Cognitive slippage in schizotypic individuals

Developing and validating the Japanese version of the Referential Thinking Scale: A cross-sectional study

It has been shown that ideas of reference in the context of paranoia (IoR-P) and schizophrenia spectrum disorders (IoR-S) are caused by different psychological constructs. Although it is well known that both IoR-P and IoR-S are frequently evoked during the same period of life, how they interact with each other is unknown. The purpose of the present study was to develop the Japanese version of the Referential Thinking Scale (J-REF) to assess IoR-S, examine its validity and reliability, and explore the predictors of IoR-P and IoR-S. In this study, several subgroups of Japanese individuals in their 20s were included in the analysis. The J-REF had high internal consistency, high test-retest reliability, good convergent, and discriminant validity. Two hierarchical regression analyses showed that public self-consciousness predicted the manifestation of IoR-P, while the dimensions of schizotypy predicted that of IoR-S. Moreover, social anxiety and negative moods could cause IoR-P and IoR-S. This study directly showed the existence of two different types of ideas of reference in terms of their predictors. It is also significant in that it first examined referential thinking using the REF scale in the context of Asia and showed that there may not be much difference in the frequency of ideas of reference from other cultures. Future research directions are also discussed.

Does childhood trauma predict schizotypal traits? A path modelling approach in a cohort of help-seeking subjects

Schizotypy constitutes a susceptibility to beneficial and deleterious schizotypal traits, ranging from coping mechanisms to schizotypal personality disorder on a psychosis continuum. Growing evidence indicates a relationship between childhood adversity and trauma and schizotypy. However, the exact influence of childhood adversity and trauma on schizotypy and its relation to sex is not sufficiently understood. Therefore, we investigated sex-adjusted connections between childhood adversity and trauma subdomains (emotional/physical/sexual abuse, emotional/physical neglect) and positive (magical ideation, perceptual aberration) as well as negative schizotypy (physical/social anhedonia). In total, 240 outpatients of the Early Detection and Intervention Centre of the University Hospital Cologne were assessed with the Trauma and Distress Scale for childhood adversity and trauma and the Wisconsin Schizotypy Scales for schizotypy. Path analyses were performed to investigate sex-adjusted correlations. The well-fitting path model of the total sample linked emotional abuse to magical ideation (p = 0.03; SE = 0.20) and emotional neglect to social anhedonia (p = 0.01; SE = 0.26). In females, physical abuse predicted magical ideation (p = 0.01; SE = 0.33), while emotional neglect forecasted physical anhedonia (p = 0.03; SE = 0.34) and social anhedonia (p = 0.03; SE = 0.32). In males, sexual abuse predicted perceptive aberration (p = 0.04; SE = 0.19) and emotional abuse forecasted magical ideation (p = 0.03; SE = 0.27). Overall, the significance of sex-specific interrelations between trauma and schizotypy were highlighted. Magical ideation and perceptive aberration occurred prominently in the absence of negative and disorganized schizotypy, thus positive schizotypy could be discussed as a beneficial expression of coping with emotional, physical and sexual abuse. Furthermore, emotional neglect should be addressed particularly to prevent deleterious negative schizotypy in females.Trial registration number (20-1243), date of registration (May 19th 2020), retrospectively registered.

Costs of schizotypal disorder: A matched-controlled nationwide register-based study of patients and spouses

OBJECTIVE

Information on societal cost of patients with schizotypal disorder is limited. The aim was to investigate the societal costs of schizotypal disorder before and after initial diagnosis including both patients and their spouses.

METHODS

A register-based cohort study of 762 patients with incident schizotypal disorder (ICD-10; F21) including their spouses and 3048 matched controls, during 2002 to 2016. Total healthcare costs, home care costs, and costs of lost productivity of patients and spouses were included in the analysis.

RESULTS

Total costs amounted €47,215 per year for patients with schizotypal disorder, which was fifteen times higher than the matched controls. Of these, 41% were healthcare and home care costs and 59% were costs of lost productivity. Healthcare costs and costs of lost productivity were increased during five years before initial diagnosis of schizotypal disorder. Total costs of spouses to patients were €21,384 compared with € 2519 among spouses of controls. 75% of the total costs of spouses to patients were related to lost productivity. The total costs were higher than the costs of borderline personality disorder, but on the same level as the costs of schizophrenia identified in earlier comparable studies.

CONCLUSIONS

The total societal costs of patients with schizotypal disorder drawn from national registers differed substantially from the controls representing the general population. As evidence-based recommendations for diagnoses and treatment of patients with schizotypal disorder do not exist, future research should focus on developing effective treatment for this group of patients to reduce cost of illness.

The interaction between positive schizotypy and high sensitivity C-reactive protein on response inhibition in female individuals

This study aimed to measure the associations between high sensitivity C-reactive protein (hsCRP), childhood maltreatment (CM), schizotypy and response inhibition, and to explore the interactions between hsCRP, CM and schizotypy on response inhibition. Two hundred and fourteen participants completed the Stop-Signal Task (SST), the Schizotypy Personality Questionnaire (SPQ) and the Childhood Trauma Questionnaire-Short Form (CTQ), which measured response inhibition, schizotypy and history of CM respectively. The level of hsCRP was also measured. The high schizotypy group (n = 114) had higher scores on SPQ and CTQ, higher hsCRP levels and longer SST reaction times (SSRTs) than the low schizotypy group (n = 100). In female participants, SSRT had a positive correlation with the SPQ positive factor and the disorganized SPQ factor and a positive correlation with physical neglect. HsCRP was positively correlated with the SPQ negative factor and positive SPQ factor. In male participants, SSRT was negatively correlated with emotional neglect and physical neglect. The majority of correlations between CTQ and SPQ variables were significant in both female and male participants. In female participants, hsCRP significantly predicted SSRT, and hsCRP significantly interacted with positive schizotypy in predicting SSRT.

