Joana Rosselló

The linguistics of schizophrenia: thought disturbance as language pathology across positive symptoms

We hypothesize that linguistic (dis-)organization in the schizophrenic brain plays a more central role in the pathogenesis of this disease than commonly supposed. Against the standard view, that schizophrenia is a disturbance of thought or selfhood, we argue that the origins of the relevant forms of thought and selfhood at least partially depend on language. The view that they do not is premised by a theoretical conception of language that we here identify as ‘Cartesian’ and contrast with a recent ‘un-Cartesian’ model. This linguistic model empirically argues for both (i) a one-to-one correlation between human-specific thought or meaning and forms of grammatical organization, and (ii) an integrative and co-dependent view of linguistic cognition and its sensory-motor dimensions. Core dimensions of meaning mediated by grammar on this model specifically concern forms of referential and propositional meaning. A breakdown of these is virtually definitional of core symptoms. Within this model the three main positive symptoms of schizophrenia fall into place as failures in language-mediated forms of meaning, manifest either as a disorder of speech perception (Auditory Verbal Hallucinations), abnormal speech production running without feedback control (Formal Thought Disorder), or production of abnormal linguistic content (Delusions). Our hypothesis makes testable predictions for the language profile of schizophrenia across symptoms; it simplifies the cognitive neuropsychology of schizophrenia while not being inconsistent with a pattern of neurocognitive deficits and their correlations with symptoms; and it predicts persistent findings on disturbances of language-related circuitry in the schizophrenic brain.

A systematic linguistic profile of spontaneous narrative speech in pre-symptomatic and early stage Huntington's disease

Cognitive decline accompanying the clinically more salient motor symptoms of Huntingtons disease (HD) has been widely noted and can precede motor symptoms onset. Less clear is how such decline bears on language functions in everyday life, though a small number of experimental studies have revealed difficulties with the application of rule-based aspects of language in early stages of the disease. Here we aimed to determine whether there is a systematic linguistic profile that characterizes spontaneous narrative speech in both pre-manifest and/or early manifest HD, and how it is related to striatal degeneration and neuropsychological profiles. Twenty-eight early-stage patients (19 manifest and 9 gene-carriers in the pre-manifest stage), matched with 28 controls, participated in a story-telling task. Speech was blindly scored by independent raters according to fine-grained linguistic variables distributed over 5 domains for which composite scores were computed (Quantitative, Fluency, Reference, Connectivity, and Concordance). Voxel-based morphometry (VBM) was used to link specific brain degeneration patterns to loci of linguistic decline. In all of these domains, significant differences were observed between groups. Deficits in Reference and Connectivity were seen in the pre-manifest stage, where no other neuropsychological impairment was detected. Among HD patients, there was a significant positive correlation only between the values in the Quantitative domain and gray matter volume bilaterally in the putamen and pallidum. These results fill the gap of qualitative data of spontaneous narrative speech in HD and reveal that HD is characterized by systematic linguistic impairments leading to dysfluencies and disorganization in core domains of grammatical organization. This includes the referential use of noun phrases and the embedding of clauses, which mediate crucial dimensions of meaning in language in its normal social use. Moreover, such impairment is seen prior to motor symptoms onset and when standardized neuropsychological test profiles are otherwise normal.

The image of mind in the language of children with autism

While it is widely agreed today that autism involves a cognitive change (Baron-Cohen, 1988), the main psychological models have put the explanatory weight on changes in such non-linguistic neurocognitive variables as “theory of mind” (ToM), weak central coherence, or executive functioning. Linguistic deficits, including ones identified as “pragmatic” and taken to be universal in people with autism spectrum disorders (ASD) (Tager-Flusberg, 1996; Lord and Paul, 1997; Tager-Flusberg et al., 2001), or even the absence of functional language could then be seen as a secondary consequence of a primary defect in non-linguistic (particularly social) cognition (Mundy and Markus, 1997). A “modular” perspective, which separates language from cognition, has been widely adopted with regard to the internal organization of language itself, which is taken to comprise phonology, syntax, semantics, and pragmatics as relatively independent components. In this regard, Tager-Flusberg (1981) formulates the classical view that “phonological and syntactic development follow the same course as in normal children and in other disordered groups, though at a slowed rate, while semantic and pragmatic functioning may be specially deficient in autism.”

Can delusions be understood linguistically

ABSTRACT Delusions are widely believed to reflect disturbed cognitive function, but the nature of this remains elusive. The “un-Cartesian” cognitive-linguistic hypothesis maintains (a) that there is no thought separate from language, that is, there is no distinct mental space removed from language where “thinking” takes place; and (b) that a somewhat broadened concept of grammar is responsible for bestowing meaning on propositions, and this among other things gives them their quality of being true or false. It is argued that a loss of propositional meaning explains why delusions are false, impossible and sometimes fantastic. A closely related abnormality, failure of linguistic embedding, can additionally account for why delusions are held with fixed conviction and are not adequately justified by the patient. The un-Cartesian linguistic approach to delusions has points of contact with Frith’s theory that inability to form meta-representations underlies a range of schizophrenic symptoms. It may also be relevant to the nature of the “second factor” in monothematic delusions in neurological disease. Finally, it can inform the current debate about whether or not delusions really are beliefs.

