Tag Archives: psychosis

Polythematic Delusions and Logico-Theoretical vs. Experimentalist Turn of Mind

A paper published in the Journal for Neurocognitive Research,  Vol.  2013, 55, No. 1-2.

This article aims to contribute to cognitive therapy of polythematic delusions by proposing a preliminary step to the implementation of traditional cognitive therapy, based on the construction of alternative hypotheses to delusions and testing of the latter. This additional step resides in the construction in the patient of the necessary skills to use the general experimentalist method of knowledge acquisition. Such an approach is based on the contrast between the logico-theoretical and the experimentalist turn of mind. Some elements such as to allow any such construction in the patient are then described and analyzed.

This article is cited in:

Ondrej Pec, Petr Bob,and Jiri Raboch (2014) Splitting in Schizophrenia and Borderline Personality Disorder, PLoS One 9-3 e91228.


Polythematic Delusions and Logico-Theoretical vs.  Experimentalist Turn of Mind

Classical cognitive therapy targeted at polythematic delusions associated with schizophrenia is based on the search for evidence related to delusional ideas and the construction of alternative hypotheses to the latter. This article aims to contribute to cognitive therapy for polythematic delusions by proposing a preliminary step to this classical cognitive therapy. Such a step aims to strengthen the patient’s ability to use the general approach of experimentalist type for knowledge acquisition—an approach which is based on the opposition between the theoretical-logical and the experimentalist turn of mind. Some elements such as to enable the reinforcement of such a capability in the patient are thus described and analyzed.

Theoretical-logical vs. experimentalist turn of mind

Cognitive therapy of schizophrenia aimed at polythematic delusions includes a component mainly oriented toward teaching the patient skills for search of evidence relating to the ideas associated with polythematic delusions, as well as the construction of alternative hypotheses (Kingdon & Turkington, 1994, 2002). It consists thus, on the one hand, of teaching the patient how to construct alternative hypotheses to delusions such as “television is talking about me”, “a satellite sends me thoughts”, “aliens are plotting against me”, etc., and secondly to encourage him/her to test both delusions and the associated alternative hypotheses, in order to validate or invalidate them. Such an approach applies then, in a specific way, to polythematic delusions which are inherent to the patient, and the corresponding alternative hypotheses. At this point, we can observe that this approach is associated with a general methodology of the same nature, which is not based on the very polythematic delusions inherent to the patient. Such an approach proves then grounded on the acquisition of the general ability to build up alternative hypotheses and to carry out tests on different hypotheses. Unlike traditional therapy that bears specifically on the content of the polythematic delusions, such an approach presents a general nature and proves likely to refer to any type of hypotheses. We can describe the general nature of such an approach as experimentalist.

We can observe here that the fact that classical cognitive therapy is based on strengthening in the patient the ability to develop alternative hypotheses to delusions and to perform tests on them, implicitly relies on the fact that such an ability is low or deficient in the patient, at least with respect to the delusions developed by the latter. We suggest then to make the wider assumption that the overall ability to develop alternative hypotheses and tests in order to validate or invalidate ideas, could be low or deficient in the patient, and that the problem encountered with delusions represents the visible part of a more general problem that is inherent to the patient. We also propose that the two above-mentioned elements (test implementation and construction of alternative hypotheses) are also part of an overall ability that also includes additional elements, and can be defined as the ability to implement the experimentalist method of knowledge acquisition.

For the purpose of the present study, it is necessary to further clarify the very notion of general methodology of experimentalist nature. To this end, it is worth contrasting first the experimentalist turn of mind with the logico-theoretical one. Such opposition allows for a better understanding of the experimentalist approach itself. This opposition corresponds essentially to a classical opposition in science, which contrasts two particular styles that each lead to acquisition of knowledge. Whereas the method of experimentalist inspiration proceeds by elaborating hypotheses and testing them, the logico-theoretical method proceeds by logical deduction or induction from a set of knowledge of which the one who exerts it strives to maintain consistency. Both methods, on the scientific level, each have their supporters and detractors. However, advances in knowledge are to be credited to both methods, which ultimately appear as complementary and may eventually be regarded as two ways of accessing scientific knowledge.

The opposition between experimentalist vs. logico-theoretical turn of mind is not limited, however, to the scientific field. Indeed, such opposition has a more general scope and also applies to any body of knowledge, including that resulting from the process of acquiring information and knowledge concerning everyday life. In this context, the logico-theoretical turn of mind notably proceeds by deduction, by trying to acquire knowledge in a logical way; it is aimed at explaining and interpreting facts and phenomena. Such an approach is underpinned by a concern for consistency of the whole corresponding set of knowledge, by also trying to identify and remedy any internal contradiction. The logico-theoretical approach may also proceed by inductive reasoning, thus making use of inductive generalization. In addition, when an internal contradiction is found, thus rendering the whole set of knowledge inconsistent, the one who proceeds in a logico-theoretical way strives to quickly restore this consistency, by possibly modifying some elements that are part of the overall knowledge at his/her disposal. Conversely, the one who proceeds with the help of the experimentalist approach is basically concerned with validating theories and hypotheses, through experimentation, testing, and search for evidence. He/she is then concerned with only retaining ultimately that knowledge that has been validated by experience and whose strength lies in the evidence which has been thus collected.

Thus characterized through their opposition, it is no less apparent that each of the experimentalist or logico-theoretical method of knowledge acquisition has its drawbacks when pushed to the extreme. When applied in excess, the logico-theoretical method thus leads to risky speculation and lack of evidence, to unrealistic and disconnected from the reality viewpoints. Conversely, experimentation pushed to the extreme leads to knowledge that lacks power of abstraction, explanatory and predictive power, and does not allow understanding of the data and the phenomena. In order to better emphasize the related notions and also better highlight the relationship with the different neighboring concepts, it is worth providing some additional insight over the opposition between experimentalist and logico-theoretical methodology. We shall propose then to make use of the matrices of concepts described in Franceschi (2002), which allow to emphasize the relationships between some given concepts. A matrix of concepts thus consists of six concepts, distributed along two dual poles: A and Ā. Each of these poles admits of respectively a concept of neutral A0, Ā0, positive (A+, Ā+) and negative (A, Ā) nature. In total, the matrix consists of the six following concepts: A+, A0, A, Ā+, Ā0, Ā.

