Wednesday, November 03, 2010

Our minds extend beyond our heads.

I've always liked the idea, lucidly presented by Andy Clark over many years, that our minds are impossible to distinguish from our environment, because they really can't exist in the absence of a cognitive coupling between the two. I am relaying below the entire text of an instructive and interesting book review by Erik Myin of a book of commentaries on an influential 1998 paper by Andy Clark and David Chalmers titled "The extended mind." (very much worth reading, PDF here).

Where is the mind? "In the head" or "in the brain," most people might respond. The philosopher Gilbert Ryle gave a different answer:

The statement "the mind is in its own place," as theorists might construe it, is not true, for the mind is not even a metaphorical "place." On the contrary, the chessboard, the platform, the scholar's desk, the judge's bench, the lorry, the driver's seat, the studio and the football field are among its places. (1)

Recently, this idea of the mind not being confined to the head has been reinvigorated by philosophers and cognitive scientists, who see the mind as "spreading out" or "extending" into the world. "How do you know the way to San José?" philosopher John Haugeland has famously asked (2). Chances are you don't have some inner analog of a printed map. Rather, you know where you should enter the highway, and then you get there by following the road signs. Your knowledge seems to be partially "implemented" in the environment. There is now a blooming field of research into "situation cognition," which explores how cognitive or mental phenomena such as problem solving or remembering can be strongly dependent on interactions between subjects and their environments.

The possible far-reaching implications of a situated view of cognition were brought into sharp focus by Andy Clark and David Chalmers in their 1998 paper "The extended mind" (3). There they defend the idea that the mind "extends" into the environment in cases in which a human organism and the environment become cognitively coupled systems. Their by now iconic illustration of cognitive coupling involves "Otto," a "slightly amnesic" person, who uses a notebook to write down important facts that he is otherwise likely to forget. Unlike a person who remembers the address of the Museum of Modern Art by relying on natural memory, Otto recalls it by accessing his notebook. If one supposes that the notebook is constantly available to Otto and that what is written in it is endorsed by Otto, it becomes plausible—so Clark and Chalmers argue—that Otto's memory extends to include the notebook. After all, they notice, Otto's notes seem to play exactly the same role as memory traces in other people. Wouldn't it be chauvinistic to restrict the mind's extent to what's natural and inner?

Clark and Chalmers's paper has triggered a vigorous and continuing debate. Nonbelievers concede that numerous tight causal couplings between minds and environments exist, but they deny that it therefore makes sense to speak of an extended mind instead of a mind in a person that closely interacts with an environment. All things considered, they argue, thoughts remain in persons—never in objects like notebooks, however closely dependent a person could become on them.

Enthusiasts for the extended mind thesis insist that a close causal coupling between persons and environments can license the conclusion that the mind spreads into the environment. Some follow the argument in Clark and Chalmers that infers extendedness from the fact that external elements can play a role that would be considered as cognitive if played by something internal to a person.

Other supporters of the idea are suspicious of this argument from parity. They note that the most interesting cases of causal coupling are those in which the environment does not simply function as some ersatz internal milieu—when the involvement of external means makes possible forms of cognition that were not possible without them. For example, when pen and paper, symbolic systems, or computers make possible calculations, computations, and, ultimately, scientific theories. Those taking this position hold that it is when the environment becomes a necessary factor in enabling novel cognitive processes that the mind extends.

In The Extended Mind, philosopher Richard Menary (University of Wollongong) brings together the Clark and Chalmers paper and several responses to it. The collection, lucidly introduced by Menary, will neither definitively prove nor deal the deathblow to the idea that "the place of the mind" is the world—nor even establish that there really is such a question about "the place of the mind" that needs to be answered. Rather, the volume provides carefully drawn arguments for and against different interpretations of the extended mind thesis, often with extensive reference to empirical material. Several of the papers in the collection are excellent.

