RESUMO
The "Reading the Mind in the Eyes" Test (Eyes Test) is a widely used assessment of "theory of mind." The NIMH Research Domain Criteria recommends it as one of two tests for "understanding mental states." Previous studies have demonstrated an on-average female advantage on the Eyes Test. However, it is unknown whether this female advantage exists across the lifespan and across a large number of countries. Thus, we tested sex and age differences using the English version of the Eyes Test in adolescents and adults across 57 countries. We also tested for associations with sociodemographic and cognitive/personality factors. We leveraged one discovery dataset (N = 305,726) and three validation datasets (Ns = 642; 5,284; and 1,087). The results show that: i) there is a replicable on-average female advantage in performance on the Eyes Test; ii) performance increases through adolescence and shallowly declines across adulthood; iii) the on-average female advantage is evident across the lifespan; iv) there is a significant on-average female advantage in 36 out of 57 countries; v) there is a significant on-average female advantage on translated (non-English) versions of the Eyes Test in 12 out of 16 countries, as confirmed by a systematic review; vi) D-scores, or empathizing-systemizing, predict Eyes Test performance above and beyond sex differences; and vii) the female advantage is negatively linked to "prosperity" and "autonomy," and positively linked to "collectivism," as confirmed by exploratory country-level analyses. We conclude that the on-average female advantage on the Eyes Test is observed across ages and most countries.
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Olho , Caracteres Sexuais , Adulto , Adolescente , Humanos , Masculino , Feminino , EmpatiaRESUMO
Psychiatric disorders show high co-morbidity, including co-morbid expressions of subclinical psychopathology across multiple disease spectra. Given the limitations of classical case-control designs in elucidating this overlap, new approaches are needed to identify biological underpinnings of spectra and their interaction. We assessed autistic-like traits (using the Autism Quotient, AQ) and schizotypy - as models of subclinical expressions of disease phenotypes and examined their association with volumes and regional cerebral blood flow (rCBF) of anterior, mid- and posterior hippocampus segments from structural MRI scans in 318 and arterial spin labelling (ASL) in 346 nonclinical subjects, which overlapped with the structural imaging sample (N = 298). We demonstrate significant interactive effects of positive schizotypy and AQ social skills as well as of positive schizotypy and AQ imagination on hippocampal subfield volume variation. Moreover, we show that AQ attention switching modulated hippocampal head rCBF, while positive schizotypy by AQ attention to detail interactions modulated hippocampal tail rCBF. In addition, we show significant correlation of hippocampal volume and rCBF in both region-of-interest and voxel-wise analyses, which were robust after removal of variance related to schizotypy and autistic traits. These findings provide empirical evidence for both the modulation of hippocampal subfield structure and function through subclinical traits, and in particular how only the interaction of phenotype facets leads to significant reductions or variations in these parameters. This makes a case for considering the synergistic impact of different (subclinical) disease spectra on transdiagnostic biological parameters in psychiatry.
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Functional impairment is a core feature of both autism and schizophrenia spectrum disorders. While diagnostically independent, they can co-occur in the same individual at both the trait and diagnostic levels. The effect of such co-occurrence is hypothesized to worsen functional impairment. The diametric model, however, suggests that the disorders are etiologically and phenotypically diametrical, representing the extreme of a unidimensional continuum of cognition and behavior. A central prediction of this model is that functional impairment would be attenuated in individuals with mixed symptom expressions or genetic liability to both disorders. We tested this hypothesis in two clinical populations and one healthy population. In individuals with chronic schizophrenia and in individuals with first episode psychosis we evaluated the combined effect of autistic traits and positive psychotic symptoms on psychosocial functioning. In healthy carriers of alleles of copy number variants (CNVs) that confer risk for both autism and schizophrenia, we also evaluated whether variation in psychosocial functioning depended on the combined risk conferred by each CNV. Relative to individuals with biased symptom/CNV risk profiles, results show that functional impairments are attenuated in individuals with relatively equal levels of positive symptoms and autistic traits-and specifically stereotypic behaviors-, and in carriers of CNVs with relatively equal risks for either disorder. However, the pattern of effects along the "balance axis" varied across the groups, with this attenuation being generally less pronounced in individuals with high-high symptom/risk profile in the schizophrenia and CNV groups, and relatively similar for low-low and high-high individuals in the first episode psychosis group. Lower levels of functional impairments in individuals with "balanced" symptom profile or genetic risks would suggest compensation across mechanisms associated with autism and schizophrenia. CNVs that confer equal risks for both disorders may provide an entry point for investigations into such compensatory mechanisms. The co-assessment of autism and schizophrenia may contribute to personalized prognosis and stratification strategies.
