Proverb comprehension impairments in schizophrenia are related to executive dysfunction

Proverb comprehension in schizophrenia: A comprehensive review and meta-analysis.2

BACKGROUND

Examination of proverb comprehension has a long tradition in clinical diagnostics of individuals with schizophrenia (iSCZ). Deficits in the comprehension are considered common. Interpretations of proverbs are traditionally measured by their degree of abstraction and concreteness ('literalness'), but iSCZ's responses may also be illogical or 'bizarre'. Experimental research on proverb comprehension starts in the 1940s. Since then, the specificity of proverb tests has often been questioned, but has never been the subject of a meta-analysis. The aim of this meta-analysis is to include all experimental research, including historical studies, that meets quality criteria and compares the responses to proverbs in iSCZ with those in healthy controls (HC) or clinical controls (CC).

METHODS

PubMed, Web of Science, and PsycInfo databases were searched. After coding 121 articles, 27 (median publication year 1982) were included and multi-level meta-analyses performed. Moderator analyses were performed on response format (multiple-choice vs. verbal responses), proverb test, scoring method, language, acute vs. chronic stage of iSCZ, time of publication, clinical vs. healthy control group, age, IQ/education, and gender. Publication bias was assessed using funnel plots, trim and fill method and Egger's test.

RESULTS

The search identified 27 eligible studies for inclusion. Studies were published between 1956 and 2020 and predominantly older than 30 years (median: 1982). The Gorham Proverbs Test was the most established test and predominantly conducted in English. CC mostly consisted of depressive disorders. Pooled estimates yielded statistically significant less abstract (g = -1.00; 95%CI, -1.34 to -1.67), more concrete (g = 0.69; 95%CI, 0.35-1.03), and more bizarre (g = 1.08; 95%CI, 0.74-1.41) responses in iSCZ compared to controls. The type of control group moderated all three effects, with greater differences of iSCZ compared to HC than to CC in abstraction and bizarreness, and no significant group difference between iSCZ and CC in concreteness. Meta-regressions indicated IQ/education and age as possible sources of variability in abstraction and bizarreness.

CONCLUSIONS

While lower abstraction and higher bizarreness seems a characteristic of iSCZ, the diagnostic specificity of a concrete response was astonishingly low. The lack of a unified definition for concretism and limited consideration of cultural diversity contributed to these complex findings. Future research should focus on exploring the qualitative aspects of proverb comprehension and the association between symptomatology types and misinterpretations to improve diagnostic accuracy.

Specific learning disorders in young adults: Investigating pragmatic abilities and their relationship with theory of mind, executive functions and quality of life

BACKGROUND

Specific Learning Disorders (SLD) are lifelong conditions often associated with language difficulties, executive dysfunctions, and psychological problems. Previous research has shown that communicative-pragmatic ability may be impaired in SLD. However, the role of other cognitive abilities in explaining pragmatic difficulties has still not been fully investigated. The relationship between pragmatics and quality of life is not yet clear, as well.

AIMS

Firstly, the study assessed pragmatic comprehension abilities in adults with SLD. Secondly, we examined the relationship between pragmatics, theory of mind, executive functions and quality of life.

METHOD AND PROCEDURES

We enrolled 26 adults with SLD and 30 adults without SLD. Standardized tests assessing pragmatic comprehension, theory of mind and executive functions were used. The quality of life was investigated with a self-reported questionnaire.

OUTCOMES AND RESULTS

Pragmatic comprehension abilities were compromised in young adults with SLD. In this clinical population we also found a link between pragmatic comprehension and visual theory of mind. Finally, independently from the presence of SLD, pragmatics abilities were in relationship with quality of life.

CONCLUSIONS AND IMPLICATIONS

Overall, these data highlight the importance of including pragmatic abilities both in the clinical evaluation, as well as in psychological intervention for adults with SLD.

Interpretation of familiar metaphors and proverbs by Polish people in middle and late adulthood

BACKGROUND

The ability to understand figurative language, including metaphors and proverbs, decreases with age, although the phenomenon is not universal. Cognitive capacities and education play an important role in the competence connected with figurative language use and comprehension in people during the second half of life.

AIMS

To identify possible similarities and differences in task performance by subjects representing middle adulthood (40-49 and 50-59 years old) and late adulthood (60-69 and 70-92 years old). Additionally, the analyses took into account factors significantly affecting the results, that is, tasks type (metaphors versus proverbs), the way the answer is given (open-ended versus multiple choice) and types of answers (abstract and concrete). This study also aimed to identify some cognitive correlates of task completion.

