Brains
On Philosophy of Mind and Related Matters
On Philosophy of Mind and Related Matters
Brains
First mention of 'content/vehicle' distinction?
The conceptual distinction between representational vehicles and representational contents is very old, probably older than Plato.
Lately, however, I've been wondering when the first use of this actual terminology emerged. Pete Mandik took time out from hammering brains to tell me he thinks the first use of this terminology might be from Dennett and Kinsborn (1992):
Of course conceptually this distinction has been known probably forever. In one of my favorite examples it is used to construct a sexy little paradox. The following is from Frank Ramsey (1935), but he attributes the proof to Weyl:
Finally, I did find a tantalizing case in which 'meaning' was contrasted with 'vehicle' from a book published in 1722, but it seems clear this isn't the same distinction as our content/vehicle distinction. Rather, Wollaston basically says that the body is a vehicle like a cart is a vehicle, and it carries the nonmaterial meanings as a passenger. From Wollaston (1722):
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UPDATE 1:
I received this response from Dennett on the origins of the distinction:
"Susan Hurley cites my 1991 (CONSCIOUSNESS EXPLAINED) and Millikan as the source. She was a good scholar. I bet she's right."
(The Millikan citation is her article 'Perceptual Content and Fregean Myth', also 1991)
UPDATE 2:
In the comments someone pointed out that in 1990 Adrian Cussins employs the distinction in his 'Connectionist Construction of Concepts'.
UPDATE 3:
After a furious bout with google books and amazon search capacities, I think the winner may be Dennett:
Dennett, D. C. (1978), Toward a Cognitive Theory of Consciousness, in C.W. Savage, ed.,Minnesota Studies in the Philosophy of Science, Volume 9: Perception and Cognitions, Issues in the Foundation of Psychology. Minneapolis: University of Minnesota Press, pp. 201-228.
He uses the distinction a couple of times in nascent form. For instance:
Content and Consciousness (p 56 1969):
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References
Daniel Dennett and Marcel Kinsbourne (1992) Time and the observer: the whereand when of consciousness in the brain. Behavioral and Brain Sciences,15, 183-247.
Ramsey, FP (1931) Foundations of Mathematics, Routledge, London.
William Wollaston (1722) The religion of nature delineated (quote is taken from 1725, 3rd ed J Palmer, London).
Lately, however, I've been wondering when the first use of this actual terminology emerged. Pete Mandik took time out from hammering brains to tell me he thinks the first use of this terminology might be from Dennett and Kinsborn (1992):
[T]he general principle of the content/vehicle distinction is relevant to information-processing models of the brain in ways that have not been well appreciated.Is that the first mention of the 'content/vehicle' distinction in those words?
In general, we must distinguish features of representings from the features of representeds; someone can shout "softly, on tiptoe" at the top of his lungs, there are gigantic pictures of microscopic objects, and oil paintings of artists making charcoal sketches. The top sentence of a written description of a standing man need not describe his head, nor the bottom sentence his feet. To suppose otherwise is to confusedly superimpose two different spaces: the representing space and the represented space.
Of course conceptually this distinction has been known probably forever. In one of my favorite examples it is used to construct a sexy little paradox. The following is from Frank Ramsey (1935), but he attributes the proof to Weyl:
Some adjectives have meanings which are predicates of the adjective word itself; thus the word 'short' is short, but the word 'long' is not long. Let us call adjectives whose meanings are predicates of the them, like 'short', autological; others heterological. Now is 'heterological' heterological? If it is, its meaning is not a predicate of it; that is, it is not heterological. But if it is not heterological, its meaning is a predicate of it, and therefore it is heterological. So we have a complete contradiction.Take that, Frege!
Finally, I did find a tantalizing case in which 'meaning' was contrasted with 'vehicle' from a book published in 1722, but it seems clear this isn't the same distinction as our content/vehicle distinction. Rather, Wollaston basically says that the body is a vehicle like a cart is a vehicle, and it carries the nonmaterial meanings as a passenger. From Wollaston (1722):
In short, words seem to be as it were bodies or vehicles to the sense or meaning, which is the spiritual part, and which without the other can hardly be fixed in the mind.Italics are in the original.
===========================
UPDATE 1:
I received this response from Dennett on the origins of the distinction:
"Susan Hurley cites my 1991 (CONSCIOUSNESS EXPLAINED) and Millikan as the source. She was a good scholar. I bet she's right."
