The role of atypical semantic activation and stress in odd speech: implications for individuals with psychometrically defined schizotypy

Atypical semantic cognition in schizotypal personality disorder and borderline personality disorder

Increased schizotypal traits have previously been associated with atypical semantic cognition in community samples. However, no study has yet examined whether adults diagnosed with schizotypal personality disorder (SPD) display atypical semantic fluency and memory. We hypothesized that 24 adults diagnosed with SPD would name more idiosyncratic words on the semantic fluency task and show decreased semantic recall for animal and fruit category words compared with 29 participants with borderline personality disorder (BPD) and a community sample of 96 age-matched controls. We examined whether atypical semantic cognition was specifically associated with disorganized and eccentric speech and thinking, or more broadly with pathological personality traits and personality functioning. Our main hypothesis was confirmed, as the SPD participants named more idiosyncratic words and recalled fewer semantically related words compared with controls. Surprisingly, participants with BPD likewise named more atypical words compared with controls. More idiosyncratic semantic fluency was associated with more eccentric speech and thinking. Increased idiosyncratic semantic fluency and reduced semantic recall were both coupled to increased detachment and lowered personality functioning, while reduced semantic recall further was related to increased interpersonal problems. Our findings suggest that persons with SPD, and to a lesser degree BPD, show atypical semantic cognition, which is associated with eccentric speech and thinking, and more broadly with impaired personality function, social withdrawal, and emotional flatness. The idiosyncratic semantic cognition may worsen difficulties with social reciprocity seen in SPD and BPD.

Executively-mediated language skills are related to performance-based social functioning in the early psychosis spectrum

Social impairment is a core deficit in psychotic spectrum disorders (PSDs). Prior work shows that language abnormalities can predict psychosis onset and are related to social outcomes in PSDs. Few studies have investigated nuanced relationships between language/verbal abilities and social functioning in the early psychosis spectrum, including at-risk (schizotypy) and first episode of psychosis (FEP) individuals. This study aimed to examine the relationship to between language/verbal performance and performance-based and examiner-rated social functioning. We also aimed to replicate prior models that demonstrate neurocognition is related to social functioning through negative symptoms and social cognition. Low schizotypy (n = 42), high schizotypy (n = 44), and FEP (n = 15) participants completed a battery of language/verbal, social cognition, and social functioning measures. Regression analyses revealed that Proverb Test performance was uniquely and significantly associated with performance-based but not examiner-rated social functioning. Other language/verbal measures were not significantly related to social functioning. In mediational analyses, language/verbal performance was indirectly related to social functioning through negative traits, and also through social cognition. Findings extend support for negative symptom and social cognitive intervention in the early psychosis spectrum, and uniquely suggest that executively-mediated language skills may be an additional target to improve social functioning.

High Predictive Accuracy of Negative Schizotypy With Acoustic Measures

Negative schizotypal traits potentially can be digitally phenotyped using objective vocal analysis. Prior attempts have shown mixed success in this regard, potentially because acoustic analysis has relied on small, constrained feature sets. We employed machine learning to (a) optimize and cross-validate predictive models of self-reported negative schizotypy using a large acoustic feature set, (b) evaluate model performance as a function of sex and speaking task, (c) understand potential mechanisms underlying negative schizotypal traits by evaluating the key acoustic features within these models, and (d) examine model performance in its convergence with clinical symptoms and cognitive functioning. Accuracy was good (> 80%) and was improved by considering speaking task and sex. However, the features identified as most predictive of negative schizotypal traits were generally not considered critical to their conceptual definitions. Implications for validating and implementing digital phenotyping to understand and quantify negative schizotypy are discussed.

Cognitive correlates of 'Formal Thought Disorder' in a non-clinical sample with elevated schizotypal traits

Different dimensions of formal thought disorder (FTD) are distinguished by different patterns of cognitive dysfunction in patients with schizophrenia; however, inconsistent findings may relate to patient-related confounds. To avoid these confounds, we examined relationships between FTD dimensions and cognitive domains in a non-clinical sample with attenuated schizophrenia-like traits, or schizotypal traits, on the Schizotypal Personality Questionnaire (N = 91). To our knowledge, no study has done this. FTD dimension scores were derived following principal component analysis of the Scale for the Assessment of Thought, Language and Communication (TLC dimensions: Disorganisation, Verbosity, Emptiness) and the Thought and Language Index (TLI dimensions: Negative, Idiosyncratic). The sample completed a comprehensive neuropsychological battery. Findings indicate that higher-order reasoning, executive function (set shift and generative ability) and language/semantic functioning are the primary drivers of FTD in our non-clinical sample with elevated schizotypal traits, in line with schizophrenia research. FTD may have shared aetiology along the schizophrenia spectrum.