METHODS & PROCEDURES

A total of 86 Caucasian subjects, aged 40-92 years, participated in this study (M_{whole group} = 62.37, SD = 15.53); the group included 20 subjects aged 40-49 years (M_age = 45.4; SD = 3.05), 20 aged 50-59 years (M_age = 55.50; SD = 2.64), 20 aged 60-69 years (M_age = 64.40; SD = 2.78), and 26 aged 70-92 years (M_age = 79.15; SD = 6.27). A total of 20 well-known Polish metaphors and 20 popular Polish proverbs were used to assess the level of proverb and metaphor comprehension. The Montreal Cognitive Assessment Scale and Vocabulary subtest of the Polish version of WAIS-R were applied to assess the cognitive functions.

OUTCOMES & RESULTS

The results of the analyses suggest that there are differences as well as certain similarities between the groups. At 70+ years of age, the ability to explain and comprehend metaphors and proverbs decreases when compared with younger adults. In the 70+ group, the ability to grasp the meaning of both metaphors and proverbs is similar, unlike in the younger groups which present a better ability to explain and comprehend metaphors than proverbs. The conditions related to the types of tasks, that is, spontaneous interpretation and choice of responses, do not affect scores of the oldest subjects.

CONCLUSIONS

The analysis of response types, that is, abstract versus concrete, shows that, compared with younger groups, people aged 70+ years tend to less frequently provide abstract explanations and more often give concrete (but correct) responses, referring to situational data or examples from everyday life. Moreover, attention, short-term/delayed memory and lexical reserve influence the ability to use and comprehend figurative language to a varied degree.

WHAT THIS PAPER ADDS

What is already known on the subject Studies focusing on metaphor and proverb interpretation by people in middle and late adulthood are rather scarce, and what is more, they provide inconclusive results. Research has shown that the capacities related to attention and memory, as well as language resources and executive functions, all deteriorate in older people, which negatively affects their ability to understand metaphors and proverbs. However, varied methods are applied to assess these skills, which may explain why the related findings are inconsistent. What this paper adds to existing knowledge The novelty of this study lies in the fact that the analyses took into account the type of task (metaphors versus proverbs), the method of responding (open-ended versus multiple-choice) and the nature of the answer (abstract versus concrete). This allowed us to highlight intergroup differences and to show specific characteristics of proverb and metaphor spontaneous interpretation and choice of correct answers. The results were compared among the participants representing relatively narrow age ranges classified as middle and late adulthood. What are the potential or actual clinical implications of this work? Analysis of how people in middle and late adulthood interpret metaphors and proverbs might constitute an element of preliminary screening assessment showing whether a decrease in this capacity is in the normal range or if it reflects a serious cognitive decline. It would be worthwhile if the diagnostic process included varied task designs, that is, both metaphors and proverbs, as well as spontaneous interpretation and multiple-choice, as well as varied types of responses.

Multimodal assessment of communicative-pragmatic features in schizophrenia: a machine learning approach

An impairment in pragmatic communication is a core feature of schizophrenia, often associated with difficulties in social interactions. The pragmatic deficits regard various pragmatic phenomena, e.g., direct and indirect communicative acts, deceit, irony, and include not only the use of language but also other expressive means such as non-verbal/extralinguistic modalities, e.g., gestures and body movements, and paralinguistic cues, e.g., prosody and tone of voice. The present paper focuses on the identification of those pragmatic features, i.e., communicative phenomena and expressive modalities, that more reliably discriminate between individuals with schizophrenia and healthy controls. We performed a multimodal assessment of communicative-pragmatic ability, and applied a machine learning approach, specifically a Decision Tree model, with the aim of identifying the pragmatic features that best separate the data into the two groups, i.e., individuals with schizophrenia and healthy controls, and represent their configuration. The results indicated good overall performance of the Decision Tree model, with mean Accuracy of 82%, Sensitivity of 76%, and Precision of 91%. Linguistic irony emerged as the most relevant pragmatic phenomenon in distinguishing between the two groups, followed by violation of the Gricean maxims, and then extralinguistic deceitful and sincere communicative acts. The results are discussed in light of the pragmatic theoretical literature, and their clinical relevance in terms of content and design of both assessment and rehabilitative training.

The Role of Working Memory in the Processing of Scalar Implicatures of Patients With Schizophrenia Spectrum and Other Psychotic Disorders