Figure 1. Structure of a matrix of concepts

Among the main relationships that can be defined between concepts of the same matrix, it is worth citing: (i) the duality relation, between two neutral concepts of different poles: A0 and Ā0; (ii) the relation of antinomy (or of contrary) between two concepts that are not neutral (that is to say, positive or negative) of opposite polarity and of different poles: A+ and Ā, as well as A and Ā+; (iii) the complementary relationship between two concepts of same polarity (positive or negative) and of different poles: A+ and Ā+ as well as A and Ā. For example, the matrix of concepts corresponding to the concepts of courage, cowardice and temerity is thus as follows:

Figure 2. An instance of a matrix of concepts

At this step, we are in a position to construct the matrix of concepts that applies to the opposition between theoretical-logical and experimentalist turn of mind. Each of these concepts presents an intrinsic neutral nature, but is likely to give rise to a positive and a negative form. The corresponding matrix of concepts is thus the following:

Figure 3. The matrix of concepts associated with the theoretical-logical/experimentalist turn of mind

We can see here that the theoretical-logical turn of mind presents a positive form which leads to fruitful theorization, and a negative form that engenders unrealistic ideas and hazardous speculations. Conversely, the experimentalist turn of mind has a positive form which entails the solidity of knowledge and the search for evidence, and a negative form which leads to extreme empiricism, associated with lack of understanding and absence of explanation.

General application of the experimentalist methodology

The foregoing analysis leads to the hypothesis that it might be advisable to rebuild preliminarily in the patient the general ability to implement the experimentalist method of knowledge acquisition, before applying it later in a specific way to polythematic delusions. Cognitive therapy targeted at polythematic delusions would accordingly involve two phases: the first aimed at restoring in the patient the functional ability to the experimentalist general approach; and the second intended to implement the latter, in a specific way, by applying it to polythematic delusions. Several arguments seem to lean in favor of such an option. Firstly, it seems preferable that the patient be first convinced of the merits of the experimentalist method of acquiring knowledge, even before applying it to polythematic delusions. In other words, it seems better than the patient has himself/herself acquired first the belief that the theoretical-experimental method is effective and useful before applying it to the specific topics corresponding to delusions. Second, it also seems preferable that the patient would acquire a prior good practice and be exercised first to the experimentalist method on external, neutral and impersonal facts, before applying it to his/her own delusions which present for him/her an eminently emotional, personal and sensitive nature. Presumably also the choice of topics external to the patient should be such as to enable him/her to mobilize his/her cognitive abilities optimally. Thirdly, it is reasonable to think that the fact of applying the experimentalist methodology exclusively to the content of polythematic delusions, without possessing at the same time such a general ability might have some disadvantages. One of these drawbacks may lie in the fact that the patient could quickly rebuild some other delusions from other themes than those usual to him/her. Finally, it is worth mentioning that the acquisition and the general practice of the experimentalist methodology on topics that are completely independent of the content itself of the polythematic delusions should be non-confrontational, and likely to preserve the therapeutic alliance.

At this point, it is possible to sketch an outline of what could consist such a preliminary part of cognitive therapy for polythematic delusions. This last part would include a component targeted at learning the construction of alternative hypotheses, and a component designed to the learning of testing different hypotheses. However, in order to form a coherent whole, it is reasonable to think that this part of the therapy should also include an explanation of a number of related concepts, among which we can mention: the distinction between fact and hypothesis; the notion of proof; the distinction between evidence and conviction; the notion of validation and invalidation of a hypothesis; the distinction between fact and interpretation of fact; the distinction between fact and perception of fact; the distinction between fact and fact narration; the construction of alternative hypotheses; the development of tests with regard to a hypothesis; the causal relationship between facts; the proof of the causal relationship; the distinction between facts whose cause is intentional or non-intentional; the notion of explanation of a given phenomenon. Several of these elements, especially those related to the construction of alternative hypotheses, are integral part of the training program for metacognition developed by Moritz et al. (2010, 2011).

It is also useful to point out here several areas where the above-mentioned principles could be put into practice. These areas are potentially very diverse, but it is however possible to describe more accurately some of them, which relate to electronics and computer science. In the field of electronics first, consideration could be given to take an interest in electronic circuits (or computer simulations thereof) and their operation. Thus, the patient’s attention could focus on the operational problems of such and such circuit and especially on the search for causes of observed failures (e.g. the fact that a led indicator does not light up). It will then be necessary to formulate different hypotheses regarding the cause of the malfunction, which may relate to different circuit components (transistors, power supply, the led indicator itself, etc..) which can then be tested in order to be validated or invalidated, and later give rise, depending on the test results to other hypotheses, etc..

The field of computer science, second, could offer various fields of applications, especially in programming. We may notably consider a computer program that is supposed to produce a given result but has a defect in its execution, due to a “bug”. It will be then a matter of accurately determining the cause of this bug i.e., of finding the specific instruction within the program, which is responsible. The patient would thus be required to make assumptions regarding the specific instruction in the program among instr1, instr2, instr3, …, instrn, which is at the origin of the bug and to test successively the latter. This will lead for example to eliminate the instruction instr1 of which it will be assumed that it is the origin of the bug and to test the program without it, etc.. If the latter test invalidates the hypothesis, such an approach will then lead to test another instruction instr2, and so on.

Specific application of the experimentalist methodology to polythematic delusions

Classical cognitive therapy of schizophrenia (Kingdon & Turkington, 1994; Beck & Rector, 2000; Kingdon & Turkington, 2002) aims to gradually reduce the degree of belief in the patient’s delusions. For this purpose, the therapist suggests to the patient, in a spirit of dialogue of Socratic inspiration to build alternative hypotheses. He/she also teaches to the patient the process of testing the various competing hypotheses by seeking evidence, thus allowing to confirm or refute them.