Cognitive-perceptual and disorganized schizotypal traits are nonlinearly related to atypical semantic content on tasks of semantic fluency

Language deficits emerge early in the course of schizophrenia, yet research findings in those at-risk for schizophrenia, such as those with schizotypy, are mixed. The purpose of the present study was to elucidate the relationship of language ability, measured via semantic fluency, to schizotypy, examining both linear and non-linear relations. Semantic fluency data from 295 individuals with varying amounts of schizotypal traits were analyzed utilizing traditional methods (i.e., counting words generated that fit a specific semantic category). The content of semantic fluency responses was also analyzed via a semantic infrequency score (i.e., how infrequent participant responses were relative to all responses generated for the category in the study sample) and a total semantic productivity score (i.e., how many unique words generated overall, including those that did not fit the semantic category). Using traditional methods of scoring, schizotypy was not related to semantic fluency. However, schizotypy was non-linearly related to semantic infrequency and productivity, reflecting atypical semantic activation and processing. In particular, cognitive-perceptual and disorganized, but not interpersonal, traits were related to semantic infrequency and productivity. Valuable content-based information is missed when only analyzing semantic fluency data via the traditional method in the schizophrenia spectrum population. Cognitive-perceptual and disorganized traits, attenuated thought disorder symptoms, evidence the strongest relationship to semantic fluency, further illustrating the link between language and schizophrenia symptoms along the schizophrenia spectrum.

Semantic priming and schizotypal personality: reassessing the link between thought disorder and enhanced spreading of semantic activation

The term schizotypy refers to a group of stable personality traits with attributes similar to symptoms of schizophrenia, usually classified in terms of positive, negative or cognitive disorganization symptoms. The observation of increased spreading of semantic activation in individuals with schizotypal traits has led to the hypothesis that thought disorder, one of the characteristics of cognitive disorganization, stems from semantic disturbances. Nevertheless, it is still not clear under which specific circumstances (i.e., automatic or controlled processing, direct or indirect semantic relation) schizotypy affects semantic priming or whether it does affect it at all. We conducted two semantic priming studies with volunteers varying in schizotypy, one with directly related prime-target pairs and another with indirectly related pairs. Our participants completed a lexical decision task with related and unrelated pairs presented at short (250 ms) and long (750 ms) stimulus onset asynchronies (SOAs). Then, they responded to the brief versions of the Schizotypal Personality Questionnaire and the Oxford-Liverpool Inventory of Feelings and Experiences, both of which include measures of cognitive disorganization. Bayesian mixed-effects models indicated expected effects of SOA and semantic relatedness, as well as an interaction between relatedness and directness (greater priming effects for directly related pairs). Even though our analyses demonstrated good sensitivity, we observed no influence of cognitive disorganization over semantic priming. Our study provides no compelling evidence that schizotypal symptoms, specifically those associated with the cognitive disorganization dimension, are rooted in an increased spreading of semantic activation in priming tasks.

Speech production and disorganization in schizotypy: Investigating the role of cognitive and affective systems

Diminished productivity and elevated disorganization have been detected in the speech of individuals with schizotypy. However, the underlying mechanisms for these disruptions are not well understood. Separate lines of research suggest potential contributions from cognitive and affective systems. In this study, disorganized speech and speech production were examined in speech samples generated by schizotypy (n = 47) and non-schizotypy (n = 51) groups by assessing "reactivity" (i.e., a change in experimental compared with baseline conditions) across baseline, affective, and dual-task (i.e., cognitive) conditions. Relationships with social functioning were also examined within each group. Three key findings emerged: 1) compared to the non-schizotypy group, those with schizotypy exhibited diminished speech production in the affective condition and affective reactivity was observed; 2) the schizotypy group displayed greater levels of disorganized speech in dual-task conditions and cognitive reactivity was observed; and 3) affective reactivity for disorganized speech was linked to worse social functioning within the schizotypy group. This study provides evidence that cognitive and affective systems are uniquely involved in separate characteristics of speech in schizotypy. At this stage, cognitive systems appear to have a specific role in the organization of speech, whereas affective systems are more heavily involved in speech production. Regarding the association between affective reactivity and social functioning, previous research has demonstrated individuals highly reactive to emotional stimuli carry additional risk for conversion to psychosis. Future research identifying a subset with schizotypy who demonstrate affective reactivity could lead to a better understanding of links between schizotypy and future psychosis symptoms.

