Schizophrenia: Communication Disorders and Role of the Speech-Language Pathologist.

PURPOSE: This clinical focus article aims to provide a comprehensive overview of schizophrenia and understanding of communication disorders resulting from its psychopathology. Schizophrenia is a spectrum disorder with varying levels of symptom expression. It is characterized by positive and negative symptoms that can cause communication disorders of different severity levels. Communication difficulties manifest as a range of symptoms such as alogia, disorganized speech, and impaired social communication. These challenges may result in receptive and expressive language deficits that lead to misunderstandings, reduced social interactions, and difficulties expressing thoughts and emotions effectively. The purpose of this clinical focus article is to explore the role of the speech-language pathologist (SLP) in assessing and treating communication disorders presented in schizophrenia. CONCLUSIONS: In order to understand the role of the SLP in assessing and treating communication disorders in schizophrenia, it is imperative to understand the overall course, etiology, assessment, and treatment consideration of this condition. SLPs can provide services in the areas of social skills training and community-based intervention contexts.

Neurocognitive and linguistic correlates of positive and negative formal thought disorder: A meta-analysis.

Executive dysfunction and language impairment are the most prominent neuropsychological models of formal thought disorder (FTD) in schizophrenia. However, available studies have provided contradictory findings regarding the accuracy of these models. Furthermore, specific neurocognitive underpinnings of positive FTD (PosFTD) and negative FTD (NegFTD) are not clear. Following the systematic review of schizophrenia studies, a random-effects meta-analysis of the relationship between FTD and neurocognition/language in schizophrenia was conducted in 52 reports including 2805 patients. Neurocognition was significantly associated with both PosFTD (r = -0.21, CI = -0.14 to -0.27) and NegFTD (r = -0.24, CI = -0.18 to -0.30). Both PosFTD (r = ranged from -0.18 to -0.27) and NegFTD (r = ranged from -0.19 to -0.23) were significantly correlated with verbal memory, visual memory, attention, and processing speed. In meta-analyses of executive functions, PosFTD was significantly associated with working memory (r = -0.21), planning (r = -0.19), and inhibition (r = -0.21) and NegFTD was significantly associated with planning (r = -0.27), fluency (r = -0.27), and working memory (r = -0.24). In meta-analyses of linguistic variables, PosFTD was associated with deficits in syntactic comprehension (r = -0.27) and semantic processing (r = -0.18). In contrast, NegFTD was associated only with semantic comprehension (r = -0.21). Both PosFTD and NegFTD were significantly associated with executive dysfunction, neurocognitive deficits and semantic dysfunction but syntactic deficits were more specific to PosFTD. There were also some distinct patterns of relationships between the pattern of executive dysfunction and types of FTD. Fluency deficit was associated more strongly with NegFTD and poor inhibition was more specifically related to PosFTD. Current findings suggest that neurocognitive and linguistic correlates of PosFTD and NegFTD might be partly different.

Altered topological characteristics of morphological brain network relate to language impairment in high genetic risk subjects and schizophrenia patients.

OBJECTIVE: Evidence suggests relationships between abnormalities in various cortical and subcortical brain structures and language dysfunction in individuals with schizophrenia, and to some extent in those with increased genetic risk for this diagnosis. The topological features of the structural brain network at the systems-level and their impact on language function in schizophrenia and in those at high genetic risk has been less well studied. METHOD: Single-subject morphological brain network was constructed in a total of 71 subjects (20 patients with schizophrenia, 19 individuals at high genetic risk for schizophrenia, and 32 controls). Among these 71 subjects, 56 were involved in our previous neuroimaging studies. Graphic Theoretical Techniques was applied to calculate the global and nodal topological characteristics of the morphological brain network of each participant. Index scores for five language-related cognitive tests were also attained from each participant. RESULTS: Significantly smaller nodal degree in bilateral superior occipital gyri (SOG) were observed in individuals with schizophrenia, as compared to the controls and those at high risk; while significantly reduced nodal betweenness centrality (quantifying the level of a node in connecting other nodes in the network) in right middle frontal gyrus (MFG) was found in the high-risk group, relative to controls. The right MFG nodal efficiency and hub capacity (represented by both nodal degree and betweenness centrality) of the morphological brain network were negatively associated with the wide range achievement test (WRAT) standard performance score; while the right SOG nodal degree was positively associated with the WRAT standard performance score, in the entire study sample. CONCLUSIONS: These findings enhance the understanding of structural brain abnormalities at the systems-level in individuals with schizophrenia and those at high genetic risk, which may serve as critical neural substrates for the origin of the language-related impairments and symptom manifestations of schizophrenia.