To take one fascinating idea, consider Susan Hurley on "variable neural correlates." We are comfortable with the correlation between types of experience and types of brain states, and undoubtedly such variation is one important source for the idea that the mind is in the head. Hurley notes, however, that there is also a dependence of experience on type of interaction with the environment, one not aligned to strictly neural properties. For example, when blind people haptically read Braille text, activity in the visual cortex seems to correlate with tactile experience. In people who are not blind, tactile experience correlates with activity in the tactile cortex. What explains the common enabling of tactile experience by the different kinds of cortex seems to be tactile causal coupling with the environment, rather than strictly neural type. According to Hurley, and others, the same kind of correlation-tracking reasoning that convinces us, in standard cases, that the mind is in the brain should here lead to the conclusion that the mind is not in the head.


* 1. G. Ryle, The Concept of Mind (Hutchinson, London, 1949).
* 2. J. Haugeland, Having Thought: Essays in the Metaphysics of Mind (Harvard Univ. Press, Cambridge, MA, 1998).
* 3. A. Clark, D. J. Chalmers, Analysis 58, 7 (1998).


  1. I have never liked this position. Largely because it requires the presupposition that most neuroscientists, cognitive scientists, philosophers etc... believe that the mind operates without input.

    It's another one of those positions that claims to be daring, edgy and new by attacking a straw man that no one actually believes in.

    Oh, and Hurley is wrong. "Tactile" and "visual" cortex are not different "types" of cortex. The neocortex is homogeneous. The only reason they are called "tactile" or "visual" is because we have labeled them so *after* observing what they appear to do during neuroimaging. This makes Hurley's argument circular. Blind people use what is lableled "visual" cortex in the non-blind to process tactile information because their brain isn't receiving any visual input, so the available cortex is used to process other things.

  2. Anonymous7:24 AM

    Interesting stuff: do you have a ref to Hurley's work?
    And I have the polar opposite view of the previous responder :) I actually think Hurley's ideas are the most interesting. And no, not all neuroscientists treat the brain as if it gets no input, actually no one does.

    But the previous comment does point out nicely why this 'extended' mind idea is trivial. Of course minds/brains receive input from the outside world and use this input. That is trivial. Talking about calling that extended mind or not is just wasting time on debating labels.

  3. If you enter the phrase "susan hurley extended min" in google you find a list of publications.

  4. A couple of thoughts

    The blind person in this example is still working to see isn't he- even though he's using his fingers instead of his eyes? So why wouldn't the seeing part of the brain show activation?

    When we differentiate between mind and brain, aren't we already indicating something beyond the real estate of the brain?

  5. Anonymous9:33 AM

    - "We are comfortable with the correlation between types of experience and types of brain states"

    Are we? we don't even know what those type of experience consist of.

    -"What explains the common enabling of tactile experience by the different kinds of cortex seems to be tactile causal coupling with the environment, rather than strictly neural type"

    There is no coupling at all, it is simply neural stimulation, we could actually stimulate directly the cortex.

  6. I think a better understanding of this kind of thing is Perls Hefferline and Goodman's Gestalt Therapy (the theory section).

    That is: the unit of analysis is the-person-in-their-situation - the meaning of behaviour is situationally embedded - but the elements can certainly be distinguished - my liver is not my heart though they are both me, the situation and the person can be (fairly readily) distinguished though they are inseparable parts of the-person-in-their-situation.

    I don't think I've found any particularly novel or useful insights (that is that are capable of affecting our everyday lives rather than extending medical research) from the contributions of neuroscientists - and they seem remarkably ill-informed about philosophy. (I'm still in recovery from Candace Pert asserting that her discovery of the new role and distribution of neurotransmitters had 'solved the mind-body problem'.)

  7. @Anonymous 7:24AM: "And no, not all neuroscientists treat the brain as if it gets no input, actually no one does."

    -This is precisely my point, acceptance of the "extended mind" concept hinges on the idea that current scientists only consider the brain in complete isolation, and don't consider it in terms of it's environmental context, otherwise it's a meaningless term at worst and semantic word games at best. The problem with "extended mind" is as you say *no-one* working in neuro/cognitive sciences considers the brain in isolation...

    @Mike Gottschalk: "The blind person in this example is still working to see isn't he- even though he's using his fingers instead of his eyes? So why wouldn't the seeing part of the brain show activation?"