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Transtorno do Espectro Autista , Transtorno Autístico , Transtornos Psicóticos , Esquizofrenia , Transtorno do Espectro Autista/complicações , Transtorno do Espectro Autista/genética , Transtorno Autístico/complicações , Variações do Número de Cópias de DNA , Humanos , Funcionamento Psicossocial , Transtornos Psicóticos/genéticaRESUMO
BACKGROUND: Autism spectrum disorder (ASD) and schizotypal disorder (SD) both have a heterogenous presentation, with significant overlaps in symptoms and behaviour. Due to elevated recognition and knowledge of ASD worldwide, there is a growing rate of referrals from primary health professionals to specialised units. At all levels of assessment, the differential diagnostic considerations between ASD and SD exert major challenges for clinicians. Although several validated screening questionnaires exist for ASD and SD, none have differential diagnostic properties. Accordingly, in this study, we aim to develop a new screening questionnaire, the schiZotypy Autism Questionnaire (ZAQ), which provides a combined screening for both conditions, while also indicating the relative likelihood of each. METHODS: We aim to test 200 autistic patients and 100 schizotypy patients recruited from specialised psychiatric clinics and 200 controls from the general population (Phase 1). The results from ZAQ will be compared to the clinical diagnoses from interdisciplinary teams at specialised psychiatric clinics. After this initial testing phase, the ZAQ will be validated in an independent sample (Phase 2). CONCLUSIONS: The aim of the study is to investigate the discriminative properties (ASD vs. SD), diagnostic accuracy, and validity of the schiZotypy Autism Questionnaire (ZAQ). FUNDING: Funding was provided by Psychiatric Centre Glostrup, Copenhagen Denmark, Sofiefonden (Grant number: FID4107425), Trygfonden (Grant number:153588), Takeda Pharma. TRIAL REGISTRATION: Clinical Trials, NCT05213286, Registered 28 January 2022, clinicaltrials.gov/ct2/show/NCT05213286?cond = RAADS&draw = 2&rank = 1.
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Transtorno do Espectro Autista , Transtorno Autístico , Transtorno da Personalidade Esquizotípica , Humanos , Adulto , Transtorno do Espectro Autista/diagnóstico , Transtorno do Espectro Autista/epidemiologia , Transtorno Autístico/diagnóstico , Transtorno da Personalidade Esquizotípica/diagnóstico , Transtorno da Personalidade Esquizotípica/psicologia , Inquéritos e QuestionáriosRESUMO
OBJECTIVES: Functional disruption is a main feature of schizophrenia and still represents a major treatment challenge. A more in-depth identification of functional predictors is crucial for the creation of individualized rehabilitation treatments, which can translate into better functional outcomes. In this study, we aimed at pinpointing specific domains that affect different functional profiles, using a data-driven approach. METHODS: We included a comprehensive evaluation of functional predictors, namely demographic, cognitive, sociocognitive and clinical variables, with a focus on constituent subdomains of autistic symptoms that have been associated with functioning in the recent literature. RESULTS: In 123 schizophrenia patients, a two-step cluster analysis identified two groups of patients with different functional profiles (low vs high functioning). A backward stepwise logistic regression analysis showed that the odds of being a member of the high functioning group are significantly higher for individuals with (1) more years of education, (2) better Theory of Mind abilities, (3) higher levels of stereotypies/narrowed interests, (4) lower difficulties in social interaction, (5) lower communication difficulties and with (6) being male. CONCLUSION: Findings raise the intriguing possibility that stereotypic behaviors may have a beneficial effect on functioning in schizophrenia. While the underlying mechanism is currently unknown, we hypothesize that patients may benefit from contexts in which more predictive relationships between environmental entities can systematically be established. This study underscores the potential utility of routinely assessing autistic symptomatology in schizophrenia, which can be instrumental in identifying novel therapeutic targets that can be utilized to improve daily functioning.