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.

Diminished emotional expression in schizophrenia: an interdisciplinary approach based on behavioral interventions.

BACKGROUND: Negative symptoms represent the main cause of disability in schizophrenia, having recently been grouped into two general dimensions: avolition and diminished emotional expression, which includes affective flattening and alogia. The aim of this study was to explore the response of these two symptoms to a set of behavioral interventions based on contingency management, performed in an interdisciplinary context. METHOD: Behaviors of interest were monitored and evaluations before and after the treatment were performed on 9 schizophrenic inpatients with persistent negative symptoms. The program included 12 group double sessions aimed at developing facial expression and verbal communication, and a nursing care plan to generalize and strengthen these behaviors synergistically. RESULTS: there were appreciable differences in facial expression, which were less clear for alogia. The clinical evaluation using PANSS-N did not find notable differences at group level, but the nursing assessment using NOC indicators did. CONCLUSIONS: although difficult to modify, negative symptoms are not insensitive to the influence of behavioral interventions. Specific psychological interventions that address negative symptoms as a priority focus of attention and care need to be promoted and developed, particularly when considering the crucial role of context in their progression.

Language and hope in schizophrenia-spectrum disorders.

Hope is integral to recovery for those with schizophrenia. Considering recent advancements in the examination of clients' lexical qualities, we were interested in how clients' words reflect hope. Using computerized lexical analysis, we examined social, emotion, and future words' relations to hope and its pathways and agency components. Forty-five clients provided detailed narratives about their life and mental illness. Transcripts were analyzed using the Linguistic Inquiry and Word Count program (LIWC), which assigns words to categories (e.g., "anxiety") based on a pre-existing dictionary. Correlations and linear multiple regression were used to examine relationships between lexical qualities and hope. Hope and its subcomponents had significant or trending bivariate correlations in expected directions with several emotion-related word categories (anger and sadness) but were not associated with expected categories such as social words, positive emotions, optimism, achievement, and future words. In linear multiple regressions, no LIWC variable significantly predicted hope agency, but anger words significantly predicted both total hope and hope pathways. Our findings indicate lexical analysis tools can be used to investigate recovery-oriented concepts such as hope, and results may inform clinical practice. Future research should aim to replicate our findings in larger samples.

Can the Acoustic Analysis of Expressive Prosody Discriminate Schizophrenia?

Emotional states, attitudes and intentions are often conveyed by modulations in the tone of voice. Impaired recognition of emotions from a tone of voice (receptive prosody) has been described as characteristic symptoms of schizophrenia. However, the ability to express non-verbal information in speech (expressive prosody) has been understudied. This paper describes a useful technique for quantifying the degree of expressive prosody deficits in schizophrenia, using a semi-automatic method, and evaluates this method's ability to discriminate between patient and control groups. Forty-five medicated patients with a diagnosis of schizophrenia were matched with thirty-five healthy comparison subjects. Production of expressive prosodic speech was analyzed using variation in fundamental frequency (F0) measures on an emotionally neutral reading task. Results revealed that patients with schizophrenia exhibited significantly more pauses (p < .001), were slower (p < .001), and showed less pitch variability in speech (p < .05) and fewer variations in syllable timing (p < .001) than control subjects. These features have been associated with «flat¼ speech prosody. Signal processing algorithms applied to speech were shown to be capable of discriminating between patients and controls with an accuracy of 93.8%. These speech parameters may have a diagnostic and prognosis value and therefore could be used as a dependent measure in clinical trials.