    -Mike, the problem is that the "seeing part" of the brain is only called that because it appears to be activated when sighted people perceive visual stimuli. Blind people *don't have* a "seeing part" of the brain because they don't receive visual input.

    There's nothing special about the area we call "visual cortex" that earmarks it to process visual information other than the fact that in sighted people it receives visual information. On a neuronal level any patch of cortex is exactly the same as any other - you can't tell them apart.

    In blind people the area of the brain used to process tactile information expands to include what is conventionally called the "visual cortex" in sighted people because they are not getting any visual information. The brain doesn't waste space.

  8. @Joe Duncan- Based on what you're saying Joe,it seems to me that there needs to be another organizing factor involved that is different than the "module system"

  9. The extended mind idea can be viewed as a straw man, but it seems a useful one as an antidote to more completely brain centric ('brain in a vat'
    ) approaches. Its built in developmental perspective is useful, because no human mind can develop in the absence of interactions with social and physical forces in the environment. As the brain wiring that manages behavior is established it can be taken 'offline' in mental imaging and rehearsal, but it still remains coupled with, and modifiable by, the environment. One factual point is that while the cortex is initially largely undifferentiated, and the early sensory cortices of the brain can be viewed as synesthetic, there appear to be gene expressions distinctive to different cortical areas that relate to optimizing normal adult visual, auditory, tactile, etc function. This has to be considered a genetic 'nudge' or fine tuning, because a given cortical area can take on new functions, as noted in the above comments.

  10. Anonymous5:45 AM

    Very nice discussion here, thanks for posting this Deric.
    That said, I tend to agree a bit more with Mike Gottschalk. I think that it is an illusion to think that neuroscientists treat the brain as if it receives no input (as Mike correctly points out, and as I already posted earlier: no-one in neuroscience thinks this), so in that sense the extended mind idea is not a big change of perspective.
    You (Deric) mention the "brain in the vat"-idea. Now that is something rather different. This doesn't state that the brain produces its own inputs, it just states that for the brain it does not matter where it receives its input from. It could be from a real external world, or indeed, it could be that the brain is in the vat, receiving input from a bunch of electrodes, cleverly connected to its receiving nerves (like in the "matrix"). Some people find this a scary or depressing idea, but I'm afraid that this is just empirically correct. Your experiences are just entirely determined by your brain states, regardless of what caused these brain states. That is not some philosophical stance or conviction, it just happens to be the case. The experience associated with a brain state is independent of what caused that brain state. We find that in many cases. Hallucinogenic drugs, electric brain stimulation, brain disease, etc. being among the many examples. And yes, that just implies that we are essentially a brain in the vat, and that eventually to decode what someone experiences, we can just look at his brain state (and totally ignore what caused that brain state).

  11. @Mike Gottschalk: Yes and no. It depends on what parts of the brain you are talking about. The sub-cortical parts of the brain are all highly specialized, heterogeneous, and their development is the same for everyone. So a modular description of them is appropriate.

    However, for the cortex, every part of it basically does the same thing, just with different inputs. The organization of the cortex depends on the type and history of inputs it receives. People who use highly specific tools to perform tasks (e.g. hockey players & hockey sticks) end up with part of their cortex dedicated to processing the inputs and outputs of the tool. If we used hockey players as our control and then compared the brain activity of non-hockey players to them, we would conclude that, wow, non-hockey players use their "hockeystick-cortex" to process tactile information!

    The organizing factor of the cortex is learning and previous experience.

    @Deric: "it seems a useful one as an antidote to more completely brain centric ('brain in a vat'
    ) approaches"

    -No one I am aware of actually holds this approach though, so being an antidote to a non-existent approach is not of much value.

    In contrast, most neuro- and cognitive scientists that I am aware of care very much about social and environmental interactions and the impact they have on the brain's information processing.

  12. To respond to anonymous (5:45) just above,
    I don't think the statement
    "Your experiences are just entirely determined by your brain states…we are essentially a brain in the vat, and that eventually to decode what someone experiences, we can just look at his brain state (and totally ignore what caused that brain state)"
    is quite correct. Your experiences depend on those states happening, but those states don't exist in the absence of active coupling with the body (autonomic nervous system sympathetic and parasympathetic nuclei outside the brain, the hypothalamus-pituitary-adrenal (outside the brain) axis, etc. and, in turn, with the environment.

