![[dr. bob]](/dr-bob-sm.gif)
Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 14 of 14. This is the beginning of the thread.
Posted by alexandra_k on December 20, 2004, at 13:21:35
From Perception to Belief: the Problem of the Unwanted Prediction
After considering problems with several attempts to characterize the nature of the second factor Davies et al. (2002 p. 149) maintain that the second factor may be described as ‘a loss of the ability to reject a candidate for belief on the grounds of its implausibility and its inconsistency with everything else that the patient knows’. They then consider that ‘attempts to say in more detail what this loss of ability amounts to face many problems’ (2002 p. 149). They note that typically normal subjects believe what they perceive and they call this tendency a pre-potent doxastic response. Normal subjects are thought to be able to inhibit this response when what they perceive diverges too radically from prior perceptions or beliefs. Delusional subjects, on the other hand, are thought to develop delusions because they are unable to inhibit this response in the face of an erroneous perceptual experience (Davies et al., 2002 p.153). This line is similar to one interpretation of Stone and Young’s suggestion that the delusional error is that the subject favors observational adequacy over conservativeness, or accepts bottom-up (perceptual) information over top-down (rationally considered) evidence (1997 p. 349).
Davies et al, (2002 p. 152) consider that a difficulty with their account of the nature of the second factor - and this is a difficulty that would seem to apply to Stone and Young’s account also - is that they run up against what Davies et al. refer to as an ‘unwanted’ prediction. A visual illusion (such as the Muller-Lyer illusion, or the Ames room) would provide an erroneous visual perception for the delusional subject. On Davies et al.’s and on Stone and Young’s account of the nature of the second factor the delusional subject would be expected to accept this erroneous percept despite any rational evidence to the contrary (such as after measuring the lines, or coming to understand how the illusion is produced). Davies et al. would seem to be correct in considering this prediction to be implausible, although it should be said that it has not been empirically tested.
I would like to suggest that we may be able to avoid the unwanted prediction by suitably refining the kind of anomalous experience that is relevant to the production of delusion, and by a suitable analysis of the content of delusional utterance. If visual illusions do not produce the relevant kind of anomalous experience then it would not count against the two-factor account if a delusional subject did not accept an illusory percept to be veridical. A reconsideration of the nature of the anomalous experience can avoid the unwanted prediction currently implied by Davies et al.’s two-factor account, but moreover it can be seen to bring us closer to Maher’s line on the sufficiency of certain kinds of anomalous experience for the production of delusion.
Posted by alexandra_k on December 21, 2004, at 1:14:58
In reply to 1.3, posted by alexandra_k on December 20, 2004, at 13:21:35
I have been sooooooooo tempted to take a picture of the Muller Lyer illusion along to therapy with me to ask peoples in the waiting room whether they think the lines are of equal length or not.
I think this may be considered unethical, though...
Given that the best theory we've got and all would predict that I should induce a delusion in these people! Still, its a relatively safe place to go inducing delusions, I would have thought (and everyone thinks it is a crap prediction anyways).
Someone or other (Gleaves I think) was given ethical approval to attempt to induce DID in first year psych students! He wanted to show that the symptoms could be induced by hypnosis, and they let him!
I am tempted to say 'only in America' - but I should probably be a bit careful there ;-)
Posted by smokeymadison on December 21, 2004, at 16:37:20
In reply to Re: 1.3, posted by alexandra_k on December 21, 2004, at 1:14:58
In Kay Redfield Jamison's book "An Unquiet Mind" she describes how once when she was manic she was administered the inkblot test in class (i know the thing starts w/ a W but i can't remember the name right now or how to spell it). anyway, she went on to write elaborate descriptions of what the ink blots were. the prof pulled her aside and she got to work in a lab w/ him on persoality and mood, or something like that.
my point is, what is the relationship between mood and the ability to create a delusion? it is well known that severely manic or depressed people can become delusional. i would guess that utterances of paranoia would be made when a person is feeling extreme anxiety (like when i thought that my boyfriend was going to kill me). is it possible that the brain is more likely to produce a delusion when a person is feeling extreme emotion? is it possible that delusions can ONLY be formed in the context of extreme emotion? I know that in schizophrenia and depression, flat affect is common, but that is affect, not what the person is actually feeling inside. some thoughts...