Cognitive fusion and affective isolation: Blurred self-concept and empathy deficits in schizotypy

This is a cross-sectional nonclinical sample study to examine the different levels of the Ipsiety Disturbance Model (IDM) for schizophrenia spectrum disorders (introduced by Sass and Parnas, 2003). Three faces of schizotypy were studied: diminished self-presence, hyper-reflexivity, and distortion in experience of own self and another person's self-discrimination. A sample of college students (N = 1312) was provided a questionnaire packet that contained the Schizotypy Personality Questionnaire Brief-Revisited (SPQ-BR), the Self-Concept Clarity Sale, the Tellegen Absorption Scale, and Interpersonal Reactivity Index measures. Results: higher absorption capabilities predict higher scores on both the SPQ-BR cognitive and SPQ-BR disorganization factors. High scores in cognitive empathy predicted a low score on both SPQ-BR cognitive and SPQ-BR interpersonal scores. In contrast, higher affective empathy predicted high scores on the SPQ-BR interpersonal factor. The deficiency in self-concept clarity predicted an elevated score on the SPQ-BR cognitive, interpersonal, and disorganization schizotypy symptoms. We argue that a lack of self-concept clarity manifested in both the hyperreflexivity level (measured by absorption) and the metallization level (measured by empathy). We argue that the IDM is a reliable way to interpret functioning with different levels of schizotypy.

Association of Schizotypy With Dimensions of Cognitive Control: A Meta-Analysis

Schizotypy is defined as a time-stable multidimensional personality trait consisting of positive, negative, and disorganized facets. Schizotypy is considered as a model system of psychosis, as there is considerable overlap between the 2 constructs. High schizotypy is associated with subtle but fairly widespread cognitive alterations, which include poorer performance in tasks measuring cognitive control. Similar but more pronounced impairments in cognitive control have been described extensively in psychosis. We here sought to provide a quantitative estimation of the effect size of impairments in schizotypy in the updating, shifting, and inhibition dimensions of cognitive control. We included studies of healthy adults from both general population and college samples, which used either categorical or correlative designs. Negative schizotypy was associated with significantly poorer performance on shifting (g = 0.32) and updating (g = 0.11). Positive schizotypy was associated with significantly poorer performance on shifting (g = 0.18). There were no significant associations between schizotypy and inhibition. The divergence in results for positive, negative, and disorganized schizotypy emphasizes the importance of examining relationships between cognition and the facets of schizotypy rather than using the overall score. Our findings also underline the importance of more detailed research to further understand and define this complex personality construct, which will also be of importance when applying schizotypy as a model system for psychosis.

Schizophrenia spectrum personality disorders in psychometrically identified schizotypes at two-year follow-up

Earlier (Bolinskey et al., 2015), we reported that psychometrically identified schizotypes displayed greater symptom levels and higher incidences of schizophrenia spectrum (schizotypal, schizoid, paranoid, and avoidant) personality disorders (PDs). In this study, 49 schizotypes and 39 matched controls participated in follow-up assessments after two years. Participants were previously identified as schizotypes or controls based on scores on the Chapman Psychosis Proneness Scales (CPPS), and were interviewed at baseline and follow-up with the Personality Disorder Interview for DSM-IV (PDI-IV). At follow-up, schizotypes displayed significantly higher symptom levels compared to controls, with medium to large effects, and appeared to meet criteria for diagnosis of each PD more often than controls, although significant differences were only observed for paranoid PD. Overall, schizotypes were more likely to have met criteria for a diagnosis at either baseline or follow-up. Finally, we observed a widening disparity over time between schizotypes and controls in avoidant and schizoid PDs. These results suggest that schizophrenia spectrum PDs, as well as subthreshold symptoms of these disorders, can represent a greater liability for schizophrenia in individuals identified as at-risk on the basis of psychometric means only. Furthermore, these findings demonstrate that such differences persist, and in some cases increase, over time.

Neuropsychological correlates of schizotypy: a systematic review and meta-analysis of cross-sectional studies

INTRODUCTION

Cognitive deficits can precede the onset of psychotic episodes and predict the onset of the illness in individuals with schizotypy traits. In some studies, high levels of schizotypy were associated with impairments in memory, attention, executive functions, and verbal fluency. This review provides a more comprehensive understanding of cognitive impairments related to schizoytpy.

METHODS

 A systematic review of "schizotypy and neuropsychological measures" was conducted, and it retrieved 67 studies. All papers with case-control design showing means and standard deviations from neuropsychological measures were included in a meta-analysis (n = 40). A comparison between our finding and another metaanalysis with patients with schizophrenia-spectrum disorders [Fatouros-Bergman, H., Cervenka, S., Flyckt, L., Edman, G., & Farde, L. (2014). Meta-analysis of cognitive performance in drugnaive patients with schizophrenia. Schizophrenia Research. doi: 10.1016/j.schres.2014.06.034 ] was performed to study the similarities on the MATRICS domains between the two disorders.

RESULTS

We found evidence of worse functioning of verbal and visual-spatial working memory, and of language in people with schizotypy or with schizotypal traits. Working memory deficit is present in both schizotypy and schizophrenia with larger effect sizes compared to other domains.

CONCLUSIONS

 Working memory deficit might be a cognitive marker of the risk of psychosis. Interventions targeting cognitive deficits early may be crucial to the prevention of psychosis.

Individual differences in the executive control of attention, memory, and thought, and their associations with schizotypy

A large correlational study took a latent-variable approach to the generality of executive control by testing the individual-differences structure of executive-attention capabilities and assessing their prediction of schizotypy, a multidimensional construct (with negative, positive, disorganized, and paranoid factors) conveying risk for schizophrenia. Although schizophrenia is convincingly linked to executive deficits, the schizotypy literature is equivocal. Subjects completed tasks of working memory capacity (WMC), attention restraint (inhibiting prepotent responses), and attention constraint (focusing visual attention amid distractors), the latter 2 in an effort to fractionate the "inhibition" construct. We also assessed mind-wandering propensity (via in-task thought probes) and coefficient of variation in response times (RT CoV) from several tasks as more novel indices of executive attention. WMC, attention restraint, attention constraint, mind wandering, and RT CoV were correlated but separable constructs, indicating some distinctions among "attention control" abilities; WMC correlated more strongly with attentional restraint than constraint, and mind wandering correlated more strongly with attentional restraint, attentional constraint, and RT CoV than with WMC. Across structural models, no executive construct predicted negative schizotypy and only mind wandering and RT CoV consistently (but modestly) predicted positive, disorganized, and paranoid schizotypy; stalwart executive constructs in the schizophrenia literature-WMC and attention restraint-showed little to no predictive power, beyond restraint's prediction of paranoia. Either executive deficits are consequences rather than risk factors for schizophrenia, or executive failures barely precede or precipitate diagnosable schizophrenia symptoms. (PsycINFO Database Record