It seems useful, at this point, to describe the different stages that occur differently depending on the level—primary, secondary or tertiary—of the corresponding delusions (Franceschi (2008). We shall consider in turn each of these levels. We propose to analyze here the delusions of reference, given that the analysis can be transposed to the delusions of influence, of telepathy, of thought projection or of control.

A primary delusional argument of reference, first, has the following structure (the symbol denotes the conclusion):

(R1)in T1 I was drinking an aperitifpremiss1
(R2)in T2 the presenter of the show said: “Don’t drink!”premiss2
(R3)∴ in T2 the presenter of the show said: “Don’t drink!” because in T1 I was drinking an aperitifconclusion

The corresponding delusional idea is that according to which the presenter said in T2: “Don’t drink!” because the patient has been drinking an aperitif in T1. The structure of such a delusional idea is as follows: the event E1 (in T1 I was drinking an aperitif) is the cause of the event E2 (in T2 the presenter of the show said: “Don’t drink!”). In this case, the logical structure of the alternative hypothesis to the delusional conclusion (R3) is that the event E1 which is internal to the patient is not the cause of the external event E2. The different alternative hypotheses identify then themselves with alternative causes to the event E2. Thus, the delusional conclusion (R3) may be confronted with an alternative hypothesis such as: the presenter said in T2: “Don’t drink!” because the script of this television program contained it. Another alternative hypothesis is that it is the assistant presenter who suggested to say it, etc..

One may think, however, that the fact of proposing to the patient alternative hypotheses to the delusional conclusion (R3) just mentioned, could prove insufficient. In effect, the patient’s delusional idea that the event E1 internal to the patient is the cause of the external event E2, not only has the nature of a hypothesis, but also has explanatory power, in the sense that it constitutes an explanation of the fact that appears bewildering to the patient that the presenter has said: “Do not drink!” immediately after the patient has been drinking an aperitif. In comparison, the fact that the event E2 internal to the patient is not the cause of the external event E2, constitutes an alternative hypothesis, but proves devoid of such explanatory power. For this reason, we believe that the mere statement, under this form, of the latter alternative hypothesis should not suffice to gain the support of the patient. For it is necessary to submit to the latter an alternative hypothesis to the conclusion (R3), which is also able to provide an explanation for the rapid succession of events E1 and E2. In this context, an alternative hypothesis that also allows to provide an explanation for the rapid succession of two phenomena, is the one according to which the external event E2 succeeded immediately after internal event E1, by the effect of a coincidence. Under these conditions, the patient faces two competing hypotheses that may explain the rapid and disturbing sequence of events E1 and E2: the first hypothesis being that E1 is the cause of E2; and the second being that the rapid succession of E1 and E2 is but a coincidence.

Secondly, the structure of secondary delusional arguments of reference is as follows:

(R1)in T2 the presenter of the show spoke according to what I was doingpremiss1
(R2)in T4 the presenter of the show spoke according to what I feltpremiss2
(R3)in T6 the presenter of the show spoke according to what I was doingpremiss3
(R…)
(R10)∴ the presenters of the shows speak according to what I do or what I feelconclusion

The corresponding delusional idea of reference is then the conclusion (R10) that the presenters of the shows speak according to what the patient makes or feels. The conclusion (R10) is of an inductive nature and constitutes a generalization from the several instances (R1), (R2), (R3), … Here, the logical structure of the alternative hypothesis to the conclusion (R10) is that the presenters of the shows do not speak according to what the patient makes. But in the same way as above, such a hypothesis proves devoid of explanatory power. In contrast, the alternative hypothesis, which has an additional explanatory power, is the fact that by the effect of coincidences, the rapid succession of two events that may give the impression of the existence of a relationship causality, occurs frequently.

Finally, the ternary delusional arguments of reference exhibit the following structure:

(R10)∴ the presenters of the shows speak according to what I do or what I feelpremiss
(R11)∴ television speaks about meconclusion

The ternary delusional idea of reference is the one according to which television speaks of the patient. The logical structure of the alternative hypothesis is the one under which television does not speak of the patient. However, in the same way as above, such a hypothesis does not possess in itself an explanatory power. For the conclusion (R11) has, in the patient’s mind, an explanatory function to the succession of events that he/she experienced. It proves thus necessary, at this stage, to propose an alternative explanation, which resides in the fact that through the effect of coincidences, it frequently happens that the patient’s internal events are immediately followed by external events, which can give the impression that there is a causal relationship between the two successive events. However, it may be pointed out to the patient, there is a much larger number of pairs of successive events that are not consistent with a causal relationship. It is indeed a common attitude to pay attention only to the succession of two events that could be meaningful, even though it occurs every day many more successions of two unmeaningful events and to which one does not pay any attention. This appears as a special case of misinterpretation of random data (Bressan, 2002).

Conclusion

At this point, it is worth translating the previous elements in terms of testable hypotheses by the clinician. This leads thus to test the hypothesis that cognitive therapy applied to polythematic delusions may be more effective if it included two successive steps: the first advocated by the present study that aims to reconstruct the patient’s general ability to acquisition of knowledge through the practice of the experimentalist method; and the second, classically defined by cognitive therapy of schizophrenia that leads to apply specifically the skills thus acquired to the content of polythematic delusions.

Finally, it is possible to synthesize the ideas expressed in Franceschi (2011) regarding the co-morbidity of schizophrenia with the elements resulting from the present study. We are thus able to define the different stages of the resulting process for cognitive therapy of delusions inherent to schizophrenia. This would mean thus, in a first step, determining the co-morbid disorders (specific phobias, generalized anxiety disorder, social phobia, intermittent explosive disorder, etc.). associated in the patient with the delusional ideas and to apply first a specific cognitive therapy. In a second step, it would mean applying the learning phase of the above-mentioned method experimentalist of a general nature. Finally, in a final phase, it should be proceeded as indicated by classical cognitive therapy, by applying specifically the experimentalist methodology to the content of delusions. This can be translated as follows in terms of testable hypotheses: a cognitive therapy of schizophrenia that would proceed according to these three successive stages could be more effective than classical cognitive therapy.

