Schizotypy and mentalizing: An fMRI study

Speech-Gesture Matching and Schizotypal Traits: A Network Approach

BACKGROUND AND HYPOTHESIS

Impaired speech-gesture matching has repeatedly been shown in patients with schizophrenia spectrum disorders. Here, we tested the hypothesis that schizotypal traits in the general population are related to reduced speech-gesture matching performance and reduced self-reports about gesture perception. We further explored the relationships between facets of schizotypy and gesture processing in a network model.

STUDY DESIGN

Participants (1094 mainly healthy adults) were presented with concrete or abstract sentences accompanied with videos showing related or unrelated gestures. For each video, participants evaluated the alignment between speech and gesture. They also completed self-rating scales about the perception and production of gestures (Brief Assessment of Gesture scale) and schizotypal traits (Schizotypal Personality Questionnaire-Brief 22-item version). We analyzed bivariate associations and estimated a non-regularized partial Spearman correlation network. We characterized the network by analyzing bridge centrality and controllability metrics of nodes.

STUDY RESULTS

We found a negative relationship between both concrete and abstract gesture-speech matching performance and overall schizotypy. In the network, disorganization had the highest average controllability and it was negatively related to abstract speech-gesture matching. Bridge centralities indicated that self-reported production of gestures to enhance communication in social interactions connects self-reported gesture perception, schizotypal traits, and gesture processing task performance.

CONCLUSION

The association between impaired abstract speech-gesture matching and disorganization supports a continuum between schizophrenia and schizotypy. Using gestures to facilitate communication connects subjective and objective aspects of gesture processing and schizotypal traits. Future interventional studies in patients should test the potential causal pathways implied by this network model.

Larger putamen in individuals at risk and with manifest bipolar disorder

BACKGROUND

Individuals at risk for bipolar disorder (BD) have a wide range of genetic and non-genetic risk factors, like a positive family history of BD or (sub)threshold affective symptoms. Yet, it is unclear whether these individuals at risk and those diagnosed with BD share similar gray matter brain alterations.

METHODS

In 410 male and female participants aged 17-35 years, we compared gray matter volume (3T MRI) between individuals at risk for BD (as assessed using the EPIbipolar scale; n = 208), patients with a DSM-IV-TR diagnosis of BD (n = 87), and healthy controls (n = 115) using voxel-based morphometry in SPM12/CAT12. We applied conjunction analyses to identify similarities in gray matter volume alterations in individuals at risk and BD patients, relative to healthy controls. We also performed exploratory whole-brain analyses to identify differences in gray matter volume among groups. ComBat was used to harmonize imaging data from seven sites.

RESULTS

Both individuals at risk and BD patients showed larger volumes in the right putamen than healthy controls. Furthermore, individuals at risk had smaller volumes in the right inferior occipital gyrus, and BD patients had larger volumes in the left precuneus, compared to healthy controls. These findings were independent of course of illness (number of lifetime manic and depressive episodes, number of hospitalizations), comorbid diagnoses (major depressive disorder, attention-deficit hyperactivity disorder, anxiety disorder, eating disorder), familial risk, current disease severity (global functioning, remission status), and current medication intake.

CONCLUSIONS

Our findings indicate that alterations in the right putamen might constitute a vulnerability marker for BD.

Mentalizing in individuals with state and trait risk for psychosis: a systematic review

Background

Mentalization is an umbrella concept defined as the ability to interpret one's and others' mental states. Previous studies have hypothesized that mentalization may be a crucial resilience factor that significantly moderates the likelihood of developing psychotic disorders in individuals with both state and trait risk factors for the illness.

Purpose

The study reviews the role of mentalizing abilities (e.g., reflective functioning, Theory of Mind (ToM), and metacognition) in young adults with At-Risk Mental States (ARMS) and schizotypal traits. Specifically, the objective is to include articles that (a) evaluate the links between low mentalizing and both state (ARMS/CHR) and trait (schizotypy) risk for psychosis (b) compare the differences in mentalizing abilities between individuals with ARMS, schizotypy, full-blown psychosis, and healthy controls.

Method

Electronic databases (PsycINFO, PubMed, Scopus, and Google Scholar) were used to search for articles, while Rayyan was employed to facilitate the screening and selection of studies. Eligible studies are original English-language; peer-reviewed research articles on populations that met validated risk diagnostic criteria for psychosis, ARMS, and healthy controls; empirical studies evaluating the association or differences between psychotic risk and mentalizing abilities. Non-English language studies, the ones not considering state or trait risk for psychosis, and qualitative studies were excluded. After the application of the PRISMA checklist and the inclusion and exclusion criteria previously mentioned, 10 articles were extracted. The systematic review has been registered on Prospero (CRD42023397594).