SM
Posted by alexandra_k on December 21, 2004, at 17:02:04
In reply to Re: 1.3, posted by smokeymadison on December 21, 2004, at 16:37:20
There is some evidence that reasoning deficits turn up when the infomation to be processed has a strong affective componant. If you give someone with delusions two arguments (of the same form) and ask if the conclusions follow and one is neutral (about grass and rain) while the other is emotionally loaded (about people trying to kill you) then the faulty logic will show up on the second but not the first task.
This has led to some speculation that delusional subjects reasoning errors are the same as the reasoning errors exhibited by non-delusional subjects who are under a lot of emotional stress.
Here is something you might find interesting:
People with the Cotard delusion may claim that they are dead. It tended to occur in severe cases of depression, and it is less frequent now because of anti-depressants / shock treatment. What has been found is that while normal subjects have a heightened skin galvanisation response (sweat on the skin) to various stimuli - subjects with the Cotard delusion have a global lack of response.If you read the utterance 'I am dead' as expressing a claim about biological death then evidence against the delusion would be such things as 'do you feel your heart beating'. The fact that subjects who said 'I am dead' did not take their heart beating to count as evidence against their delusion was interpreted as evidence for their irrationality.
But lets try another interpretation of the utterance. Imagine (by empathy) how things must seem if you no longer feel affectively connected to either yourself or things in the world. This may plausibly lead to a sense of disembodiment or detachment. We often talk of emotional death or numbness. If this is what subjects with the Capgras delusion are trying to express then it is irrelevant to their expression of this that their heart is still beating! We have simply missed the point.
Can similar stories be told for all the different kinds of delusions?
I shall try...
PS just what a lack (or presence) of skin galvanisation response ammounts to is controversial. I talk about the f'd up galvinisation responses of subjects with the Capgras delusion in 1.4 and hypothesise a finding for subjects with the Fregoli delusion...
Posted by smokeymadison on December 21, 2004, at 17:08:33
In reply to Re: 1.3 » smokeymadison, posted by alexandra_k on December 21, 2004, at 17:02:04
i can totally understand how the delusional statement "I am dead" can occur with extreme depression. during my worst depression, when i hadn't eaten or slept in a week, i felt totally numb and pretty much dead, yeah, pretty far gone. it makes sense, that delusion. it is actually quite logical given what the person is FEELING.
Posted by alexandra_k on December 21, 2004, at 17:22:36
In reply to Re: 1.3, posted by smokeymadison on December 21, 2004, at 17:08:33
Indeed!
This delusion (people saying 'I am dead') was taken to be a prime example of an 'ununderstandable' delusion. A delusion whose content is self defeating in some way. I have even read some psychiatrist or other claiming that it is a blatant absurdity as Descartes proved the Cogito!
But that is simply missing the point!
That is what I want to say:Delusions are normal, understandable responses to certain kinds of anomalous experiences. The relevant kind of anomalous experience in the case of the Cotard delusion, for example, is global lack of affective response.
This does involve some interpretation (or perhaps reinterpretation of the delusional subjects utterances, however). Thats another reason why I go with what they say rather than what they believe - it allows for there to be a 'related' or 'lateral' meaning.
:-)
Posted by alexandra_k on December 21, 2004, at 17:27:01
In reply to Re: 1.3 » smokeymadison, posted by alexandra_k on December 21, 2004, at 17:22:36
But then what Davies et al want to say is that not EVERYONE with a global loss of affective response develops the Cotard delusion.
So they consider that there must be another factor to account for why some subjects develop delusion in the face of such an anomalous expereince while others do not.
They also want to say that they should say it is AS IF they have died, not that they HAVE died.
What do you think, are they still missing the point?
Posted by smokeymadison on December 21, 2004, at 19:39:06
In reply to 1.3, posted by alexandra_k on December 20, 2004, at 13:21:35
>>After considering problems with several attempts to characterize the nature of the second factor Davies et al. (2002 p. 149) maintain that the second factor may be described as ‘a loss of the ability to reject a candidate for belief on the grounds of its implausibility and its inconsistency with everything else that the patient knows’. They then consider that ‘attempts to say in more detail what this loss of ability amounts to face many problems’ (2002 p. 149). They note that typically normal subjects believe what they perceive and they call this tendency a pre-potent doxastic response. Normal subjects are thought to be able to inhibit this response when what they perceive diverges too radically from prior perceptions or beliefs. Delusional subjects, on the other hand, are thought to develop delusions because they are unable to inhibit this response in the face of an erroneous perceptual experience (Davies et al., 2002 p.153). This line is similar to one interpretation of Stone and Young’s suggestion that the delusional error is that the subject favors observational adequacy over conservativeness, or accepts bottom-up (perceptual) information over top-down (rationally considered) evidence (1997 p. 349).
