I want to keep this in mind as I turn to the second paper but before we do I also like Gottlieb’s paper because it actually references this blog! I think this may be the first time my personal blog has been cited in a philosophy journal! I will have more to say about that at some point but for now: cool!

The second paper is by Nicholas D’Aloisio-Montilla and came out in Ratio in December 2017. It is called A Brief Argument for Consciousness without Access. This paper is very interesting and I am glad I became aware of it and D’Alosio-Montilla’s work in general. He is trying to develop a case for phenomenological overflow based on empirical work on aphantasics. These are people who report lack of the ability to form mental imagery. I have to admit that I think of myself this way (with the exception of auditory imagery) so I find this very interesting. But at any rate the basic point seems to be that there is no correlation between one’s ability to form mental imagery (as measured in various ways) and one’s ability to perform the Sperling-like tasks under discussion in the overflow debate.  His basic argument is that if you deny phenomenological overflow then you must think that unconscious representations are the basis of subject’s abilities. Further, if that is the case then it must be because subjects form a (delayed) mental image of the original (unconscious) representation. But there is evidence that subject’s don’t form mental images and so evidence that we should not deny overflow.

I disagree with the conclusion but it is nice to see this very interesting argument and I hope it gets some attention. Even so, I think there is some mis-characterization of my view related to what we have just been talking about in Gottlieb’s paper. D’Alosio-Montilla begins by setting the problem up in the following way,

The reports of subjects [in Sperling-like tasks] imply that their phenomenology (i.e. conscious experience) of the grid is rich enough to include the identities of letters that are not reported (Block, 2011, p.1; Land- man et al., 2003; cf. Phillips, 2011b). As Sperling (1960, p.1) notes, they ‘enigmatically insist that they have seen more than they can … report afterwards’. Introspection therefore suggests that subjects consciously perceive almost all 12 items of the grid, even if they are limited to accessing the contents of just one row (Block 2011; Carruthers, 2015). The ‘overflow’ argument uses this phenomenon as evidence in favor of the claim that the capacity of consciousness outstrips that of access. Overflow theorists maintain that almost all items of the grid are consciously represented by perceptual and iconic representations (D’Aloisio-Montilla, 2017; Block, 1995, 2007, 2011, 2014; Bronfman et al., 2014; for further discussion, see Burge, 2007; Dretske, 2006; Tye, 2006).

This is a nice statement of the overflow argument and the claim that it is the specific identifies of the items of the grid which are consciously experienced but this way of framing the argument begs the question against the higher-order interpretation. The reports in question do not imply rich phenomenology because, as we have just discussed, subjects are correct that they have consciously seen all of the letters even if they are wrong that they consciously experienced the details. Because of this the higher-order no-overflow theorist can accept that there is no correlation between mental imagery ability and Sperling-like task performance and for pretty much the same reasons that the first-order theorist does: because there is a persisting conscious experience.

D’Aloisio-Montilla then goes on to give two objections to his interpretation of my account. He puts it this way,

A final way out for the no-overflow theorist might be to allow for a limited phenomenology of the cued item to occur without visual imagery (Brown, 2012, 2014; Carruthers, 2015). Brown (2012, p. 3) suggests that subjects can form a ‘generic’ experience of the memory array’s items while the array is visible, since attention can be thinly distributed to bring fragments of almost all items to both phenomenal and access consciousness. Phenomenology, for example, might include the fact that ‘there is a formation of rectangles in front of me’ without specifying the orientation of each rectangle (Block, 2014). However, there a still number of problems with an appeal to generic phenomenology. First, subjects report no shift in the precision of their conscious experience when they are cued to a subset of items that they subsequently access (Block, 2007; Block, 2011).

First, I would point out that my goal has always been to show that the higher-order theory of consciousness is both a.) compatible with the existence of overflow but also b.) compatible with no-overflow views and gives a different account of this than Global Workspace Theories (or other working memory-based views). So I am not necessarily a ‘no-overflow theorist’ though I am someone who thinks that i.) overflow has not been established but assumed to exist and ii.) even if there is overflow it is mostly an argument against a particular version of the Global Workspace theory of consciousness, not generally against cognitive theories of consciousness.

But ok, what about his actual argument? I hope it is clear from what we have said above that one would not expect subjects to report ‘a shift in precision’ of their phenomenology. One has a conscious experience (generic or vague in certain respects) but in so doing you help to maintain the first-order (detailed) state. When you get the cue you focus on the aspect of the state which you had only generically been aware of (by coming to have a higher-order awareness with a different content) but what it is like for you is just like feeling like you see all of the details and then focusing in on some of the details. No change in precision. But even so these appeals to the subject’s reports are all a bit suspect.  I use the Sperling stimulus in my classes every semester as a demo of iconic memory and an illustration of how philosophical issues connect to empirical ones and my students seem to be mixed on whether they think they “see all of the letters”. Granted we only do 10-20 trials in the classroom and not in the lab (in Sperling they did thousands of trials) and these are super informal reports made orally in the classroom…but I still think there is a issue here. I have long wanted there to be some experimental philosophy done on this question. It would be nice to see someone replicate Sperling’s results but also include some qualitative comments from subjects about their experience. I almost tried to get this going with Wesley Buckwalter years ago but it didn’t go through. I still think someone should do this and that the results would be useful in this debate.

D’Aloisio-Montilla goes on to say,

Second, subjects are still capable of generating a ‘specific’ image – that is, a visual image with specific content – when the cue is presented. Assuming that the cued item is generically conscious on the cue’s onset, imagery would necessarily be implicated in maintaining any persisting consciousness of the cued item (whether gist-like or specific) throughout the blank interval. Thus, we can still expect to see a correlation between imagery abilities and task performance, because subjects can generate either (1) a visual image with specific phenomenology, or (2) a visual image with generic phenomenology (Phillips, 2011a; Brown, 2014). In any case, subjects who generate a specific phenomenology of the cued item should perform better than those who rely solely on a gist-like experience, and so Brown’s interpretation is also called into question.

But again this seems to miss the point of the kind of no-overflow account the higher-order thought theory of consciousness delivers. It is not committed to mental imagery as a solution. Subjects have a persisting conscious experience which may be less detailed than they experience it as.

Shesh that is a lot and I am sure there is a lot more to say about it but nap time is over and I have to go and play Dinosaur now.

Papa don’t Teach (again!)


The Brown Boys

2018 is off to an eventful start in the Brown household. My wife and I have just welcomed our newborn son Caden (pictured with older brother Ryland and myself to the right) and I will soon be going on Parental Leave until the end of April. Because of various reasons I had to finish the last two weeks of the short Winter semester after Caden was born (difficult!). That is all wrapped up now and there is just one thing left to do before officially clocking out.

Today I will be co-teaching a class with Joseph LeDoux at NYU. Joe is teaching a course on The Emotional Brain and he asked me to come in to discuss issues related to our recent paper. I initially recorded the below presentation to get a feel for how long the presentation was (I went a bit overboard I think) but I figured once it was done I would post it. The animations didn’t work out (I used powerpoint instead of Keynote), I lost some of the pictures, and I was heavily rushed and sleep-deprived (plus I seem to be talking very slow when I listen back to it) but at any rate any feedback is appreciated. Since this was to be presented to a neuroscience class I tried to emphasize some of the points made recently by Hakwan Lau at his blog.