Gold and Hohwy, Rationality and Schizophrenic Delusion

Transcription

1 PHIL 5983: Irrational Belief Seminar Prof. Funkhouser 2/6/13 Gold and Hohwy, Rationality and Schizophrenic Delusion There are two plausible departments of rationality: procedural and content. Procedural rationality is characterized as follows: On the procedural account, therefore, one is irrational if one s thoughts or actions fail to be governed by the relevant ideal, rule or reasoning procedure Central to the procedural account is the claim that the particular contents of one s thoughts are not in general relevant to the analysis of rationality. (148) A thought (or action) is content irrational if its content is itself implausible or ineligible. Some beliefs or desires, such as a desire for a saucer of mud, might have contents that are so bizarre that it is irrational to have them even if no procedural violation occurs. Gold and Hohwy s thesis is that there are delusions, such as those that often accompany schizophrenia, which are irrational but do not fall under either of these two departments. These are cases of experiential irrationality. Is this claim true? From a theoretical point of view, however, what is more significant than the bizarreness of delusion is the fact that, in the delusional state, the patient s mind seems invaded by an alien force The alien quality of delusional experience is, in our view, the key to understanding at least some of the delusions of schizophrenia and the nature of the irrationality of schizophrenic delusion. (150) Frith s theory of intentional action: Frith further posits the existence of a cognitive monitor that keeps track of both kinds of intention as well as of the actions that are actually chosen by the subject. In effect, the monitor is a mechanism of metarepresentation: it represents the ordered pair of the intention (whether stimulus or willed) and the action chosen as a result of that intention. Crucially, the effect of metarepresenting an intention is to bring that intention into the subject s consciousness. (151) We can apply this theory to thought insertion as follows: Suppose one of my goals is to go to work on time each morning. On a particular morning, I form the intention to catch the bus and then perform the action of thinking Catch the bus! If I have not monitored the 1

2 intention to catch the bus, I will find myself with a particular thought without any awareness of the intention that initiated it. As a result, I may experience the thought as having been put into my head by someone else a delusion of thought insertion. (152) This experiential rationality proposal should sound familiar, as we found a similar claim made by Gerrans. Gold and Hohwy echo Gerrans when they write: We propose that delusional irrationality consists in a failure of what we will call egocentricity, a property of thought closely related to the selfmonitoring central to Frith s theory. Self- monitoring is the cognitive process of representing an intention; egocentricity is the property a thought gets in virtue of being so monitored. It is the property of the thought which allows the thinker of that thought to recognize it as having originated in his mind. (153) Gold and Hohwy argue that neither procedural nor content irrationalities can explain the delusion of thought insertion. They discuss various proposals. Reflective Equilibrium. Reflective equilibrium would require rejecting thought insertion in favour of an explanation that cohered better with one s set of background beliefs, including those shared by the culture at large. In general, any account of rationality that requires coherence among beliefs will be violated by the hypothesis of thought insertion. (155) Response: These errors should not be domain specific, if this were the case. But, they are domain specific. if the schizophrenic agent has a global impairment in his ability to maintain coherence among his beliefs, one would expect this impairment to be domain-general one would expect the agent to experience of every imaginable kind. (157) But, who said that the impairment would have to be global? Or, why would it have to be so widespread? Evidence. Delusional schizophrenics ignore relevant evidence and treat other evidence with extreme bias. Response: Again, Gold and Hohwy claim that this problem should also lead to false beliefs more globally. Methodology. Those who believe in thought insertion break the rule that we should suspend belief when no reasonable explanation is at hand. Response: Gold and Hohwy claim that this is too demanding. 2

3 In asking the schizophrenic subject to refrain from explaining his experience, we would be asking him to forgo any story about why his experience is so strange, and that seems to be a demand that no agent at least no agent that approximates actual human agents could meet. (159) But is it too demanding to require that a methodologically rational person, in this situation, believe that she is mentally ill? Content-ineligibility. Further, the schizophrenic subject manages to incorporate the implausible belief into his system of delusion in a way that is reminiscent of Lewis s description of the twisting of belief and desire, namely, by a system of beliefs each of which is highly improbable or impossible on its own but which seems to acquire a veneer of plausibility from its coherence with the others. (157) Response: Once more, they claim that if this were true there should be very wide spread bizarre beliefs. (160) But, couldn t this same response be given to any isolated case of apparent content irrationality? But surely there are such cases. Gold and Hohwy claim that the experience itself is irrational. We claim, therefore, that the source of thought insertion and related delusions is the experience itself of the schizophrenic sub- ject, and, in particular, its alien quality it is the experience of non-egocentric thought as alien that is the delusion itself. Q: So, such irrationality exists even if the agent who has this experience correctly judges herself to be mentally ill? Gregory Currie, Imagination, Delusion, and Hallucination Currie s main thesis is: Loss of the distinction between what is imagined and what is true, or seriously a candidate for truth, can be psychologically disastrous, and I shall suggest that this is what we see in the delusions and hallucinations that mark certain phases of schizophrenia. (167) A disorder of imagination is characteristic of schizophrenia. Rationality is not all or nothing, and there could be quite specific functional 3