Schizotypal personality and semantic functioning: Revisiting category fluency effects in a subclinical sample

Semantic disturbances have been proposed as a possible cause of formal thought disorder in schizophrenia. Fluency tasks, in which volunteers are asked to produce as many exemplars as they can for a given category during one minute, are usually applied to the assessment of semantic processing. However, studies associating fluency and proneness to psychosis have provided conflicting results so it is not clear whether these disturbances can be identified at subclinical stages. We conducted two experiments. In the first one, 71 volunteers completed written category fluency tasks with four semantic categories (animals, fruits, clothing and vehicles). In the second experiment, 77 new participants completed oral category and phonological fluency tasks (words starting with f, t, p and c). In both experiments, we assessed schizotypal personality and vocabulary size. Schizotypal traits were not reliably associated with either productivity or originality of the responses in any experiment. In contrast, vocabulary size significantly predicted the participants' scores in all the tasks. Along with results of other recent studies, our data cast doubt on the reliability of previous observations pointing out an association between schizotypy and lexical-semantic disturbances, at least in relation to productivity and originality in fluency tests.

Evidence of disturbances of deep levels of semantic cohesion within personal narratives in schizophrenia

Since initial conceptualizations, schizophrenia has been thought to involve core disturbances in the ability to form complex, integrated ideas. Although this has been studied in terms of formal thought disorder, the level of involvement of altered latent semantic structure is less clear. To explore this question, we compared the personal narratives of adults with schizophrenia (n=200) to those produced by an HIV+ sample (n=55) using selected indices from Coh-Metrix. Coh-Metrix is a software system designed to compute various language usage statistics from transcribed written and spoken language documents. It differs from many other frequency-based systems in that Coh-Metrix measures a wide range of language processes, ranging from basic descriptors (e.g., total words) to indices assessing more sophisticated processes within sentences, between sentences, and across paragraphs (e.g., deep cohesion). Consistent with predictions, the narratives in schizophrenia exhibited less cohesion even after controlling for age and education. Specifically, the schizophrenia group spoke fewer words, demonstrated less connection between ideas and clauses, provided fewer causal/intentional markers, and displayed lower levels of deep cohesion. A classification model using only Coh-Metrix indices found language markers correctly classified participants in nearly three-fourths of cases. These findings suggest a particular pattern of difficulties cohesively connecting thoughts about oneself and the world results in a perceived lack of coherence in schizophrenia. These results are consistent with Bleuler's model of schizophrenia and offer a novel way to understand and measure alterations in thought and speech over time.

Semantic coherence in psychometric schizotypy: An investigation using Latent Semantic Analysis

Technological advancements have led to the development of automated methods for assessing semantic coherence in psychiatric populations. Latent Semantic Analysis (LSA) is an automated method that has been used to quantify semantic coherence in schizophrenia-spectrum disorders. The current study examined whether: 1) Semantic coherence reductions extended to psychometrically-defined schizotypy and 2) Greater cognitive load further reduces semantic coherence. LSA was applied to responses generated during category fluency tasks in baseline and cognitive load conditions. Significant differences between schizotypy and non-schizotypy groups were not observed. Findings suggest that semantic coherence may be relatively preserved at this point on the schizophrenia-spectrum.

Disorganised schizotypy is selectively associated with poorer semantic processing in non-clinical individuals

The nature and severity of semantic memory (SM) impairments in schizophrenia has been related to symptoms, mainly formal thought disorder (FTD), and other clinical factors like length of illness. Symptom-related studies in schizophrenia are often confounded by clinical factors, for example medication and hospitalisations. We completed a schizotypy analogue study to examine the relationship between SM processing and FTD using an analogue schizotypy score referred to as cognitive disorganisation. Sixty individuals without a history of mental illness (M=22.92, SD=2.70) completed a schizotypy questionnaire and three semantic tasks - naming pictures, category fluency and semantic priming. Only decreasing fluency was associated with increasing cognitive disorganisation scores (p=0.029). In line with the prevailing dyssemantic theories, the results highlight that cognitive disorganisation is associated with some difficulties in SM processes, though not all. The observed differential relationships of SM processes to disorganised schizotypy are discussed in relation to previous work, and in terms of potential developmental trajectories for SM impairment in schizophrenia.