Schizotypy--do not worry, it is not all worrisome

A long-standing tradition in personality research in psychology, and nowadays increasingly in psychiatry, is that psychotic and psychotic-like thoughts are considered common experiences in the general population. Given their widespread occurrence, such experiences cannot merely reflect pathological functioning. Moreover, reflecting the multi-dimensionality of schizotypy, some dimensions might be informative for healthy functioning while others less so. Here, we explored these possibilities by reviewing research that links schizotypy to favorable functioning such as subjective wellbeing, cognitive functioning (major focus on creativity), and personality correlates. This research highlights the existence of healthy people with psychotic-like traits who mainly experience positive schizotypy (but also affective features mapping onto bipolar disorder). These individuals seem to benefit from a healthy way to organize their thoughts and experiences, that is, they employ an adaptive cognitive framework to explain and integrate their unusual experiences. We conclude that, instead of focusing only on the pathological, future studies should explore the behavioral, genetic, imaging, and psychopharmacological correlates that define the healthy expression of psychotic-like traits. Such studies would inform on protective or compensatory mechanisms of psychosis-risk and could usefully inform us on the evolutionary advantages of the psychosis dimension.

Cognition and brain function in schizotypy: a selective review

Schizotypy refers to a set of personality traits thought to reflect the subclinical expression of the signs and symptoms of schizophrenia. Here, we review the cognitive and brain functional profile associated with high questionnaire scores in schizotypy. We discuss empirical evidence from the domains of perception, attention, memory, imagery and representation, language, and motor control. Perceptual deficits occur early and across various modalities. While the neural mechanisms underlying visual impairments may be linked to magnocellular dysfunction, further effects may be seen downstream in higher cognitive functions. Cognitive deficits are observed in inhibitory control, selective and sustained attention, incidental learning, and memory. In concordance with the cognitive nature of many of the aberrations of schizotypy, higher levels of schizotypy are associated with enhanced vividness and better performance on tasks of mental rotation. Language deficits seem most pronounced in higher-level processes. Finally, higher levels of schizotypy are associated with reduced performance on oculomotor tasks, resembling the impairments seen in schizophrenia. Some of these deficits are accompanied by reduced brain activation, akin to the pattern of hypoactivations in schizophrenia spectrum individuals. We conclude that schizotypy is a construct with apparent phenomenological overlap with schizophrenia and stable interindividual differences that covary with performance on a wide range of perceptual, cognitive, and motor tasks known to be impaired in schizophrenia. The importance of these findings lies not only in providing a fine-grained neurocognitive characterization of a personality constellation known to be associated with real-life impairments, but also in generating hypotheses concerning the aetiology of schizophrenia.

Cognitive slippage, psychosis-proneness, and schizotypy: a comment on Loas, et al. (2013)

Loas, et al. (2013) is an interesting study that raises two important issues: namely, the validity of the Miers and Raulin Cognitive Slippage Scale and the nature of the relationship between thought disorder and schizotypy. Given that thought disorder has been observed in both schizophrenic and affective disordered patients for years, it is important to consider what aspects of thought disorder may be specifically related to a schizophrenia diathesis. In this brief commentary, I discuss some research findings that provide insights in this regard.

Using the MMPI-2-RF to discriminate psychometrically identified schizotypic college students from a matched comparison sample

This study investigates the extent to which the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF) profiles of 52 individuals making up a psychometrically identified schizotypes (SZT) sample could be successfully discriminated from the protocols of 52 individuals in a matched comparison (MC) sample. Replication analyses were performed with an additional 53 pairs of SZT and MC participants. Results showed significant differences in mean T-score values between these 2 groups across a variety of MMPI-2-RF scales. Results from discriminant function analyses indicate that schizotypy can be predicted effectively using 4 MMPI-2-RF scales and that this method of classification held up on replication. Additional results demonstrated that these MMPI-2-RF scales nominally outperformed MMPI-2 scales suggested by previous research as being indicative of schizophrenia liability. Directions for future research with the MMPI-2-RF are suggested.

Neurocognition in psychometrically defined college Schizotypy samples: we are not measuring the "right stuff"

Although neurocognitive deficits are an integral characteristic of schizophrenia, there is inconclusive evidence as to whether they manifest across the schizophrenia-spectrum. We conducted two studies and a meta-analysis comparing neurocognitive functioning between psychometrically defined schizotypy and control groups recruited from a college population. Study One compared groups on measures of specific and global neurocognition, and subjective and objective quality of life. Study Two examined working memory and subjective cognitive complaints. Across both studies, the schizotypy group showed notably decreased subjective (d51.52) and objective (d51.02) quality of life and greater subjective cognitive complaints (d51.88); however, neurocognition was normal across all measures (d’s,.35). Our meta-analysis of 33 studies examining neurocognition in at-risk college students revealed between-group differences in the negligible effect size range for most domains. The schizotypy group demonstrated deficits of a small effect size for working memory and set-shifting abilities. Although at-risk individuals report relatively profound neurocognitive deficits and impoverished quality of life, neurocognitive functioning assessed behaviorally is largely intact. Our data suggest that traditionally defined neurocognitive deficits do not approximate the magnitude of subjective complaints associated with psychometrically defined schizotypy.

Formal Thought Disorder and language impairment in schizophrenia

Schizophrenia is a psychiatric illness in which disorders of thought content are a prominent feature. The disruption of normal flow of thought, or “Formal Thought Disorder” (FTD), has been traditionally assessed through the content and form of patients’ speech, and speech abnormalities in schizophrenia were considered as a by-product of the disruption in conceptual structures and associative processes related to psychosis. This view has been changed due to increasing evidence that language per se is impaired in schizophrenia, especially its semantic, discursive, and pragmatic aspects. Schizophrenia is currently considered by some authors as a “language related human specific disease” or “logopathy”, and the neuroanatomical and genetic correlates of the language impairment in these patients are under investigation. Such efforts may lead to a better understanding about the pathophysiology of this devastating mental disease. We present some current concepts related to FTD as opposed to primary neurolinguistic abnormalities in schizophrenia.