(The Millikan citation is her article 'Perceptual Content and Fregean Myth', also 1991)
UPDATE 2:
In the comments someone pointed out that in 1990 Adrian Cussins employs the distinction in his 'Connectionist Construction of Concepts'.
UPDATE 3:
After a furious bout with google books and amazon search capacities, I think the winner may be Dennett:
Dennett, D. C. (1978), Toward a Cognitive Theory of Consciousness, in C.W. Savage, ed.,Minnesota Studies in the Philosophy of Science, Volume 9: Perception and Cognitions, Issues in the Foundation of Psychology. Minneapolis: University of Minnesota Press, pp. 201-228.
He uses the distinction a couple of times in nascent form. For instance:
The content of a particular vehicle of information, a particular information-bearing event or state, is and must be a function of its function in the system.UPDATE 4:
Content and Consciousness (p 56 1969):
The crucial point that emerges from this is that the candidates for vehicles of content or significance in the brain are compound.Not sure what that means, exactly, but it looks like another incipient use of the distinction.
================================
References
Daniel Dennett and Marcel Kinsbourne (1992) Time and the observer: the whereand when of consciousness in the brain. Behavioral and Brain Sciences,15, 183-247.
Ramsey, FP (1931) Foundations of Mathematics, Routledge, London.
William Wollaston (1722) The religion of nature delineated (quote is taken from 1725, 3rd ed J Palmer, London).
Updated Resources for Students (and Some New Papers)
I finally updated most of my website after over a year of neglect. With help from Jim Virtel, we added a whole bunch of new links to my list of resources for students, such as information on how to study, apply to grad school, publish, and apply for jobs. Let me know if you know of other useful resources that I should add. I also posted a bunch of new papers on my "my works" page.
Challenging Neuroscience to Explain Cognition
C, R, Gallistel and A. P. King, Memory and the Computational Brain: Why Cognitive Science Will Transform Neuroscience, Wiley-Blackwell, 2009.
This is a rich and thought-provoking book. I cannot do it justice in a brief post so I apologize in advance for that.
Roughly speaking, the book argues that (1) many cognitive functions (such as dead reckoning of the type observed in ants and bees) require a read/write memory, and (2) neuroscience/connectionism has no room for such a read/write memory, and (3) such a read/write memory is probably stored in molecules such as RNA (as opposed to the connection strengths between neurons that are usually taken to be the memory mechanism by neuroscientists), and therefore (4) neuroscientists ought to embrace a digital computationalist theory of cognition and look for the right kind of memory mechanism in the nervous system.
Some of the thoughts the book provokes are healthy and invigorating. It challenges theorists of cognition to think hard about (i) which computing mechanisms are required for certain cognitive functions and (ii) how they can be realized in the nervous system. The book points out that there is a lot that we don't understand about how the brain fulfills various cognitive functions, and this is true. The book points out that some connectionists and neuroscientists are somewhat narrow minded about the kinds of processes and mechanisms they accept as possible explanations of cognitive functions and might benefit by thinking outside the box. The book also includes a fairly clear introduction to foundational topics such as Shannon's information theory, computation, and representation. This is all good.
But there are also plenty of problems. For one thing, the main argument of the book is unsound.
I agree with (1) (though I don't buy Gallistel and King's stronger claim that the read/write memory must be of a digital type like that of digital computers).
But (2) is just wrong. Strangely enough, Gallistel and King themselves point out that a read/write memory might be realized either as a "reverberating" neural activity (working memory) or in the connection strengths between neurons in a network (long term memory, cf. p. 285). But while they reluctantly admit that you can build a read/write memory out of accepted neural mechanisms, they offer some (unconvincing) reasons why that's not good enough and proceed to act as if those possibilities don't count. They act as though their argument goes through anyway.
Gallistel and King give no empirical evidence for (3). What's worse is that they show no awareness that (3) is an old theory that was experimentally tested in the 1950s or so, and was eventually abandoned for lack of evidence. Before trying to resurrect a molecular theory of memory, Gallistel and King should at least discuss the available evidence.
As to (4), again it's something that's been tried before: computer scientists determining that the brain must work like a digital computer and telling neuroscientists to look for the digital computing mechanisms that _must_ be there. The oldest example that I know of is an old lecture by Allen Newell to an audience of neuroscientists, in which Newell asked "where in the nervous system I can find symbols” (Gerard and Duyff 1963, p. 343). (Newell is one of the founders of classical, or "symbolic" AI. Needless to say, neuroscientist have not found the kind of symbols that Newell was asking about.) While Newell's hubris might have been understandable in the early '60s, it's a lot less understanable after 50 more years of detailed investigations of the nervous system.