In the case of the delusional statement "I am dead" it makes sense what Davies et al. said about delusional subjects being unable to inhibit the knowledge that they cannot be dead because their hearts are still beating, etc (which would be the "prior perceptions/beliefs" mentioned above) instead, the delusional subjects are going with what they are experiencing at the moment. And that experience is telling them that they are dead mentally, emotionally, etc. the delusion is "understandable" in my humble opinion.
as far as a second factor, i think that there must be one. i agree with the two factor theory in as much as it takes an experience and a person who has the capacity to beleive p and q at the same time. these people who are saying that they are dead, i think that a part of them knows that they are not, as with any delusional subject, but the part that believes that they are is the one who is "doing the talking"
i would like some feedback on the notion that in order to have a delusion, there has to be a fragmentation of the conscious mind. i am speaking from my own experience only, really, and haven't done any research on the subject myself. but it makes sense to me.
Basically, extreme emotion fragments the mind and different parts rationalize reality to different ends. a delusion is born when reality is p but the part of the mind that believes q is in control and does the talking, producing the utterances you are talking about.
SM
Posted by alexandra_k on December 21, 2004, at 20:11:28
In reply to Re: 1.3, posted by smokeymadison on December 21, 2004, at 19:39:06
Okay. So they say 'I am dead'. Then the question becomes, what is it that they actually believe (assuming delusions are beliefs), or what is it that they mean by their utterance? Now we need to engage in radical translation (this is a philosophical term with a history, but just think of it as specifying what meaning they are attempting to convey with their utterance).
Translation one: I am biologically dead.
Translation two: I am emotionally dead.
Now if they intend one then their utterance is false. They are not biologically dead. If they intend two then their utterance is true. They are emotionally dead (we speak of this in other contexts so it isn't that odd really). On translation one evidence that their heart is beating is evidence that their belief is false. On translation two evidence that their heart is beating is not even relevant to what they are saying. If they are expressing the nature of their experience then their claims are true in the way that expressions of experience are incorrigable. What seems to be the case is the case. If they are making a claim about the way the world is (as in one), however, then their utterances can be false and in this case they are. The very act of making the utterance entails that you are alive (on translation one).
> i would like some feedback on the notion that in order to have a delusion, there has to be a fragmentation of the conscious mind. i am speaking from my own experience only, really, and haven't done any research on the subject myself. but it makes sense to me.Okay. Maybe your case would be a bit different from the standard becasue maybe you never really lost 'insight' into the falsity of the belief. Maybe you wouldn't have been classified as delusional on those grounds. The notion is that some people do not have insight into the falsity of their beliefs however. Thats why the DSM says that they are held with a 'firm conviction'. But then it becomes an empirical matter as to whether there are in fact any delusions if we take the DSM to be authorative on the definition.
What if all 'delusions' (that are not acted on) are simply expressions of first person experience? What if their anomalous experience is so compelling that they are just continually giving expression to it?
What if the anomalous experience that was relevant to your case was an intense feeling that you were in danger; that someone wished you harm? Then your delusion would be understandable in light of that anomalous experience. We could distinguish between the specific and general form of the delusion. The general form could be given by the anomalous experience, and the specific form (that it was your boyfriend) could be a rationalisation for your experience. That would mean that you could waver with respect to the specific form - but there could be a conviction with respect to the general. I want to say that medication assists by removing or muting the anomalous experience. Get rid of the experience, and there we go.
> Basically, extreme emotionBut once again, the Cotard subject doesn't have extreme emotion. That is precisely the problem for the Cotard subject, that they don't feel anything at all. To maintain that delusions arise in response to extreme emotions would indeed require a second factor. It would also not be able to explain all of the delusions on the list (Cotard, for example).