Lexical Characteristics of Emotional Narratives in Schizophrenia: Relationships With Symptoms, Functioning, and Social Cognition.

Previous research has suggested that complexity of speech, speech rate, use of emotion words, and use of pronouns are all potential indicators of important clinical components of schizophrenia, but little research has examined the relationships of these disturbances to cognitive variables impaired in schizophrenia, including social cognition. The current study examined these lexical differences to better characterize the cognitive substrates of speech disturbances in schizophrenia. Brief narratives of individuals with schizophrenia (n = 42) and non-clinical controls (n = 48) were compared according to their lexical characteristics, and these were examined for relationships to social cognition and real-world functioning. Significant differences between the groups were found in words per sentence (related to functioning, but not negative symptoms) as well as pronoun use (related to attributional style and theory of mind). Additionally, lexical characteristics effectively distinguished individuals with schizophrenia from non-clinical controls. Language disturbances in schizophrenia seem related to social cognition impairments and real-world functioning, and are a robust indicator of clinical status.

Neuropsychological characteristics of verbal and non-verbal fluency in schizophrenia patients.

This review paper provides analyses confirming correlation between various brain regions activity, particularly its prefrontal portions, and schizophrenia patients' performance in verbal fluency tests. Various factors modifying patients' performance in the aforementioned tasks were singled out and discussed. Systematically we have reviewed the results of non-verbal fluency tests conducted in the schizophrenic patients. The authors also summarizes findings of earlier studies stressing the role of semantic fluency as a predictor of first-episode psychosis. Verbal and non-verbal fluency tests engage complex cognitive processes and executive functions in patients. As a result, the interpretation of their results is often complicated and requires special competences. The tests are popular neuropsychological tools used for assessment of verbal memory, executive functions, visual-spatial abilities and psychomotor speed in patients with mental and neurological disorders. The aim of this paper is to discuss diagnostic tools used for measuring both types of fluency (verbal and non-verbal), test interpretation methods, as well as their usefulness in clinical diagnostics and scientific research.

Differential lexical correlates of social cognition and metacognition in schizophrenia; a study of spontaneously-generated life narratives.

OBJECTIVES: Social cognition and metacognition have been identified as important cognitive domains in schizophrenia, which are separable from general neurocognition and predictive of functional and treatment outcomes. However, one challenge to improved models of schizophrenia has been the conceptual overlap between the two. One tool used in previous research to develop cognitive models of psychopathology is language analysis. In this article we aimed to clarify distinctions between social cognition and metacognition in schizophrenia using computerized language software. METHODS: Fifty-eight (n=58) individuals with schizophrenia completed the Metacognitive Assessment Scale Abbreviated and measures of social cognition using the Hinting, Eyes, BLERT and Picture Arrangement test. A lexical analysis of participants' speech using Language Inquiry and Word Count software was conducted to examine relative frequencies of word types. Lexical characteristics were examined for their relationships to social cognition and metacognition. RESULTS: We found that lexical characteristics indicative of cognitive complexity were significantly related to level of metacognitive capacity while social cognition was related to second-person pronoun use, articles, and prepositions, and pronoun use overall. The relationships between lexical variables and metacognition persisted after controlling for demographics, verbal intelligence, and overall word count, but the same was not true for social cognition. CONCLUSIONS: Our findings provided support for the view that metacognition requires more synthetic and complex verbal and linguistic operations, while social cognition is associated with the representation and clear identification of others.

A computational language approach to modeling prose recall in schizophrenia.