By way of supporting (4), Gallistel and King draw an analogy with genes and DNA. Before Watson and Crick figured out the structure of DNA, no one knew how genes are physically realized, but that was not a good reason to reject genes. By the same token, a molecular read/write memory may well be needed for cognition, and should not be dismissed just because we don't know how it's physically realized. But the analogy breaks down at a crucial place. Before Watson and Crick (and collaborators) figured out how to investigate the structure of DNA, such structure was beyond the observational power of available experimental techniques. Not so for the nervous system. The basic structure of the nervous system was figured out a century ago, and more and more details about its working have been progressively figured out. Before Watson and Crick, genes could be treated like black boxes because no one knew how to study their molecular structure. But to suggest that today nervous systems should be treated like black boxes is neither here nor there.
Neuroscience has produced a huge amount of empirical evidence over the last decades. Any serious attempt at a theory of cognition must take this evidence seriously. Unfortunately, Gallistel and King do not. They dismiss neuroscience as associationist, antirepresentationalist, and unable to provide mechanisms with the right amount of computational power. Much of Gallistel and King's argument attacks a straw man by calling him names. In fact, most cognitive neuroscientists are representationalists, and it is not at all clear that the mechanisms countenanced by neuroscience are insufficiently powerful to explain the cognitive functions discussed in this book. And if they are, it is extremely unlikely that the right mechanisms will look anything like those suggested by Gallistel and King.
A final (minor) example of the authors' cavalier attitude. Gallistel and King cite one of my papers (among others) in support of the claim that "The neural network architecture lacks [an addressable read/write memory] because neuroscientists have yet to discover a plausible basis for such a mechanism. That lack makes the problem of variable binding an unsolved problem in neural network computation" (p. 153). But if anything, my paper entails the opposite. For as I point out in it, digital computers (which have an addressable read/write memory and can do variable binding just fine) are just one very specialized kind of neural networks. (Gallistel and King often draw a contrast between digital computers and neural networks, but they never define "neural network".)
In conclusion, this is a stimulating book, which in many ways goes in the right direction—that of developing a detailed mechanistic theory of cognition. But the way forward will require handling neuroscientific evidence and discussing issues of computational architectures more carefully and rigorously than Gallistel and King have done. Of course, working out in greater detail how Gallistel and King's arguments break down would be a very valuable exercise. I'll leave that to Alex Morgan, ok Alex?
This is a rich and thought-provoking book. I cannot do it justice in a brief post so I apologize in advance for that.
Roughly speaking, the book argues that (1) many cognitive functions (such as dead reckoning of the type observed in ants and bees) require a read/write memory, and (2) neuroscience/connectionism has no room for such a read/write memory, and (3) such a read/write memory is probably stored in molecules such as RNA (as opposed to the connection strengths between neurons that are usually taken to be the memory mechanism by neuroscientists), and therefore (4) neuroscientists ought to embrace a digital computationalist theory of cognition and look for the right kind of memory mechanism in the nervous system.
Some of the thoughts the book provokes are healthy and invigorating. It challenges theorists of cognition to think hard about (i) which computing mechanisms are required for certain cognitive functions and (ii) how they can be realized in the nervous system. The book points out that there is a lot that we don't understand about how the brain fulfills various cognitive functions, and this is true. The book points out that some connectionists and neuroscientists are somewhat narrow minded about the kinds of processes and mechanisms they accept as possible explanations of cognitive functions and might benefit by thinking outside the box. The book also includes a fairly clear introduction to foundational topics such as Shannon's information theory, computation, and representation. This is all good.
But there are also plenty of problems. For one thing, the main argument of the book is unsound.
I agree with (1) (though I don't buy Gallistel and King's stronger claim that the read/write memory must be of a digital type like that of digital computers).
But (2) is just wrong. Strangely enough, Gallistel and King themselves point out that a read/write memory might be realized either as a "reverberating" neural activity (working memory) or in the connection strengths between neurons in a network (long term memory, cf. p. 285). But while they reluctantly admit that you can build a read/write memory out of accepted neural mechanisms, they offer some (unconvincing) reasons why that's not good enough and proceed to act as if those possibilities don't count. They act as though their argument goes through anyway.