Results

Low levels of reflective functioning and metacognition may predict a transition to psychosis. In addition, reflective functioning and metacognitive impairments are associated with attenuated psychotic symptoms in both state risk groups and in non-clinical individuals with schizotypal traits. Concerning ToM tasks, mixed results emerged.

Conclusion

The results obtained from the review suggest that the application of strategies to attenuate maladaptive metacognitive beliefs and low mentalization may be equally effective in improving psychotic symptoms. The assessment of mentalization and metacognition could potentially provide additional prognostic value over factors predisposing to psychosis. Good mentalization and metacognition functioning should be considered as protective factors able to minimize the transition to psychosis.

The Predictive Potential of Altered Voxel-Based Morphometry in Severely Obese Patients With Meibomian Gland Dysfunction

Objective

To investigate voxel-based morphometry (VBM) by using magnetic resonance imaging (MRI) in meibomian gland dysfunction patients with severe obesity (PATs) and to explore the application of VBM in the early diagnosis, prevention of cognitive impairment and targeted treatment of this disease.

Methods

Sixteen PATs and 12 healthy controls (HCs) were enrolled and underwent MRI. Whole-head images were analyzed using VBM and data were compared between groups using an independent samples t-test. Receiver operating characteristic (ROC) curves were utilized to assess the diagnostic value of this approach. Mini-mental state examination (MMSE) scores were used to assess cognitive impairment and were analyzed using an independent samples t-test.

Results

Compared with HCs, the VBM values in PATs were reduced in the left cerebellum and right thalamus but increased in the right brainstem, right precuneus and right paracentral lobule. The results of ROC curve analysis indicated that VBM may be useful in meibomian gland disease diagnosis. Comparison of MMSE scores between groups showed mild cognitive impairment in PATs.

Conclusion

PATs showed altered VBM values in some brain areas. These findings may provide information about the pathophysiology of meibomian gland dysfunction and may help to explain the underlying mechanisms of clinical manifestations in PATs, such as cognitive impairment. Abnormal VBM values in these brain areas may serve as predictive factors for development of meibomian gland disease in severely obese people and as indicators for individualized treatment.

The Relationship Among Mentalization, Mindfulness, Working Memory, and Schizotypal Personality Traits in the General Population

Individuals with high schizotypal traits are less able to observe, describe, and monitor inner feelings, thoughts, and experiences, commonly referred to as mindfulness and mentalization. High schizotypy is also associated with impaired working memory (WM). However, the relationship among mindfulness, mentalization, WM, and schizotypal traits is unknown. Three hundred individuals from the community (mean age: 38.0 years, SD = 10.5; 49.3% women) completed questionnaires examining schizotypal traits, mindfulness, and mentalization and performed working memory tasks. Results revealed that mentalization was a general predictor of schizotypal traits, including unusual experiences, cognitive disorganization, introverted anhedonia, and impulsive nonconformity, when the effect of mindfulness and working memory was controlled. We also found a positive correlation between mindfulness and mentalization. Low mindfulness and mentalization performances were associated with high schizotypy. However, poor working memory was only weakly linked to cognitive disorganization and introverted anhedonia. These findings suggest that weak mentalization is a core feature of schizotypy independent of mindfulness and working memory.

Functional Brain Connectivity in Mild Cognitive Impairment With Sleep Disorders: A Study Based on Resting-State Functional Magnetic Resonance Imaging

Purpose

To investigate the effect of sleep disorder (SD) on the changes of brain network dysfunction in mild cognitive impairment (MCI), we compared network connectivity patterns among MCI, SD, and comorbid MCI and sleep disorders (MCI-SD) patients using resting state functional magnetic resonance imaging (RS-fMRI).

Patients and Methods

A total of 60 participants were included in this study, 20 each with MCI, SD, or MCI-SD. And all participants underwent structural and functional MRI scanning. The default-mode network (DMN) was extracted by independent component analysis (ICA), and regional functional connectivity strengths were calculated and compared among groups.