Many cortical disorders are associated with memory problems. In schizophrenia, verbal memory deficits are a hallmark feature. However, the exact nature of this deficit remains elusive. Modeling aspects of language features used in memory recall have the potential to provide means for measuring these verbal processes. We employ computational language approaches to assess time-varying semantic and sequential properties of prose recall at various retrieval intervals (immediate, 30 min and 24 h later) in patients with schizophrenia, unaffected siblings and healthy unrelated control participants. First, we model the recall data to quantify the degradation of performance with increasing retrieval interval and the effect of diagnosis (i.e., group membership) on performance. Next we model the human scoring of recall performance using an n-gram language sequence technique, and then with a semantic feature based on Latent Semantic Analysis. These models show that automated analyses of the recalls can produce scores that accurately mimic human scoring. The final analysis addresses the validity of this approach by ascertaining the ability to predict group membership from models built on the two classes of language features. Taken individually, the semantic feature is most predictive, while a model combining the features improves accuracy of group membership prediction slightly above the semantic feature alone as well as over the human rating approach. We discuss the implications for cognitive neuroscience of such a computational approach in exploring the mechanisms of prose recall.

Abnormal dynamics of language in schizophrenia.

Language could be conceptualized as a dynamic system that includes multiple interactive levels (sub-lexical, lexical, sentence, and discourse) and components (phonology, semantics, and syntax). In schizophrenia, abnormalities are observed at all language elements (levels and components) but the dynamic between these elements remains unclear. We hypothesize that the dynamics between language elements in schizophrenia is abnormal and explore how this dynamic is altered. We, first, investigated language elements with comparable procedures in patients and healthy controls. Second, using measures of reaction time, we performed multiple linear regression analyses to evaluate the inter-relationships among language elements and the effect of group on these relationships. Patients significantly differed from controls with respect to sub-lexical/lexical, lexical/sentence, and sentence/discourse regression coefficients. The intercepts of the regression slopes increased in the same order above (from lower to higher levels) in patients but not in controls. Regression coefficients between syntax and both sentence level and discourse level semantics did not differentiate patients from controls. This study indicates that the dynamics between language elements is abnormal in schizophrenia. In patients, top-down flow of linguistic information might be reduced, and the relationship between phonology and semantics but not between syntax and semantics appears to be altered.

Category fluency, latent semantic analysis and schizophrenia: a candidate gene approach.

BACKGROUND: Category fluency is a widely used task that relies on multiple neurocognitive processes and is a sensitive assay of cortical dysfunction, including in schizophrenia. The test requires naming of as many words belonging to a certain category (e.g., animals) as possible within a short period of time. The core metrics are the overall number of words produced and the number of errors, namely non-members generated for a target category. We combine a computational linguistic approach with a candidate gene approach to examine the genetic architecture of this traditional fluency measure. METHODS: In addition to the standard metric of overall word count, we applied a computational approach to semantics, Latent Semantic Analysis (LSA), to analyse the clustering pattern of the categories generated, as it likely reflects the search in memory for meanings. Also, since fluency performance probably also recruits verbal learning and recall processes, we included two standard measures of this cognitive process: the Wechsler Memory Scale and California Verbal Learning Test (CVLT). To explore the genetic architecture of traditional and LSA-derived fluency measures we employed a candidate gene approach focused on SNPs with known function that were available from a recent genome-wide association study (GWAS) of schizophrenia. The selected candidate genes were associated with language and speech, verbal learning and recall processes, and processing speed. A total of 39 coding SNPs were included for analysis in 665 subjects. RESULTS AND DISCUSSION: Given the modest sample size, the results should be regarded as exploratory and preliminary. Nevertheless, the data clearly illustrate how extracting the meaning from participants' responses, by analysing the actual content of words, generates useful and neurocognitively viable metrics. We discuss three replicated SNPs in the genes ZNF804A, DISC1 and KIAA0319, as well as the potential for computational analyses of linguistic and textual data in other genomics tasks.

Language-dependent performance on the letter fluency task in patients with schizophrenia.