  13. "The organizing factor of the cortex is learning and previous experience."

    Wow- Joe, this is where science and poetry share the same space. And please take this as a compliment- I would wear this thought on a t-shirt.

    Thank you all for an insightful conversation!

    This is my takeaway: As I understand it, middle C would sound the same on any instrument were it not for the overtones specific to the instrument; I think everyone's viewpoint here communicated important overtones, even if or when we felt things were not properly denoted.

    Having read Deric's post and all your commentary here, I think about mind even more richly.

  14. Deric, I'm just now seeing your comment to Anonymous, and I was especially struck by your phrase "active coupling". This will be the subject of my stewing today....

    Btw, Thanks again for the terrific work you do!

  15. Anonymous8:57 AM

    Hi Deric,

    I think you misunderstood me. I didn't say that in actual reality the body does not play a role in creating brain states, or the actual environment doesn't. Of course it does.
    However, my point is that for your eventual experience the only thing that matters is the brain state. So let's say we find brain state X, and this is caused by factors Y (environmental reasons, bodily situation and so on), and we compare this to the situation where brain state X is caused by factors Z (so the brain state is exactly the same, but now the causing factors include electrodes and drugs).
    Do you think there is any change in experience between the two situations? And as I point out: this is not a philosophical question: all the data points in the direction that it really does not matter what causes the brain state. In the end it is just the brain state that determines your experience.
    That's the main point. Please let me know if you disagree with that, because then we have a real discussion on our hands :)
    If you agree that it is only the brain state that causes the experience, and that it does not matter what caused that brain state, then I think our whole discussion is just semantics.
    I would say that if only the brain determines the contents of our mind, then the mind is basically limited to our brain, but if you say, well the body and environment cause the brain state, so they are also part of the mind, I would say you can phrase it like that if you want to, but I wouldn't say that you are touching upon something interesting then (as pointed out before, it is trivial to say that environmental and bodily factors influence brain states).

  16. This probably mainly tripping over semantics. A brain state it necessary for an experience, in some cases it doesn't occur without correlate body states (or environmental states) with which it communicates.

  17. Anonymous3:18 AM

    hi Deric,

    Thanks for your answer, I was just wondering. Yes, I guess we are pretty much on the same page then.

  18. Anonymous3:19 AM

    Ooh and btw, just like other commenters said, thanks again for the good work with the blog. I really enjoy reading it, it's pretty thought-evoking!

  19. I have been thinking about this some more and it occurs to me that those that expound the "extended mind" concept are making a category error.

    They are mistaking inputs to processing for processing itself.

    Take for example a function in a computer program:


    "foo" is the function and contains the processing. "bar" is simply input provided to that processing.

    Undoubtedly, "bar" may have a profound or radical effect on what "foo" actually ends up doing, but it would be a categorical error to state that "bar" actually constitutes some of the processing itself.

  20. Sorry, but what's a mind anyway. It's a word that's really up for grabs (is that an Australianism?). Does it only include conscious stuff? Does it include visceral feelings or the visceral processes that allow the visceral feelings. Does it exist when you aren't noticing it, or are asleep? It's a dog's breakfast!

    It clearly can't include the actual objects of the world because they are too complicated to be known at all (a grain of sand contains unknowable zillions of atoms) so the mind can only only contain includes simplified imaginary versions of them. There is no "green" in the world, but we "see" green trees. Thus, the tree-in-our-mind cannot be (identically) the real tree, it's a kind of virtual reality tree presented to consciousness as a working model of the tree, which we almost always naively assume to be the actual tree. (Obviously, this is a very useful assumption in most practical situations. We only notice the difference when the model fails wildly, for example if the tree were to appear blue in weird lighting, or appear to move, or talk to us.) The actual tree may be a/the source of our modelled tree (i.e. the tree-in-the-mind) but it simply can't be the same thing.

    But I still don't really have a clear idea of what the mind is, so I could have missed the point!

  21. the brain is taking place in mind. mind is taking place in consciousness. flip the basic model, a lot of decades of research will be saved.