Results

Compared to MCI patients, The DMN of MCI-SD patients demonstrated weaker functional connectivity with left middle frontal gyrus, right superior marginal gyrus, but stronger connectivity with the left parahippocampus, left precuneus and left middle temporal gyrus. Compared to the SD group, MCI-SD patients demonstrated weaker functional connectivity with right transverse temporal gyrus (Heschl’s gyrus), right precentral gyrus, and left insula, but stronger connectivity with posterior cerebellum, right middle occipital gyrus, and left precuneus.

Conclusion

Patients with MCI-SD show unique changes in brain network connectivity patterns compared to MCI or SD alone, likely reflecting a broader functional disconnection and the need to recruit more brain regions for functional compensation.

Factors of influence in prisoner's dilemma task: a review of medical literature

The Prisoner's Dilemma (PD) is one of the most popular concepts amongst the scientific literature. The task is used in order to study different types of social interactions by giving participants the choice to defect or cooperate in a specific social setting/dilemma. This review focuses on the technical characteristics of the PD task as it is used in medical literature and describes how the different PD settings could influence the players' behaviour. We identify all the studies that have used the PD task in medical research with human participants and distinguish, following a heuristic approach, seven parameters that can differentiate a PD task, namely (a) the opponent parties' composition; (b) the type of the opponent as perceived by the players; (c) the interaction flow of the game; (d) the number of rounds; (e) the instructions narrative and options that are given to players; (f) the strategy and (g) the reward matrix and payoffs of the game. We describe how each parameter could influence the final outcome of the PD task and highlight the great variability concerning the settings of these parameters in medical research. Our aim is to point out the heterogeneity of such methods in the past literature and to assist future researchers with their methodology design.

Language Can Obscure as Well as Facilitate Apparent-Theory of Mind Performance: Part 2-The Case of Dyslexia in Adulthood

Many studies imply causal links between linguistic competencies and Theory of Mind (ToM). But despite Dyslexia being a prime example of linguistic deficits, studies on whether it is related to ToM have been relatively unforthcoming. In the first of 2 studies (N = 89), independently-diagnosed dyslexic adults and non-dyslexic adults were presented with false-belief vignettes via computer, answering 4 types of question (Factual, Inference, 1st-order ToM & 2nd-order ToM). Dyslexia related to lower false-belief scores. Study 2 (N = 93) replicated this result with a non-computer-based variant on the false-belief task. We considered the possibility that the apparent-issue with ToM is caused by processing demands more associated to domains of cognition such as language, than to ToM itself. Addressing this possibility, study 2 additionally utilised the ToM30Q questionnaire, designed largely to circumvent issues related to language and memory. Principal-Components analysis extracted 4 factors, 2 capturing perceptual/representational ToM, and the other 2 capturing affective components related to ToM. The ToM30Q was validated via its associations to a published measure of empathy, replication of the female gender advantage over males, and for one factor from the ToM30Q there was a correlation with an existing published index of ToM. However, when we considered the performance of dyslexic and non-dyslexic participants using the ToM30Q, we found absolutely no difference between them. The contrasting findings from our 2 studies here, arguably offer the first experimental evidence with adults, that there is in fact no ToM deficit in dyslexia. Additionally, this finding raises the possibility that some other groups considered in some sense atypical, failed ToM tasks, not because they actually have a ToM deficit at all, but rather because they are asked to reveal their ToM competence through cognitive domains, such as language and memory.

Neuroanatomical Correlates of Social Intelligence Measured by the Guilford Test

Social interactions are a crucial aspect of human behaviour. Numerous neurophysiological studies have focused on socio-cognitive processes associated with the so-called theory of mind-the ability to attribute mental states to oneself and others. Theory of mind is closely related to social intelligence defined as a set of abilities that facilitate effective social interactions. Social intelligence encompasses multiple theory of mind components and can be measured by the Four Factor Test of Social Intelligence (the Guilford-Sullivan test). However, it is unclear whether the differences in social intelligence are reflected in structural brain differences. During the experiment, 48 healthy right-handed individuals completed the Guilford-Sullivan test. T1-weighted structural MRI images were obtained for all participants. Voxel-based morphometry analysis was performed to reveal grey matter volume differences between the two groups (24 subjects in each)-with high social intelligence scores and with low social intelligence scores, respectively. Participants with high social intelligence scores had larger grey matter volumes of the bilateral caudate. The obtained results suggest the caudate nucleus involvement in the neural system of socio-cognitive processes, reflected by its structural characteristics.