Using lexical analysis to identify emotional distress in psychometric schizotypy

Through the use of lexical analysis software, researchers have demonstrated a greater frequency of negative affect word use in those with schizophrenia and schizotypy compared to the general population. In addition, those with schizotypy endorse greater emotional distress than healthy controls. In this study, our aim was to expand on previous findings in schizotypy to determine whether negative affect word use could be linked to emotional distress. Schizotypy (n=33) and non-schizotypy groups (n=33) completed an open-ended, semi-structured interview and negative affect word use was analyzed using a validated lexical analysis instrument. Emotional distress was assessed using subjective questionnaires of depression and psychological quality of life (QOL). When groups were compared, those with schizotypy used significantly more negative affect words; endorsed greater depression; and reported lower QOL. Within schizotypy, a trend level association between depression and negative affect word use was observed; QOL and negative affect word use showed a significant inverse association. Our findings offer preliminary evidence of the potential effectiveness of lexical analysis as an objective, behavior-based method for identifying emotional distress throughout the schizophrenia-spectrum. Utilizing lexical analysis in schizotypy offers promise for providing researchers with an assessment capable of objectively detecting emotional distress.

Examining lexical processing with two word tasks using the schizotypy analogue

Semantic processing is impaired in schizophrenia, and is often assessed using word-based semantic tasks that additionally require lexical processing for accurate performance. This study aimed to examine lexical processing in relation to psychosis proneness. 61 individuals (mean age=22.92, SD=2.67) completed a schizotypy questionnaire and two lexical processing tasks (recognition and production). Results revealed no relationship between increasing schizotypy scores and overall performance on either lexical processing task. Lexical processing performance is not related to psychosis-proneness. This is discussed in relation to schizophrenia semantic processing research.

Category fluency in psychometric schizotypy: how altering emotional valence and cognitive load affects performance

INTRODUCTION

In clinical high-risk populations, category fluency deficits are associated with conversion to psychosis. However, their utility as clinical risk markers is unclear in psychometric schizotypy, a group experiencing schizophrenia-like traits that is at putative high risk for psychosis.

METHODS

We examined whether introducing affective or cognitive load, two important stress vulnerability markers, altered category fluency performance in schizotypy (n = 42) and non-schizotypy (n = 38) groups. To investigate this question, we developed an experimental paradigm where all participants were administered category fluency tests across baseline, pleasant valence, unpleasant valence, and cognitive load conditions.

RESULTS

Compared to the non-schizotypy group, those with schizotypy performed significantly worse in pleasant and unpleasant valence conditions, but not cognitive load or baseline fluency tests.

CONCLUSIONS

This study demonstrated the role of affect - but not cognitive load - on category fluency in psychometric schizotypy, as group differences only emerged once affective load was introduced. One explanation for this finding is that semantic memory may be unimpaired under normal conditions in psychometric schizotypy, but may be compromised once affective load is presented. Future studies should examine whether fluency deficits - particularly when affect is induced - predict future conversion to psychosis in psychometric schizotypy cohorts.

Conceptual disorganization weakens links in cognitive pathways: Disentangling neurocognition, social cognition, and metacognition in schizophrenia

Disentangling links between neurocognition, social cognition, and metacognition offers the potential to improve interventions for these cognitive processes. Disorganized symptoms have shown promise for explaining the limiting relationship that neurocognition holds with both social cognition and metacognition. In this study, primary aims included: 1) testing whether conceptual disorganization, a specific disorganized symptom, moderated relationships between cognitive processes, and 2) examining the level of conceptual disorganization necessary for links between cognitive processes to break down. To accomplish these aims, comprehensive assessments of conceptual disorganization, neurocognition, social cognition, and metacognition were administered to 67 people with schizophrenia-spectrum disorders. We found that conceptual disorganization significantly moderated the relationship between neurocognition and metacognition, with links between cognitive processes weakening when conceptual disorganization is present even at minimal levels of severity. There was no evidence that conceptual disorganization-or any other specific disorganized symptom-drove the limiting relationship of neurocognition on social cognition. Based on our findings, conceptual disorganization appears to be a critical piece of the puzzle when disentangling the relationship between neurocognition and metacognition. Roles of specific disorganized symptoms in the neurocognition - social cognition relationship were less clear. Findings from this study suggest that disorganized symptoms are an important treatment consideration when aiming to improve cognitive impairments.