4 impairments that generate or maintain delusions. So it may be possible to understand the peculiarities of schizophrenic thought as resulting from specific, functionally localizable damage to a system the proper function of which is to support reason. (168) Note the distinction between horizontal and vertical support for a psychological thesis: Suppose that our hypothesis was that symptom-group S is due to the failure of functional component F, and that we have some independent reason to think that F is realized in a certain brain area B. Then our original hypothesis, together with the independently motivated claim that B realizes F, entails that people with S will show abnormality in B. If they do, then the original hypothesis gets additional support. Call that adding support vertically : the original hypothesis get additional support be being linked to a hypothesis at the lower, implementation level. But there is also such a thing as adding support horizontally: a theory that postulates a deficit in the functional organization of some mental system in order to explain one disorder might then be recruited to the explanation of another disorder. (168) Autism involves a lack of imagination. Hypothesis: Schizophrenia involves a disorder, but not a lack, of imagination. Frith argues that schizophrenics suffer from a deficit in metarepresentation the capacity to formulate thoughts about thoughts. (169) Frith s position is as follows: Frith suggests that poverty of action is due to an inability to produce selfwilled (as opposed to stimulus-elicited) action, that this is in turn due to an inability to access one s goals and that it is failure of metarepresentation which is responsible for this lack of access to goals. For the same reason, delusions of persecution and reference are due to a faulty awareness of other people s intentions, and delusions of control and thought insertion are due to faulty awareness of one s own intentions. (169) Currie responds, in part: Our sense that our actions are our own surely arises from the operation of more primitive, subpersonal mechanisms than those that are supposed to be operative in metarepresentation. (171) The idea is that schizophrenia involves a loss of a sense of agency. How- ever, schizophrenics sometimes overestimate their agency as well (e.g., the releasing bombs by urinating example). Frith proposes that there is impairment of action monitoring in schizophrenia due to impaired efference copying, and that there is comparably based impairment to intention monitoring. Thus it becomes 4

5 difficult for the schizophrenic person to detect her own actions, and also her own acts of will. (172) Hypothesis: The schizophrenic misidentifies imaginings that p for beliefs that p. Currie does not posit a metarepresentation deficit for schizophrenics. But one can misidentify an imagining without elevating it to the status of a belief e.g., it could be a mere idea. This is still a cognitive hallucination. (175) Imaginings are known as such because they are typically actions. But, schizophrenics have lost a sense of agency. This could explain why they do not recognize their imaginings as imaginings. But, how does one go from that error to the delusional belief of thought insertion? The thought, particularly in the case where it has bizarre content that does not cohere at all with her beliefs, may seem to be inserted, but she does not recognize herself as the agent who inserts it. She might then be tempted to make sense of the experience in terms of this being a thought which is inserted by someone else. (178) Hohwy and Rosenberg, Unusual Experiences, Reality Testing, and Delusions of Alien Control 1. * Many delusions seem to involve unusual experiences, as with Capgras. H&R will consider delusions of alien control, which involve an unusual experience of loss of agency. Schizophrenics often experience such a sense of passivity. * H&R pose a dilemma concerning the rationality of these delusional subjects: Proposals that do not posit a deficit of reasoning seem committed to the implausible prediction that normal healthy subjects will develop delusional states whenever they have any kind of unusual experience, such as seeing illusions. Proposals that do posit a deficit of reasoning (e.g., in terms of reasoning or attributional biases) seem committed to the prediction, which straight off seems implausible, that delusional patients will develop delusions whenever they have unusual experiences, such as seeing illusions (Davies et al., 2001). (142) They argue that the rationality failure is local, rather than a general competence failure. 2. * We normally are able to monitor our intentions so as to distinguish self-willed from externally motivated movement. We are also typically able to anticipate the changes brought about by self-willed action. In cases of alien control, the subject has the unusual 5

6 experience of one s movements being initiated by another agent (because it is known to be intentional). But early on in the process, the identity of this external agent is unknown. 3. * Typically, we believe what we perceive. Prior beliefs can inhibit this response, though. One might form a delusional belief on the bases of their experience. But why is it held tenaciously, rather than being inhibited by background beliefs (including cultural acceptance)? Perhaps it is because the experience reliably recurs. But if a healthy person repeatedly has an unusual experience, like the Muller-Lyer illusion, then why aren t they similarly delusional? Or why don t the schizophrenic patients fall victim to repeated Muller-Lyer illusions? We reject our eyesight on Muller-Lyer illusions because the inter-modal (and even some intra-modal) evidence outweighs what we see at first glance. Theoretical beliefs, the beliefs of others, as well as background beliefs can also lead to inhibition. But these do so, H&R claim, only to the extent that they are claims that could be tested empirically. * H&R claim that the unusual experiences that cause the alien control delusions are not susceptible to intra-modal or inter-modal empirical testing. This is also true for our ordinary experiences of emotion. H&R claim that there is no other way to test if you are the originator of your movements. In this regard, alien thought control differs from, say, anarchic hand movements. So far, the suggestion adds up to this: unusual beliefs arise when unusual experiences are taken as veridical because they occur in sensory modalities or at processing stages where application of the available reality testing procedures keeps giving the same result and where further intra- or inter-modal reality testing cannot be performed. These performance failures happen even though the patient does not have a deficit of reality testing competence, that is, even though the patient is able to inhibit the pre-potent doxastic response for other experiential contents. Tenaciously maintained monothematic delusions in their nascent state arise when these experiences recur. (153) * But how, then, do they reach the bizarre, particular content (e.g., involving aliens, or the CIA, or whatever) of their delusional beliefs? H&R say that these explanations are the best they can be offer given their commitment to the belief that some external agent or other is controlling them. This commitment also explains why the mental illness possibility is not accepted. * Well, why don t they just suspend belief? Or, why don t they defer to background implausibility of external control? H&R say that there is nothing to inhibit the formation and retention of this belief there is no further reality testing. So, they are committed to these experiences necessitating these kinds of delusions! 6