Thought disorder in offspring of schizophrenic parents: findings from the New York High-Risk Project

The goal of the present analyses was to examine the hypothesis that mild forms of thought disorder (TD) may serve as an indicator of genetic liability for schizophrenia. A subset of 232 subjects drawn from the New York High-Risk Project was used to compare individuals at high risk for schizophrenia (ie, offspring of parents with schizophrenia; n = 63) with 2 groups of individuals at low risk for schizophrenia (ie, offspring of parents with affective disorder [n = 52] and offspring of psychiatrically normal parents [n = 117]). Subjects were administered the Rorschach Inkblot Test, and their responses were assessed according to the Thought Disorder Index (TDI). The high-risk offspring displayed significantly more TD than the other 2 groups, as shown by significantly higher TDI scores. Moreover, they had more deviant verbalizations, according to their significantly higher scores on a composite Idiosyncratic Verbalizations score. As expected, the offspring who developed psychosis produced more TD in adolescence than those who did not develop psychosis. In the sample as a whole, TD scores during late adolescence/early adulthood were positively associated with schizotypal features during mid-adulthood. These findings support the assertion that the presence of TD serves as an endophenotypic marker of a schizophrenia diathesis.

Social anhedonia and schizotypy in a community sample: the Maryland longitudinal study of schizotypy

Social anhedonia has been employed in psychometric high-risk studies to identify putative schizotypes. To date, this research has focused almost exclusively on college samples. The current study sought to examine the validity of social anhedonia as an indicator of risk for schizophrenia-spectrum disorders within a community sample. Furthermore, we evaluated the role of other individual difference variables in accounting for variable clinical severity within the social anhedonia group including trait affectivity, social support, and family environment. Following the mailed questionnaire screening of 2434 eighteen-year olds, laboratory assessments were conducted with individuals identified as being high in social anhedonia (n=86) and a comparison sample (n=89). Compared with the control group, individuals in the social anhedonia group were found to have higher rates of mood disorders, elevated schizophrenia-spectrum personality disorder characteristics, greater negative symptom characteristics, and lower global functioning. Individuals within the social anhedonia group also reported greater trait negative affectivity, lower positive affectivity, less social support, and more family conflict. Low social support and problematic family environment were found to be related to elevations in spectrum personality disorder characteristics and poorer functioning within the social anhedonia group. These cross-sectional findings from a community sample provide further support for social anhedonia as a possible indicator of schizotypy.

Subjective awareness of everyday dysexecutive behavior precedes 'objective' executive problems in schizotypy: a replication and extension study

This study aimed to examine the subjective awareness of everyday dysexecutive function and the 'objective' executive function in individuals with schizotypal personality features. Forty-nine individuals with schizotypal personality disorder (SPD) proneness (25 negative schizotypy and 24 non-negative schizotypy were identified using cluster analysis) and 44 non-SPD individuals completed a battery of 'objective' executive function tests and a self-reported Dysexecutive Questionnaire (DEX) on everyday executive problems. The findings showed that individuals with SPD proneness including negative schizotypy and non-negative schizotypy did not have significant worse performance than non-SPD in most of 'objective' executive function tests, but self-reported significantly disproportionate more dysexecutive problems than non-SPD. Furthermore, SPD proneness, especially negative schizotypy was found to give undependable estimation on their everyday dysexecutive function while non-negative schizotypy was not. The current findings suggest that the subjective awareness of dysexecutive function may precede actual 'objective' executive function impairments in a subtype of SPD (non-negative schizotypy) and the subjective complaint of the daily dysexecutive behavior in SPD proneness, especially negative schizotypy might result from their unreliable estimation of executive function.

Schizotypal traits and N400 in healthy subjects

We examined whether correlations previously found between symptoms of schizophrenia patients and the amplitude of an event-related potential (ERP), the N400, could be also found between schizotypal experiences of healthy subjects and the N400. We chose a semantic categorization task previously used with patients. Schizotypal experiences were measured with the schizotypal personality questionnaire (SPQ). The effects of the other factors were controlled for when assessing the correlations between each SPQ factor and N400s. These correlations were assessed at each electrode site to see whether their distribution on the scalp follows that of the N400 effect. Disorganization and interpersonal scores were found to correlate with ERPs in the N400 time window, as previously reported for the comparable symptoms of patients. However, the scalp distribution of these correlations differed from that of the N400 effect.

Schizotypal, schizoid and paranoid characteristics in the biological parents of social anhedonics

Mounting evidence suggests that social anhedonia may be a marker of genetic liability for schizophrenia-spectrum pathology. To examine this hypothesis, we conducted a study of severity of schizotypal, schizoid and paranoid pathology (i.e., Cluster A personality disorders) in the biological parents of individuals with high levels of social anhedonia and healthy controls. Eighty-six individuals with social anhedonia, 89 healthy controls and their biological parents were recruited from a large community. Structured clinical interviews were conducted to obtain Cluster A diagnoses and symptom ratings for parents. The biological parents of socially anhedonic probands had elevated rates of Cluster A disorders (24%) compared with the parents of control probands (12%). Post hoc analyses revealed that these group differences were the result of elevated rates of diagnoses in the fathers of social anhedonic probands, but not the mothers. This finding was replicated when Cluster A symptoms were examined dimensionally. These findings are consistent with the hypothesis that social anhedonia is a promising indicator of the genetic vulnerability to schizophrenia-spectrum pathology. The unexpected findings of elevated pathology in fathers, but not mothers of socially anhedonic probands, require further exploration.

Behavioral signs of schizoidia and schizotypy in the biological parents of social anhedonics

A community sample of 88 putative schizotypes (48 social anhedonics, 40 controls), aged 18 to 19 years, and their biological parents (42 mothers of social anhedonics, 37 mothers of controls; 24 fathers of social anhedonics, 20 fathers of controls) receive videotaped diagnostic evaluations that serve as the basis for ratings of behavioral signs of schizoidia and schizotypy. Proband social anhedonics exhibit more atypical interpersonal behaviors characteristic of schizoid and schizotypal personality disorders than controls. Mothers of social anhedonics display more atypical interpersonal behaviors characteristic of schizotypal personality disorder than mothers of controls. In contrast, clinical symptom ratings of schizotypy do not differentiate mothers of social anhedonics from mothers of controls. Meaningful, though not statistically significant, effects are observed for behavioral sign ratings in the smaller sample of fathers of social anhedonics. Results provide preliminary support for the familiality of atypical interpersonal behavior in social anhedonics.

Is semantic processing impaired in individuals with high schizotypy?