References

Beck, A. (2002). Delusions: A Cognitive perspective. Journal of Cognitive Psychotherapy, 16–4, 455–468.

Bressan, P. (2002). The connection between random sequences, everyday coincidences, and belief in the paranormal. Applied Cognitive Psychology, 16, 17–34.

Franceschi, P. (2002). Une classe de concepts. Semiotica, 139–1/4, 211–226. English translation.

Franceschi, P. (2008). Une défense logique du modèle de Maher pour les délires polythématiques. Philosophiques, 35-2, 451–475. English translation.

Franceschi, P. (2011). Traitement cognitif différentiel des délires polythématiques et du trouble anxieux généralisé. Journal de Thérapie Comportementale et Cognitive, 21–4, 121–125. English translation.

Kingdon, D. & Turkington, D. (1994). Cognitive-behavioural Therapy of Schizophrenia. New York: Guilford.

Kingdon, D. & Turkington, D. (Eds.) (2002). The Case Study Guide to Cognitive Behaviour Therapy of Psychosis. Chichester: Wiley.

Moritz, S., Woodward, T. S., & Metacognition Study Group. (2010). Metacognitive training for schizophrenia (MCT). Manual (4th ed.), Hamburg: VanHam Campus.

Moritz, S., Kerstan, A., Veckenstedt, R., Randjbar, S., Vitzthum, F., Schmidt, C., Heise, M., Woodward, T.S. (2011). Further evidence for the efficacy of a metacognitive group training in schizophrenia. Behaviour Research and Therapy, 49, 151–157.

On the Plausibility of Psychotic Hallucinations

A paper published in the Journal for Neurocognitive Research,  Vol. 53, No 1-2 (2011).

In this paper, we describe several factors that can contribute, from the patient’s viewpoint, to the plausibility of psychotic hallucinations. We sketch then a Plausibility of Hallucinations Scale, consisting of a 50-item questionnaire, which aims at evaluating the degree of plausibility of hallucinations. We also emphasize the utility of pointing out to the patient the several factors that contribute to the plausibility of his/her hallucinations, in the context of cognitive therapy for schizophrenia.

This paper is cited in:

  • Mark Grimshaw, Tom Garner, Sonic Virtuality: Sound as Emergent Perception, New York: Oxford University Press, 2015
  • Charlotte Aynsworth, Daniel Collerton, Robert Dudley, Measures of visual hallucinations: Review and recommendations, Clinical Psychology Review, Volume 57, 2017, Pages 164-182
  • I. de Chazeron, B. Pereirae, I. Chereau-Boudete, G. Broussee, D. Misdrahie, G. Fénelone, A.-M. Tronchee, R. Schwane, C. Lançone, A. Marquese, B. Debillye, F. Durife, P.M. Llorca, Validation of a Psycho-Sensory Hallucinations Scale (PSAS) in schizophrenia and Parkinson’s disease, Schizophrenia Research, Volume 161, Issues 2-3, Pages 269–276, 2015

On the plausibility of psychotic hallucinations

Cognitive therapy of hallucinations is part of cognitive therapy for schizophrenia. Several accounts of cognitive therapy of hallucinations have been described in the literature (Chadwick et al.,1996; Rector & Beck, 2002; Kingdon & Turkington, 2005). On the one hand, Chadwick et al. (1996) stress the importance of the ABC model for cognitive therapy of hallucinations: the hallucinations are the activating events, which engender cognitions, which in turn yield emotional distress and anger. By working on beliefs about the voices, they primary aim at reducing the negative emotions which are the consequences of automatic thoughts following the occurrence of hallucinations. Chadwick et al. also have a special emphasis on the omnipotence and omniscience of the voices. On the other hand, Kingdon & Turkington (2005) propose the cognitive model of hallucinations as an alternative explanation for the voices: auditory hallucinations are the patient’s automatic thoughts that are perceived as originating from outside the patient’s mind. Kingdon & Turkington weigh the available evidence for both competing explanations and finally work on reattribution of auditory hallucinations. Rector & Beck (2002) take a similar stance, and stress that the final aim of the therapy “is to help patients recognize that the voices simply reflect either their own attitudes about themselves or those they imagine others to have about them”.

The purpose of the present paper is to contribute to cognitive therapy for schizophrenia by focusing on the plausibility of psychotic hallucinations. Our concern will be with providing an account of complex hallucinations encountered in schizophrenia that stresses multiple factors which reinforce, from the patient’s viewpoint, the intrinsic plausibility of the hallucinations. The purpose of this paper is then to expose how hallucinations can seem plausible and credible to the patient. In section 1, we describe several factors that contribute to the plausibility of hallucinations occurring in schizophrenia. We sketch then in section 2 a scale which is designed to measure accurately the plausibility of hallucinations. In section 3, we point out what could be the impact on cognitive therapy for schizophrenia of the present account. Finally, we point out the limitations of the present study and some directions for further research.

1. Factors of plausibility of hallucinations

We shall enumerate in what follows several factors that can contribute, from the patient’s viewpoint, to the plausibility of the hallucinations that he/she experiences. Hallucinations are one major symptom of schizophrenia. According to DSM-IV, a hallucination is defined as “A sensory perception that has the compelling sense of reality of a true perception but that occurs without external stimulation of the relevant sensory organ”. (DSM-IV, p. 767). By plausibility, we mean the fact that the patient’s abnormal perceptions are seemingly attributable to an external source (usually, other people). The plausibility that results from certain phenomenological features of auditory hallucinations has notably been hinted at by Stephane et al. (2003):

(…) hearing “multiple voices” is associated with attribution of the “voices” to others, which is plausible intuitively as well. This indicates that the patients’ experiences of hallucinations could be understood, intuitively, based on common sense experiences of the world.

In this paper, we shall expand this idea, by pointing out that multiple factors are susceptible of congruently strengthening the patient’s conviction that his/her abnormal perceptions come from the external world.

Hallucinations come in a variety of modalities. In order to shed light on the factors that can lead to the plausibility of hallucinations occurring in schizophrenia, it is worth drawing first some useful distinctions.

