Language disintegration under conditions of severe formal thought disorder

Abstract

On current models of the language faculty, the language system is taken to be divided by an interface with systems of thought. However, thought of the type expressed in language is difficult to access in language-independent terms. Potential interdependence of the two systems can be addressed by considering language under conditions of pathological changes in the neurotypical thought process. Speech patterns seen in patients with schizophrenia and formal thought disorder (FTD) present an opportunity to do this. Here we reanalyzed a corpus of severely thought-disordered speech with a view to capture patterns of linguistic disintegration comparatively across hierarchical layers of linguistic organization: 1. Referential anomalies, subcategorized into NP type involved, 2. Argument structure, 3. Lexis, and 4. Morphosyntax. Results showed significantly higher error proportions in referential anomalies against all other domains. Morphosyntax and lexis were comparatively least affected, while argument structure was intermediate. No differential impairment was seen in definite vs. indefinite NPs, or 3 rd Person pronouns vs. lexical NPs. Statistically significant differences in error proportions emerged within the domain of pronominals, where covert pronouns were more affected than overt pronouns, and 3 rd Person pronouns more than 1 st and 2 nd Person ones. Moreover, copular clauses were more often anomalous than non-copular ones. These results provide evidence of how language and thought disintegrate together in FTD, with language disintegrating along hierarchical layers of linguistic organization and affecting specific construction types. A relative intactness of language at a procedural, morphosyntactic surface level masks a profound impairment in the referential functioning of language.

Grammatical impairment in schizophrenia: An exploratory study of the pronominal and sentential domains

“…However, let us observe that both null pronouns and null 3Person referential pronouns were less significantly correlated with FTD, thought disorder, as measured by PANSS P2 scores ([N]: r = 0.419; p = 0.007, and [N3P+R]: r = 0.402; p = 0.010). Hence, in tension with previous observations that language issues pattern together with FTD in SZ [ 30 , 51 ], our results indicate that atypical overuse of null pronouns is significantly associated with positive symptoms in general, but less so with FTD.…”

“…Therefore, we conclude that, due to methodological issues, our samples are not informative about pronominal anomaly in SZ, but it is important to notice that the SZ groups produced significantly more null 3Person referential pronouns in WK narratives, and more null 3Person referentially anomalous pronouns in all narrative types across samples. Tovar et al—as far as we know, the only study that investigated the use of null pronouns in patients with SZ—reported more errors in the use of null referential pronouns as compared to overt pronouns [ 51 ]. Our finding converges with that of Tovar et al’s with respect to that.…”

“…According to previous studies [6,[77][78][79][80][81], speech samples shorter than 10-minutes do not provide sufficient linguistic material for analyses of structural and referential failures. Tovar et al, who also examined interview narratives, collected 5-page reports, resulting in a mean number of 888.6 words [51]. The mean number of words in DM was 207.8 ± 52.7 in sample 1, and 53.2 ± 26.2 in sample 2.…”

“…Hence, given that SZ is universal, being found within different linguistic communities, outlining its linguistic profile requires a comprehensive understanding of grammatical variation across languages. Tovar et al’s study on the usage of pronouns in a sample of Spanish speakers with SZ shows a significantly higher rate of referential anomaly with null pronouns as compared to overt pronouns [ 51 ]. This is not observable in a non-null-subject language, such as English.…”

Linguistic marker of schizotypy: a study on nominal reference

“…There is growing evidence that schizophrenia leads to semantic and pragmatic impairments. It has been reported, for instance, that schizophrenic patients overuse expressions with implicit, generic or ambiguous reference (Harvey;Weintraub;Neale, 1982, Rodriguez-Ferrera;McCarthy;McKenna, 2001, Hinzen;Sheehan, 2015), have difficulties with definiteness, ineffectively using indefinite DPs for new information and definite DPs for old information, as well as difficulties with third person pronominal coreference (Rochester;Martin 1979, Harvey;Weintraub;Neale, 1982, Chaika;Lambe, 1989, Çokal et al, 2018, Sevilla et al, 2018, Tovar et al, 2019. It has also been shown that these speakers have difficulties integrating contextual information David, 1998, Kuperberg et al, 2006, being more influenced by lexical meaning (Chapman;Chapman;Miller, 1964), in addition to difficulties using information shared with the interlocutor (Champagne -Lavau;…”