A number of studies have demonstrated pragmatic language difficulties in people with Schizophrenia Spectrum and Other Psychotic Disorders. However, research about how people with schizophrenia spectrum and other psychotic disorders understand scalar implicatures (SIs) is surprisingly rare, since SIs have generated much of the most recent literature. Scalar implicatures are pragmatic inferences, based on linguistic expressions like some, must, or, which are part of a scale of informativeness (e.g., some/many/all). Logically, the less informative expressions imply the more informative ones, but pragmatically people usually infer that the presence of a less informative term implies that the more informative term was not applicable. In one of the few existing studies with people with schizophrenia spectrum and other psychotic disorders, Wampers et al. (2018) observed that in general, people with schizophrenia spectrum and other psychotic disorders were less likely to derive SIs than controls. The current study has three main aims. First, we want to replicate the original finding with the scalar terms some-all. Second, we want to investigate how these patients deal with different scalar terms, that is, we want to investigate if scalar diversity is also observed in this clinical group. Third, we investigate the role of working memory, often seen as another important mechanism to enable inferring SIs. Twenty-one individuals with a psychotic disorder and 21 matched controls answered 54 under-informative statements, in which seven different pairs of scalar terms were used. In addition, working memory capacity was measured. Patients with schizophrenia spectrum and other psychotic disorders did not make more logical interpretations when processing quantifiers, disconfirming Wampers et al. (2018). However, certain scalar scales elicited more pragmatic interpretations than others, which is in line with the scalar diversity hypothesis. Additionally, we observed only partial evidence for the role of working memory. Only for the scalar scale and-or, a significant effect of working memory was observed. The implications of these results for patients with schizophrenia spectrum and other psychotic disorders are discussed, but also the role of working memory for pragmatic inferences, as well as the place of SIs in experimental pragmatics.

The Cerebellum and Implicit Sequencing: Evidence from Cerebellar Ataxia

The cerebellum recognizes sequences from prior experiences and uses this information to generate internal models that predict future outcomes in a feedforward manner [Front Hum Neurosci 8: 475, 2014; Cortex 47: 137-44, 2011; Cerebellum 7: 611-5, 2008; J Neurosci 26: 9107-16, 2006]. This process has been well documented in the motor domain, but the cerebellum's role in cognitive sequencing, within the context of implicit versus explicit processes, is not well characterized. In this study, we tested individuals with cerebellar ataxia and healthy controls to clarify the role of the cerebellum sequencing using variations on implicit versus explicit and motor versus cognitive demands across five experiments. Converging results across these studies suggest that cerebellar feedforward mechanisms may be necessary for sequencing in the implicit domain only. In the ataxia group, rhythmic tapping, rate of motor learning, and implicit sequence learning were impaired. However, for cognitive sequencing that could be accomplished using explicit strategies, the cerebellar group performed normally, as though they shifted to extra-cerebellar mechanisms to compensate. For example, when cognitive and motor functions relied on cerebellar function simultaneously, the ataxia group's motor function was unaffected, in contrast to that of controls whose motor performance declined as a function of cognitive load. These findings indicated that the cerebellum is not critical for all forms of sequencing per se. Instead, it plays a fundamental role for sequencing within the implicit domain, whether functions are motor or cognitive. Moreover, individuals with cerebellar ataxia are generally able to compensate for cognitive sequencing when explicit strategies are available in order to preserve resources for motor function.

The Gap Between Cognition and Adaptive Behavior in Students with Autism Spectrum Disorder: Implications for Social Anxiety and the Moderating Effect of Autism Traits

The gap between cognitive ability and adaptive behavior has been thought to enhance psychopathology among people with autism, particularly among those without intellectual disability. We examined this association by exploring the gap between cognitive understanding of social behavior and socially adaptive behavior, and its impact on social anxiety symptoms, obsessive-compulsive symptoms, and depressive symptoms, among 53 university students with autism (without intellectual disability). A higher cognition-social adaptation discrepancy was associated with more social anxiety, but this effect was moderated by autistic trait (AT) levels; a greater gap was associated with more avoidance symptoms of social anxiety only among students with high AT. Cognitive flexibility and prosocial behavior may mitigate the effects of AT. Potential implications and interventions are discussed.

Pragmatics, Theory of Mind and executive functions in schizophrenia: Disentangling the puzzle using machine learning

OBJECTIVE

Schizophrenia is associated with a severe impairment in the communicative-pragmatic domain. Recent research has tried to disentangle the relationship between communicative impairment and other domains usually impaired in schizophrenia, i.e. Theory of Mind (ToM) and cognitive functions. However, the results are inconclusive and this relationship is still unclear. Machine learning (ML) provides novel opportunities for studying complex relationships among phenomena and representing causality among multiple variables. The present research explored the potential of applying ML, specifically Bayesian network (BNs) analysis, to characterize the relationship between cognitive, ToM and pragmatic abilities in individuals with schizophrenia and healthy controls, and to identify the cognitive and pragmatic abilities that are most informative in discriminating between schizophrenia and controls.

METHODS

We provided a comprehensive assessment of different aspects of pragmatic performance, i.e. linguistic, extralinguistic, paralinguistic, contextual and conversational, ToM and cognitive functions, i.e. Executive Functions (EF)-selective attention, planning, inhibition, cognitive flexibility, working memory and speed processing-and general intelligence, in a sample of 32 individuals with schizophrenia and 35 controls.