Gallistel and King give no empirical evidence for (3). What's worse is that they show no awareness that (3) is an old theory that was experimentally tested in the 1950s or so, and was eventually abandoned for lack of evidence. Before trying to resurrect a molecular theory of memory, Gallistel and King should at least discuss the available evidence.
As to (4), again it's something that's been tried before: computer scientists determining that the brain must work like a digital computer and telling neuroscientists to look for the digital computing mechanisms that _must_ be there. The oldest example that I know of is an old lecture by Allen Newell to an audience of neuroscientists, in which Newell asked "where in the nervous system I can find symbols” (Gerard and Duyff 1963, p. 343). (Newell is one of the founders of classical, or "symbolic" AI. Needless to say, neuroscientist have not found the kind of symbols that Newell was asking about.) While Newell's hubris might have been understandable in the early '60s, it's a lot less understanable after 50 more years of detailed investigations of the nervous system.
By way of supporting (4), Gallistel and King draw an analogy with genes and DNA. Before Watson and Crick figured out the structure of DNA, no one knew how genes are physically realized, but that was not a good reason to reject genes. By the same token, a molecular read/write memory may well be needed for cognition, and should not be dismissed just because we don't know how it's physically realized. But the analogy breaks down at a crucial place. Before Watson and Crick (and collaborators) figured out how to investigate the structure of DNA, such structure was beyond the observational power of available experimental techniques. Not so for the nervous system. The basic structure of the nervous system was figured out a century ago, and more and more details about its working have been progressively figured out. Before Watson and Crick, genes could be treated like black boxes because no one knew how to study their molecular structure. But to suggest that today nervous systems should be treated like black boxes is neither here nor there.
Neuroscience has produced a huge amount of empirical evidence over the last decades. Any serious attempt at a theory of cognition must take this evidence seriously. Unfortunately, Gallistel and King do not. They dismiss neuroscience as associationist, antirepresentationalist, and unable to provide mechanisms with the right amount of computational power. Much of Gallistel and King's argument attacks a straw man by calling him names. In fact, most cognitive neuroscientists are representationalists, and it is not at all clear that the mechanisms countenanced by neuroscience are insufficiently powerful to explain the cognitive functions discussed in this book. And if they are, it is extremely unlikely that the right mechanisms will look anything like those suggested by Gallistel and King.
A final (minor) example of the authors' cavalier attitude. Gallistel and King cite one of my papers (among others) in support of the claim that "The neural network architecture lacks [an addressable read/write memory] because neuroscientists have yet to discover a plausible basis for such a mechanism. That lack makes the problem of variable binding an unsolved problem in neural network computation" (p. 153). But if anything, my paper entails the opposite. For as I point out in it, digital computers (which have an addressable read/write memory and can do variable binding just fine) are just one very specialized kind of neural networks. (Gallistel and King often draw a contrast between digital computers and neural networks, but they never define "neural network".)
In conclusion, this is a stimulating book, which in many ways goes in the right direction—that of developing a detailed mechanistic theory of cognition. But the way forward will require handling neuroscientific evidence and discussing issues of computational architectures more carefully and rigorously than Gallistel and King have done. Of course, working out in greater detail how Gallistel and King's arguments break down would be a very valuable exercise. I'll leave that to Alex Morgan, ok Alex?
The Identity Theory in 2-D
(cross-posted at Philosophy Sucks!)
I plan on writing a series of posts discussing various themes that came up in discussion at the online consciousness conference over the next few weeks.
I have long been a type-type identity theorist. There was a time when I thought that I would write my dissertation defending a version of identity theory (in fact the very first talk I gave at a professional meeting was what I thought of as a 'pre-prospectus' available here: Saying "I Do" to Identity. I presented this as a poster at the ASSC in Antwerp and as a talk at the SPP in Barcelona (I called this my "European Identity Tour"))...When I approached Michael Devitt about the idea he said that people used to be interested in the identity theory but that people had moved on...it turns out that people are getting re-interested in the identity theory in the wake of work by people like Tom Polger, Chris Hill, and Ned Block. One thing that came out very clearly in the discussion is the difference between the identity theory that Block holds from the kind that I hold. The main difference concerns how we will eventually come to discover the mind-brain identities. Broadly speaking there are two different camps.