[Theory of mind and schizotypy: A review]

OBJECTIVES

Schizophrenia spectrum disorders are associated with incapacitating social impairments, mostly due to Theory of Mind (ToM) deficits. Theory of mind difficulties often precede the beginning of schizophrenia spectrum disorders and contribute highly to the social withdrawal of patients. They also predict bad outcome for individuals suffering from this condition. The use of samples of individuals presenting subclinical forms of schizophrenia spectrum disorders constitute an opportunity to study theory of mind capacities. Notably, the study of theory of mind deficits in schizotypy allows a better understanding of predictive markers of schizophrenia spectrum disorders. They also contribute to the identification of primary processes involved in social difficulties associated with these disorders.

METHODS

We searched PubMed, Science Direct and Google Scholar databases for peer-reviewed articles studying the association between theory of mind performance and schizotypal traits up to the 1 April 2020. The following syntax was used: schizotypy AND ("theory of mind" OR "social cognition" OR "irony" OR "false belief" OR "social inference" OR "hinting task"). We also checked the references from these articles for additional papers. Only English and French written articles were considered.

RESULTS

Twenty-three articles were included in the review. The majority of these studies (n=20) used behavioral measures of theory of mind (i.e. percentages of correct responses on a theory of mind task). Only a few (n=3) recent studies used brain imaging to study theory of mind in psychometric schizotypy. In those 23 studies, 18 report theory of mind difficulties in individuals with high schizotypal traits. Ten out of these 19 studies report an association between positive schizotypy and theory of mind deficits/hypomentalizing. The positive dimension was the most associated with theory of mind difficulties. The negative dimension was associated with theory of mind deficits in six studies out of 19 (33 %). The association between disorganization and theory of mind deficits was weak, mostly because of a lack of studies measuring this dimension (only one study out of 13 measured this particular trait). The association between hypermentalizing and schizotypy was poorly characterized, due to high heterogeneity in how this feature was conceptualized and measured. In summary, some authors consider good performance on a theory of mind task as a sign of hypermentalizing, while other authors consider that this feature relates to the production of erroneous interpretations of mental states. We advocate in favor of the second definition, and more studies using this framework should be conducted. Interestingly, the three studies using fMRI showed no significant behavioral differences between high and low schizotypal groups on theory of mind performance, while the patterns of brain activation differed. This shows that in individuals with schizotypy, theory of mind anomalies are not always captured just by behavioral performance. Brain imagery should be included in more studies to better understand theory of mind in schizotypy. In general, high heterogeneity in ways of assessing schizotypy, and in the tasks used to evaluate theory of mind, were found. Notably, some tasks require shallower theory of mind processing than others. It is a priority to design theory of mind tasks that allow for manipulating the difficulty of the items within one task, as well as the level of help that can be given, in order to allow for a better assessment of the impact of theory of mind difficulties and the ways to compensate for them.

CONCLUSIONS

The studies included in this review confirm the association between psychometric schizotypy and theory of mind. But the high heterogeneity in methods used in these studies, and notably the diversity in ways of assessing schizotypal traits and theory of mind, hinder a precise description of such an association. Additional studies are required. In particular, fMRI studies using tasks allowing for a precise description of altered and preserved theory of mind processes could be of great use in characterizing theory of mind difficulties associated with schizotypy.

Distinct and opposite profiles of connectivity during self-reference task and rest in youth at clinical high risk for psychosis

Self-reference is impaired in psychotic disorders such as schizophrenia, associated with disability, and closely related to characteristic patterns of aberrant brain connectivity. However, at present, it is unclear whether self-reference is impacted in pathogenesis of the disorder. Alterations in connectivity during a self-reference task or resting-state in the psychosis risk (i.e., prodromal) period may yield important clues for biomarker development, as well as for novel treatment targets. This study examined a task-based and resting-state functional magnetic resonance imaging in individuals at clinical high risk (CHR) for psychosis (n = 22) and healthy control unaffected peers (n = 20). The self-reference task comprised three task conditions where subjects were asked if an adjective was relevant to themselves (self), a designated other individual (other), or to evaluate the word's spelling (letter). Connectivity analyses examined medial prefrontal cortex (mPFC) and posterior cingulate cortex (PCC), regions commonly found in conjunction analyses of self-reference, during both the self-reference task and rest. In task connectivity analyses, CHR individuals exhibited decreased mPFC-PCC connectivity when compared to controls. In resting-state analyses, CHR participants showed greater mPFC-PCC connectivity. Taken together, results suggest that psychosis-like alterations in mPFC-PCC connectivity is present prior to psychosis onset across both task and rest.