Schizophrenia Research-Cognition最新文献

Schizotypal traits (i.e., personality characteristics that range from mild eccentricities to more pronounced schizophrenia-like perceptions, thought patterns, and behaviours) have been associated with a variety of cognitive impairments, including difficulties in language processing. Although these difficulties span several aspects of language (e.g., semantic processing, verbal fluency, visual word recognition), it is unclear whether reading abilities are also affected. Thus, the current study employed the Schizotypal Personality Questionnaire (SPQ) – Brief (Raine and Benishay, 1995) to examine how schizotypal traits impact both word-level and text-level reading skills (using a battery of standardized assessments) in a sample of healthy young adults. We found some evidence that higher schizotypal traits, specifically, increased Disorganized factor scores (reflecting aberrant thinking, communication patterns, and behaviour), were associated with reduced word-level reading abilities. However, this finding did not remain significant after correcting for multiple comparisons. Overall, our study suggests that reading may be another aspect of language affected by schizotypal traits, although additional research (with greater power) is needed to further explore and confirm this finding.

Background

Anhedonia is a deficit of dynamic reward process, and a large proportion of schizophrenia patients continue to experience anhedonia even during the stable phase. However, few studies have examined the multiple aspects of performance in reward processing in patients with stable schizophrenia and evidence suggests that physical and cognitive effort may involve different neural mechanisms.

Methods

Parallel measures of effort-based expenditure for reward tasks (EEfRT) and self-report questionnaires of pleasure were applied in 61 patients with stable schizophrenia (SSZ) and 46 healthy controls (HCs), and percentages of hard task choices (HTC%) were used to assess motivation in reward processing. Negative symptoms, neurocognitive and social function were evaluated in SSZ patients, and associations with performance in reward tasks were explored.

Results

SSZ patients reported more severe consummatory and anticipatory anhedonia and social anhedonia. HTC% in reward tasks of SSZ patients were significantly lower than that of HCs, especially in cognitive-effort tasks. HTC% in cognitive tasks were correlated with motivation and pleasure dimension of negative symptoms, whereas HTC% in physical tasks were associated with expression dimension. Anticipatory anhedonia and negative symptoms were correlated with Personal and Social Performance Scale (PSP) scores.

Conclusion

Patients with stable schizophrenia have social anhedonia, physically consummatory and anticipatory anhedonia and reduced reward motivation. They are less willing to make cognitive effort than physical effort for reward. The different associations of physical and cognitive effort with negative symptoms indicate physical and cognitive effort may represent disparate neuropsychological processes. Anticipatory anhedonia is closely related to social functioning.

Background

Visual exploration is abnormal in schizophrenia; however, few studies have investigated the physiological responses during selecting objectives in more ecological scenarios. This study aimed to demonstrate that people with schizophrenia have difficulties observing the prominent elements of an image due to a deficit mechanism of sensory modulation (active sensing) during natural vision.

Methods

An electroencephalogram recording with eye tracking data was collected on 18 healthy individuals and 18 people affected by schizophrenia while looking at natural images. These had a prominent color element and blinking produced by changes in image luminance.

Results

We found fewer fixations when all images were scanned, late focus on prominent image areas, decreased amplitude in the eye-fixation-related potential, and decreased intertrial coherence in the SCZ group.

Conclusions

The decrease in the visual attention response evoked by the prominence of visual stimuli in patients affected by schizophrenia is generated by a reduction in endogenous attention mechanisms to initiate and maintain visual exploration. Further work is required to explain the relationship of this decrease with clinical indicators.

Distorted body representations play a major role in the onset and maintenance of Schizophrenia. However, these distortions are difficult to assess because explicit assessments can provoke intense fears about the body and require a good insight. We proposed an implicit motor imagery task to a 14-year-old girl with Early-Onset Schizophrenia. The test consisted of presenting different openings varying in width. For each aperture, the young girl has to say if she could pass through without turning her shoulders. A critical aperture is determined as the first aperture for which she considered she could no longer pass, compared to her shoulders' width. The girl perceived herself as 51 % wider than she was, indicating a significant oversized body schema. The implicit assessments of body schema generate less anxiety and does not require a great level of insight; moreover, those are promising tools for early detection of disease in prodromal phases of Schizophrenia and assistance with differential diagnosis.

Patients with schizophrenia show substantial cognitive deficits and abnormalities in neurotransmitter-related levels of mRNA in brain or peripheral blood lymphocytes. However, the relationship of cognitive deficits as measured by the MATRICS battery and mRNA levels in brain or lymphocytes has not been sufficiently explored. We measured levels of methylation or neurotransmitter-related mRNAs in lymphocytes of 38 patients with chronic schizophrenia (CSZ) and 33 non-psychotic controls (controls) by qPCR using TaqMan probes. We assessed cognitive function in these patients and controls with the MATRICS battery. We used correlation analysis and scatter plots to assess the relationship of lymphocyte mRNA levels to MATRICS domain and composite scores. CSZ subjects had a consistently negative correlation between mRNA levels in lymphocytes and MATRICS cognitive variables of speed of processing, attention-vigilance, working memory, visual learning, and overall composite score. It is uncertain whether these negative correlations represent a causative relation between specific mRNA levels and cognitive deficits. Controls had either positive correlations or non-significant correlations between mRNA and most of the MATRICS variables. There were statistically significant differences in the correlations between mRNA and MATRICS variables between CSZ vs controls for several mRNAs (DNMT1, DNMT3A, BDNF, NR3C1, FPRF3, CNTNAP2). Our data show a different relationship between mRNA levels in peripheral blood lymphocytes and MATRICS cognitive variables in CSZ vs controls. The substantive significance of these differences needs further investigation.