>fragments the mind and different parts rationalize reality to different ends. a delusion is born when reality is p but the part of the mind that believes q is in control and does the talking, producing the utterances you are talking about.Yeah, someone is working on that currently in Australia. I don't know much about what he is up to. Except that the notion is that he is going to attempt to come up with a model of this that can be run as a computer simulation. I think this is a promising area, but it is one I have bypassed because I don't know enough about programming or coming up with models that are capable of being programmed.
Posted by alexandra_k on December 22, 2004, at 17:42:28
In reply to Re: 1.3, posted by alexandra_k on December 21, 2004, at 17:27:01
> But then what Davies et al want to say is that not EVERYONE with a global loss of affective response develops the Cotard delusion.
So maybe some people don't express their experience, while others do. Can we really hope to come up with necessary and sufficient conditions for someone saying a delusional utterance? I mean, can we really come up with necessary and sufficient conditions for someone saying a non-delusional utterance (such as 'please pass the salt'? Perhaps yes, but the necessary and sufficient conditions would have to be very abstract indeed...
> They also want to say that they should say it is AS IF they have died, not that they HAVE died.When you are expressing your experience in other contexts you don't say it is 'as if'. You don't say 'the weather is as if it is hot'. 'It is as if there is a red patch in front of me'. That would be a very odd thing to say indeed! Why should expressing delusional anomalous experience be any different?
Posted by smokeymadison on December 22, 2004, at 22:38:08
In reply to Re: 1.3, posted by alexandra_k on December 22, 2004, at 17:42:28
i really don't think that it is a very far jump from very severe depression to the Cotard delusion. it takes a...what should i say...artistic? person to make the jump. i mean, someone who is so absorbed into what they are feeling at the moment that all else falls away. as far as necessary and sufficient conditions--you aren't going to be able to define them even for the same person. i have said that a delusion is a result of fragmentation of the rational mind. each part rationalizes what is reality separately. so within each person there are these revolving "chunks" at any given moment one "chunk" is the one most forward in the mind and the one doing the talking.
we all are fragmented to a certain extent. we all have certain thoughts that are diametrically opposed to one another. ok, so maybe people with BPD have more of these :) anyway, trying to determine the necessary and sufficient conditions for a certain kind of person to become delusional would not include the people who have delusional thoughts that are not at the forefront of their minds.
let me try it this way. you are trying to determine the necessary and suffient conditions that lead to a person uttering a delusional statement. i think that it would have to be a two step clause. first, the N and S conditions that a delusional thought is in the person's head. then, the N and S conditions that that thought is contained in the part of the person's consciousness that is speaking. i know that that isn't very neurobiologically oriented for ya but there it is.
SM
Posted by alexandra_k on December 23, 2004, at 16:12:23
In reply to Re: 1.3, posted by smokeymadison on December 22, 2004, at 22:38:08
>someone who is so absorbed into what they are feeling at the moment that all else falls away.
Yup, someone who has become focused on giving expression to their anomalous experience.
>as far as necessary and sufficient conditions--you aren't going to be able to define them even for the same person.
Welllllll. What about if we hit upon some suitable level of abstraction and invoke a ceteris parabis (other things being equal) clause? E.g., necessary and sufficient conditions for someone saying 'please pass the salt': They BELIEVE that by asking for the salt they will get it AND they DESIRE salt, ceteris parabis. Ceteris parabis covers saying it in the context of a play, reading from a book, just talking nonsense, saying it in the context I have just said it in etc etc. Maybe it is cheating... maybe we can't cash out the ceteris parabis clause very well, but this seems to be a reasonable attempt.
I am not sure that we can generalise across ALL people who utter things characteristic of those different kinds of delusion. I am in sympathy for your line, but worry that it might ammount to giving up.
How about the necessary and sufficient conditions for uttering something characteristic of the Cotard delusion being: they (1) have an anomalous experience that has the content that they are no longer emotionally connected to anything and they (2) have the desire to express that. Ceteris parabis, of course :-)
>delusional thoughts that are not at the forefront of their minds.
