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

A machine-learning approach to investigating the complexity of theory of mind in individuals with schizophrenia

Individuals with schizophrenia have difficulty attributing mental states to themselves and to others - Theory of Mind (ToM). ToM is a complex, multifaceted theoretical construct comprising first and second order, first and third person, egocentric and allocentric perspective, and cognitive and affective ToM. Most studies addressing ToM deficit in people with schizophrenia consider it an "all-or-nothing" ability and use a classical statistical methodology to test a null hypothesis. With the present study, we investigated ToM in individuals with schizophrenia, considering its complex nature and degrees of impairment. To do this, we used a machine-learning approach to detect patterns in heterogeneous and multivariate data. Our findings highlight the complex nature of ToM deficit in individuals with schizophrenia and reveal the relationship between various different aspects of ToM.

Speech disturbances in schizophrenia: Assessing cross-linguistic generalizability of NLP automated measures of coherence

INTRODUCTION

Language disorders - disorganized and incoherent speech in particular - are distinctive features of schizophrenia. Natural language processing (NLP) offers automated measures of incoherent speech as promising markers for schizophrenia. However, the scientific and clinical impact of NLP markers depends on their generalizability across contexts, samples, and languages, which we systematically assessed in the present study relying on a large, novel, cross-linguistic corpus.

METHODS

We collected a Danish (DK), German (GE), and Chinese (CH) cross-linguistic dataset involving transcripts from 187 participants with schizophrenia (111DK, 25GE, 51CH) and 200 matched controls (129DK, 29GE, 42CH) performing the Animated Triangles Task. Fourteen previously published NLP coherence measures were calculated, and between-groups differences and association with symptoms were tested for cross-linguistic generalizability.

RESULTS

One coherence measure, i.e. second-order coherence, robustly generalized across samples and languages. We found several language-specific effects, some of which partially replicated previous findings (lower coherence in German and Chinese patients), while others did not (higher coherence in Danish patients). We found several associations between symptoms and measures of coherence, but the effects were generally inconsistent across languages and rating scales.

CONCLUSIONS

Using a cumulative approach, we have shown that NLP findings of reduced semantic coherence in schizophrenia have limited generalizability across different languages, samples, and measures. We argue that several factors such as sociodemographic and clinical heterogeneity, cross-linguistic variation, and the different NLP measures reflecting different clinical aspects may be responsible for this variability. Future studies should take this variability into account in order to develop effective clinical applications targeting different patient populations.

Voice Patterns as Markers of Schizophrenia: Building a Cumulative Generalizable Approach Via a Cross-Linguistic and Meta-analysis Based Investigation

BACKGROUND AND HYPOTHESIS

Voice atypicalities are potential markers of clinical features of schizophrenia (eg, negative symptoms). A recent meta-analysis identified an acoustic profile associated with schizophrenia (reduced pitch variability and increased pauses), but also highlighted shortcomings in the field: small sample sizes, little attention to the heterogeneity of the disorder, and to generalizing findings to diverse samples and languages.

STUDY DESIGN

We provide a critical cumulative approach to vocal atypicalities in schizophrenia, where we conceptually and statistically build on previous studies. We aim at identifying a cross-linguistically reliable acoustic profile of schizophrenia and assessing sources of heterogeneity (symptomatology, pharmacotherapy, clinical and social characteristics). We relied on previous meta-analysis to build and analyze a large cross-linguistic dataset of audio recordings of 231 patients with schizophrenia and 238 matched controls (>4000 recordings in Danish, German, Mandarin and Japanese). We used multilevel Bayesian modeling, contrasting meta-analytically informed and skeptical inferences.

STUDY RESULTS

We found only a minimal generalizable acoustic profile of schizophrenia (reduced pitch variability), while duration atypicalities replicated only in some languages. We identified reliable associations between acoustic profile and individual differences in clinical ratings of negative symptoms, medication, age and gender. However, these associations vary across languages.

CONCLUSIONS

The findings indicate that a strong cross-linguistically reliable acoustic profile of schizophrenia is unlikely. Rather, if we are to devise effective clinical applications able to target different ranges of patients, we need first to establish larger and more diverse cross-linguistic datasets, focus on individual differences, and build self-critical cumulative approaches.

Differences in pragmatic communication skills of adults with intellectual disabilities and dual diagnoses

INTRODUCTION

Pragmatics includes a set of skills related to language structure and meaning that allow the speaker to use the language appropriately and in accordance with different communication situations. The aim of this research was to determine the differences in pragmatic communication skills of adults with intellectual disabilities, dual diagnoses, and typical development, and to determine the effects of gender, age, the level of intellectual functioning and speech comprehension on their achievements on two assessment instruments.

METHODS

The sample included 180 adults (60 typically developing participants, 60 with intellectual disabilities, and 60 participants with dual diagnoses). We used two instruments to assess pragmatic communication skills - Communication Checklist - Adult, CC-A, and the Assessment Battery for Communication, ABaCo. In order to test the differences between the three groups of participants, we used canonical discriminant analysis.