The aim of this study was to identify the impact of staging on a six-months transition in Ultra-High Risk (UHR) youth.

Subjects were enrolled at assessment; evolution was monitored for six months. Clinical determinants (unusual thought content, perceptual abnormalities, cognitive complaint, etc.) were collected.

37 non-psychotic and 39 UHR subjects were included. 13 UHR (35.2 %) experienced psychotic transition, while none of non-psychotic subjects did log-rank p < 0.001. Self-reported cognitive complaint was inversely associated to transition OR 0.13 95 % IC [0.03–0.64]. Unusual Thought Content was associated to psychotic transition 0R 8.57 95 % IC [1.17–63]. Self-reported cognitive complaint could be a protective transition marker in UHR.

Introduction

It is known that cognitive deficits are a core feature of schizophrenia and that in the general population, prior beliefs significantly influence learning and reasoning processes. However, the interaction of prior beliefs with cognitive deficits and their impact on performance in schizophrenia patients is still poorly understood. This study investigates the role of beliefs and cognitive variables (CVs) like working memory, associative learning, and processing speed on learning processes in individuals with schizophrenia. We hypothesize that beliefs will influence the ability to learn correct predictions and that first-episode schizophrenia patients (FEP) will show impaired learning due to cognitive deficits.

Methods

We used a predictive-learning task to examine how FEP (n = 23) and matched controls (n = 23) adjusted their decisional criteria concerning physical properties during the learning process when predicting the sinking behavior of two transparent containers filled with aluminum discs when placed in water.

Results

On accuracy, initial differences by group, trial type, and interaction effects of these variables disappeared when CVs were controlled. The differences by conditions, associated with differential beliefs about why the objects sink slower or faster, were seen in patients and controls, despite controlling the CVs' effect.

Conclusions

Differences between groups were mainly explained by CVs, proving that they play an important role than what is assumed in this type of task. However, beliefs about physical events were not affected by CVs, and beliefs affect in the same way the decisional criteria of the control or FEP patients' groups.

Background

Cognitive impairment is a widespread feature of schizophrenia, affecting nearly 80 % of patients. Prior research has linked the anticholinergic burden of psychiatric medications to these cognitive deficits. However, the impact of the anticholinergic burden from medications for physical morbidity remains underexplored. This study aimed to evaluate the anticholinergic burden of psychiatric and physical medications in patients with schizophrenia and assess its impact on cognitive function.

Methods

A total of 178 patients with schizophrenia were recruited. The assessments included an ad hoc questionnaire for collecting demographic and clinical data. Anticholinergic burden was evaluated using the cumulative Drug Burden Index (cDBI) for each participant, and cognitive function was assessed using MATRICS. Psychopathology was measured using the PANSS, CDSS, CAINS, and the CGI-S. Statistical analysis included Student's t-tests, ANOVA, Pearson correlations, and multiple linear regressions.

Results

The average cDBI was 1.3 (SD = 0.9). The model developed explained 40.80 % of the variance. The variable with the greatest weight was the cDBI (B = −11.148, p = 0.010). Negative-expression (B = -2.740, p = 0.011) and negative-experiential (B = −1.175, p = 0.030) symptoms were also associated with lower global cognitive score. However, more years of education (B = 5.140, p < 0.001) and cigarettes per day (B = 1.331, p < 0.001) predicted a better global cognitive score.

Conclusion

This study identified specific predictors of global cognition in schizophrenia, with anticholinergic burden emerging as the strongest factor. Our findings underscore the importance of considering the anticholinergic burden of treatments, in addition to negative symptoms, when designing interventions to optimize or maintain cognitive function in patients with schizophrenia.

Aberrant attentional salience has been implicated in the cannabis-psychosis association. Here, history and frequency of cannabis use were examined against changes in overshadowing (OS), a cue competition paradigm that involves salience processing. Additionally, we examined the association between OS and alternative measures of aberrant salience, as well as schizotypy, in a non-clinical adult sample.

280 participants completed an online geometry learning-based OS task, while a subset (N = 149) also completed the Salience Attribution Task (SAT) measure of aberrant salience. All completed the Schizotypal Personality Questionnaire (SPQ), Aberrant Salience Inventory (ASI), and the modified Cannabis Experience Questionnaire (CEQmv). Differences across OS and SAT performance stages and between cannabis use groups were assessed using mixed ANOVAs. Multiple regression and correlational analyses assessed the relationships between OS and SAT task metrics and SPQ and ASI subscale scores.

Current cannabis users had significantly lower OS scores during the testing phase relative to those who do not use cannabis, at medium effect sizes. Schizotypy or ASI scores did not mediate this relationship. In the SAT, current cannabis users presented significantly higher implicit aberrant salience relative to non-users. Scores in the first training phase of the OS task significantly predicted higher explicit aberrant and adaptive salience scores in the SAT.

These data indicate an association between regular cannabis use and abnormalities in cue competition effects in a healthy adult sample. Comparisons of OS and SAT cast new light on putative overlapping mechanisms underlying performance across different measures of salience.