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Esquizofrenia , Teoria da Mente , Feminino , Humanos , Masculino , Esquizofrenia/terapia , Psicologia do EsquizofrênicoRESUMO
BACKGROUND: There is increasing interest in the clinical and aetiological overlap between autism spectrum disorders and schizophrenia spectrum disorders, reported to co-occur at both diagnostic and trait levels. Individually, sub-clinical autistic and psychotic traits are associated with poor clinical outcomes, including increased depressive symptomatology, self-harming behaviour and suicidality. However, the implications when both traits co-occur remain poorly understood. The study aimed to (1) examine the relationship between autistic and psychotic traits and (2) determine if their co-occurrence increases depressive symptomatology, self-harm and suicidality. METHODS: Cross-sectional data from a self-selecting (online and poster advertising) sample of the adult UK population (n = 653) were collected using an online survey. Validated self-report measures were used to assess sub-clinical autistic and psychotic traits, depressive symptomatology, self-harming behaviour and suicidality. Correlation and regression analyses were performed. RESULTS: A positive correlation between sub-clinical autistic and positive psychotic traits was confirmed (rs = 0.509, p < 0.001). Overall, autistic traits and psychotic traits were, independently, significant predictors of depression, self-harm and suicidality. Intriguingly, however, depression was associated with a negative interaction between the autistic domain attention to detail and psychotic traits. CONCLUSIONS: This study supports previous findings that sub-clinical autistic and psychotic traits are largely independently associated with depression, self-harm and suicidality, and is novel in finding that their combined presence has no additional effect on depression, self-harm or suicidality. These findings highlight the importance of considering both autistic and psychotic traits and their symptom domains in research and when developing population-based depression prevention and intervention strategies.
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Transtorno Autístico , Comportamento Autodestrutivo , Suicídio , Adulto , Humanos , Transtorno Autístico/epidemiologia , Depressão/epidemiologia , Depressão/diagnóstico , Estudos Transversais , Comportamento Autodestrutivo/epidemiologiaRESUMO
'Hyperfocus' is a phenomenon that reflects one's complete absorption in a task, to a point where a person appears to completely ignore or 'tune out' everything else. Hyperfocus is most often mentioned in the context of autism, schizophrenia, and attention deficit hyperactivity disorder, but research into its effect on cognitive and neural functioning is limited. We propose that hyperfocus is a critically important aspect of cognition, particularly with regard to clinical populations, and that it warrants significant investigation. Hyperfocus, though ostensibly self-explanatory, is poorly defined within the literature. In many cases, hyperfocus goes undefined, relying on the assumption that the reader inherently knows what it entails. Thus, there is no single consensus to what constitutes hyperfocus. Moreover, some studies do not refer to hyperfocus by name, but describe processes that may be related. In this paper, we review how hyperfocus (as well as possibly related phenomena) has been defined and measured, the challenges associated with hyperfocus research, and assess how hyperfocus affects both neurotypical and clinical populations. Using this foundation, we provide constructive criticism about previously used methods and analyses. We also propose an operational definition of hyperfocus for researchers to use moving forward.
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Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Atenção/fisiologia , Viés de Atenção/fisiologia , Transtorno Autístico/fisiopatologia , Pesquisa Biomédica/estatística & dados numéricos , Cognição/fisiologia , Esquizofrenia/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Psychopathic tendencies are associated with difficulties in affective theory of mind (ToM), that is, in recognizing others affective mental states. In clinical and non-clinical adult samples, it has been shown that where psychopathic tendencies co-occur with schizophrenia spectrum disorders, the impairing effects of psychopathic tendencies on ToM are attenuated. These effects are yet to be examined in adolescents. We examined if the impairing effect of psychopathic tendencies on affective ToM was attenuated with increasing severity of schizotypal personality disorder (PD) in a sample of 80 incarcerated adolescent boys. We showed that the impairing effect of psychopathic tendencies on the recognition of neutral mental states, but not positive or negative mental states, was evident when the relative severity of schizotypal PD was low. However, with higher scores on both measures, we observed better performance in judging neutral mental states. The preservation of affective ToM in adolescents who show elevations in psychopathic tendencies and schizotypal PD may enable them to manipulate and extort their victims for personal gain. Our results emphasize the need to consider comorbidity in clinical case formulation when working with adolescents with conduct problems and psychopathic tendencies. More broadly, our results also suggest that the pattern of social cognitive abilities associated with co-occurring psychopathology does not always conform to an often-theorized double-dose of deficit hypothesis.