RESULTS

Discriminant analysis revealed two significant canonical functions. Function one (speech comprehension and the level of intellectual disability, social engagement, and paralinguistic scale) differentiates between typically developing participants and participants with dual diagnoses the most. The second canonical function (language structure, linguistic scale, paralinguistic scale, extralinguistic scale, and context scale) differentiates between participants with intellectual disabilities and participants with dual diagnoses the most. According to the results, age did not affect pragmatic achievements.

DISCUSSION

Pragmatic skills are very complex, and different instruments measure different dimensions of these abilities. The results of this research lead to the conclusion that we can differentiate between the pragmatic abilities of typically developing people, people with intellectual disabilities, and those with dual diagnoses with the help of the ABaCo battery and the CC-A questionnaire.

A cross-sectional study to assess pragmatic strengths and weaknesses in healthy ageing

Background

Ageing refers to the natural and physiological changes that individuals experience over the years. This process also involves modifications in terms of communicative-pragmatics, namely the ability to convey meanings in social contexts and to interact with other people using various expressive means, such as linguistic, extralinguistic and paralinguistic aspects of communication. Very few studies have provided a complete assessment of communicative-pragmatic performance in healthy ageing.

Methods

The aim of this study was to comprehensively assess communicative-pragmatic ability in three samples of 20 (N = 60) healthy adults, each belonging to a different age range (20–40, 65–75, 76–86 years old) and to compare their performance in order to observe any potential changes in their ability to communicate. We also explored the potential role of education and sex on the communicative-pragmatic abilities observed. The three age groups were evaluated with a between-study design by means of the Assessment Battery for Communication (ABaCo), a validated assessment tool characterised by five scales: linguistic, extralinguistic, paralinguistic, contextual and conversational.

Results

The results indicated that the pragmatic ability assessed by the ABaCo is poorer in older participants when compared to the younger ones (main effect of age group: F(2,56) = 9.097; p < .001). Specifically, significant differences were detected in tasks on the extralinguistic, paralinguistic and contextual scales. Whereas the data highlighted a significant role of education (F(1,56) = 4.713; p = .034), no sex-related differences were detected.

Conclusions

Our results suggest that the ageing process may also affect communicative-pragmatic ability and a comprehensive assessment of the components of such ability may help to better identify difficulties often experienced by older individuals in their daily life activities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03304-z.

Efforts for the Correct Comprehension of Deceitful and Ironic Communicative Intentions in Schizophrenia: A Functional Magnetic Resonance Imaging Study on the Role of the Left Middle Temporal Gyrus

Deficits in social cognition and more specifically in communication have an important impact on the real-life functioning of people with schizophrenia (SZ). In particular, patients have severe problems in communicative-pragmatics, for example, in correctly inferring the speaker's communicative intention in everyday conversational interactions. This limit is associated with morphological and functional alteration of the left middle temporal gyrus (L-MTG), a cerebral area involved in various communicative processes, in particular in the distinction of ironic communicative intention from sincere and deceitful ones. We performed an fMRI study on 20 patients with SZ and 20 matched healthy controls (HCs) while performing a pragmatic task testing the comprehension of sincere, deceitful, and ironic communicative intentions. We considered the L-MTG as the region of interest. SZ patients showed difficulties in the correct comprehension of all types of communicative intentions and, when correctly answering to the task, they exhibited a higher activation of the L-MTG, as compared to HC, under all experimental conditions. This greater involvement of the L-MTG in the group of patients could depend on different factors, such as the increasing inferential effort required in correctly understanding the speaker's communicative intentions, and the higher integrative semantic processes involved in sentence processing. Future studies with a larger sample size and functional connectivity analysis are needed to study deeper the specific role of the L-MTG in pragmatic processes in SZ, also in relation to other brain areas.

EXPRESS: An eye-tracking investigation of the cognitive processes involved in the comprehension of simple and complex communicative acts

Indirect speech acts communicate more than their literal meaning, and their comprehension relies on the listener's ability to draw the appropriate inferences in a given context. We used eye-tracking to investigate the cognitive processing involved in the comprehension of simple (direct) and complex (unconventional indirect) communicative acts, a more general distinction that applies not only to sincere speech acts, but also to irony and deceit. We recorded the eye movements of 40 participants while they read 60 stories (20 sincere, 20 deceitful, 20 ironic) consisting of a context and a target answer. For each story, we created two different contexts so that the same identical target answer was a simple (direct) and a complex (unconventional indirect) communicative act, respectively. We also assessed the indirectness of simple and complex communicative acts, as well as participants' working memory (WM) and Theory of Mind (ToM). Eye-pattern analysis showed that complex communicative acts were more difficult to understand than simple acts; differences between simple and complex acts held for all the pragmatic phenomena investigated, though processing differences were greater for sincere acts than for irony and deceit. We found a role of indirectness and ToM in the pragmatic processing of simple and complex acts, whereas the role of WM was modest. The present findings underscore the importance of adopting an encompassing theory that can account for different types of indirect speech acts, such as sincere, deceitful and ironic acts; they also suggest the importance of assessing individual differences in inferential and cognitive abilities.