RESULTS

The results showed that the BNs classifier discriminated well between patients with schizophrenia and healthy controls. The network structure revealed that only pragmatic Linguistic ability directly influenced the classification of patients and controls, while diagnosis determined performance on ToM, Extralinguistic, Paralinguistic, Selective Attention, Planning, Inhibition and Cognitive Flexibility tasks. The model identified pragmatic, ToM and cognitive abilities as three distinct domains independent of one another.

CONCLUSION

Taken together, our results confirmed the importance of considering pragmatic linguistic impairment as a core dysfunction in schizophrenia, and demonstrated the potential of applying BNs in investigating the relationship between pragmatic ability and cognition.

Voice patterns in schizophrenia: A systematic review and Bayesian meta-analysis

Voice atypicalities have been a characteristic feature of schizophrenia since its first definitions. They are often associated with core negative symptoms such as flat affect and alogia, and with the social impairments seen in the disorder. This suggests that voice atypicalities may represent a marker of clinical features and social functioning in schizophrenia. We systematically reviewed and meta-analyzed the evidence for distinctive acoustic patterns in schizophrenia, as well as their relation to clinical features. We identified 46 articles, including 55 studies with a total of 1254 patients with schizophrenia and 699 healthy controls. Summary effect sizes (Hedges'g and Pearson's r) estimates were calculated using multilevel Bayesian modeling. We identified weak atypicalities in pitch variability (g = -0.55) related to flat affect, and stronger atypicalities in proportion of spoken time, speech rate, and pauses (g's between -0.75 and -1.89) related to alogia and flat affect. However, the effects were mostly modest (with the important exception of pause duration) compared to perceptual and clinical judgments, and characterized by large heterogeneity between studies. Moderator analyses revealed that tasks with a more demanding cognitive and social component showed larger effects both in contrasting patients and controls and in assessing symptomatology. In conclusion, studies of acoustic patterns are a promising but, yet unsystematic avenue for establishing markers of schizophrenia. We outline recommendations towards more cumulative, open, and theory-driven research.

A leopard cannot change its spots: A novel pragmatic account of concretism in schizophrenia

Concretism is a well-known feature of schizophrenia, tracing back to the early descriptions of the disease and commonly associated with the literal interpretation of figurative expressions such as proverbs, metaphors, and idioms. However, figurative expressions are not all alike in terms of linguistic and pragmatic processes. Determining if some figurative types are more impaired than others and if the type of task affects the performance constitutes an open issue with implications for the description of the clinical profile and for treatment. We run a fine-grained assessment of figurative language comprehension by comparing 47 patients with schizophrenia and 39 controls in three figurative types (idioms, metaphors, proverbs) presented in two response formats (multiple-choice, verbal-explanation), considering also the role of cognitive and clinical variables and the impact on quality of life. Mixed-effects models analysis revealed that: i) patients performed worse than controls across figurative types and response formats, indicating a diffuse impairment; ii) there is an interplay of figurative type and response format, which makes verbal-explanation of proverbs especially challenging; iii) in patients, problems in figurative language are largely connected with formal thought disorder and global IQ. Moreover, multiple-choice of metaphors was associated with patients' quality of life. This study offers a novel account of concretism, framed in pragmatics and figurative language processing. Adopting this perspective allowed us to describe the nuances of concretism, which areas in the figurative domain are especially challenging for patients and which ones capture differences in functioning, in order to guide intervention programs and integration in society.

Non-literal understanding and psychosis: Metaphor comprehension in individuals with a diagnosis of schizophrenia

Previous studies suggest that understanding of non-literal expressions, and in particular metaphors, can be impaired in people with schizophrenia; although it is not clear why. We explored metaphor comprehension capacity using a novel picture selection paradigm; we compared task performance between people with schizophrenia and healthy comparator subjects and we further examined the relationships between the ability to interpret figurative expressions non-literally and performance on a number of other cognitive tasks. Eye-tracking was used to examine task strategy. We showed that even when IQ, years of education, and capacities for theory of mind and associative learning are factored in as covariates, patients are significantly more likely to interpret metaphorical expressions literally, despite eye-tracking findings suggesting that patients are following the same interpretation strategy as healthy controls. Inhibitory control deficits are likely to be one of multiple factors contributing to the poorer performance of our schizophrenia group on the metaphor trials of the picture selection task.