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Afeto/fisiologia , Transtorno da Conduta/psicologia , Psicopatologia/métodos , Transtorno da Personalidade Esquizotípica/psicologia , Adolescente , Humanos , MasculinoRESUMO
The commonly used paradigm to investigate Dennet's 'intentional stance' compares neural activation when participants compete with a human versus a computer. This paradigm confounds whether the opponent is natural or artificial and whether it is intentional or an automaton. This functional magnetic resonance imaging study is, to our knowledge, the first to investigate the intentional stance by orthogonally varying perceptions of the opponents' intentionality (responding actively or passively according to a script) and embodiment (human or a computer). The mere perception of the opponent (whether human or computer) as intentional activated the mentalizing network: the temporoparietal junction (TPJ) bilaterally, right temporal pole, anterior paracingulate cortex (aPCC) and the precuneus. Interacting with humans versus computers induced activations in a more circumscribed right lateralized subnetwork within the mentalizing network, consisting of the TPJ and the aPCC, possibly reflective of the tendency to spontaneously attribute intentionality to humans. The interaction between intentionality (active versus passive) and opponent (human versus computer) recruited the left frontal pole, possibly in response to violations of the default intentional stance towards humans and computers. Employing an orthogonal design is important to adequately capture Dennett's conception of the intentional stance as a mentalizing strategy that can apply equally well to humans and other intentional agents.
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Teoria da Mente , Mapeamento Encefálico/métodos , Computadores , Humanos , Imageamento por Ressonância Magnética , Lobo Parietal , Lobo TemporalRESUMO
Many of us "see red," "feel blue," or "turn green with envy." Are such color-emotion associations fundamental to our shared cognitive architecture, or are they cultural creations learned through our languages and traditions? To answer these questions, we tested emotional associations of colors in 4,598 participants from 30 nations speaking 22 native languages. Participants associated 20 emotion concepts with 12 color terms. Pattern-similarity analyses revealed universal color-emotion associations (average similarity coefficient r = .88). However, local differences were also apparent. A machine-learning algorithm revealed that nation predicted color-emotion associations above and beyond those observed universally. Similarity was greater when nations were linguistically or geographically close. This study highlights robust universal color-emotion associations, further modulated by linguistic and geographic factors. These results pose further theoretical and empirical questions about the affective properties of color and may inform practice in applied domains, such as well-being and design.
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Emoções , Idioma , Cor , Percepção de Cores , Humanos , Ciúme , Linguística , Aprendizado de MáquinaRESUMO
Currently, there is an intense pursuit of pathognomonic markers and diagnostic ('risk-based') classifiers of psychiatric conditions. Commonly, the epidemiological prevalence of the condition is not factored into the development of these classifiers. By not adjusting for prevalence, classifiers overestimate the potential of their clinical utility. As valid predictive values have critical implications in public health and allocation of resources, development of clinical classifiers should account for the prevalence of psychiatric conditions in both general and high-risk populations. We suggest that classifiers are most likely to be useful when targeting enriched populations.
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Biomarcadores , Transtornos Mentais/diagnóstico , Transtorno do Espectro Autista/diagnóstico , Transtorno do Espectro Autista/epidemiologia , Testes Genéticos , Humanos , Transtornos Mentais/epidemiologia , População , Prevalência , Medição de Risco , Fatores de RiscoRESUMO
OBJECTIVE: While diagnostically independent, autism and schizotypal disorders can co-occur. Their concurrent impact on outcomes and phenotypes has not been investigated. We investigated the impact of comorbid autism and schizotypal disorders in children on executive functioning and socio-pragmatic skills - core features of both disorders. METHOD: Executive functioning (assessed with the Cambridge Neuropsychological Test Automated Battery) and socio-pragmatic skills (assessed using the Melbourne Assessment of Schizotypy in Kids) were investigated in a total of 67 (6-12 year old) children with autism ( n = 15; M/F = 10/5), schizotypal disorder ( n = 8; M/F = 5/3) and comorbid autism and schizotypal disorder ( n = 12; M/F = 5/7) and typically developing children ( n = 32; M/F = 17/15). RESULTS: Both the autism and schizotypal disorder groups performed more poorly than the typically developing group on socio-pragmatic skills and overall performance (i.e. number of stages completed) of the intra-/extra-dimensional set-shifting task (all ps < 0.001). Clear distinctions between the autism and schizotypal groups were present in the intra-/extra-dimensional task relative to the typically developing group - the autism group had difficulties with extra-dimensional shifts ( p < 0.001), and the schizotypal disorder group with intra-dimensional shifts ( p = 0.08). Interestingly, the overall performance of the comorbid group on the intra-/extra-dimensional task was not significantly different from the typically developing group, and they were superior to both the autism ( p = 0.019) and schizotypal disorder ( p = 0.042) groups on socio-pragmatic skills. CONCLUSION: The phenotypical overlap between autism and schizotypal disorders may be precipitated by different cognitive styles and/or mechanisms associated with attention and information processing. We propose that sustaining and switching attention represent two poles of irregularities across the autism and schizotypal spectra, which appear to converge in a compensatory manner in the comorbid group. Our findings highlight the importance of investigating children with a dual diagnosis of autism and schizotypal disorders, and raise intriguing questions about possible mechanisms to explain the attenuated impairment observed in the group of children with comorbid autism and schizotpyal disorders.