Oh, delusional hypotheses occur to nondelusional subjects all the time. The problem is how come some people adopt the hypothesis as a belief and why they retain it despite 'incontrovertible and obvious proof or evidence to the contrary' (though I do question whether we typically produce evidence that is relevant to what the delusional subject is trying to express. Wellll, maybe the specific form, but not the general)
It used to be the case (well, it still is really) that the problems were the following:
(You can read these as pertaining to the bit of the brain that takes control of the language production areas on your model)
1) Why does the delusional hypothesis occur to some subjects?
2) Why is the hypothesis adopted as a belief?
3) Why is it retained as a belief despite 'incontrovertible and obvious proof and / or evidence to the contrary'?Maher's version of the empiricist model has it that the delusional hypothesis occurs as an explanation (rationalising strategy) for an anomalous experience.
All sorts of hypotheses occur to subjects when they attempt a rationalising strategy - but there is some evidence that some subjects tend towards an INTERNALISING bias in their explanation whereas others tend towards an EXTERNALISING bias. It was thought for a while that the experience of subjects with the Capgras and Cotard delusions was the same but the Capgras subject has an EXTERNALISING bias and blames the thing in the world for the anomalous experience (in that OTHER PEOPLE have been replaced) whereas the Cotard subject has an INTERNALISING bias and blames themself maintaining that they have changed in that they have died. But then there was the finding of concurrent Cotard and Capgras delusions which put a spanner in the works slightly (surely one cannot exhibit both an internalising and externalising bias at the same time - such a thing would render the distinction meaningless), and now it is typically acknowledged that the anomalous experience in the cases is different - Cotard, global loss of response, Capgras, loss of response to familiar faces.
Then it was found that delusional subjects outperform normal controls on probabilistic reasoning tasks - sorry, that compared to nondelusional controls they have a tendancy to 'jump to conclusions'. It was thought that some kind of bias might mean that some kinds of hypotheses occur to the subject, but not others. Then once the delusional hypothesis has occured delusional subjects are more likely to 'jump to the conclusion' that that hypothesis is correct.
(A worry here is that delusional subjects also tended to quickly 'jump out' of the conclusion that they had jumped into and they showed a tendancy to change their mind which is a problem when it comes to explaining why delusions are held despite evidence to the contrary).
So why is the hypothesis retained?
Thats where Davies et al and Stone and Young come in with the 'observational adequacy over conservativeness' or the inability to inhibit the 'believe what you perceive' response.
Someone asked - why do they believe the delusional hypothesis 'I have died' over 'something has gone wrong with my brain'? They are both internal attributions. (But of course neurological explanation is very different from intentional explanation and offering one when the other is sought simply ammounts to CHANGING THE TOPIC IMO - though cognitive explanation can be a bridge between them)
So why is the hypothesis retained???
IMO the recurrance of the anomalous experience in the face of no alternative ways to reality test.I guess that is a summary of what I know of what has been proposed of the second factor. All of the above is attempting to cash out what the 'cogntive bias / deficit' amounts to. None of it seems very promising to me. It is all very messy and hard to interpret. The data is a mess, all over the place. What typically sorts out that problem with the data is the phenomenon of theorists (and scientists) fairly much converging on a single theory - but that is a separate issue...
I really want to bypass most of that if possible.
I guess that if there are different mental modules and one believes the delusional hypothesis while another does not - well, then all of the above would apply to the module that does accept and retain the delusional belief.
I am worried about cases where people do act on their delusion. Maybe that can't be covered by the 'expression of experience' model that I propose... Maybe all I have done is said of the class of utterances that are not acted on, that they are not delusions proper...
Aaargh. This is driving me nuts at the moment.
Posted by Larry Hoover on January 16, 2005, at 14:22:02
In reply to Re: 1.3, posted by alexandra_k on December 23, 2004, at 16:12:23
> 1) Why does the delusional hypothesis occur to some subjects?
I don't think delusional hypotheses are anything but commonplace, occurring to all people with high frequency.
> 2) Why is the hypothesis adopted as a belief?
Because it makes sense.
> 3) Why is it retained as a belief despite 'incontrovertible and obvious proof and / or evidence to the contrary'?
Here's the rub. The declaration that there is incontrovertible evidence or proof is relative. For it to be true, there must be some sort of objective place of truth. No observer is without bias. All is subjective. All is relative. That a view is commonly held does not make it incontrovertible. From the supposed delusional's perspective, the delusion is sensible. And no matter what I might make of what is called a delusion, I don't ever want to lose sight of that fact.