Two types of verbal fluency tasks (letter fluency task; LFT, category fluency task; CFT) have been widely used to assess cognitive function in people with psychiatric diseases including schizophrenia. The task demand of the LFT is considered to vary across languages, as the cognitive process largely relies on sound and writing systems. Specifically, a sound unit for a letter (s) and a manner of association between them are assumed to be related with the performance. In the current study, three analyses have been conducted to examine this issue, using Japanese, Turkish, and English-speaking patients with schizophrenia. It was hypothesized that severity of letter fluency impairment would be in the order of Japanese, Turkish, and English speaking patients according to the inflexibility of a word search. First, performance on the LFT and the CFT was compared among Japanese (N=40), Turkish (N=30), and the US (N=31) patients (Analysis 1). A significant difference was found between the US and other two groups only in the LFT. Second, verbal fluency performance was compared between Japanese and Turkish patients by contrasting the degree of disassociations from normal controls (Japanese: N=20, Turkish: N=30) (Analysis 2). In Japanese patients, performance on the LFT was more severely impaired compared to that on the CFT while the opposite trend was found in the Turkish counterpart, suggesting that letter fluency performance was more degraded in Japanese patients. Finally, Analysis 3 was conducted to examine the relative order of letter fluency impairment among Japanese, Turkish and English-speaking patients. Disassociation in English users with schizophrenia was estimated based on previous meta-analytic reviews. The effect size (ES) for the letter fluency deficit was the largest in the Japanese sample, while the other two groups share similar ESs. The results from the three analyses partially supported the hypothesis for the severity of the letter fluency impairment in patients with schizophrenia. The language-dependency of letter fluency impairment was thought to be explained by the theoretical model built on unique properties of sound and writing systems. The considerations presented here would provide useful information for optimizing the portability of cognitive tasks across languages.

Verbatim recall in formal thought disorder in schizophrenia: a study of contextual influences.

INTRODUCTION: We have previously reported that people with schizophrenia and formal thought disorder (FTD) were disproportionately impaired in recalling sentences verbatim and in judging their plausibility. We proposed that these deficits were due to impairment in integrating higher-order semantic information to construct a global whole. However, it is also possible that a lower-level linguistic problem affecting lexical activation could account for this pattern. METHODS: The present study analysed and compared the sentence repetition errors produced by people with FTD, people with schizophrenia who were non-FTD and healthy controls. Errors due to failure of activation of the target lexical items were differentiated from those due to erroneous integration of information. RESULTS: People with FTD produced significantly more unrelated lexical substitutions and omissions in their corpora than the other two groups, indicating an impairment of activation. In addition, they made significantly more erroneous contextual inferences and unrelated references, suggesting they were impaired in reconstructing the global whole from successfully activated items. CONCLUSION: These findings are consistent with a dual process account of impairments in FTD. Difficulties in repeating and judging sentence acceptability arises due to a combination of difficulty with activation and deficits in using linguistic context to process and produce speech. It is suggested that processing difficulties in FTD result from an impairment in using semantic context to drive lexical access and construction of a global whole.

Neural correlates of the relationship between discourse coherence and sensory monitoring in schizophrenia.

Unusual language use is a core feature of psychosis, but the nature and significance of this are not understood. In particular, thought disorder in schizophrenia (SZ) is characterized by markedly bizarre speech, but the cognitive components that contribute to this and the brain correlates of these components are unknown. A number of studies have demonstrated language abnormalities in single word processing, but few have examined speech in SZ at the discourse level. This has been at least partly due to the difficulty in quantifying content of discourse. Recently, methods in computational linguistics have been found to be useful for detecting differences in semantic coherence during discourse between different clinical groups. We build on this work by demonstrating how these methods can be combined with funtional magnetic resonance imaging (fMRI) in order to tease apart factors that underlie free discourse and its deviations, and how they relate to brain activity. Eleven volunteers with SZ and eleven controls participated in an interview during which they were asked to talk as much as they could about 'religious belief'. These same participants underwent fMRI during a word monitoring task, during which modality of monitoring was manipulated by varying the congruence of auditory and visual stimuli. Semantic coherence scores, measured from free discourse, were examined for their relationship to brain activations during fMRI. In healthy controls, regions associated with executive function were related to coherence. In persons with SZ, coherence was mainly related to auditory and visual regions, depending on the modality of monitoring, but superior/middle temporal cortex related to coherence regardless of task. These findings are consistent with existing evidence for a role of superior temporal cortex in thought disorder, and demonstrate that computational measures of semantic content capture objective measures of coherence in speech that can be usefully related to underlying neurophysiological processes.