Control Consciousness: The Pure Perceptual Model

There are various reasons why it might be appealing to assimilate control consciousness to a form of sensory consciousness. Of our various mental states, the ones most vividly present to us are our states of sensory consciousness. Sensory consciousness, especially visual consciousness, is, from the point of view of science, perhaps our best-understood form of consciousness. Further, the institution of science itself is influenced by a long tradition of empiricism, an early motto of which is that there is nothing in the mind that is not first in the senses.

What, then, would it mean to assimilate control consciousness to sensory consciousness? It is natural among researchers to take deliberate bodily motion as a basic and paradigmatic case of an action. And the most natural way to assimilate consciously moving parts of one’s own body to a form of sensory consciousness is to do so in terms of sensory feedback from the muscles, tendons, and skin as the body parts in question are moved. Now, part of what makes the pure perceptual model pure is its denial of any direct contribution of a motor command signal to the subjective aspect of control consciousness. And it is precisely this denial that leads to the key weakness of the pure perceptual model of control consciousness.

We can perhaps best appreciate the shortcomings of the pure perceptual model by noting that the pure perceptual model entails the following two possibilities.

Possibility 1: Two subjectively indistinguishable arm movements that, though subjectively indistinguishable, differ objectively in that one was the consequence of the subject’s motor command and the other was unaccompanied by any motor command of the subject.

Possibility 2: An arm movement resulting from the subject’s issuing a motor command but, due to effects of anesthesia, is unaccompanied by sensory feedback, and, lacking sensory feedback, the subject is completely unaware of having either moved or even having tried to move his or her own arm.

In some sense of possibility, say, logical possibility, (1) and (2) represent genuine possibilities. However, in a sense of possibility more relevant to scientific interests, say natural or empirical possibility, there’s good reason to believe that neither (1) nor (2) are possible. For example, contra (2), as pointed out by Prinz (2007, p. 344) and Peacocke (2007, p. 359), a subject may be quite aware that they are moving a body part even though they are not perceiving the part due to either local anesthetic or severing of afferent nerves.
It is tempting to conclude from such cases that motor commands are not irrelevant to control consciousness in the way entailed by the pure perceptual model. However, to put the point in a way that is more neutral between the motor theory and the imagery theory, sensory input alone seems insufficient for control consciousness. Something more than sensory input is needed to account for such cases. The motor theory holds that the something more is the contribution of motor commands. The imagery theory holds that the something more is the contribution of sensory imagery. In the next post, I examine these two proposals in further detail.

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1. Control Consciousness

4 Responses to “Control Consciousness: The Pure Perceptual Model”

  1. Eric Thomson says:

    This is a great topic.

    I’m still not entirely sure what you mean by control consciousness. It seems (from your first post) to basically be consciousness of voluntary behavior (so, for instance, consciousness of salivating after being classically conditioned wouldn’t be control, but consciousness of pushing lever in a Skinner box would).

    Possibility 1 may be actual in certain cases of neglect. E.g., patients act as if the hand isn’t theirs, even while they see it grabbing keys and such. They treat it just as they would if someone else’s hands were grabbing the keys.

    Stepping back, it could be that motor commands provide important inputs to the consciousness box, but that experience is still purely sensory. E.g., I don’t feel my eye movement control signals, but they have a strong influence on what I see (e.g., compare voluntary saccade to someone pushing your eye with the same velocity).The saccade efference copy has a big effect on what I see, but still what I see is [visual], not [visual + efference copy] (or whatever) in flavor.

  2. Pete Mandik says:

    Hi Eric,

    Thanks for the comments. Quite helpful!

    Regarding what I mean by ‘control consciousness,” I think you get my meaning. Of course, an Oxbridge Word Ninja could swoop in here and say there’s some sort of difference between “consciousness of voluntary behavior” and “conscious voluntary behavior” that needs to be obsessed about, but I think for present purposes it’s safe to say to the imagined Oxbridge Word Ninja: “fuck that”.

    The neglect case is interesting and I’m not totally sure what’s best to say about it. If neglect is, as some say, largely an attentional deficit — like the neglect patients can’t attend to subjective differences that are there nonetheless — then maybe the case is not an example of possibility # 1 after all. But I don’t know. I just pulled that out of my…hat.

    Regarding the whole “important inputs…but still entirely sensory” thing, I think that’s a really interesting and important suggestion that I attempt to deal with in upcoming posts. (It’s a move my main sparring-partner on this, Jesse Prinz, is most certainly going to find quite appealing.) As I’ll deal with it there, I take the issues to hinge on “relative directness” of influence. I propose you wait and see if what I say then sucks.

    However…one thing I’m tempted to say now about, for instance, the Helmholtz eye-nudge sort of thing is that what it shows is that efference copies figure into the visual what-it’s-like-ness of the experiences in question — that visual what-it’s-like-ness is underdetermined by afferent signals. Other places where I talk about this sort of thing are:

    Mandik 1999 “Qualia Space and Control” and
    Mandik 2005 “Action Oriented Representation”

  3. Eric Thomson says:

    I look forward to following this. I once claimed that all consciousness is purely sensory, but have sort of backed off that based on things like ‘tip of the tongue’ phenomena, but I am curious how you will make an argument against the purely sensory theory based on control consciousness.

    You said of eye-nudge type experiments that they show ‘visual what-it’s-like-ness is underdetermined by afferent signals’: this clearly seems right.

  4. [...] Posts 1. Control Consciousness 2. The Pure Perceptual Model 3. The Motor Theory 4. The Imagery Theory 5. Introducing AEI 6. Control Consciousness Explained 7. [...]