Einstein's theory of relativity explained reality far better than did Newtonian "objectivity". Reality does depend on where you view it from.
Lar
Posted by alexandra_k on January 17, 2005, at 16:10:43
In reply to Re: 1.3 » alexandra_k, posted by Larry Hoover on January 16, 2005, at 14:22:02
> > 1) Why does the delusional hypothesis occur to some subjects?
> I don't think delusional hypotheses are anything but commonplace, occurring to all people with high frequency.
Ok. I guess I agree.
> > 2) Why is the hypothesis adopted as a belief?
> Because it makes sense.Ok, but why does it make sense to some subjects but not others? Or; why is it that some people develop delusions while others do not? Some people adopt the hypothesis as a belief while others may contemplate it without actually adopting it. What is the difference between these two sets of people? Is it a difference in the anomalous experience that they are expressing / trying to explain? Is it a difference in something else - ie their inability to inhibit believing in 'crazy' hypotheses?
Stone and Young consider the difference is a tendancy to let observational adequacy trump conservativeness. They consider that there are two opposing principles that are typically in tension.
(1) Observational adequacy - updating out beliefs in the face of new experiences.
(2) Conservativeness - adopting the beliefs that require the least changes in our belief network.They consider that the delusional error is to basically give up on (2). They adopt a 'crazy hypothesis' despite 'everything they previously knew to be true'.
Davies et al maintain that the delusional error is the 'inability to inhibit pre-potent doxastic response'. Here the idea is that there is a mechanism that produces a 'believe what you perceive' response. If you perceive a computer in front of you then this mechanism would have you come to believe that there is a computer in front of you. They consider that normal subjects are able to inhibit this response 'when what they perceive diverges too much from everything the subject previously knew to be true'. Delusional subjects seem unable to inhibit their coming to believe the 'crazy' hypothesis, whereas non delusional subjects seem able to inhibit this response.
> > 3) Why is it retained as a belief despite 'incontrovertible and obvious proof and / or evidence to the contrary'?
> Here's the rub.
Indeed :-)
>The declaration that there is incontrovertible evidence or proof is relative.
Ya. The DSM says 'held despite incontrovertible and / or obvious proof or evidence to the contrary'. Walkup, 1995 says that it is far from clear that delusional subjects are routinely presented with this kind of evidence before diagnosis or that they gain access to this kind of evidence during their recovery. It may be that delusional hypotheses are the sorts of things that it is hard to find supporting / disconfirming evidence for (such as some spiritual or religious beliefs, conspiracy theories, belief in UFO's, belief that one is living in a matrix or a dream).
I would say that we need to be clear on (delineate the content or meaning of) what it is that the delusional subject is saying BEFORE we can assess it for truth and BEFORE we can grasp what KIND of evidence would be relevant to support of disconfirm the belief.
For example. Cotard subjects say 'I am dead'. If they are saying that they are no longer biologically alive then the hypothesis is false. Evidence against it would be such stuff as their heart beating and their being able to walk around etc. If they are saying that they are emotionally dead then that would be true. It would not be relevant to what they are saying that their heart is beating. To consider that to be evidence against the belief is to have missed the point in what they are saying. To attribute a content (meaning) they never intended.
>For it to be true, there must be some sort of objective place of truth.
Ah well that depends on your theory of truth :-)
The correspondance theory of truth is probably the most common sense (intuitive) account of truth when it comes to people making assertions about the way the world is. What makes their claim true is the world being that way and what makes it false is the worlds not being that way. This does seem to require an objective world.But this is to suppose that the delusional subject is making a claim about how things are with the world. If the subject is expressing their experience then none of that would be relevant (expressions of experience cannot be false if genuine. If you say you feel hot then it is true that you feel hot. The way the objective world is is not relevant for assessing the truth or falsity of your claim).
When people do act on their delusion. When the guy decapitated his stepfather to look for the batteries and microfilm in his head - then it seems that we do need to consider his claim 'my stepfather has been replaced by an impostor' to be making a (false) claim about the objective world.
> From the supposed delusional's perspective, the delusion is sensible.
Yes, but what do they mean by what they say. I need to spell it out so that it is sensible for the rest of us.
This is the end of the thread.
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