It is useful to remind ourselves of what the originators of the identity theory held. In "Is Consciousness a Brain Process?" U. T. Place says,
The answer seems to be that we treat the two sets of observations as observations of the same event in those cases where the technical scientific observations set in the context of the appropriate body of scientific theory provide an explanation of the observation of the man in the street. Thus we conclude that lightning is nothing more than a motion of electric charges, because we know that a motion of electric charges through the atmosphere, such as occurs when lightning is reported, gives rise to the visual stimulation which would lead an observer to report a flash of lightning (p. 58 in Chalmers 2002)J.J.C. Smart in "sensations and Brain Processes" writes,
Why do I wish to resist [the suggestion that qualia are irreducibly psychial]? Mainly because fo Occam's razor. It seems to me that science is increasingly giving us a viewpoint whereby organisms are able to be seen as psyico-chemical mecanisms: it seems that even the behavior of man himself will one day be explicable in mechanistic terms...That everything should be explicable in terms of physics (together of course with the descriptions of the ways in which the parts are put together —roughly, biology is to physics as radio-engineering is to electro-magnetism) except the occurrence of sensations seems to me to be frankly unbelievable. Such sensations would be "nomological danglers," to use Feigl's expressionWe can see here an emphasis on the notions of explanation and parsimony.
16 years later David Lewis and David Armstrong establish the alternative camp. Lewis puts it most clearly when he writes,
Psychophysical identity theorists often say that the identifications they anticipate between mental and neural states are essentially like various uncontroversial theoretical identifications: the identification of water with H2O, of light with electromagnetic radiation, and so on. Such theoretical identifications are usually described as pieces of voluntary theorizing as follows. Theoretical advances make it possible to simplfy total science by positing brdge laws identifying some of the entities discussed in one theory with entities discussed in another theory. In the name of parsimony, we posit those bridge laws forthwith. Identifications are made, not found.In 'An Argument for teh Identity Theory," I claimed that this was a bad picture of psychophysical identification, since a suitable physiological theory could imply psychophysical identites —not merely make it reasonable to posit them for the sake of parsimony. The implication was as follows:Mental state M=the occupant of causal role R (definition of M)Neural state N=the occupant of causal role R (by the physiological theory)Therefore Mental state M=neural state N (by transitivity of =)Nor is this peculiar to psychophysical identifications. He goes on,
...the usual account is, I claim, wrong; theoretical identifications in general are implied by the theories that make them possible —not posited independantly. This follows from a general hypothesis about the meaning of theoretical terms: that they are definable functionally, by reference to causal roles (Psychophysical and Theoretical Identifications)In a recent paper on functional reduction Ned Block targets the Lewisian view in favor of the Place/Smart view. Here is what he says,
If we want to know why water = H2O, freezing = molecular lattice formation, heat = molecular kinetic energy, temperature = mean molecular kinetic energy, etc, we have to start with the fact that water, temperature, heat, freezing and other magnitudes form a family of causally inter-related “macro” properties. This macro family is mirrored by a family of “micro” properties: H2O, mean molecular kinetic energy, molecular kinetic energy and formation of a lattice of H2O molecules. (Of course a given level can be micro with respect to one level, macro with respect to another.) The key fact is that the causal and explanatory relations among the macro properties can be explained if we suppose that the following relations hold between the families: that water = H2O, temperature = mean molecular kinetic energy, heat = molecular kinetic energy and freezing = lattice formation. For example, why does decreasing the temperature of water cause it to freeze? Why does ice float on water? Here is a sketch of the explanation: The oxygen atom in the H2O molecule has two pairs of unmated electrons, which attract the hydrogen atoms on other H2O molecules. When the kinetic energy of the molecules decreases, (i.e. the temperature decreases) each oxygen atom tends to attract two hydrogen atoms on the ends of two other H2O molecules. When this process is complete, the result is a lattice in which each oxygen atom is attached to four hydrogen atoms.Ice is this lattice and freezing is the formation of such a lattice, which is why decreasing temperature causes water to freeze. Because of the geometry of the bonds, the lattice has an open, less dense structure than amorphously structured H2O (viz., liquid water)—which is why ice (frozen water) floats on liquid water. Suppose we reject the assumption that temperature is identical to mean molecular kinetic energy in favor of the assumption that temperature is merely correlated with mean molecular kinetic energy? And