Deficits in nominal reference identify thought disordered speech in a narrative production task

Formal thought disorder (TD) is a neuropathology manifest in formal language dysfunction, but few behavioural linguistic studies exist. These have highlighted problems in the domain of semantics and more specifically of reference. Here we aimed for a more complete and systematic linguistic model of TD, focused on (i) a more in-depth analysis of anomalies of reference as depending on the grammatical construction type in which they occur, and (ii) measures of formal grammatical complexity and errors. Narrative speech obtained from 40 patients with schizophrenia, 20 with TD and 20 without, and from 14 healthy controls matched on pre-morbid IQ, was rated blindly. Results showed that of 10 linguistic variables annotated, 4 showed significant differences between groups, including the two patient groups. These all concerned mis-uses of noun phrases (NPs) for purposes of reference, but showed sensitivity to how NPs were classed: definite and pronominal forms of reference were more affected than indefinite and non-pronominal (lexical) NPs. None of the measures of formal grammatical complexity and errors distinguished groups. We conclude that TD exhibits a specific and differentiated linguistic profile, which can illuminate TD neuro-cognitively and inform future neuroimaging studies, and can have clinical utility as a linguistic biomarker.

Language abnormality in deaf people with schizophrenia: a problem with classifiers

ABSTRACT Introduction: Although there is evidence for language abnormality in schizophrenia, few studies have examined sign language in deaf patients with the disorder. This is of potential interest because a hallmark of sign languages is their use of classifiers (semantic or entity classifiers), a reference-tracking device with few if any parallels in spoken languages. This study aimed to examine classifier production and comprehension in deaf signing adults with schizophrenia. Method: Fourteen profoundly deaf signing adults with schizophrenia and 35 age- and IQ-matched deaf healthy controls completed a battery of tests assessing classifier and noun comprehension and production. Results: The patients showed poorer performance than the healthy controls on comprehension and production of both nouns and entity classifiers, with the deficit being most marked in the production of classifiers. Classifier production errors affected handshape rather than other parameters such as movement and location. Conclusions: The findings suggest that schizophrenia affects language production in deaf patients with schizophrenia in a unique way not seen in hearing patients.

F13 Deviant language patterns in huntington’s spontaneous speech

Background Language has been shown to be affected in Huntington’s disease (HD) in several experimental tasks, independently of cognitive disabilities and since the earliest stages of the disease. However, studies of spontaneous speech are scarce and provide contradictory results. Aims To systematically profile the earliest spontaneous speech errors in HD and to test whether they extend to referential dysfunction in production, as it has been described in previous experimental work testing comprehension. Methods 28 native HD gene-carriers (9 pre-HD) and 28 matched controls were recorded while telling the Cinderella story using a visual support. Speech samples were transcribed and rated by two independent raters using Computarised Language Analysis (CLAN). Measures were normalised and errors were clustered in five different components. All participants underwent MRI scanning and high resolution T1 images were analysed using voxed-based morphometry (VBM) in order to study brain atrophy. Results Manifest HD patients showed increased errors in all five components: Quantitative, comprising the Mean Length of Utterances, the Number of Words, and Words per Minute; Fluency, capturing disturbances in the flow of speech due to abnormal Pauses and Truncations; Connectivity, related to the combining of clauses; Reference, capturing all variables relating to the referential use of language in discourse such as the use of noun phrases to identify objects and establish topics of the discourse; Concordance, related to deficits in grammatical Agreement. In the case of the preHD group, these differences were observed in Connectivity and Reference measures. Correlations of these measures with the voxels showing VBM differences between patients and controls showed that the Quantitative measure correlated with atrophy in bilateral caudate and putamen. The remaining components showed no significant correlation with the VBM differences. Conclusions Striatal atrophy is associated to spontaneous speech deficits. However, deficits in spontaneous speech in HD are characterised not only by dysfluencies related to motor dysfunction but also by syntactic and referential errors in their discourse. Specific deficits in connecting clauses and reference are detectable even before overt clinical symptomatology.

F15 Asymptomatic carriers and early stages huntington’s disease patients show an impaired linguistic profile

Background It is widely recognised that patients with Huntington’s disease (HD) present not only with motor but also with cognitive impairments. The question arises whether these cognitive changes are associated with linguistic changes, given a tight correlation between language and higher cognition, or language and thought, which a number of recent models in theoretical linguistics and studies across populations with cognitive disorders support. Aims To study linguistic deficits in asymptomatic carriers and in the early stages of HD, intending to build a profile of the grammatical changes characteristic of this disorder. Methods A sample of 32 individuals were recruited: 8 manifest HD patients (stages 1, 2), 8 asymptomatic carriers and 16 matched controls. Linguistic and cognitive variables were collected throughout an experiment based on 5 different tasks (spontaneous speech, verbal and non-verbal video clip commentaries, pairing test of phrases and images, adjective control test) and a neuropsychological battery (Abbreviated Boston naming test, Tap test, verbal fluency test, STROOP test, Trail Making Test A&B. Symbol-Digit Modalities Test. MMSE). Linguistic samples were transcribed and analysed. ANOVA and Kruskall-Wallis test were applied to find significant differences between controls, asymptomatic carriers and manifest HD patients. Results The results indicate that the linguistic profile of patients is impaired from the initial stage of the disease in various fields (prosody, morphology, syntax, semantics and discourse). These patients also exhibit difficulties in interpreting sentences containing ToM and subordinate contexts. Conclusions This work can be conceived as a first approach to the linguistic and cognitive profile of asymptomatic carriers and early HD patients. It can also serve as a basis for the creation of clinical tests (from a linguistic point of view) whose objective is to determine the progression of certain cognitive disorders.