On the So-Called Directness of Neuro-Introspection




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Originally uploaded by Pete Mandik

Dan Cavedon-Taylor raised some pretty interesting questions here regarding whether the neuro-introspection I defend in Ch. 2 of The Subjective Brain is, as Paul Churchland puts a similar thesis, “direct”. Instead of leaving my response buried in an old-ish comment thread, I reproduce it here:

I think most if not all that needs to be said about the relevant issues concerning perception can be done in terms of a three-way distinction (a tristinction!) between sensation, perception, and inferences based on what’s perceived. A similar tristinction may be drawn between sensation, introspection, and inferences based on what’s introspected. Sensations are non-conceptual and carry information about themselves and their causes. Perceptions are conceptual and involve the automatic conceptual exploitation of information that sensations carry about their causes. Introspections are conceptual and involve the conceptual exploitation of information that sensations carry about themselves. Inferences involve the non-automatic application of concepts.

I try to illustrate all of this stuff in terms of the story of George, John, and the man in the gorilla suit in section 3 of chapter 2. George, the special effects expert, and John, the novice, both have the same sensations, I suppose. George is able to see the person as a man in a gorilla suit. I might just as well say that George is able to see that this is a man in a gorilla suit. John is able only to infer, based on what he perceives (plus what George tells him), that this is a man in a gorilla suit. This is not to deny, however, that John is incapable of seeing this as something or seeing that something is the case. John may being seeing this as a living organism.

I’m not particularly thrilled about the vocabulary of “direct” and “indirect”. A lot of what some people want to call direct perception I would call “sensation” and a lot of what some people want to call indirect perception I wouldn’t call perception at all, but conclusions of inferences. I worry about certain baggage associated with “direct”, in particular, the view that there can be unmediated epistemic access to anything. That strikes me as a nutty view and I don’t want to be read as assuming its truth.

Ok, now to explicitly address your points and questions:

You ask: “[D]o we *see* heat? We can *see that* something is hot (again by seeing some feature of it). Do you think seeing heat and seeing that something is hot are the same? The first sounds direct, the second–indirect.”

Let me start by saying that I assume seeing to be a kind of perceiving. So, visual sensation alone would not count as seeing. Further, I acknowledge a distinction between seeing heat and seeing that something is hot. I also take this to be the same distinction as that between seeing heat and seeing heat as heat. I don’t think, however, that there’s such a thing as seeing heat without seeing it as something or without seeing that something is the case. A visual sensory response to heat without concept application would be sensation, not seeing. I really don’t know how best to apply the “direct” and “indirect” vocabulary to these kinds of cases. Is the direct thing the sensation? Or is it the seeing of the heat as something but not seeing it as heat? I propose to just do without that vocabulary.

You propose:
“[P]erceiving the heat of the coffee by perceiving its steam looks like a case of *indirect* perception (i.e. the claim seems to be I perceive x by perceiving y)”

Another way of describing what’s going on in the coffee case is that I have a visual sensation which is caused by hot steam and thus carries information both about the presence of heat and of steam and I perceive (visually!) both heat and steam though none either more or less directly than the other. (I think I need to be much clearer about this in a revised version of the chapter.)

Regarding introspection, you ask:
“[I]n what sense can the introspection of one’s brain states be direct if it is mediated by mental states? I take it the neuro-introspectionist doesn’t claim that one could introspect their brain states without introspecting mental states. Rather, they claim we introspect brain states as such by first introspecting mental states (again, this sounds like such introspection of brain states is thereby indirect). Or am I wrong??”

Here’s how I’d describe what’s going on. Sensation is one mental state. When I introspect the sensation, that involves a second mental state, which itself is a conceptual representation of the first state. Also, the occurrence of the second state must be an automatic response to the first state. Now, some people who don’t hate the word “direct” would say that the introspection is direct insofar as it is automatic. Others would say it is not direct because it involves a representation. I prefer to say what’s going on without using the word “direct”.

Raising some interesting concerns about modality individuation, you write:
“I would have thought that if heat perception is to be direct, then the sense modality through such an experience is afforded is going to have to be tactile, rather than visual (otherwise it just sounds a bit like a category error).”

I think the distinction between dermal thermoreceptors and retinal photoreceptors will be important for distinguishing between seeing heat and feeling it. But I don’t see that much work can be done about directness in terms of receptors. Patterns of activity in the retina carry information about all sorts of stuff, like what color it is, how hot it is, whether it was manufactured in China, etc. Anything I can figure out by looking at something must involve information that passes through my retina, so I’m not optimistic that one can settle questions concerning directness in terms of what can and cannot be transduced at the site of reception. But then again, I don’t feel particularly motivated to settle questions concerning directness, at least, not in the vocabulary of “directness”.

2 Responses to “On the So-Called Directness of Neuro-Introspection”

  1. Hi Pete,

    I’ve been meaning to reply to your comments (especially on neuro-introspectionism and MR) for a while, but things are very hectic here right now–I hand in my MPhil thesis in little over a month’s time!

    There’s lots in your comments to think about. I think they clear up most of my issues about neuro-introspectionsim and directness. Although I still have some nagging concerns which I’ll see if I can articulate sometime soon.

    One last thing. When you write:

    “Now, some people who don’t hate the word “direct” would say that the introspection is direct insofar as it is automatic.”

    Do you think this is the sense of “direct” that Churchland had in mind?

  2. Pete Mandik says:

    Yes. Especially if the choice is between automatic and not mediated by representation.