suppose we reject the claim that freezing is lattice-formation in favor of a correlation thesis. And likewise for water/H2O. Then we would have an explanation for how something that is correlated with decreasing temperature causes something that is correlated with frozen water to float on something correlated with liquid water, which is not all that we want. The reason to think that the identities are true is that assuming them gives us explanations that we would not otherwise have and does not deprive us of explanations that we already have or raise explanatory puzzles that would not otherwise arise. The idea is not that our reason for thinking these identities are true is that it would be convenient if they were true. Rather, it is that assuming that they are true yields the most explanatory overall picture. In other words, the epistemology of theoretical identity is just a special case of inference to the best explanation. (See Block, 1978a; Block, 2002; Block & Stalnaker,1999).Block goes on to argue that the Lewis style view is incompatible with the metaphysics of physicalism. Block distinguishes between ontology and metaphysics. Ontological physicalism is just the claim that in our ontological commitment to the existence of qualia we commit ourselves only to physical entities (ontological dualists deny this). Metaphysical physicalism is the claim that qualitative properties are essentially or metaphysically physical. That is to say that all qualitative properties will share the same physical properties in so far as they are physical. the Lewis style physicalism is ontologically but nit metaphysically physicalist. This is because as it happens all of the realizers of mental states are physical but metaphysically pain is a functional state for Lewis and only contingently a physical state. Metaphysical physicalism —real physicalism in Block's view— says that it is not contingent but necessary that pain is a physical state.
But if we adopt the 2-D framework and put the Lewisian claims in terms of it this is no longer a problem. On this kind of view the functional definition gives us the primary intension of 'pain' and the physical state gives us the secondary intension. This allows us to treat 'pain' just as we do 'water'. 'Water is H2O' has a contingent primary intension and a necessary secondary intension. So we can update Lewis view that 'pain' isn't a rigid designator as the claim that the primary intension of pain is contingent (just like 'water'). 'Pain' is still a rigid designator in the ordinary sense that its secondary intension is necessary. In all worlds considered as counter-factual pain is a brain state. However we accommodate the conceivability of Martians and disembodied minds by noting that in some worlds considered as actual pain is not a brain state (just as in some worlds considered as actual water is not H2O). This does not threaten the identity; it is the usual way that theoretical identities work. Notice also that this 2-D identity theory is a metaphysical physicalism in Block's sense and not merely an ontological physicalism.
Of course the real resistance to the 2-D Lewisian identity theory is that qualitative states are not supposed to be functionally definable. In fact Block and Chalmers often talk as though qualitative properties are definable as 'the not functionally definable properties of experience' (more on that later). If that is your view then you cannot do the Lewsian deduction of the identity. What are we to make of this? I will come back to this in the next post.
A bibliography on modularity
I have been asked to write up a commentated bibliography on modularity for a new journal by OUP. It is not meant to be exhaustive; rather it should focus on the important articles and books and organize this in meaningful sections.
Perhaps some of you will have comments and suggestions. I might have missed some articles, and it might be useful to add another section.
The paper can be read here.
Thanks,
Edouard
Congratulations
Gualtiero is too modest to announce it here, so I'll do it! Congratulations for your tenure, Gualtiero! Very well-deserved.
Edouard
HOT Damn!
I have not been too good keeping up with the NYU Mind and Language Seminar like I had originally planned. Part of the problem was the Online Consciousness Conference (about which more later) the other part of the problem has been that I teach until 3:30 and the sessions start at 4:00. At any rate I managed to make it down yesterday for David Rosenthal's session on his "Sensory Qualities, Consciousness and Perception" which was very interesting.
The commentary by Ned Block focused on the usual issues that he has with HOTheads (i.e. eitology ad hoc, the mismatch problem, conceptual content too unconstrained, etc) though there was an interesting new objection (at least I hadn't heard Ned give it before). The mismatch problem (red first-order state/green HOT) presents the HOThead with a dilemma. Either what it is like for the person is like seeing red in which case HOT is false or it is like seeing green in which case there is no difference between having an experience and thinking that one has the experience. It is not clear why the second horn of the dilemma is supposed to be bad. If HOT theory is right then having the conscious experience os seeing blue will consist in having the appropriate HOT so the horn just restates the theory.