Semantic processing deficits are present in schizophrenia. However, this research has often been criticized for methodological artifacts and confounds, including long hospitalizations and medication of patient samples. Utilizing high schizotypes (psychosis-prone individuals) can overcome these confounds. Previously, similar deficits have been reported in high schizotypes and schizophrenia on semantic priming tasks. In contrast to schizophrenia research, no other types of semantic processing have been examining in high schizotypes. Semantic processing is multifaceted, thus, deficits on semantic priming can not answer whether high schizotypes have difficulty with explicit semantic processing, that is, on tasks that require the conscious recollection of semantic information. In the current study, 24 high and 30 low scorers on the O-LIFE schizotypy scale were administered a battery of semantic processing measures. The high schizotypy group did not show global semantic processing impairments (as has been shown in schizophrenia), only impairments on a task designed to examine subtle categorization processing. Such deficits can be equated to those found on semantic priming tasks, in that both require quick and accurate access to semantic networks.

Endophenotypes in schizophrenia: a selective review

BACKGROUND

Given the wealth of data in the literature on schizophrenia endophenotypes, it is useful to have one source to reference their frequency data. We reviewed the literature on disease-liability associated variants in structural and functional magnetic resonance images (MRI), sensory processing measures, neuromotor abilities, neuropsychological measures, and physical characteristics in schizophrenia patients (SCZ), their first-degree relatives (REL), and healthy controls (HC). The purpose of this review was to provide a summary of the existing data on the most extensively published endophenotypes for schizophrenia.

METHODS

We searched PubMed and MedLine for all studies on schizophrenia endophenotypes comparing SCZ to HC and/or REL to HC groups. Percent abnormal values, generally defined as >2 SD from the mean (in the direction of abnormality) and/or associated effect sizes (Cohen's d) were calculated for each study.

RESULTS

Combined, the articles reported an average 39.4% (SD=20.7%; range=2.2-100%) of abnormal values in SCZ, 28.1% (SD=16.6%; range=1.6-67.0%) abnormal values in REL, and 10.2% (SD=6.7%; range=0.0-34.6%) in HC groups.

CONCLUSIONS

These findings are reviewed in the context of emerging hypotheses on schizophrenia endophenotypes, as well as a discussion of clustering trends among the various intermediate phenotypes. In addition, programs for future research are discussed, as instantiated in a few recent large-scale studies on multiple endophenotypes across patients, relatives, and healthy controls.

Cognitive and meta-cognitive dimensions of psychoses

This paper outlines cognitive approaches to understanding and treating positive psychotic symptoms, such as hallucinations, delusions, and dissociations. Recent cognitive accounts of psychosis are reviewed along with the claim that it is not the symptoms themselves but cognitive and meta-cognitive appraisals (attributions and beliefs) about the significance of the symptoms that cause distress and dysfunction. Psychotic symptoms do lie on a continuum with normal experience. Cognitive appraisal dimensions may interact with reasoning styles such as inferential confusion, cognitive slippage, fantasy proneness, and perceptual immersion (styles also normally distributed in the population) and together persuade the person with psychosis to live in fictional narratives as if they were real. Recent clinical studies suggest that addressing beliefs about symptoms modifying inferential styles and normalizing experiences may help symptom management.

Distinct conflict resolution deficits related to different facets of Schizophrenia

An important issue in understanding the nature of conflict processing is whether it is a unitary or multidimensional construct. One way to examine this is to study whether people with impaired conflict processing exhibit a general pattern of deficits or whether they exhibit impairments in distinct aspects of conflict processing. One group who might exhibit conflict deficits are people with schizophrenia. Schizophrenia is a heterogeneous disorder, with one way to break down the heterogeneity of schizophrenia is to examine specific symptoms. Previous research has found that specific symptoms of schizophrenia are associated with specific deficits in conflict processing. In particular, disorganization is associated with increased response conflict, alogia is associated with increased retrieval conflict, and anhedonia is associated with increased emotional conflict. Moreover, there is evidence that different types of conflict processing are unassociated with each other. This evidence suggests that conflict processing is a multidimensional construct and that different aspects of schizophrenia are associated with impairments in processing different types of conflict.

Prospective memory deficits in subjects with schizophrenia spectrum disorders: a comparison study with schizophrenic subjects, psychometrically defined schizotypal subjects, and healthy controls

Memory impairment is one of the core deficits in schizophrenia. This study explored the memory profiles of schizophrenic and psychometrically defined schizotypal subjects. The study participants included 15 patients with schizophrenia, 41 schizotypal subjects, and 20 healthy controls. All of the participants completed verbal and visual memory, working memory, and prospective memory tasks. The results showed that patients with schizophrenia were impaired in all aspects of memory function, whereas the schizotypal subjects tended to show moderate to large impairment effect sizes in prospective memory. It is suggested that prospective memory be considered a potential endophenotype of schizophrenia.

Stress-induced dopamine release in humans at risk of psychosis: a [11C]raclopride PET study

Drugs that increase dopamine levels in the brain can cause psychotic symptoms in healthy individuals and worsen them in schizophrenic patients. Psychological stress also increases dopamine release and is thought to play a role in susceptibility to psychotic illness. We hypothesized that healthy individuals at elevated risk of developing psychosis would show greater striatal dopamine release than controls in response to stress. Using positron emission tomography and [(11)C]raclopride, we measured changes in synaptic dopamine concentrations in 10 controls and 16 psychometric schizotypes; 9 with perceptual aberrations (PerAb, ie positive schizotypy) and 7 with physical anhedonia (PhysAn, ie negative schizotypy). [(11)C]Raclopride binding potential was measured during a psychological stress task and a sensory-motor control. All three groups showed significant increases in self-reported stress and cortisol levels between the stress and control conditions. However, only the PhysAn group showed significant stress-induced dopamine release. Dopamine release in the entire sample was significantly negatively correlated with smooth pursuit gain, an endophenotype linked to frontal lobe function. Our findings suggest the presence of abnormalities in the dopamine response to stress in negative symptom schizotypy, and provide indirect evidence of a link to frontal function.

Communication disturbances, working memory, and emotion in people with elevated disorganized schizotypy

This study examined whether people with elevated disorganized schizotypy would differ from control participants on characteristics associated with disorganization symptoms in schizophrenia and also whether disorganized schizotypy was associated with problems processing emotion. People with disorganized schizotypy (n=32) exhibited greater communication disturbances (CD) than control participants (n=34) for emotionally negative topics but not for positive topics. In addition, the disorganized group exhibited poorer performance on a working memory task but not on a psychometrically matched verbal intelligence task. In addition, poor working memory was associated with increased CD for negative topics and, after controlling for group differences in working memory, group differences in CD were not significant. Moreover, the disorganized group exhibited greater emotional ambivalence and ambivalence was associated with increased CD in the disorganized group. These results suggest that people with disorganized schizotypy exhibit some similar characteristics to people with schizophrenia who have disorganization symptoms and that disorganized schizotypy is also associated with poor emotion processing.