1.1 Unimodal and multi-modal hallucinations

Let us consider, to begin with, the distinction between unimodal and multi-modal hallucinations. Unimodal hallucinations can be classified into five types, corresponding to our five sensory pathways: auditory, visual, olfactory, tactile and gustatory. Multi-modal hallucinations are made up of unimodal hallucinations of different types which occur simultaneously (or quasi-simultaneously). There are accordingly 26 combinations of multi-modal hallucinations (plus 5 unimodal ones). The latter can be enumerated exhaustively as follows (we also describe an instance of some common multi-modal cases, since it can be useful for explanatory purposes):

(i) 1-modal: auditory, visual, olfactory, tactile, gustatory

(ii) 2-modal: auditory-visual (“I saw x sitting on my bed and I heard him saying ‘Bastard!’”), auditory-olfactory (“I heard x saying ‘I will smoke a cigar! ’ and at this very moment I smell a taste of tobacco”), auditory-tactile (“I heard x saying ‘You will be stung by a scorpion!’ and at this very moment I felt a sharp sting of pain on my left arm”), auditory-gustatory, visual-olfactory (“I saw x on my bed smoking a cigar and I also smell the taste of tobacco”), visual-tactile (“I saw a scorpion on my left arm and at this very moment I felt a sharp sting of pain there”), visual-gustatory (“I saw blood dripping from my finger and it had the taste of blood when I put it on my tongue”), olfactory-tactile, olfactory-gustatory, tactile-gustatory

(iii) 3-modal: auditory-visual-olfactory, auditory-visual-tactile (“I heard x saying ‘You will be stung by a scorpion!’ and at this very moment I saw a scorpion on my left arm while feeling a sharp sting of pain there”), auditory-visual-gustatory (“I heard ‘I will harm you’ and at this very moment I saw blood dripping from my finger and it had the taste of blood when I put it on my tongue”), auditory-olfactory-tactile, auditory-olfactory-gustatory, auditory-tactile-gustatory, visual-olfactory-tactile, visual-olfactory-gustatory, visual-tactile-gustatory, olfactory-tactile-gustatory

(iv) 4-modal: auditory-visual-olfactory-tactile, auditory-visual-olfactory-gustatory, auditory-visual-tactile-gustatory (“I heard ‘I will harm you’ and then I saw blood dripping from my finger, while I felt a sharp pain there. It had the taste of blood when I put it on my tongue”), auditory-olfactory-tactile-gustatory, visual-olfactory-tactile-gustatory

(v) 5-modal: auditory-visual-olfactory-tactile-gustatory

At this step, it should be noted that multi-modal hallucinations retain their force from the plausibility that results from the simultaneous (or quasi-simultaneous) occurrence of two or more unimodal hallucinations of different types. For this reason, multi-modal hallucinations retain considerable power with regard to unimodal ones. The sense of reality that results from multi-modal hallucinations is due to the fact that several sensory pathways are congruently involved in the hallucinatory process. If we consider, for example, bimodal hallucinations of the auditory-visual type, it proves to be that the simultaneous occurrence of an additional visual hallucination strongly reinforces the sense of reality that results from the auditory hallucination. As the above examples illustrate, multi-modal hallucinations are seemingly highly more plausible and realistic than unimodal ones, and result in a much greater sense of realism. More generally, it illustrates how (n + 1)-modal hallucinations are seemingly much more realistic than n-modal ones, a supplementary sensory pathway being involved in the hallucinatory process.

1.2 Factors of plausibility of auditory hallucinations

It is worth mentioning, second, several factors that can contribute to the intrinsic plausibility of auditory hallucinations:

(i) structured versus unstructured auditory hallucinations: structured sounds notably consist of comments on the patient’s thoughts or activities, conversations of several persons, or commands ordering the patient to do things, etc., while on the other hand, unstructured sounds consist of ringing, buzzing, whistling, etc.

(ii) auditory hallucinations having an external versus an internal origin: auditory hallucinations seemingly coming out from outer space could reinforce the idea that the voices have an external origin, e.g. are attributable to other people.

(iii) the locus (Chadwick et al., 1996, p. 103) – i.e. the space location – of auditory hallucinations is also susceptible of reinforcing their intrinsic plausibility. We can consider, for example, a patient who hears the voice of the presenter of the show saying ‘Bastard!’. Now this sounds more realistic if the locus of the voice is the television device rather than the ashtray. Let us suppose now that the patient hears a voice saying ‘I can read your thoughts’. Now it sounds more likely to the patient if the voice comes out from the telephone than from the halogen lamp.

It is worth noting here that this criterion is susceptible to vary from culture to culture.1 In effect, depending on the individuals, a speaking tree or a speaking animal could be, in certain cases, consistent with the patient’s cultural background.

(iv) bilateral versus unilateral auditory hallucinations: auditory hallucinations coming indifferently from the patient’s right or from his/her left are more plausible than unilateral ones.2

(v) time location related versus unrelated to the patient’s thoughts, emotions or actions (Stephane et al. 2003 make mention of the “relation to the moment”). In this regard, auditory hallucinations that are simultaneous with the patients internal phenomena gain more plausibility.

(vi) phrases versus single words: in this context, phrases, conversations, elaborate sentences gain are more plausible than single words.

(vii) multiple voices versus single voice (Stephane et al., 2003).

(viii) auditory hallucinations fitting versus not fitting with the patient’s desires or fears: this factor consists of whether the hallucinations experienced by a patient fit adequately or not with his/her individual fears or desires. For in the affirmative, it would greatly increase the plausibility of the corresponding hallucinations. Let us take an example. The patient is very anxious about the evolution of his/her illness. He/she hears a voice that says: ‘You will relapse next month’. Now the content of this auditory hallucination fits adequately with the patient’s own fears. The reason why auditory hallucinations fitting with desires or fears are more plausible, is that they are coherent with the patient’s belief system. By contrast, had the content of auditory hallucinations been unrelated or contradictory with the patient’s desires and fears, the corresponding information would have then resulted in a lack of coherence with the patient’s belief system (this is in line with the approach to hallucinations exposed in Rector & Beck, 2002, which is concerned with: “(…) how the specific voice content and beliefs about the voices reflect the person’s prehallucinatory fears, concerns, interests, preoccupations and fantasies”).