The Ability of Patients With Schizophrenia to Comprehend and Produce Sincere, Deceitful, and Ironic Communicative Intentions: The Role of Theory of Mind and Executive Functions

Patients with schizophrenia are often described as impaired in several cognitive domains. Specifically, patients with schizophrenia often exhibit problems in solving tasks requiring theory of mind (ToM), i.e., the ability to ascribe mental states to oneself and others, communicative-pragmatic ability, i.e., the ability to use language and non-verbal expressive means to convey meaning in a given context, and executive functions (EF). This study aims to investigate the role of cognitive functions, such as general intelligence, selective attention, processing speed, and especially EF (working memory, cognitive flexibility, inhibition, and planning), and ToM in explaining the performance of individual with schizophrenia in comprehending and producing communicative acts expressed with different communicative intentions (i.e., sincere, deceitful, and ironic), and realized through linguistic and extralinguistic/non-verbal expressive means. Thirty-two patients with schizophrenia and an equal number of healthy controls performed tasks aiming to investigate their capacity to comprehend and produce sincere, deceitful, and ironic communicative acts in addition to a series of cognitive tasks evaluating EF and ToM. The results indicated that individuals with schizophrenia performed worse than the controls in the comprehension and production of all pragmatic phenomena investigated, as well as in all the cognitive functions examined. The patients with schizophrenia also exhibited an increasing trend of difficulty in comprehending and producing sincere, deceitful, and ironic communicative acts expressed through either linguistic or extralinguistic means. Furthermore, a multiple regression analysis of the patients' performance on the pragmatic tasks revealed that overall, the role of attention, general intelligence, and processing speed did not appear to significantly explain the patients' communicative-pragmatic performance. The inclusion of EF into the analysis did not contribute to increase the explained variance of the patients' ability to comprehend and produce the various pragmatic phenomena investigated. Only the addition of ToM could significantly increase the explained variance, but only in the comprehension and production of deceit expressed by language and the production of sincere communicative acts, also limited to linguistic production. We conclude that neither EF nor ToM are able to explain the decreasing trend detected in the patients' pragmatic performance.

Higher-order language dysfunctions as a possible neurolinguistic endophenotype for schizophrenia: Evidence from patients and their unaffected first degree relatives

The purpose of the study was to examine the presence of pragmatic dysfunctions in first episode (FE) subjects and their healthy first degree relatives as a potential endophenotype for schizophrenia. Thirty-four FE patients, 34 parents of the patients (REL) and 32 healthy controls (HC) took part in the study. Pragmatic language functions were evaluated with the Right Hemisphere Language Battery, attention and executive functions were controlled, as well as age and education level. The parents differed from HC but not from their FE offspring with regard to overall level of language and communication and the general knowledge component of language processing. The FE participants differed from HC in comprehension of inferred meaning, emotional prosody, discourse dimensions, overall level of language and communication, language processing with regard to general knowledge and communication competences. The FE participants differed from REL regarding discourse dimensions. Our findings suggest that pragmatic dysfunctions may act as vulnerability markers of schizophrenia; their assessment may help in the diagnosis of early stages of the illness and in understanding its pathophysiology. In future research the adoptive and biological parents of schizophrenia patients should be compared to elucidate which language failures reflect genetic vulnerability and which ones environmental factors.

Cognitive abilities and theory of mind in explaining communicative-pragmatic disorders in patients with schizophrenia

Patients with schizophrenia usually show an impairment in their communicative-pragmatic performance; they also have difficulties in cognitive functioning and Theory of Mind (ToM). In the literature it has been proposed that ToM and cognitive deficits have a role in explaining the communicative-pragmatic difficulties of patients with schizophrenia. However, the exact interplay of these functions is still not completely clear. The present research investigates the relationship between communicative-pragmatic, ToM and cognitive impairments (i.e. general intelligence, selective attention, speed processing and EF -working memory, inhibition and flexibility-) in a sample of 26 individuals with schizophrenia and matched controls. The linguistic and extralinguistic scales of the Assessment Battery of Communication (ABaCo), and a series of ToM and cognitive tasks were administered to patients and healthy controls. The results showed that individuals with schizophrenia performed less well than controls in all the tasks investigated. However, a hierarchical regression analysis showed that only ToM, and not cognitive functions, seems to be a predictive variable of patients' performance. Finally, a Fisher's exact test showed that there was not a stable significant relationship between ToM or EF and pragmatic impairment.

The Comprehension of Familiar and Novel Metaphoric Meanings in Schizophrenia: A Pilot Study

Miscomprehension of nonliteral (“figurative”) language like metaphors, proverbs, idioms, and ironic expressions by patients with schizophrenia is a phenomenon mentioned already in historical psychiatric descriptions. However, it was only recently that studies did differentiate between novel and conventional metaphors, a factor that is known to influence the difficulty of comprehension in healthy subjects. Further, familiarity with stimuli is an important factor for comprehension, which was not recommended in utmost previous studies. In this study, 23 patients with DSM IV schizophrenia and 19 healthy control subjects performed a newly-developed German metaphor comprehension test with three types of stimuli: novel metaphors, conventional German metaphors, and meaningless statements. During the test procedure, participants indicated familiarity with the stimulus and then matched the meaning with one out of four given alternatives. Familiarity rankings did not significantly differ between patients and control subjects. However, on descriptive level, there was a tendency for healthy controls to be more familiar with conventional metaphors than schizophrenic patients. Further, comprehension of conventional and novel metaphors differed significantly between the groups, with higher performance in healthy controls. Considering only those metaphors that had been ranked as familiar, patients only revealed significant lower performance opposed to controls regarding novel metaphors, while they did not differ in conventional metaphors. Taken together, the results indicate that patients with schizophrenia might show an altered way of comprehension in novel metaphors, leading to more misunderstandings. However, their previously reported impairments in conventional metaphors might rather be due to a lack of familiarity with the stimuli—making conventional metaphors to novel metaphors in the individual case.

