Supervenience and Neuroscience

Supervenience and Neuroscience. Draft. Comments welcome.

ABSTRACT: I assume physicalism and argue against non-reductive physicalism on the following grounds. Extant forms of non-reductive physicalism spell out their commitment to physicalism in terms of a notion of supervenience incapable of ruling out obviously unappealing scenarios that I call “doubled-qualia” and “mental-mental-supervenience.” Such scenarios involve multiple minds supervening on all and only the same physical properties. Such scenarios can be ruled out by a natural extension of the supervenience thesis that I call “fine-grained supervenience.” I argue further that the combination of non-reductive physicalism with fine-grained supervenience leads to a regress. I argue further still that if the regress is to be avoided, the form of reductive physicalism most preferable is one in which mental properties reduce to neural properties.

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Related posts: Doubled Qualia; A Regress for Non-reductive Physicalism; Fine-grained Supervenience, Cognitive Neuroscience, and the Future of Functionalism

4 Responses to “Supervenience and Neuroscience”

  1. Hi Pete,

    I really enjoyed reading your paper.
    Here are some notes:

    1. First one, I think, is technical in nature:
    In principles of physicalism (1) and (2), what is talked about is entity which has physical and mental properties, where “entity” seems not to be equated neither with its physical, nor with its mental properties.
    But the scenario presented (doubled qualia) as motivation for FGS, seems to require further explication of what is meant by “entity” in (1) and (2).
    Your discussion implicitly assumes that the entities of which (1) and (2) talk are entities because of their physical properties. Based on that assumption, you speak of one entity which has property of “having both green and red mind”. But in different interpretation of meaning of “entity”, one might say that both green and red minds are entities, and thus that them sharing the same supervenience base is ruled out by (1). In any case, it is clear that (1) and (2) have to be revised one way or another to cover doulbled qualia and intermittently doubled qualia scenarios, and maybe I’m just being too pedantic.

    2.Something that confuses me:
    You seem to accept Block’s Chinese nation counterexample to functionalism where every person can act as a neuron, because with your change added (where direct mind-to-mind communication is implemented) it would cause mental-mental supervenience.
    On other side after presenting the argument against any non-reductionistic physicalism, at the end you argue that you believe that mental will reduce to neural properties. What should be understood by “neural properties” and generally by “neurons” here? Probably what “neuron” is won’t be defined by the role it plays in the network as that would go against Block’s counterexample.
    Maybe you use “neurons” to refer to the specific neurons with specific physical make-up in the brain, but then wouldn’t it mean that the reduction *is* chemical, quantum-mechanics, or whatever the fundamental physical base is?
    Or is it the case that you use “neuron” where it is defined by extension, e.g. as reference to whatever cells exist in the brain of humans? If it is it so, it seems it wouldn’t help much in explaining the mental, as it would fail to provide general account by which we could tell if aliens have mental properties (in the definition by extension their cells wouldn’t be counted as “neurons”).

    3.And a side note: You mentioned Churchland’s theory about color qualia as consistent with FGS, but I’m not sure if that is important as Churchland’s theory fails to address Gegenfutner experiments with colors of fruits, or things like this one. Maybe there is qualia/neuron identity, but it is probably “deeper” in the brain.

  2. Pete Mandik says:

    Hi Tanasije,

    Thank you for your comments. Here are some responses.

    1.
    I think it is implicit in (1), (2), and FGS that whatever an entity is, no entity lacks physical properties.

    2.
    I like something similar to what you call the definition in extension option, but what I have in mind would not rule out the possibility of non-human neurons, or even extraterrestrial neurons. Such a definition would say something like “neurons are (a) cells that comprise the nervous systems of terrestrial animals and (b) any cells similar to degree n in respect m to the cells mentioned in (a)”. What n and m are is open to revision as further investigation is conducted, which I take to be pretty typical for scientific terms. However, I don’t see any reason to think that m will include a requirement of coming from our planet.

    3.
    While I agree that Churchland’s theory does not explain the phenomena you suggest, I don’t think that those phenomena falsify his theory. Churchland’s theory is primarily a theory of what color qualia are whereby they are points in a three-dimensional activation space where the three dimensions are defined by the opponent processes of light-dark, yellow-blue, and red-green. Secondarily, the theory is a theory of under what conditions the visual system will enter into states with such-and-such qualia, e.g. under certain stimulus and fatigue conditions. The main aspect of the Churchland account that prevents it from accounting for phenomena like the Gegenfutner data or illusions like the Cornsweet illusion is that the Churchland’s network model is strictly feed-forward. Accounting for these data will require addition of recurrent and lateral connections to the network. However, adding such connections will not add to the dimensionality of the activation space and thus will be fully consistent with the primary point of the theory: to explain what color qualia are. And more to the point for my paper: none of these modifications will involve anything inconsistent with FGS.

  3. mehdi fadaie says:

    hi dear peter i am mehdi fadaie a post graduate student from university of tehran
    I really enjoyed reading your paper
    if is possible i want know that can you help me regarding to some question about intuitional epistemology and other related topic ?
    please reply your answer to my mail after reading the text.
    thanks a lot

  4. Pete Mandik says:

    Mehdi,

    I’m happy to attempt to help, but can’t promise that I know much that’s useful about “intuitional epistemology”.