Seminar

LINGUISTICALLY PROFILING SCHIZOPHRENIA WITH/WITHOUT 
FORMAL THOUGHT DISORDER 

Derya Çokal 
Queen Mary, University of London 

DATE : Friday, 18 January 2019
TIME : 12.40-13.30
ROOM : A 130
BUILDING : FEASS

While formal thought disorder (FTD) clinically manifests as disorganized speech, there have been few investigations of its linguistic properties. In this talk, I will discuss three ways in which disturbance of thought may relate to the referential function of language as expressed in the use of noun phrases (NPs), the complexity of sentence structures, and the syntactic positions of speech dysfluencies. I will report result of three studies, in which we used a comic-strip description task and a sentence-picture matching task to elicit language samples from 30 participants with schizophrenia (SZ) (15 with moderate or severe FTD (SZ+FTD), 15 with minimal or no FTD (SZ-FTD)), 15 first-degree relatives of people with SZ (FDRs) and fifteen neurotypical controls (NC). In the first study, we predicted that anomalies in the normal referential use of noun phrases (NPs) (sub-divided into definite and indefinite NPs), would identify FTD and that FTD would also be linked to reduced linguistic complexity (measured by the number of embedded clauses and grammatical dependents). In the second study, we also predicted disturbances of thought in schizophrenia would manifest in patterns at the level of speech dysfluency and these would also be seen in FDRs. In the third study, we explored whether problems of language may extend to comprehension and clause embedding in particular.
Our results demonstrate: (1) FTD can be identified in specific grammatical patterns that provide new targets for detection, early intervention, and neurobiological studies; (2) the temporal organization of speech is an important window on thought-process disturbances.

BIO: Dr. Derya Çokal is currently a research associate on a project funded by the European Research Council (Advanced ERC grant) at Queen Mary University of London. The goal of this project is to use computational and experimental methods, as well as Bayesian models, to tackle the fundamental issue of disagreements in anaphora interpretation. After obtaining her joint PhD at Middle East Technical University & Edinburgh University, she was a post-doctoral researcher at the Institute for Mind and Brain at the University of South Carolina (USC) & Department of Psychology: University of California, Davis (UCD), where she examined online processing of noisy input in language. She continued her postdoctoral research in the Department of Psychology at the University of Edinburgh investigating the role of individual differences in online processing of anaphoric expressions. Subsequently, she was a research associate on the project Language and Mental Health based at Durham University, University College London, and the Institute of Neuroscience at Newcastle University, which profiled the language of patients with schizophrenia (with/without formal thought disorder) and compared the language profiles of patients with schizophrenia to those with aphasia.