Is There a Schizophasia? A Study Applying the Single Case Approach to Formal Thought Disorder in Schizophrenia

Abstract

It has been suggested that formal thought disorder, the incoherent speech of schizophrenia, may involve a language disturbance among other abnormalities, or even be a form of dysphasia. Six patients with and seven without formal thought disorder were evaluated on an aphasia test battery. Spontaneous speech was also analysed using Brief Syntactic Analysis. Poor performance on the aphasia test battery was found to be associated with general intellectual impairment but not with formal thought disorder. Naming was preserved in both groups. Patients with formal thought disorder, but not those without, produced semantic errors in their spontaneous speech, and these were unrelated to general intellectual status. The disorder of language in formal thought disorder thus appears to be one of expressive semantic abnormality, which, however, spares naming. Further analysis of two intellectually preserved patients suggested that formal thought disorder may be associated with an additional difficulty in constructing an appropriate model for generating one's own speech.

Grammatical processing in schizophrenia: Evidence from morphology

“…The pattern of intrusion errors, which have been linked to thought disorder (Oh, McCarthy, & McKenna, 2002), and were also found on regular and novel but not irregular verbs, may also be consistent with this view. The results appear to be inconsistent with claims that thought disorder reflects a general cognitive dysfunction (see Introduction), since any general dysfunction seems unlikely to affect regular and novel verbs differently from irregular verbs, particularly given the factors controlled for in the present study.…”

“…Oh and McKenna (2002) suggested that intrusion errors in expressive speech (not just semantic associates but also unrelated words) may reflect a semantic deficit in schizophrenia, possibly related to the disorganization of lexical/semantic knowledge discussed in other studies. On the one hand, such a semantic deficit does not seem to fully explain the pattern of intrusion errors, since it would predict higher rates for patients than controls on both real regular and real irregular verbs (and possibly for novel verbs too, if the errors reflect an attempt to “make sense” of the novel input).…”

“…That is, it is not clear whether the results reflected the same impairment across all patient subgroups, or were primarily due to only certain subgroups. Patients in this study were also not selected with respect to the presence or absence of formal thought disorder, so our findings that suggest a link between thought disorder and grammar could be followed up on with patient groups selected and categorized on this basis (Oh, McCarthy, & McKenna, 2002). Finally, while we have made some inferences regarding neuroanatomy, direct examination of the brain substrates underlying the language functions examined here would add important evidence, and should be included in future studies.…”

The genetic basis of thought disorder and language and communication disturbances in schizophrenia

“…O. Chaika & Alexander, 1986; Maher, 1972, 1983; Rodriguez-Ferrera, McCarthy, & McKenna, 2001). One possible explanation for conflicting findings was offered by Oh et al (Oh, McCarthy, & McKenna, 2002), who showed that syntactic errors occurred independent of thought disorder in schizophrenics, whereas semantic anomalies were strongly associated with the presence of thought disorder. Thus, stratifying schizophrenics on the basis of the presence or absence of thought disorder may be essential for distinguishing linguistic correlates of schizophrenia from linguistic correlates of schizophrenic thought disorder.…”

Can delusions be understood linguistically?

“…In particular, there is no anomaly at the lexical level: the words themselves are not being used in an unusual or novel way – in the first example the patient is talking about the same person as we do when we refer to Jesus, and the meanings of wine glass, stomach, the Mafia and killing are likewise entirely conventional. Nor does there seem to be any obvious violation of so-called selectional requirements, the constraints on how the individual parts of sentences can be coupled – we are not dealing with the kind of statements uttered by patients with formal thought disorder (the incoherent speech of schizophrenia) such as “The trains broke and the pond fell in the front doorway” (Oh, McCarthy, & McKenna, 2002), where the lexical features of ponds do not allow them to fall in doorways. Rather, (1)–(3) are pathological by virtue of, and only of, the way in which different sentence parts are combined at the level of propositional or grammatical meaning , where we see referential forms of meaning transpiring within specific grammatical configurations.…”