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Atenção/fisiologia , Transtorno do Espectro Autista/fisiopatologia , Função Executiva/fisiologia , Desempenho Psicomotor/fisiologia , Transtorno da Personalidade Esquizotípica/fisiopatologia , Habilidades Sociais , Transtorno do Espectro Autista/epidemiologia , Criança , Comorbidade , Feminino , Humanos , Masculino , Transtorno da Personalidade Esquizotípica/epidemiologiaRESUMO
Adolescent psychopathic tendencies are associated with phenotypic increases in proactive aggression. However, the extent to which an understanding of others' affective mental states, or affective theory of mind (ToM), contributes to proactive aggression remains unknown. We examined how performance on a well-known test of affective ToM, based on cropped images of the eye region, contributes to reactive and proactive types of aggression in a mixed ethnicity sample of 80 incarcerated adolescent boys. A hierarchical regression model showed that affective ToM predicted proactive aggression over and above the influence of clinically rated psychopathic tendencies. Importantly, affective ToM was unrelated to reactive aggression. Our results suggest that being able to recognize others' affective mental states may be an important factor in aggressing against others for personal gain. These findings have implications for interventions designed to enhance ToM in youth with conduct problems.
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Agressão/psicologia , Transtorno da Personalidade Antissocial/psicologia , Transtorno da Conduta/psicologia , Emoções/fisiologia , Comportamento Problema/psicologia , Teoria da Mente , Adolescente , Humanos , MasculinoRESUMO
Difficulties with the ability to appreciate the perspective of others (mentalizing) is central to both autism and schizophrenia spectrum disorders. While the disorders are diagnostically independent, they can co-occur in the same individual. The effect of such co-morbidity is hypothesized to worsen mentalizing abilities. The recent influential 'diametric brain theory', however, suggests that the disorders are etiologically and phenotypically diametrical, predicting opposing effects on one's mentalizing abilities. To test these contrasting hypotheses, we evaluated the effect of psychosis and autism tendencies on the perspective-taking (PT) abilities of 201 neurotypical adults, on the assumption that autism tendencies and psychosis proneness are heritable dimensions of normal variation. We show that while both autism tendencies and psychosis proneness induce PT errors, their interaction reduced these errors. Our study is, to our knowledge, the first to observe that co-occurring autistic and psychotic traits can exert opposing influences on performance, producing a normalizing effect possibly by way of their diametrical effects on socio-cognitive abilities. This advances the notion that some individuals may, to some extent, be buffered against developing either illness or present fewer symptoms owing to a balanced expression of autistic and psychosis liability.
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Transtorno Autístico/psicologia , Transtornos Psicóticos/psicologia , Teoria da Mente , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
Convincing evidence demonstrates that psychopathy is associated with premeditated aggression. However, studies have failed to explain why this association exists and whether socio-cognitive functions, such as mentalizing, could explain the relation. This cross-sectional study investigates, in 108 patients with schizophrenia, the association of psychopathy and mentalizing abilities with premeditated and impulsive aggression and probes the nature of their influence on these specific aggression patterns. Patients' engagement in premeditated aggression was associated with diminishing mentalizing and increasing psychopathic tendencies. Moreover, mediation analyses reveal that the ability to attribute mental states to others mediates the relation between psychopathy and type of aggression. This mediation is facilitated by a specific mentalizing profile characterized by the presence of intact cognitive and deficient emotional mentalizing capacities. This study is the first to report a mediating effect of mentalizing on the relationship between psychopathy and type of aggression in schizophrenia. Implications of these results are discussed.
