The Curious Case of my Interview/Discussion with Ruth Millikan

I started my YouTube interview/discussion series Consciousness Live! last summer and scheduled Ruth Millikan as the second guest. We tried to livestream our conversation July 4th 2018 and we spent hours trying to get the Google Hangouts Live to work. When it didn’t I tried to record a video call and failed horribly (though I did record a summary of some of the main points as I remembered them).

Ruth agreed to do the interview again and so we tried to livestream it Friday June 6th 2019, almost a year after our first attempt (and since which I did many of these with almost no problems). We couldn’t get Google Hangouts to work (again!) but I had heard you could now record Skype calls so we tried that. We got about 35 minutes in and the internet went out (I put the clips up here).

Amazingly Ruth agreed to try again and so we met the morning of Monday June 10th. I had a fancy setup ready to go. I had our Skype call running through Open Broadcast Studios and was using that to stream live to my YouTube Channel. It worked for about half an hour and then something went screwy. After that I decided to just record the Skype call the way we had ended up doing the previous Friday. The call dropped 3 times but we kept going. Below is an edited version of the various calls we made on Monday June 10th.

Anyone who knows Ruth personally will not be surprised. She is well known for being generous with her time and her love of philosophical discussion. My thanks to Ruth for such an enjoyable series of conversations and I hope viewing it is almost as much fun!

12 years!

I just realized that I recently passed the 12 year mark of blogging here at Philosophy Sucks! The top-5 most viewed post haven’t changed all that much from my 10 year reflections. Philosophy blogging isn’t what it used to be (which is both good and bad I would say) but this blog continues to be what it always has: A great way for me to work out ideas, jot down notes, and get excellent feedback really quickly (that isn’t facebook). Thanks to everyone who has contributed over these 12 years!

The five most viewed posts written since the ten year anniversary are below. 

5. Prefrontal Cortex, Consciousness, and….the Central Sulcus?

4. Do we live in a Westworld World?

3. Consciousness and Category Theory

2. Integrated Information Theory is not a Theory of Consciousness

  1. My issues with Dan Dennett 

 

Theories of Perception and Higher-Order Theories of Consciousness: An Analogy

I recently came across a draft of a post that I thought I had actually posted a while ago…on re-reading it I don’t think I entirely agree with the way I put things back then but I still kind of like it

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When one looks at philosophical theories of perception one can see three broad classes of theoretical approaches. These are sometimes known as ‘relationalism’ and ‘representationalism’ (and ‘disjunctivism’). According to relationalism (sometimes known as naive realism) perception is a relation between the perceiver and the object they perceive. So when I see a red apple, on this view, there is the redness of the apple and then I come to be related to those things in the right way and that counts as perceiving. Often a ‘window’ analogy is invoked. Perception is like a window through which we can look out into the world and in so doing come to be acquainted with the ways that the objects in the world are. Representationalism on the other hand holds that perception involves, well, representing the world to be be some way or other, and this may diverge from the way the world is outside of perception.

I think a similar kind of debate has been occurring within the differing camps of higher-order theories of consciousness. In this debate the first-order state, which represents properties, objects, and events in the physical environment of the animal, takes the place of the physical object in the debates about perception. If one takes that perspective then one can see that we have versions of relationalism and representationalism in higher-order theories. Relationalists take the first-order state, and it’s properties, to be revealed in the act of becoming aware of it. Representationalists think that we represent the object as having various properties and that the experiences we have when we dream or hallucinate are literally the same ones we are aware of in ordinary experience. This is the famous argument from hallucination.

I think that the misrepresentation argument against higher-order theories of consciousness is actually akin to the argument from hallucination, and shows roughly the same thing, viz. that the relationalist version of higher-order theory is not in a position to explain what it is that is in common between “veridical” higher-order states and empty higher-order states. As long as one accepts that these cases are phenomenologically the same, and some versions of higher-order theory commit you to that claim, then it seems to me that you must say that we are aware of the same thing in each case. In the perception debate representationalists tend to say that what we are ware of in each case are properties. So take my experience of a red ripe tomato and my “perfect” hallucination as of a red ripe tomato. In one case I am aware of an actual object, the tomato, and in the other case I am not aware of any object (it is a hallucination). But in both cases I am aware of the redness of the tomato and the roundness of it, etc, in the good case these properties are instantiated in the tomato and in the bad case the are uninstantiated but they are there in both cases. The representationalist can thus explain why they two cases are phenomenologically the same: in each case we represent the same properties as being present.

I think the representational version of higher-order theories of consciousness have to similarly commit to what it is that is in common between veridical higher-order states and empty ones which none the less are phenomenologically indistinguishable. In one case we are aware of a first-order mental state (the one the higher-order state is about) and in the other case we are not (the state we represent ourselves as being in is one we are not actually in, thus the higher-order state is empty). So it must be the properties of the mental states that we are aware of in both cases. So if I am consciously seeing a red ripe tomato then I am in a first-order state which represents the tomato’s redness and roundness, etc and I am representing that these properties are present and that there is a tomato present, etc (this state can occur unconsciously but we are considering its conscious occurrence). To consciously experience the redness of the tomato I need to have a higher-order state representing me as seeing a tomato. And what this means is that I have a higher-order state representing myself as being in a first-order visual state with such and such properties. The ‘such-and-such properties’ bit is filled in by one’s theory of what kinds of properties first-order mental states employ to represent properties in the environment. Suppose that, like Rosenthal, one thinks they do so by having a kind of qualitative (i.e. non-conceptual, non-intentional) property that represents these properties. On Rosenthal’s view he posits ‘mental red’ as the way in which we represent the physical property objects have when they are red. He calls this red* and says that red* represents physical red in a distinctive non-conceptual non-intentional way.

This is not a necessary feature of higher-order theories but it gives us a way to talk about the issues in a definite way. So the upshot of this discussion is that it is these properties which are common between veridical and hallucinatory higher-order states. When one has a conscious experience of seeing a red ripe tomato but there is not a first-order visual representation of the tomato or its redness, etc, one represents oneself as being in first-order states which represent the redness and roundness of the tomato, one is aware of the same properties one would be in the veridical case but these properties are uninstantiated.

 

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.

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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!

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.

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?

 

Papa don’t Teach (again!)

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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.