Asperger Syndrome and Schizophrenia: A Comparative Neuropsychological Study

There has been an increasing interest in possible connections between autism spectrum disorder (ASD) and schizophrenia in the last decade. Neuropsychological comparison studies have, however, been few. The present study examined similarities and differences in intellectual and executive functioning between adults with Asperger syndrome (AS) and adults with schizophrenic psychosis (SP). A group with AS and a group with SP were assessed neuropsychologically with WAIS-III and D-KEFS. Similarities were found between groups, as displayed by an uneven cognitive profile, limitations in working memory, processing speed and some aspects of executive functioning. Full Scale IQ was higher in the AS group. These results add to the current research illuminating similarities and differences between ASD and schizophrenia on a cognitive level.

Distinct Neuropsychological Correlates in Positive and Negative Formal Thought Disorder Syndromes: The Thought and Language Disorder Scale in Endogenous Psychoses

The correlation of formal thought disorder (FTD) symptoms and subsyndromes with neuropsychological dimensions is as yet unclear. Evidence for a dysexecutive syndrome and semantic access impairments has been discussed in positive FTD, albeit focusing mostly on patients with schizophrenia. We investigated the correlation of the full range of positive and negative as well as subjective and objective FTD with neuropsychological domains in different patient groups. Patients with ICD-10 schizophrenia (n = 51), depression (n = 51), and bipolar mania (n = 18), as well as healthy subjects (n = 60), were interviewed with the Rating Scale for the Assessment of Objective and Subjective Formal Thought and Language Disorder (TALD) and assessed using a multidimensional neuropsychological test battery (executive function, semantic and lexical verbal fluency, attention, working memory, and abstract thinking). Partial correlation analysis, controlling for age and word knowledge, revealed significant results for the objective positive FTD dimension and executive dysfunctions. Objective negative FTD was associated with deficits in lexico-semantic retrieval, as well as attention and working memory dysfunctions. The results suggest that different neuropsychological substrates correlate with the multidimensional and phenomenologically different FTD syndromes. FTD is a complex, multidimensional syndrome with a variety of neuropsychological impairments, which should be accounted for in future studies investigating the pathogenesis of FTD.

The communicative impairment as a core feature of schizophrenia: Frequency of pragmatic deficit, cognitive substrates, and relation with quality of life

BACKGROUND

Impairments in specific aspects of pragmatic competence, supporting the use of language in context, are largely documented in schizophrenia and might represent an indicator of poor outcome. Yet pragmatics is rarely included in clinical settings. This paper aims to promote a clinical consideration of pragmatics as a target of assessment and intervention. We investigated the frequency of the pragmatic deficit, its cognitive substrates, and the relation with quality of life.

METHODS

Pragmatic abilities were compared in a sample of patients with schizophrenia and healthy controls based on a comprehensive pragmatic test (APACS). We assessed also for psychopathology, cognition, social cognition, and quality of life. We explored the co-occurrence of deficits in different domains, and we used multiple regressions to investigate the effect of cognition and social cognition on pragmatics, and of pragmatics on quality of life.

RESULTS

Pragmatic abilities, especially comprehending discourse and non-literal meanings, were compromised in schizophrenia, with 77% of patients falling below cutoff. Pragmatic deficit co-occurred with cognitive or socio-cognitive deficits in approximately 30% of cases. Multiple regression analysis confirmed the interplay of cognition and social cognition in pragmatic behavior. Quality of life was predicted by symptoms and by pragmatic abilities.

CONCLUSIONS

The high frequency of impairment suggests that the pragmatic deficit is a core feature of schizophrenia, associated with quality of life. Cognitive and socio-cognitive abilities might represent necessary though not sufficient building blocks for the acquisition of pragmatic abilities throughout development. Therefore, a more precise incorporation of pragmatics in the description of the pathology is of high clinical and translational relevance.

