[Communication - IADA 2021] Topological deviation as a measure of thought organization: insight from schizophrenic corpuses in free dialogue situations analyzed with the 2TK model of interaction

Arthur Trognon, Frédéric Verhaegen, Camille Humeau, Michel Musiol

Language is a specifically human cognitive capacity which allows communication between fellow human beings, and in particular, which allows the translation of thought (semantic level) into a physical acoustic wave which will be interpreted according to its syntax, its semantics, and its pragmatics (Morris, 1934).

The syntactic level (already elaborated and particularly complex in its organization) is the one within which the linguistic matter is produced, its ultimate elements coming from a phonematic system, a morphological system and a phrastic system which organizes the words between them. The product of this system is then processed at the semantic level where sentences are related to what they represent. The sentence-proposition association is finally processed by a pragmatic system thanks to which the linguistic agent uses the proposition to act on himself and on others. While the syntactic system is thus at the heart of the entire language apparatus, representing its "generator" (Chomsky, 1957), it is in a higher-level interphrastic mechanism, discursive, which organizes the different sentences (conversational, narrative dialogical aspect) that the pragmatic system is accomplished, accounting for the integration of an element of language in a global context, dialogue being the primary structure of spoken language use (Clark, 1996; Schegloff, 2004).

Schizophrenia is characterized at the cognitive level by difficulties in integrating local cues into a global context (Talamini et al., 2010). Moreover, there are neural correlates to this phenomenon, indeed, it has been shown in diffusion tensor imaging (which measures white matter bundles), that the neural networks of schizophrenics were very densely connected at the local level (local hyperconnectivity (Nejad et al., 2012)) and very weakly connected at the global level (long distance hypoconnectivity (Li et al., 2019)). In language, the sentence is carrying a representation in a context, and this contextual representation, which falls under pragmatics, is particularly impaired in the schizophrenic context.

Thus, the debate between Chaika and Fromkin in the early 1970s (Chaika, 1974; Fromkin, 1975) when linguists were interested in the properties of schizophrenic language taught us that all the discourse inconsistencies produced by schizophrenics exist in the speech of all speakers, with the exception of inconsistencies in the sequentiality of speech, which represents the higher level of language use, and which therefore requires the global integration of linguistic markers. Indeed, the study of schizophrenic dialogue dysfunctions has a long tradition at the University of Nancy, initiated by (Trognon, 1987, 1992) and extended by (Musiol & Rebuschi, 2007; Musiol & Trognon, 2000) and then by (Musiol & Verhaegen, 2014; Verhaegen, 2007)

Following this tradition and using a new model of dialogue analysis, the 2TK model (Trognon 2021a, in prep.), which unifies the interactional dialogical topological properties evidenced by work arising from linear logic and ludic (Fouqueré et al., 2018; Ginzburg, 2012; Girard, 1987, 2001) with the properties of dialogical kinetics evidenced by work investigating the semantic-pragmatic interface of dialogue through SDRT (Asher & Lascarides, 2003; Caelen, 2003; Caelen & Nguyen, 2004; Caelen & Xuereb, 2007, 2017; Xuereb & Caelen, 2004), which we will present, we have confirmed the observation made by Fromkin through the paradigm of topological vector deviations (Trognon, 2021b, in prep. ). However, we have shown that discourse inconsistencies are significantly more represented in schizophrenic individuals than in neurotypicals, and, more interestingly, that this observation is normalized when schizophrenic individuals are treated with antipsychotic molecules. Moreover, the data suggest that this type of paradigm could ultimately be used to measure the magnitude of effect of therapeutic molecules on the organization of thought.