(ix) interactive versus non-interactive voices: whether the patient can interact or not with voices, i.e. discuss or engage in dialog with them.

1.3 Factors of plausibility of visual hallucinations

Several factors can contribute, third, to the intrinsic plausibility of visual hallucinations:

(i) formed versus unformed visual hallucinations: formed hallucinations are made up of figures, faces, morphing objects or scenes. By contrast, unformed hallucinations consist of dots, lines, geometrical figures, flashes, etc.

(ii) ordinary versus bizarre or extraordinary visual hallucinations: for obvious reasons, objects that look ordinary gain more likeliness than bizarre, unreal objects.

(iii) objects in color versus in black and white.

(iv) visual hallucinations fitting versus not fitting with surroundings: as noted by Teunisse et al. (1996), the relationship to surroundings could play an important role in the plausibility of complex hallucinations. Such or such unimodal hallucination could fit well (e.g. a person lying on a bed, a scorpion walking on the ground) or not (a figure on the ceiling) with surroundings. Now it should be apparent that fitting with surroundings visual hallucinations are consistent with the patient’s knowledge of the physical world. This renders, from the patient’s viewpoint, the hallucination very plausible. By analogy with the locus of auditory hallucinations, fitting with surroundingscan be assimilated to the locus – i.e. space location – of visual hallucinations.

(v) bilateral versus unilateral visual hallucinations.

(vi) time location of visual hallucinations related versus unrelated to the patient’s thoughts, emotions or actions (e.g. the patient thinks to a scorpion and at this very moment he/she sees a scorpion on the ground).

(vii) animated versus static images.

1.4 Factors of plausibility of olfactory hallucinations

Several factors can contribute, fourth, to the plausibility of olfactory hallucinations:

(i) bilateral versus unilateral olfactory hallucinations.

(ii) olfactory hallucinations fitting versus not fitting with the patient’s desires or fears: the patient fears of being killed and smells a poisonous gas in his/her room.

(iii) transient versus permanent olfactory hallucinations: some patients experience olfactory hallucinations that occur any time of day and also last for hours (Tousi & Frankel 2004).

1.5 Factors of plausibility of tactile hallucinations

Certain factors can contribute, fifth, to the plausibility of tactile hallucinations:

(i) bilateral versus unilateral tactile hallucinations.

(ii) tactile hallucinations fitting versus not fitting with the patient’s desires or fears: the patient fears of being murdered and feels an electric-shock sensation.

1.6 Factors of plausibility of gustatory hallucinations

Some factors can contribute, sixth, to the plausibility of gustatory hallucinations:

(i) common versus strange gustatory hallucinations: in some cases, the patient may find that his/her food tastes strange. This could decrease the plausibility of the corresponding hallucination, in contrast with gustatory hallucinations where the patient experiences normal and common tastes.

(ii) gustatory hallucinations fitting versus not fitting with the patient’s desires or fears: the patient fears of being poisoned and feels the taste of poison in his/her mouth.

2. Plausibility of hallucinations scale

From the above, it results that it could be useful to measure accurately the plausibility of the hallucinations occurring in schizophrenia. For this purpose, we shall now sketch a 50-item scale, which is targeted at evaluating the plausibility of hallucinations experienced by a patient. This binary scale consists of a questionnaire which allows for yes/no answers (each yes answer weighting 2 points):

itemquestions (0-100)
Unimodal hallucinations
Auditory hallucinations
1Does the patient hear auditory hallucinatory which consist of structured sounds?
2Does the patient experience auditory hallucinations which come out from outer space?
3Does the patient experience auditory hallucinations whose locus sounds realistic?
4Does the patient experience bilateral auditory hallucinations?
5Does the patient experience auditory hallucinations whose time location is related to the patient’s thoughts, emotions or actions?
6Does the patient experience auditory hallucinations which consist of phrases, conversations?
7Does the patient experience auditory hallucinations with multiple voices?
8Does the patient experience auditory hallucinations whose content fits with his/her fears or desires?
10Can the patient interact with auditory hallucinations, i.e. discuss or engage in dialog with them?
Visual hallucinations
11Does the patient experience formed visual hallucinations?
12Does the patient experience visual hallucinations with ordinary objects?
13Does the patient experience visual hallucinations in color?
14Does the patient experience visual hallucinations whose locus fits with surroundings?
15Does the patient experience bilateral visual hallucinations?
16Does the patient experience visual hallucinations whose time location is related to his/her thoughts, emotions or actions?
17Does the patient experience visual hallucinations consisting of scenes or sequences of animated images?
Olfactory hallucinations
18Does the patient experience bilateral olfactory hallucinations?
19Does the patient experience olfactory hallucinations whose content fits with his/her fears or desires?
20Does the patient experience transient olfactory hallucinations?
Tactile hallucinations
21Does the patient experience bilateral tactile hallucinations?
22Does the patient experience tactile hallucinations whose content fits with his/her fears or desires?
Gustatory hallucinations
23Does the patient experience gustatory hallucinations of a common type?
24Does the patient experience gustatory hallucinations whose content fits with his/her fears or desires?
Bimodal hallucinations
25Does the patient experience bimodal hallucinations of the auditory-visual type?
26Does the patient experience bimodal hallucinations of the auditory-olfactory type?
27Does the patient experience bimodal hallucinations of the auditory-tactile type?
28Does the patient experience bimodal hallucinations of the auditory-gustatory type?
29Does the patient experience bimodal hallucinations of the visual-olfactory type?
30Does the patient experience bimodal hallucinations of the visual-tactile type?
31Does the patient experience bimodal hallucinations of the visual-gustatory type?
32Does the patient experience bimodal hallucinations of the olfactory-tactile type?
33Does the patient experience bimodal hallucinations of the olfactory-gustatory type?
34Does the patient experience bimodal hallucinations of the tactile-gustatory type?
Trimodal hallucinations
35Does the patient experience trimodal hallucinations of the auditory-visual-olfactory type?
36Does the patient experience trimodal hallucinations of the auditory-visual-tactile type?
37Does the patient experience trimodal hallucinations of the auditory-visual-gustatory type?
38Does the patient experience trimodal hallucinations of the auditory-olfactory-tactile type?
39Does the patient experience trimodal hallucinations of the auditory-olfactory-gustatory type?
40Does the patient experience trimodal hallucinations of the auditory-tactile-gustatory type?
41Does the patient experience trimodal hallucinations of the visual-olfactory-tactile type?
42Does the patient experience trimodal hallucinations of the visual-olfactory-gustatory type?
43Does the patient experience trimodal hallucinations of the visual-tactile-gustatory type?
44Does the patient experience trimodal hallucinations of the olfactory-tactile-gustatory type?
quadri-modal hallucinations
45Does the patient experience quadri-modal hallucinations of the auditory-visual-olfactory-tactile type?
46Does the patient experience quadri-modal hallucinations of the auditory-visual-olfactory-gustatory type?
47Does the patient experience quadri-modal hallucinations of the auditory-visual-tactile-gustatory type?
48Does the patient experience quadri-modal hallucinations of the auditory-olfactory-tactile-gustatory type?
49Does the patient experience quadri-modal hallucinations of the visual-olfactory-tactile-gustatory type?
quinti-modal hallucinations
50Does the patient experience quinti-modal hallucinations of the auditory-visual-tactile-olfactory-gustatory type?