Impaired working memory monitoring in euthymic bipolar patients

OBJECTIVES

Converging evidence suggests that patients with remitted bipolar disorder (BD) have a persistent cognitive deficit in the executive control of working memory (WM). However, the component operations that contribute to this deficit remain unclear. The aim of the present study was to further profile the nature and specificity of WM impairment in euthymic BD.

METHODS

Fifty DSM-IV-confirmed patients with euthymic BD and demographically matched controls completed a modified version of the Self-Ordered Pointing Task (SOPT) and the Cambridge Neuropsychological Test Automated Battery Pattern Recognition Test along with traditional executive and WM tasks [Stroop, initial letter Verbal Fluency (FAS), Trail-Making, Digits Forwards and Backwards]. Prospective clinical ratings over one month prior to testing confirmed that patients were euthymic at test. Absence of basal hypercortisolaemia was confirmed by serial saliva sampling.

RESULTS

Error analysis revealed that whilst patients made more errors on the SOPT overall, they were no more likely to perseverate than controls. Patients' erroneous responses did not proliferate across trials, suggesting that proactive interference did not contribute to their poor performance, but serial position effects were evident where patients' errors clustered towards the end of a trial. No differences were found on the recognition memory test, in WM capacity, or on two of the three traditional executive procedures (FAS and Trail-Making). However, patients' Digits Backwards was impaired.

CONCLUSIONS

These data suggest that patients with BD have a deficit in their ability to monitor the contents of WM. This deficit is not an epiphenomenon of mood, but may be due to enduring brain dysfunction, integral to bipolar illness.

Traductions françaises et validations des échelles de dérapage cognitif (Cognitive Slippage Scale, Miers et Raulin, 1987) et d’ambivalence schizotypique (Schizotypal Ambivalence Scale, Raulin, 1986)

AIMS

The aim of this article is firstly to present the French translations of the Cognitive Slippage (Miers and Raulin, 1987) and the Schizotypal Ambivalence Scales (Raulin, 1986), and secondly to determine their psychometric properties in different samples of non-clinical and clinical subjects.

BACKGROUND

Chapman et al. have developed trait-oriented scales based on Meehl's manual of schizotypy, such as the Physical and Social Anhedonia Scales, the Perceptual Aberration Scale, the Magical Ideation Scale, the Impulsive Nonconformity Scale, the Cognitive Slippage Scale (CSS), and the Schizotypal Ambivalence Scale (SAS). The Chapman scales of psychosis proneness are the most internationally used instruments for the assessment of schizotypy and some of them such as the Cognitive Slippage and Schizotypal Ambivalence Scales were still not available in French.

METHOD

The study was conducted in three different samples: the non-clinical sample (n=158) comprised firstly 128 university students (113 females, 15 males) with a mean age of 24.67 years (sd=5.18) and secondly 30 healthy subjects (12 males, 18 females) with a mean age of 33.26 years (sd=7.35); the clinical sample (n=167) comprised firstly 106 psychiatric patients hospitalized in a general hospital (73 males, 33 females) with a mean age of 38.35 years (sd=11.60) and 61 (35 males, 26 females) in or outpatients of a psychiatric department with a mean age of 37.75 years (sd=10.72); 15 schizotypal university students presenting high score of the Revised Social Anhedonia Scale (1 male, 14 females) with a mean age of 21.26 years (sd=1.1). Using the ICD-10, the diagnoses for the general hospital sample were neurotic or anxious disorders (47%) and depressive disorders (24%). For the psychiatric department sample, the diagnoses were schizophrenic disorders (29%), mood disorders (16%), neurotic disorders (18%) and personality disorders (15%). The internal consistency was determined by the Kuder-Richardson coefficient (KR 20) (CSS: KR 20=0.85 in the university sample; 0.89 in the general hospital sample; 0.87 in the psychiatric department sample; SAS: KR 20=0.79 in the university sample; 0.82 in the general hospital sample; 0.85 in the psychiatric department sample).

RESULTS

The mean of the correlations between each item and the total score was calculated (CSS: 0.41 in the university sample; 0.44 in the general hospital sample; SAS: 0.46 in the university sample; 0.49 in the general hospital sample). The discriminant validity was studied by a Student's t test showing that the schizotypal university students had significant higher scores on the CSS and SAS than the healthy university students. The reliability was explored using a test-retest in the 30 healthy subjects. The subjects filled out the scales three months after the first testing. The intraclass coefficients were 0.81. Finally, the cutoff scores were calculated following the procedure described by Chapman et al. (score higher than two standard deviations above the mean of the university sample). The values for the CSS and SAS were respectively 15 and 12 for males and females.

Theory of mind, neurocognition, and functional status in schizotypy

The present study is the first to concurrently examine social cognition, neurocognition, and social functioning in psychometric schizotypes. Screening of 2108 undergraduates with the Schizotypal Personality Questionnaire-Brief (SPQ-B) identified 52 persons high in schizotypy and 40 persons low in schizotypy. All participants were administered a test battery designed to assess two elements of neurocognition, verbal secondary memory (California Verbal Learning Test) and executive functioning (Wisconsin Card Sorting Test), two elements of social cognition, emotion perception (The Awareness of Social Inference Test-Part 1) and theory of mind (The Awareness of Social Inference Test-Parts 2 and 3), and social functioning (Social Adjustment Scale-Self Report). Although the persons with high schizotypy were impaired in social functioning relative to the persons with low schizotypy, they were not impaired in theory of mind, emotion perception, verbal secondary memory, or executive functioning. Theory of mind and verbal secondary memory were correlated in persons with high schizotypy. The present findings suggest that psychometric schizotypes are not impaired in the domains of social cognition and neurocognition examined.

Abnormalities of auditory event-related potentials in students with high scores on the Schizotypal Personality Questionnaire

Some auditory event-related potential (ERP) abnormalities characterize both patients with schizophrenia and subjects with schizotypal personality disorder. It was therefore hypothesized that subjects from the community with schizotypal traits might also present ERP abnormalities. In this study, we compared auditory ERP latencies and amplitudes in 13 subjects with high (H-SPQ) and 12 subjects with low (L-SPQ) scores on the Schizotypal Personality Questionnaire (SPQ), selected from 198 Tunisian students. Auditory ERPs were recorded at Fz, Cz, and Pz, with a standard oddball paradigm. Smaller P300 amplitudes and delayed P300 latencies were found in H-SPQ compared with L-SPQ participants. Confirming previous reports, our results suggest that reduced P300 amplitudes and delayed P300 latencies may be considered as vulnerability markers of the schizophrenia spectrum in nonclinical subjects from the community.