Contextual predictability enhances reading performance in patients with schizophrenia

In the present work we analyzed fixation duration in 40 healthy individuals and 18 patients with chronic, stable SZ during reading of regular sentences and proverbs. While they read, their eye movements were recorded. We used lineal mixed models to analyze fixation durations. The predictability of words N-1, N, and N+1 exerted a strong influence on controls and SZ patients. The influence of the predictabilities of preceding, current, and upcoming words on SZ was clearly reduced for proverbs in comparison to regular sentences. Both controls and SZ readers were able to use highly predictable fixated words for an easier reading. Our results suggest that SZ readers might compensate attentional and working memory deficiencies by using stored information of familiar texts for enhancing their reading performance. The predictabilities of words in proverbs serve as task-appropriate cues that are used by SZ readers. To the best of our knowledge, this is the first study using eyetracking for measuring how patients with SZ process well-defined words embedded in regular sentences and proverbs. Evaluation of the resulting changes in fixation durations might provide a useful tool for understanding how SZ patients could enhance their reading performance.

Haemodynamic and electrophysiological markers of pragmatic language comprehension in schizophrenia

OBJECTIVES

The present study aimed at investigating neurophysiological markers of language perception in schizophrenia using simultaneous near-infrared spectroscopy (NIRS) and event-related potentials (ERPs), which have been proven to be useful for studying language processing abilities in psychiatric patients. The study shall help to integrate previous findings from ERP and fMRI studies on figurative language comprehension in schizophrenia and elucidate how electrophysiological and haemodynamic markers of language processing are related.

METHODS

Twenty-two healthy subjects and 22 schizophrenia patients judged 120 sentences regarding their meaningfulness. Phrases were literal, metaphoric, or meaningless. EEG-fNIRS signals were recorded throughout the entire experiment.

RESULTS

Schizophrenia patients showed deficient and delayed sentence comprehension. Both the early N400 and left-hemispheric activation during language comprehension were altered in patients. Correlation analyses showed that metaphor-related ERPs were strongly linked to haemodynamic cortical activity in healthy subjects, but not in patients.

CONCLUSIONS

Our results indicate group differences in cortical electrophysiological and haemodynamic activation that represent rather general impairments in the processing of complex language. Simultaneous EEG/NIRS applications are useful to depict these neural markers and to investigate their relationship. Future studies are needed to clarify the nature of respective anomalies and their potential as putative neural markers in schizophrenia research.

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.

Metaphor in psychosis: on the possible convergence of Lacanian theory and neuro-scientific research

Starting from the theories of leading psychiatrists, like Kraepelin and de Clérambault, the French psychoanalyst Jacques Lacan (1901–1981) formulated an original theory of psychosis, focusing on the subject and on the structuring role of language. In particular, he postulated that language makes up the experience of subjectivity and that psychosis is marked by the absence of a crucial metaphorization process. Interestingly, in contemporary psychiatry there is growing empirical evidence that schizophrenia is characterized by abnormal interpretation of verbal and non-verbal information, with a great difficulty to put such information in the appropriate context. Neuro-scientific contributions have investigated this difficulty suggesting the possibility of interpreting schizophrenia as a semiotic disorder which makes the patients incapable of understanding the figurative meaning of the metaphoric speech, probably due to a dysfunction of certain right hemisphere areas, such as the right temporoparietal junction and the right superior/middle temporal gyrus. In this paper we first review the Lacanian theory of psychosis and neuro-scientific research in the field of symbolization and metaphoric speech. Next, we discuss possible convergences between both approaches, exploring how they might join and inspire one another. Clinical and neurophysiological research implications are discussed.

Is the comprehension of idiomatic sentences indeed impaired in paranoid Schizophrenia? A window into semantic processing deficits

Schizophrenia patients have been reported to be more impaired in comprehending non-literal than literal language since early studies on proverbs. Preference for literal rather than figurative interpretations continues to be documented. The main aim of this study was to establish whether patients are indeed able to use combinatorial semantic processing to comprehend literal sentences and both combinatorial analysis, and retrieval of pre-stored meanings to comprehend idiomatic sentences. The study employed a sentence continuation task in which subjects were asked to decide whether a target word was a sensible continuation of a previous sentence fragment to investigate idiomatic and literal sentence comprehension in patients with paranoid schizophrenia. Patients and healthy controls were faster in accepting sensible continuations than in rejecting non-sensible ones in both literal and idiomatic sentences. Patients were as accurate as controls in comprehending literal and idiomatic sentences, but they were overall slower than controls in all conditions. Once the contribution of cognitive covariates was partialled out, the response times (RTs) to sensible idiomatic continuations of patients did not significantly differ from those of controls. This suggests that the state of residual schizophrenia did not contribute to slower processing of sensible idioms above and beyond the cognitive deficits that are typically associated with schizophrenia.

Irony and proverb comprehension in schizophrenia: do female patients "dislike" ironic remarks?