Lexical analysis in schizophrenia: how emotion and social word use informs our understanding of clinical presentation

BACKGROUND

The words people use convey important information about internal states, feelings, and views of the world around them. Lexical analysis is a fast, reliable method of assessing word use that has shown promise for linking speech content, particularly in emotion and social categories, with psychopathological symptoms. However, few studies have utilized lexical analysis instruments to assess speech in schizophrenia. In this exploratory study, we investigated whether positive emotion, negative emotion, and social word use was associated with schizophrenia symptoms, metacognition, and general functioning in a schizophrenia cohort.

METHODS

Forty-six participants generated speech during a semi-structured interview, and word use categories were assessed using a validated lexical analysis measure. Trained research staff completed symptom, metacognition, and functioning ratings using semi-structured interviews.

RESULTS

Word use categories significantly predicted all variables of interest, accounting for 28% of the variance in symptoms and 16% of the variance in metacognition and general functioning. Anger words, a subcategory of negative emotion, significantly predicted greater symptoms and lower functioning. Social words significantly predicted greater metacognition.

CONCLUSIONS

These findings indicate that lexical analysis instruments have the potential to play a vital role in psychosocial assessments of schizophrenia. Future research should replicate these findings and examine the relationship between word use and additional clinical variables across the schizophrenia-spectrum.

Schizotypy: looking back and moving forward

This article introduces and reviews the history of the construct of schizotypy for the special section appearing in the journal. Schizotypy offers a useful construct for understanding the etiology, development, and expression of schizophrenia-spectrum psychopathology and a unifying construct for linking a broad continuum of clinical and subclinical manifestations. The article reviews the descriptive psychopathology roots of schizotypy, Meehl and Claridge's classical formulations of the construct (including the debate about dimensional vs taxonic structure), and the need for a comprehensive, multidimensional model of schizotypy. The article briefly reviews the wide empirical literature supporting schizotypy and also examines several criticisms and misconceptions about the construct and research methods used to assess it. Finally, the article offers several suggested goals for future schizotypy research.

Predicting creativity: the role of psychometric schizotypy and cannabis use in divergent thinking

Evidence suggests that divergent thinking (DT), a measure of creativity, is associated with positive schizotypy and cannabis use. Given the high rates of cannabis use among those with schizotypy, it is unclear if the relation of DT to schizotypy is due to co-occurring cannabis use. In this study, we examined the relations between DT, schizotypy, and cannabis use among positive schizotypy (n=66), negative schizotypy (n=22), and non-schizotypy (n=60) groups. Results revealed that DT was greater in the positive schizotypy group, on the order of small to medium effects, compared to negative and non-schizotypy groups. Cannabis use and DT were associated in the non-schizotypy group, but not in the positive or negative schizotypy groups. Across all groups, positive schizotypy significantly predicted DT; however, cannabis use was not a significant predictor of DT. In line with previous findings, cannabis use and DT were only related in individuals low in creativity. This suggests that a ceiling effect may be present, with only cannabis users who are low in creativity receiving any increase in DT. Future research should aim to clarify the DT-cannabis relationship.

Necessary, but not sufficient: links between neurocognition, social cognition, and metacognition in schizophrenia are moderated by disorganized symptoms

Intact neurocognition has been posited as a necessary, but not sufficient prerequisite for efficient social cognition and metacognition in schizophrenia. Disorganized symptoms likely play a prominent role in these cognitive processes, given the detrimental effects of disorganization on one's ability to synthesize discrete information into an organized whole. However, the relationship between disorganized symptoms and cognitive processes remains unclear. In this study, we examined whether disorganized symptoms: 1) exhibited stronger inverse relationships with cognitive processes than other symptoms, and 2) moderated links between neurocognition and a) social cognition, and b) metacognition. Trained raters assessed psychotic symptoms, neurocognition, social cognition, and metacognition in patients with schizophrenia from a Midwestern VA Medical Center (n=68) using validated, clinician-rated instruments. We observed significantly greater inverse associations with cognitive processes for disorganized compared to reality distortion symptoms; inverse associations with neurocognition and social cognition were significantly greater for disorganized than negative symptoms. Our hypotheses that disorganized symptoms would moderate relationships between neurocognition and a) social cognition, and b) metacognition were also supported. These findings highlight the importance of disorganized symptoms in elucidating links between neurocognition and social cognitive and metacognitive abilities. Future work should assess whether similar findings occur across the schizophrenia-spectrum, and investigate if targeting disorganization can ameliorate social cognitive and metacognitive impairments in schizophrenia.