Wegner and colleague’s model of the sense of agency probably won’t explain delusions of control but there are some surprising successes

A blog on a recent paper over at Imperfect Cognitions

many thanks to Lisa and Ema for including me.

with love, DrNPC

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Delusions of Alien Control and the Sense of Agency (disorders of self consciousness pt1)

Hello all

I like to think that I have been taking the idea of the philosopher as public servant seriously. This is perhaps grounded in an intuition that we all have reciprocal responsibilities to one another. Coupled with this is the fact that even though I actively publish my research I do not make any money from that. All of the money universities spend in buying journal subscriptions goes to the publishers, who as well as producing the published volumes (both hard and e) provide centralised mechanisms for peer review (although it is worth noting that the reviewers themselves don’t get paid by the publishers for their services). So who does pay me and my fellows for our research and reviewing? Well, I am employed b y a public university which means that indirectly you pay for my work. For this pay I produce the best research I can and the best teaching I can to those who come my way. I also write this occasional blog in which I have, amongst other things, been highlight examples of bad thinking when I come across them. I’ve enjoyed doing this for you, but today I’d like to go a step further and begin to try and give you a sense of the kind of research I do. Now my research papers are available to those with the right library subscriptions and in some instances in pre-print form on my website. You are of course free to read them, but these papers are written for other philosophers of cognitive science and usually a subset of those who happen to be working on a particular topic. So here is an attempt to make the things I work on more digestible. Here I begin a series of introductions into disorders of self-consciousness.

Imagine this scenario. Suppose you are walking down a flight of stairs, as you get to your level you reach to open the door, but there is something wrong with how the door opens. Perhaps it’s moving too fast? Shortly after this you realise the reason for this- someone else is opening the door from the other side. Mundane enough, but what if some of your actions felt like that when there wasn’t anyone else around? What then? Unfortunately this isn’t idle fancy, but rather a way for us to begin to understand what it is like for people suffering from what we call delusions of alien control. Here are some examples of the sort of things people suffering this delusion say:

When I reach my hand for the comb it is my hand and arm which move, and my fingers pick up the pen, but I don’t control them… I sit there watching them move, and they are quite independent, what they do is nothing to do with me… I am just a puppet who is manipulated by cosmic strings. When the strings are pulled my body moves and I cannot prevent it (Mellor 1970 p. 18).

I felt like an automaton, guided by a female spirit who had entered me during it [an arm movement].

I thought you [the experimenter] were varying the movements with your thoughts.

I could feel God guiding me [during an arm movement] (Spence 2001 p. 165)

Now people suffering this delusion say many unusual things, but what makes them all instances of delusions of alien control is that they say that it is not themselves, but rather someone else who is controlling their actions. Now why would they say this? Well that’s a terribly difficult question and I’ll be the first to admit that we don’t have an entirely acceptable answer- especially with regards to why they can believe that some other particular person (or god or similar) is in control.

But all is not lost; consider again opening a door whilst someone else unexpectedly opens it from the other side. There are two experiences here which are especially noteworthy. First there seems to be something wrong with the movement being made, it somehow doesn’t seem to be happening as it should. Second, thinking about the action that takes place, i.e. how the door is opened, it doesn’t seem like you are doing that. Sure it seems that you are contributing to it, but not exclusively and not in the normal way. This later experience, call it the sense of agency, has been of particular interest to me and has been one of the experiences I have studied as a case study in consciousness.

The sense of agency is the feeling that you, yourself, are the one controlling what you do with your body. You are the one that acts with your body and whatever artefacts (doors, tools etc.) you happen to be using. One thing that seems to be happening in the door example is that this feeling, quite appropriately, is absent- you don’t feel like you are (completely) in control of what is happening, and you are not in fact in control.

One of the better attempts to explain delusions of alien control sees close parallels between this (perfectly ordinary) experience and delusions of alien control. This idea put forcibly by Frith, Blakemore and Wolpert (Frith et al. 2000), is that part of why those suffering from delusions of alien control think that someone else is controlling their actions is because those actions all feel similar to what it’s like when you try to open a door someone else is also opening. The patient’s actions don’t seem to happen as they should and they lack a sense of agency for them.

