Language and Mental Health

The relationship between language and thought has preoccupied philosophers since antiquity. Modern philosophising on the subject begins with Descartes and the rationalists. They regarded thought as universal, immutable, and rational, whereas language was merely expressive of it. Language was seen as an overt manifestation of thought, and could vary even when thought itself is not. Modern generative linguistics, by and large, adopts this point of view as well, regarding language as a cognitive 'module' that is relatively independent of thought. Within these views, language is not regarded as an organising principle for thought. Thought is taken to be organised by its own principles. In line with this common conceptualisation, language is not regarded as relevant for what it is to be rational, or for mental health. Language could fall away, and rationality and selfhood could be maintained. An alternative and older tradition in linguistics, however, opposes the separation of language and thought. Identifying a mode of thought that is only found in humans, this tradition maintains that language does not just express thoughts, but generates them. Without the generative mechanisms of language, and of grammar in particular, this particular mode of thought wouldn't exist. We call this an 'Un-Cartesian' view of grammar. The present project starts from a prediction that the Un-Cartesian view makes: where thought gets disorganised, grammar should get disorganised alongside, and vice versa. The Un-Cartesian view regards a particular set of grammatical principles as crucial to the organisation of meaning in language. Therefore, it makes specific prediction for which aspects of thought should break down when the grammatical principles in question do. We will explore these predictions through investigations of language in schizophrenia. Formal Thought Disorder (FTD) is one clinical symptom of schizophrenia, and which is diagnosed on the basis of abnormalities in language. In particular, we will examine if grammar as opposed to lexicon (vocabulary) is disrupted in people with FTD.
Apparent evidence against the Un-Cartesian view comes from acquired language disorders, for example conditions such as agrammatic aphasia following a stroke. In this case, language can fail to be understood and produced, yet the thoughts of the people concerned can seem normal. In the case of aphasia, there is initial evidence that the pattern of language breakdown is very different from language abnormalities found in schizophrenia. In this project, we will explore the behaviour of people with aphasia on the same tasks as those with schizophrenia in order to discover whether their grammatical profiles are distinct.
The present project assembles a multidisciplinary research team that crosses the boundaries of departments, faculties, and disciplines. We carry out theoretically guided research on language in the clinical context, and modify those theories in response to clinical evidence. We aim, in a first subproject, to extend our current research on the grammatical basis of reference in language (what speech is about). We then aim to sample spontaneous speech from people with schizophrenic thought disorder and to test whether these grammatical behaviours are specifically impaired. We also use a battery of newly designed language tests to profile language abnormalities in aphasia and schizophrenia. Finally, we will accompany our experimental work with a philosophical study assessing and rethinking the role of language for being a rational self. We hope that our project will contribute new tools for language assessment in clinical populations and generate fresh insights into both aphasia and schizophrenia, as well as shedding light on complex debates on the relationship between language and thought.

The research we propose is primarily addressed to three kinds of community: the scientific community across a range of disciplines including philosophy, linguistics, psychology, psychiatry; clinicians in psychiatry, clinical psychology and speech and language therapy; and people with schizophrenia, people with aphasia and their families. In regard to Impact, our central interest is to contribute to a new understanding of the role and importance of language in schizophrenia and mental health more generally. Based on that, there may be potential for development of new psychological and behavioural therapies for the condition. In particular, our research could contribute to improved engagement techniques in Cognitive Behavioural Therapy for people with schizophrenia and new techniques in this therapy for the treatment of thought disorder and negative symptoms such as alogia.
In addition to increasing understanding of language impairments in schizophrenia and aphasia, the project is likely to produce new methods for evaluation of language in these conditions. The implicit language processing tools that will be developed and refined across the course of the project are not routinely used in clinical evaluation of language impairments. One component of subproject B will be to produce computerised assessment methods suitable for adoption in a wide range of clinical contexts. Furthermore, these implicit language assessments will be normed on healthy age-matched control samples in order to increase their clinical utility. These new tools may be refined and disseminated for use by NHS clinicians, in particular, speech and language therapists and neuropsychologists.
Methods and outcomes of research will be reported not only in standard academic outlets, but also in publications and conferences that are clinician-led. For example, at the American Psychiatric Association Annual meeting, ECNP and at the bi-annual schizophrenia research forum meeting, and in speech and language therapy in the annual conference of the Royal College of Speech and Language Therapists and biennial conference of the British Aphasiology Society. We will also engage with local special interest groups (e.g., Speech & Language Therapy in Mental Health) in disseminating our ideas and findings and seek feedback on the project in order to stimulate future development and refinement.
During the course of the project, we will engage with charities such as Mind and Rethink and NAMI. We will invite a member of service user group to join our project steering committee in order to benefit from their insights and reflections on our plans, and also to find ways to share the findings of the project with people with schizophrenia and their families. Similarly, we would engage with AphasiaNow (http://www.aphasianow.org/) an organisation led by people with aphasia and explore ways in which our research findings can be disseminated to people with language impairment.
The relationship between language, mind and thought is one which is of considerable interest to the media, particularly where it is illuminated by evidence from people with neurological or psychiatric difficulties. For example, previous work on aphasia and thought was reported on BBC News website, The Guardian, The Times and New Scientist. Professor Varley has given interviews to the BBC Radio 4 programme Word of Mouth (on inner speech and thought) and on Richard and Judy (language problems following stroke). Professor Turkington has presented on Radio America on the subject of Cognitive Behavioral Therapy for psychotic symptoms, including thought disorder.