Do antisaccade deficits in schizophrenia provide evidence of a specific inhibitory function?

BACKGROUND

Despite its inhibitory control requirements, antisaccade deficits have been consistently associated with working memory impairments in schizophrenia. We investigated whether variance in antisaccade performance could be better accounted for in terms of a specific inhibitory function.

METHOD

We assessed 48 clinically stable out-patients with schizophrenia on an antisaccade task, as well as on measures of spatial and verbal working memory, sustained selective attention, and a simple motoric go/no-go measure of response inhibition.

RESULTS

In a stepwise multiple regression analysis, go/no-go task performance accounted for a considerably greater percentage of variance in antisaccade performance (25.3%) than either working memory (8.4%) or sustained selective attention task (9.1%).

DISCUSSION

We conclude that antisaccade deficits in schizophrenia appear to be better understood in terms of a specific deficit of inhibitory control than in terms of more general difficulties with context maintenance or goal neglect.

The antisaccade task as a research tool in psychopathology: a critical review

The antisaccade task is a measure of volitional control of behavior sensitive to fronto-striatal dysfunction. Here we outline important issues concerning antisaccade methodology, consider recent evidence of the cognitive processes and neural mechanisms involved in task performance, and review how the task has been applied to study psychopathology. We conclude that the task yields reliable and sensitive measures of the processes involved in resolving the conflict between volitional and reflexive behavioral responses, a key cognitive deficit relevant to a number of neuropsychiatric conditions. Additionally, antisaccade deficits may reflect genetic liability for schizophrenia. Finally, the ease and accuracy with which the task can be administered, combined with its sensitivity to fronto-striatal dysfunction and the availability of suitable control conditions, may make it a useful benchmark tool for studies of potential cognitive enhancers.

Schizotypy facets, cognitive control, and emotion

This research examined whether facets of schizotypy were differentially related to cognitive control and emotion-processing traits. In a confirmatory factor analysis (N = 261), a 3-factor model of schizotypy exhibited good fit and fit significantly better than a 2-factor model. In addition, only disorganized schizotypy was associated with poor cognitive control (specifically, prepotent inhibition). Moreover, disorganized but not positive schizotypy was associated with increased emotional confusion and increased emotionality. In contrast, negative schizotypy was associated with increased emotional confusion but decreased emotionality. These results suggest that disorganized schizotypy is related to dysregulation of both cognition and emotion and that negative schizotypy might reflect deficits in the experience and processing of emotion and not just in emotional expression.

Differential working memory impairment in bipolar disorder and schizophrenia: effects of lifetime history of psychosis

BACKGROUND

Although bipolar disorder and schizophrenia have long been viewed as distinct illnesses, there is growing evidence that these two complex diseases share some common genes, which may manifest as overlapping neuropsychological impairments. Although working memory dysfunction has been proposed to be central to the pathophysiology of schizophrenia, it has received less attention in studies of bipolar disorder.

METHOD

We applied measures of working memory to patients with schizophrenia (n = 15), patients with schizoaffective disorder (n = 15), patients with psychotic (n = 11) and non-psychotic (n = 15) bipolar disorder, and demographically matched healthy subjects (n = 32), in order to determine the extent to which these groups show common or unique impairments.

RESULTS

While patients with bipolar disorder (with and without psychotic features) and those with schizophrenia/schizoaffective disorder were impaired on backward digit span, only patients with a lifetime history of psychotic features, regardless of diagnosis, were impaired on spatial delayed response task.

CONCLUSIONS

Backward digit span performance is comparable in bipolar disorder and schizophrenia, and may be an appropriate endophenotypic marker that cuts across diagnostic categories. In contrast, spatial working memory performance clearly distinguishes non-psychotic bipolar disorder patients from patients with functional psychosis.

Sustained attention deficits in relation to psychometrically identified schizotypy: evaluating a potential endophenotypic marker

Sustained attention deficits have been posited as a potential endophenotypic marker of vulnerability to schizophrenia. Prior studies have indicated that schizophrenia patients, their first-degree relatives, and psychosis-prone individuals, identified on the basis of measures of positive schizotypy, have demonstrated sustained attention deficits. To date, there have been no published reports of sustained attention deficits in individuals with negative schizotypy, as measured by the revised Social Anhedonia Scale. In this study, we examined sustained attention, measured with the CPT-Identical Pairs version, in 160 individuals with elevated scores on the Chapman Perceptual Aberration and/or Magical Ideation Scales, 96 individuals with elevated scales on the Social Anhedonia Scale, and 137 controls. Both psychosis-prone groups performed more poorly than the controls in terms of discrimination ability, as measured by d', though the groups did not differ in terms of either their reaction time or overall response criterion (lnbeta). These results provide evidence that both positive and negative aspects of schizotypy are associated with sustained attention deficits, as measured by the Continuous Performance Test. The findings add to the converging evidence indicating that sustained attention deficits are a potential endophenotypic indicator of a schizophrenia diathesis.

Dimensional approaches to experimental psychopathology of schizophrenia: shift learning and report of psychotic-like experiences in college students

Adopting a dimensional approach to experimental psychopathology, and taking into account inconsistencies in the previous literature, we examined whether reports of psychotic-like experiences in undergraduate students were associated with shift-learning deficits, akin to those seen in schizophrenia. The participants (N=72) were tested on a new compound stimulus discrimination task before and after a target shift, and were administered a multi-dimensional schizotypy inventory (O-LIFE). Performance impairment following a target shift was associated with the negative (introvertive anhedonia) and the impulsive (impulsive non-conformity) dimension of schizotypy, but not with the positive (unusual experiences), nor the disorganised (cognitive disorganisation) dimension. None of the schizotypy measures were associated with performance on discrimination learning before the target shift. The obtained results are in line with past evidence that shift learning is associated with the severity of the negative symptomatology of schizophrenia. The possibility that psychotic-like features may contribute differentially to performance deficits across successive stages of learning is considered.