Difficulties in understanding irony and sarcasm are part of the social cognition deficits in patients with schizophrenia. A number of studies have reported higher error rates during comprehension in patients with schizophrenia. However, the relationships of these impairments to schizotypal personality traits and other language deficits, such as the comprehension of proverbs, are unclear. We investigated irony and proverb comprehension in an all-female sample of 20 schizophrenia patients and 27 matched controls. Subjects indicated if a statement was intended to be ironic, literal, or meaningless and furthermore rated the meanness and funniness of the stimuli and certainty of their decision. Patients made significantly more errors than controls did. Globally, there were no overall differences in the ratings. However, patients rated the subgroup of stimuli with answers given incorrectly as having significantly less meanness and in case of an error indicated a significantly higher certainty than controls. Across all of the study participants, performances in irony (r = -0.51) and proverb (r = 0.56) comprehension were significantly correlated with schizotypal personality traits, suggesting a continuum of nonliteral language understanding. Because irony is so frequent in everyday conversations, this makes irony an especially promising candidate for social cognition training in schizophrenia.

Creative thinking deficits in patients with schizophrenia: neurocognitive correlates

The aim of this study was to investigate selected measures of creativity in schizophrenic patients and their relationship with neurocognitive executive functions Forty-three inpatients with paranoid schizophrenia who were in symptomatic remission (a total of 60) and 45 healthy control participants were included. Creativity was assessed using the Barron-Welsh Art Scale (BWAS) and the inventiveness part of the Berlin Intelligence Structure Test (BIS). Executive functions were measured by means of the Wisconsin Card Sorting Test (WCST). Schizophrenic patients gave responses on the BWAS, had lower total score on the BIS and in the figural test, and performed worse on all domains of the WCST compared with control subjects. Their lower scores on the BIS correlated with lower scores on the WCST. Our results indicate that remitted schizophrenic patients perform worse on selected measures of creativity than healthy subjects and that executive dysfunctions may partially explain these deficits.

A figurative proverb test for dementia: rapid detection of disinhibition, excuse and confabulation, causing discommunication

BACKGROUND

Communicative disability is regarded as a prominent symptom of demented patients, and many studies have been devoted to analyze deficits of lexical-semantic operations in demented patients. However, it is often observed that even patients with preserved lexical-semantic skills might fail in interactive social communication. Whereas social interaction requires pragmatic language skills, pragmatic language competencies in demented subjects have not been well understood. We propose here a brief stress-free test to detect pragmatic language deficits, focusing on non-literal understanding of figurative expression. We hypothesized that suppression of the literal interpretation was required for figurative language interpretation.

METHODS

 We examined 69 demented subjects, 13 subjects with mild cognitive impairment and 61 healthy controls aged 65 years or more. The subjects were asked the meaning of a familiar proverb categorized as a figurative expression. The answers were analyzed based on five factors, and scored from 0 to 5. To consider the influence of cognitive inhibition on proverb comprehension, the scores of the Stroop Colour-Word Test were compared concerning correct and incorrect answers for each factor, respectively. Furthermore, the characteristics of answers were considered in the light of excuse and confabulation qualitatively.

RESULTS

The proverb comprehension scores gradually decreased significantly as dementia progressed. The literal interpretation of the proverb, which showed difficulties in figurative language comprehension, was related to disinhibition. The qualitative analysis showed that excuse and confabulation increased as the dementia stage progressed.

CONCLUSIONS

Deficits in cognitive inhibition partly explains the difficulties in interactive social communication in dementia. With qualitative analysis, asking the meaning of a proverb can be a brief test applied in a clinical setting to evaluate the stage of dementia, and to illustrate disinhibition, confabulation and excuse, which might cause discommunication and psychosocial maladjustment in demented patients.

Nonliteral language in Alzheimer dementia: a review

The use of nonliteral language in clinical assessment, especially testing the patients' ability to interpret proverbs, has a long tradition in psychiatry. However, its diagnostic sensitivity and specificity in dementias is not yet clear. The aim of this review article is to examine the current evidence on nonliteral/figurative language (proverb, metaphor, metonymy, idiom, irony, sarcasm) comprehension in Alzheimer's disease and related disorders. A comprehensive literature search identified 25 studies (16 proverb, 3 metaphor, 0 metonymy, 5 idiom, 3 sarcasm) on nonliteral language comprehension in dementia. Studies predominantly indicate a deficit. Most studies investigated Alzheimer's dementia. Applied correctly, nonliteral language is a worthwhile diagnostic tool to evaluate language and abstract thinking in dementias. During assessment, familiarity testing (e.g., by asking "are you familiar with the proverb XY") is obligatory. Still, future research is needed in several areas: evidence on decline of nonliteral language over the course of the illness is limited. So far, almost no studies delineated proverb comprehension in high risk populations such as patients with mild cognitive impairment. Currently, there is a lack of studies addressing performance in direct comparison to relevant differential diagnosis like older-age depression, delirium, brain lesion, or other psychiatric conditions.