It is worth noting that this 50-item scale can be regarded as non-specific to psychotic hallucinations. It is also suited to other disorders or illnesses involving hallucinations. Among these are other mental illnesses, but also Charles Bonnet syndrome (Teunisse et al., 1996; Menon et al., 2003), epilepsy (Sachdev, 1998; Schwartz & Marsh, 2000), etc. In particular, the Charles Bonnet syndrome occurs in the elderly and is usually associated with ocular pathology and severe visual impairment. The Charles Bonnet syndrome is characterized by the presence of complex and persistent visual hallucinations. The syndrome is usually associated with an absence of hallucinations in other sensory modalities. It is worth noting that the Charles Bonnet syndrome affects psychologically normal individuals with full or partial insight and the patients are accordingly non-delusional. On the other hand, auditory hallucinations are frequently associated with temporal lobe epilepsy, where hallucinations in other modalities can also occur.

It is worth mentioning that the Plausibility of Hallucinations Scale could also be used in association with other instruments for measuring insight, such as the Beck Cognitive Insight Scale (Beck et al., 2003) in order to gain more accurate knowledge of the patient’s state. For schizophrenia is usually associated with lack of insight into the internal origin of the hallucinations. By contrast, in other illnesses such as Charles Bonnet syndrome or in pseudo-hallucinations related to brain trauma or PTSD (Stephane et al., 2004), the patient usually retains insight into the internal origin of his/her hallucinations.

3. Impact on Cognitive Therapy

We suggest that the above emphasis on the plausibility of hallucinations could be usefully incorporated into the process of cognitive-behavior therapy of schizophrenia (Kingdon & Turkington, 1994, 2005; Chadwick et al., 1996; Rector & Beck, 2002). The general idea would be to point out to the patient who experiences highly plausible hallucinations those factors that confer to his/her hallucinations their intrinsic plausibility. Hopefully, this could insert itself well into the process of cognitive-behavior therapy, whose primary goal is to help the patient gaining more insight into the nature of his/her hallucinations and in particular to understand that they do not originate from an external source. In this context, stressing to the patient the plausibility of his/her hallucinations, could help him/her understand better how hallucinations can be self-deceiving.

It is worth focusing, to begin with, on multi-modal hallucinations. In this context, a first step would be to point out to the patient that multi-modal hallucinations are capable of seeming very plausible and realistic. It could then be argued and explained to the patient that multi-modal hallucinations are more plausible than unimodal ones. This could be illustrated through some examples. This latter strategy could make use of “what if statements” (Ellis & Dryden, 1997). Along these lines, it could be pointing out to the patient that if someone, instead of experiencing one single auditory hallucination, would experience simultaneously one supplementary visual hallucination, then the resulting multi-modal (of the auditory-visual type) hallucination would sound much more realistic. Along these lines, it could be pointed out to the patient that the particular case of multi-modal hallucination that he/she experiences is potentially very realistic and inherently capable of deceiving him/her.

Once the patient familiar with the concept of multi-modal hallucinations, another goal could be to learn the patient how to use by himself/herself the preceding taxonomy of multi-modal hallucinations and to apply it when he/she experiences these types of complex hallucinations. He/she would then be capable of identifying the corresponding case at hand. Hopefully, this could help the patient rationalize his/her abnormal perceptions and perhaps accept better the internal origin of his/her hallucinations as an alternative explanation.

The fact of classifying multi-modal hallucinations would be helpful to the patient, it seems, to help him/her rationalize and explain the phenomena he/she experiences. For we should bear in mind that the patient experiences abnormal phenomena, which are unfamiliar to psychologically normal people. In this context, helping the patient rationalize, classify and describe accurately the phenomena of his/her own internal world, proves then to be a valuable practical goal to attain. Accordingly, identifying, recognizing and labeling a given type of multi-modal hallucination could help lessen its associated omnipotence (Chadwick et al., 1996). This could be helpful to the patient, we suggest, who ordinarily faces an unexplained and upsetting phenomenon. More generally, the fact of identifying the various factors that render his/her complex hallucinations so plausible could help the patient gaining more insight into the internal origin of his/her hallucinations. At this step, it should be noted that the present account is notably in line – for what concerns the delusion that consists in attributing an external origin to the hallucinations – with the views advocated by Brendan Maher (1988, 1999), who sees delusions as a patient’s attempt to explain some perplexing and puzzling phenomena. According to Maher, delusions arise from normal (mainly rational but occasionally irrational) reasoning applied to abnormal phenomena. Among these abnormal phenomena which are very perplexing to the patient are the hallucinations.