Behavioral signs of schizoidia and schizotypy in social anhedonics

Social anhedonia appears to be a promising indicator of Meehl's construct of schizotypy. While findings from diagnostic, cognitive, and psychophysiological studies have supported the validity of social anhedonia as an indicator of schizotypy, the behavioral characteristics of these putative schizotypes are not yet fully understood. This study utilized a rating system for behavioral signs of schizoidia and schizotypy to determine whether atypical interpersonal behaviors were observable in social anhedonics and to examine if these behavioral signs provide unique information, beyond traditional symptom ratings, in the identification of putative schizotypes. A community sample of 170 18-19-year-olds (85 social anhedonics, 85 controls) received diagnostic evaluations which were videotaped and subsequently rated for behavioral signs of schizoidia and schizotypy. Compared to controls, the social anhedonia group displayed significantly more behavioral signs characteristic of schizoid and schizotypal personality disorders. Behavioral signs of schizoidia accounted for a significant amount of group variance even after controlling for clinical symptom ratings. These results indicate that social anhedonics display interpersonal behaviors consistent with risk for schizophrenia-spectrum disorders and that these behavioral signs convey information about group status that is not accounted for by traditional clinical interview ratings of symptomatology.

Antisaccade and smooth pursuit performance in positive- and negative-symptom schizotypy

Schizophrenic patients have well-documented abnormalities in smooth pursuit eye movements and antisaccade performance. In populations at risk for schizophrenia, smooth pursuit abnormalities are also well documented. Antisaccade deficits have been replicated in high-risk populations as well, but the findings are more variable and the reasons for the variability are not clear. Some evidence suggests that antisaccade deficits increase in high-risk populations in relation to the presence of positive symptoms. Whether antisaccade deficits increase in relation to negative symptoms in high-risk populations is relatively uninvestigated. We evaluated antisaccade and pursuit performance in "psychometric schizotypes" who had elevated scores on either the Perceptual Aberration Scale (PerAb; i.e., positive symptoms) or the Physical Anhedonia Scale (PhysAnh; i.e., negative symptoms) but not both, and in normal controls. We used the standard version of the antisaccade task, for which results in positive-symptom schizotypes have previously been reported, and investigated performance on a gap and overlap version. We replicated the finding that a significantly larger percentage of positive-symptom schizotypes than controls have elevated antisaccade error rates on the standard antisaccade task (P=0.03); the percentage of negative-symptom schizotypes with elevated antisaccade error rates did not differ from that of control subjects. Neither schizotypal group was impaired on the gap or overlap versions of the task. On the pursuit task, a higher percentage of positive- and negative-symptom schizotypes were classified as having deviant performance than control subjects (both Ps<0.04). These findings suggest that antisaccade deficits may be better at identifying high-risk subjects with positive symptoms. Pursuit deficits identified both positive- and negative-symptom schizotypes, but was better at identifying the latter.

Context-Processing Deficits in Schizotypal Personality Disorder

Research suggests that schizotypal personality disorder (SPD) is a part of the spectrum of schizophrenia-related illnesses. This article hypothesizes that a deficit in the representation and maintenance of context is a core cognitive disturbance in schizophrenia and that SPD individuals should demonstrate context-processing deficits. To test this hypothesis, the authors administered 3 versions of their AX-CPT task, designed to assess context processing, to 35 healthy controls and 26 individuals with DSM-IV SPD. They also administered working memory and selective attention tasks. SPD individuals displayed context representation deficits similar to those found in schizophrenia but did not show the same additional deficits in context maintenance. Context processing was strongly associated with working memory and selective attention performance in the SPD individuals.

Executive function assessed by memory updating and random generation in schizotypal individuals

Individuals scoring high (N=32) and low (N=27) on the unusual experiences (UnEx) scale of the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE) were selected from a large sample (N=265) of normal volunteer undergraduates. The high- and low-UnEx groups were compared on two tasks, random generation and memory updating, which target executive functions that inhibit prepotent responses and update current information. The groups differed only on the R measure of random generation that assesses inequality in the relative frequencies of response alternatives, a result attributed to superstitious behaviour rather than to executive deficit. The results suggest that the executive impairments previously observed in high schizotypal individuals using the Wisconsin Card Sorting Test and other measures are selective rather than global.

Peeling the onion: NMDA dysfunction as a unifying model in schizophrenia

N-methyl-d-aspartate receptor (NMDAR) dysfunction plays a crucial role in schizophrenia, leading to impairments in cognitive coordination. NMDAR agonists (e.g., glycine) ameliorate negative and cognitive symptoms, consistent with NMDAR models. However, not all types of cognitive coordination use NMDAR. Further, not all aspects of cognitive coordination are impaired in schizophrenia, suggesting the need for specificity in applying the cognitive coordination construct.

High-frequency synchronisation in schizophrenia: Too much or too little?

Phillips & Silverstein's focus on schizophrenia as a failure of “cognitive coordination” is welcome. They note that a simple hypothesis of reduced Gamma synchronisation subserving impaired coordination does not fully account for recent observations. We suggest that schizophrenia reflects a dynamic compensation to a core deficit of coordination, expressed either as hyper- or hyposynchronisation, with neurotransmitter systems and arousal as modulatory mechanisms.

No blind schizophrenics: Are NMDA-receptor dynamics involved?

Numerous searches have failed to identify a single co-occurrence of total blindness and schizophrenia. Evidence that blindness causes loss of certain NMDA-receptor functions is balanced by reports of compensatory gains. Connections between visual and anterior cingulate NMDA-receptor systems may help to explain how blindness could protect against schizophrenia.

Setting domain boundaries for convergence of biological and psychological perspectives on cognitive coordination in schizophrenia

The claim that the disorganized subtype of schizophrenia results from glutamate hypofunction is enhanced by consideration of current subtypology of schizophrenia, symptom definition, interdependence of neurotransmitters, and the nature of the data needed to support the hypothesis. Careful specification clarifies the clinical reality of disorganization as a feature of schizophrenia and increases the utility of the subtype.

Schizophrenia: Putting context in context

Although context-processing deficits may be core features of schizophrenia, context remains a poorly defined concept. To test Phillips & Silverstein's model, we need to operationalize context more precisely. We offer several useful ways of framing context and discuss enhancing or facilitating schizophrenic patients' performance under different contextual situations. Furthermore, creativity may be a byproduct of cognitive uncoordination.

Phenomenology, context, and self-experience in schizophrenia

Impairments in cognitive coordination in schizophrenia are supported by phenomenological data that suggest deficits in the processing of visual context. Although the target article is sympathetic to such a phenomenological perspective, we argue that the relevance of phenomenological data for a wider understanding of consciousness in schizophrenia is not sufficiently addressed by the authors.