But building on this Block quotes this passage from pages 185 in Consciousness and Mind:
HOTs do no transfer the property of being conscious from themselves to their targets; indeed, they don't induce any change whatever in those targets. Rather, they make their targets conscious because a state's being conscious consists simply in one's being conscious of oneself as being in that state, and having a HOT is the right way of being conscious of oneself as being in a state.Block then argued that in the case of the empty HOT —that is where one has a HOT that one is seeing green but has no first-order state at all— there is a conscious mental state that one is not conscious of and so we have a counter-example to the transitivity principle. Block seemed to be suggesting that if we take the above quote seriously then the HOT itself is the conscious mental state and since there is no 3rd-order thought about the HOT it is itself is a counter-example to the transitivity principle or he would need to adopt the same-order view. Rosenthal replied that the HOT was not the conscious state; it was the seeing of blue that was the conscious mental state even though it was a notional state (a lot of this came up at the online conference in Pete's excellent session). Jesse asked what the NCC of the conscious state would be in this case. It surely doesn't seem like one can have a NCC for a notional state! This prompted Stephen Stich to exclaim that David was "worse than a dualist". Uriah interjected that it was a commonplace of predicate calculus that if A is F then it follows that there is a x such that x is F and this entails that if one has a conscious mental state then there is a state that has that property. David objected to this because he thinks that the conscious mental states are states of the person not individual metal states. During the discussion I asked David to return to Ned's objection because I wasn't sure what his answer to it was. If the quoted passage is correct then a conscious mental state is identical to having the suitable HOT. What reason does David have to deny that the HOT is thereby the conscious mental state? His answer was that he did not stand by the quoted passage, which seemed really odd to me. I hope to follow up with him about this...
Another very interesting theme of the discussion of was how repression works. Someone in teh audience (a nyu student named Lisa, I think) pointed to cases of repression as a possible counter-example to the transitivity principle. When one represses some thought one has to have (unconscious) knowledge of the thought that one is suppressing, which sounds like a HOT, yet the repressed thought is not thereby made conscious. David objected that this was not the way he understood repression to work. Rather than having a HOT usually what happens is that one has unconscious guilt about the repressed thought that leads to repressing it. Ned and David argued a bit about the right way that actual Fruedians talk about repression...no consensus was reached except in so far as David acknowledge that if repression worked in the way that Ned and Lisa suggested then that would be a counter-example to the transitivity principle.
Another audience member (Eric) tried to press this line of attack using the implicit racism test. The idea was supposed to be that after one has taken this test and discovered that one has unconscious racist attitudes one can have the thought that one is having a racist thought with the thought not thereby becoming conscious. David at first denied this and maintained that the thought would be conscious but then he reconsidered and said that attitudes were dispositions and those aren't mental states.
The session ended with a discussion of the relation between Jesse's AIR theory and HOT theory (it was pointed out that Dave Chalmers is now calling CUNY the HOT AIR department). David gave his signature argument against attention being necessary for consciousness. in parafoveal vision the percepts at the periphery are conscious even if one is fixating and attending to some central point. This is a case of conscious experience without attention. Jesse's trademarked response is that attention can be spread over the entire scene to which David responds that at that point he doesn't know what attention is anymore. At that point the session ended.
Afterwards I asked Jesse if he thought that when we attended to something we became conscious of that thing. He said that he did. I then said that if that was the case AIR theory is an implementation of the transitivity principle and so is not really in competition with David's view. Jesse agreed that this was the case. I then suggested that we could think of the situation like this: David has argued that there are only two ways that we can become conscious of something: we either sense it or we think about it in the right way. He therefore sees only HOT and HOP. We can then see a lot of Jesse's work as arguing that there is a third way that we become conscious of something; by attending to it. He agreed...I knew it!
What is a visual stimulus?
Find out at my most recent consciousness post, and figure out how to decode graphs like this:
Hint: line density equals photoreceptor density, and top is bottom because images are inverted on the retina. If that doesn't make sense, check out the long version.
It's part of my eight-million post series on the neuropscyhology of consciousness.
Hint: line density equals photoreceptor density, and top is bottom because images are inverted on the retina. If that doesn't make sense, check out the long version.
It's part of my eight-million post series on the neuropscyhology of consciousness.
Call for Commentaries on Cognitive Control
Rick Cooper (psychology, U London) is putting together an issue of Topics in Cognitive Science (a new journal by the Cognitive Science Society) on the fascinating topic of cognitive control. They are soliciting commentaries on the introductory paper plus five target articles, including a nice one by our Pete Mandik. If you work in this area, you might consider contacting Rick Cooper (see the dedicated webpage here for more details and contact info).
