M190. USE OF NULL PRONOUNS IN SCHIZOPHRENIA
Authors: Chaves Monica , Mota Natália , Ribeiro Sidarta , Copelli Mario , Rodrigues Cilene 
Published: May 2020

Abstract

Background
Schizophrenic speech show consistent disturbances in referentiality, which, from a communicative standpoint, manifest as incoherent speech. Referential failures are especially detected in the usage of pronouns. Literature reports that schizophrenics either use more pronouns without clear reference or more semantically rich anaphors than pronouns. Additionally, it is reported that psychosis language in the context of schizophrenia, schizo-affective disorder and bipolar disorder present more first-person pronouns; within individuals at high genetic risk of schizophrenia those who subsequently developed schizophrenia produced significantly more second-person pronouns than those who did not manifest the illness; and individuals with diagnosis of primary psychotic disorder increased their usage of pronouns, including first-person and second-person pronouns during the period prior to a relapse hospitalization. The abnormalities observed in the use pronouns suggest that schizophrenic patients have semantic-pragmatic issues.
There are not many experimental studies devoted to pronouns in schizophrenia, and, according to our current knowledge, none of the existent ones focuses on pronouns without phonological content (null pronouns). In order to fulfill this gap, we present here an investigation of null pronouns in dream narratives produced by Brazilian schizophrenia patients.

Methods
Dream narratives from 20 schizophrenics and 20 control subjects, all native speakers of Brazilian Portuguese, were screened for null subject pronouns. Participants were prompt to talk by the command: “please report a recent dream”. Each narrative sample was then transcribed, and the occurrence of subject null pronouns were annotated, together with its morphosyntactic features (person & number) and referential status (referential vs. non-referential/expletives). The number of overt and null (with and without phonological content respectively) pronouns in subject position were converted into ratios by dividing the number of occurrences of each pronoun type (overt and null) by the total number of words in the narrative. Next, overt and null pronouns were compared within and between groups.

Results
T-test comparison showed that the schizophrenia group produced significantly more null pronouns than control group (t(25.126) = 3.919; p = .001); and, that null pronouns were significantly more produced than overt pronouns in the schizophrenia group (t(38) = 3.242; p = .002). Multiple regression showed that total of null pronouns differentiate schizophrenia from control group (F(1,38) = 15.357, p = .001, R2 = .288). In addition, analysis of null pronoun differences between groups based on morphosyntactic features and referential status, showed that schizophrenics used significantly more null pronouns with third-person singular features (t(27.523) =2.699; p =.012) and non-referential pronouns (expletives) (t(23.608) = 2.808; p = 0,010) than control group.

Discussion
A closer look at third-person null pronouns in the schizophrenic narratives showed that these pronouns are quite often loose in terms of reference: of the total occurrences of third-person null pronouns in schizophrenia approximately 30% are without clear referent. In accordance, null expletives, which are empty of reference, are overused to the point of explaining group differences. This corroborates that schizophrenic speech has a reduced semantic-pragmatic load, with a general difficulty in using pronouns within a contextually framed discourse.