4. Limitations and directions for further research

The main limitation of the present study is that the psychometric properties of the Plausibility of Hallucinations Scale have not been tested. However, given the number of items of the scale, one can expect a good sensibility. On the other hand, the reliability and validity of the scale remain to be tested.

Finally, the above developments suggest several questions, which could be usefully the subject of further study, based on the Plausibility of Hallucinations Scale. A first question that arises is the following: (i) Is the plausibility of hallucinations rate higher in schizophrenia than in other illnesses involving hallucinations, e.g. other mental illnesses, Charles Bonnet syndrome, temporal lobe epilepsy, etc.? A comparison of the plausibility of hallucinations rate occurring in schizophrenia and other illnesses involving hallucinations could be made accordingly. We suggest that such comparison could provide some useful information about the relationships of these illnesses (Sachdev, 1998). Although schizophrenia (paranoid subtype) should prima facie involve a higher rating, it seems that an accurate measure of the degree of plausibility of hallucinations could result in some interesting information. Along these lines, a comparison of the plausibility of hallucinations ratings occurring in different subtypes of schizophrenia could also be informative.

The above Plausibility of Hallucinations Scale is also designed to allow for comparisons between different chronological states in the same patient. This suggests a second type of question: (ii) Does the plausibility of hallucinations rating evolve during the course of schizophrenia? Along these lines, Nayani & David (1996) observed an increase in the complexity of auditory hallucinations over time, seemingly related to lesser distress and better coping. A similar question could be raised for other illnesses involving hallucinations. In this context, Menon et al. (2003) reported accordingly that “Elementary hallucinations may progressively evolve into complex visual hallucinations” in the Charles Bonnet syndrome.

Lastly, a third interesting question goes as follows: (iii) Is the plausibility rate of hallucinations occurring in schizophrenia correlated with the I.Q. of the patient, i.e. do patients with a high I.Q. more frequently experience complex hallucinations with a high level of plausibility? In other words, is the following hypothesis confirmed: The higher the I.Q., the higher the plausibility of hallucinations rating? Hopefully, the answer to these questions will provide some information that might well be useful to the understanding of the illness and to cognitive-behavior therapy of schizophrenia.

Acknowledgments

We thank Peter Brugger, Paul Gilbert and Hélène Verdoux for very useful comments on earlier drafts.

References

American Psychiatric Association (1994). Diagnostic and Statistical Manual of Mental Disorders (4th edition). American Psychiatric Association: Washington.
Beck, A. T., Rector, N. A. (2003). A Cognitive Model of Hallucinations. Cognitive Therapy and Research, 27(1), 19-52.
Beck, A. T., Baruch, E., Balter, J. M., Steer, R. A., Warman, D. M. (2004). A new instrument for measuring insight: the Beck Cognitive Insight Scale. Schizophrenia Research, 68(2-3), 319-329.
Chadwick, P., Birchwood, M. & Trower, P. (1996). Cognitive Therapy for Delusions, Voices, and Paranoia. Chichester: Wiley.
Ellis, A., Dryden, W. (1997). The practice of rational emotive behaviour therapy, London: Free Association Books.
Kingdon, D. & Turkington, D. (1994). Cognitive-behavioural Therapy of Schizophrenia. Guilford: New York.
Kingdon, D., & Turkington, D. (2005). Cognitive Therapy of Schizophrenia. New York, London: Guilford.
Maher, B. A. (1988). Anomalous experiences and delusional thinking: the logic of explanations. In: T.F. Oltmanns & B.A. Maher (Eds.), Delusional Beliefs,pp. 15-33.Wiley: New York.
Maher, B. A. (1999). Anomalous experience in everyday life: Its significance for psychopathology. The Monist, 82, 547-570.
Menon, G. J., Rahman, I., Menon, S. J., Dutton, G. N. (2003). Complex visual hallucinations in the visually impaired: the Charles Bonnet Syndrome. Survey of Ophthalmology, 48, 58-72.
Nayani, T. H., David, A. S. (1996). The auditory hallucination: a phenomenological survey. Psychological Medicine, 26(1), 177-189.
Rector, N. A., Beck A. T. (2002). Cognitive Therapy for Schizophrenia: From Conceptualization to Intervention. Canadian Journal of Psychiatry, 47(1), 41-50.
Sachdev, P. (1998). Schizophrenia-Like Psychosis and Epilepsy: The Status of the Association. American Journal of Psychiatry, 155(3), 325-336.
Schwartz, J. M., Marsh, L. (2000). The Psychiatric Perspectives of Epilepsy. Psychosomatics, 41(1), 31-38.
Siddle, R. (2002). Communications from my parents. In: D. Kingdon & D. Turkington (Eds.), The Case Study Guide to Cognitive Behaviour Therapy of Psychosis, pp. 109-121. Chichester: Wiley.
Stephane, M., Thuras, P., Nasrallah, H., Georgopoulos, A. P. (2003). The internal structure of the phenomenology of auditory verbal hallucinations. Schizophrenia Research, 61, 185-193. Stephane, M., Hill, T., Matthew, E., & Folstein, M. (2004) New phenomenon of abnormal auditory perception associated with emotional and head trauma: Pathological confirmation by SPECT scan. Brain and Language, 89, 503-507.
Teunisse, R. J., Cruysberg, J. R., Hoefnagels, W. H. (1996). Visual hallucinations in psychologically normal people: Charles Bonnet’s syndrome. Lancet, 347, 794-797.
Toone, B. K. (2000). The psychoses of epilepsy. Journal of Neurology, Neurosurgery and Psychiatry, 69(1), 1-3.
Tousi, B. & Frankel, M. (2004). Olfactory and visual hallucinations in Parkinson’s disease, Parkinsonism and Related Disorders, 10, 253-254.

1 We thank Paul Gilbert for the suggestion of taking into account cultural beliefs with regard to this specific criterion.

2 We owe the suggestion to include the bilateral/unilateral distinction related to hallucinations in all modalities to Peter Brugger.