Why might this happen? One idea is that maybe the sense of agency depends on (causally depends on- for the philosophers :)) actions feeling right, as happening as they are supposed to.  Looking at some older ideas about what is needed for motor control (i.e. controlling the body’s movements) we arrive at the claim that the motor control system needs to unconsciously predict what is going to happen based on what one is trying to do. The reason for this is twofold. First, it allows the person who is acting to respond to things more quickly, it takes time for sensory feedback from the body to get to the brain, so in order to correct errors more quickly the motor control system produces a prediction of what is going to happen. If the prediction is that one is going to make an error, say miss the cup one is reaching for and knock it over, then one can begin to correct this error before actually getting to the cup and knocking it over. Second it gives the person a way of distinguishing what sensory experiences one is having are due to changes in the world and which are due to what oneself is doing.

This later claim is especially important in understanding the sense of agency. One reason that the movement of the door seems so odd in our example is that it’s not happening as expected. That is it doesn’t move as predicted, it moves faster than it should. To have the experience it is supposed that we normally compare what we predict will happen to what actually does happen- according to our senses. When the prediction isn’t met, the action feels odd, like there is something wrong with it. In this case the door moves faster than it should.

Now let’s add another supposition. What if this comparison between what happens and what is predicted to happen is (causally) responsible for the sense of agency? Such that when there is a match one experiences a sense of agency and when there is no match one doesn’t experience a sense of agency. Well then we get a neat, albeit simplified, picture on which we can explain why opening the door with someone else feels like it does. The door doesn’t move as predicted, so there is no match and no sense of agency.

Can this be applied to delusions of alien control? Well one hypothesis is that those suffering this delusion sometimes fail to properly predict what will happen based on what they are trying to do. Without this prediction there can be no match between what is expected and what happens and so they lack a sense of agency. When this happens for the patient their action feels odd, like it’s not happening in the right way, and they lack a feeling of being in control of the action.

There is evidence that such patients do have problems in forming such predictions. Try and tickle yourself. Can’t do it? This is thought to happen because the sensation of touch as you try to tickle yourself is predicted by the motor system. This prediction cancels out, to an extent, the feeling of touch- it just isn’t strong enough to feel tickly. However, this is not so for those suffering delusions of alien control. These patients say that when they tickle themselves it feels just as intense and tickly as if someone else does it (Blakemore et al. 1999; Blakemore et al. 2000). This is thought to be because they do not predict the feeling of touch coming from their own action in the right way and so the feeling, when it occurs, is not cancelled out.

We have then an interesting case where a normal experience is absent in a delusion and the potential of an explanation for why this occurs. Overall this gives us a nice case study in how we come to have the experiences we have, a case study in consciousness.

Now of course the truth of this hypothesis is controversial and much of my research has been examining whether or not it is true. You can read about the evidence that supports these ideas and a comparison of this view to its rivals in my papers:

(2009) “Commentary on Synofzik, Vosgerau and Newen 2008″ in Consciousness and Cognition 18(2) pp.515-520; DOI:10.1016/j.concog.2008.05.006;

(2010) “A Comparison of Fortunes: the Comparator and Multifactorial weighting Models of the Sense of Agency” in Christensen, Schier and Sutton eds. Proceedings of the Australasian Society for Cognitive Science online copy

(2010) “A Problem for Wegner and Colleagues’ Model of the Sense of Agency” in Phenomenology and the Cognitive Sciences 9(3) pp.341-357; DOI:10.1007/s11097-010-9150-6

(2012) “The Case for the Comparator Model as an Explanation of the Sense of Agency and its Breakdowns” in Consciousness and Cognition 21(1) pp.30-45; DOI:10.1016/j.concog.2010.08.005

See my publications page for my research papers.

And there you have it. This is one of things that I do.

With Love

DrNPC

References

Blakemore, S.-J., J. Smith, R. Steel, E. C. Johnstone and C. D. Frith (2000). “The perception of self-produced sensory stimuli in patients with auditory hallucinations and passivity experiences: evidence for a break-down in self monitoring.” Psychological Medicine 30: 1131-1139.

Blakemore, S. J., C. D. Frith and D. M. Wolpert (1999). “Spatio-temporal prediction modulates the perception of self-produced stimuli.” Journal of Cognitive Neuroscience 11: 551-559.

Frith, C. D., S.-J. Blakemore and D. M. Wolpert (2000). “Abnormalities in the Awareness and Control of Action.” Philosophical Transactions of the Royal Society of London Series B – Biological Sciences 355: 1771-1788.

Mellor, C. S. (1970). “First Rank Symptoms of Schizophrenia.” British Journal of Psychiatry 117: 15-23.

Spence, S. A. (2001). “Alien Control: From Phenomenology to Cognitive Neurobiology.” Philosophy, Psychiatry, Psychology 8(2-3).