Assuntos
Agressão/psicologia , Transtorno da Personalidade Antissocial/diagnóstico , Transtorno da Personalidade Antissocial/psicologia , Esquizofrenia/diagnóstico , Psicologia do Esquizofrênico , Teoria da Mente , Adulto , Afeto , Cognição , Estudos Transversais , Emoções , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Índice de Gravidade de Doença , Reino Unido , Escalas de WechslerRESUMO
Autistic individuals can experience difficulties with attention reorienting and Theory of Mind (ToM), which are closely associated with anterior and posterior subdivisions of the right temporoparietal junction. While the link between these processes remains unclear, it is likely subserved by a dynamic crosstalk between these two subdivisions. We, therefore, examined the dynamic functional connectivity (dFC) between the anterior and posterior temporoparietal junction, as a biological marker of attention and ToM, to test its contribution to the manifestation of autistic trait expression in Autism Spectrum Condition (ASC). Two studies were conducted, exploratory (14 ASC, 15 TD) and replication (29 ASC, 29 TD), using resting-state fMRI data and the Social Responsiveness Scale (SRS) from the Autism Brain Imaging Data Exchange repository. Dynamic Independent Component Analysis was performed in both datasets using the CONN toolbox. An additional sliding-window analysis was performed in the replication study to explore different connectivity states (from highly negatively to highly positively correlated). Dynamic FC was reduced in ASC compared to TD adults in both the exploratory and replication datasets and was associated with increased SRS scores (especially in ASC). Regression analyses revealed that decreased SRS autistic expression was predicted by engagement of highly negatively correlated states, while engagement of highly positively correlated states predicted increased expression. These findings provided consistent evidence that the difficulties observed in ASC are associated with altered patterns of dFC between brain regions subserving attention reorienting and ToM processes and may serve as a biomarker of autistic trait expression.
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Transtorno do Espectro Autista , Transtorno Autístico , Adulto , Humanos , Masculino , Transtorno Autístico/diagnóstico por imagem , Mapeamento Encefálico , Transtorno do Espectro Autista/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodosRESUMO
Our ability to identify an object is often impaired by the presence of preceding and/or succeeding task-irrelevant items. Understanding this temporal interference is critical for any theoretical account of interference across time and for minimizing its detrimental effects. Therefore, we used the same sequences of 3 orientation items, orientation estimation task, and computational models, to examine temporal interference over both short (<150 ms; visual masking) and long (175-475 ms; temporal crowding) intervals. We further examined how inter-item similarity modifies these different instances of temporal interference. Qualitatively different results emerged for interference of different scales. Interference over long intervals mainly degraded the precision of the target encoding while interference over short intervals mainly affected the signal-to-noise ratio. Although both interference instances modulated substitution errors (reporting a wrong item) and were alleviated with dissimilar items, their characteristics were markedly disparate. These findings suggest that different mechanisms mediate temporal interference of different scales.
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BACKGROUND: Personality pathology affects behavioral patterns in patients with schizophrenia notwithstanding psychotic symptomatology. An investigation of the role of co-morbid personality pathology in the occurrence of aggression in schizophrenia is explored using both categorical and dimensional approaches to personality pathology. METHODS: In a cross-sectional study we evaluate, in 97 patients diagnosed with schizophrenia, the effect of personality pathology on the occurrence of aggression in schizophrenia using both a categorical approach, as described in DSM-IV-TR Axis II, and a dimensional approach, as operationalized in the Dimensional Assessment of Personality Pathology-Basic Questionnaire (DAPP-BQ). We also employ mediation analyses to explore the extent to which dimensions within the DAPP mediate the relationship between co-morbid personality disorders and aggression. RESULTS: Personality pathology accounts for aggression in schizophrenia. Both the categorical and the dimensional approaches equally well account for the occurrence of aggression, with each model accounting for 60% of the variance. Interestingly, the mediation analysis reveals that the association between categorically defined personality pathology and aggression is substantially mediated by the higher-order-trait dissocial behavior of the DAPP-BQ, accounting for 50.6 % of the total effect size. CONCLUSION: Personality pathology can be a significant predictor of aggression in patients with schizophrenia. While both the categorical and the dimensional trait models of personality disorders equally explain the aggression data, much of the relationship between the categorically defined personality disorders and the occurrence of aggression in schizophrenia can be explained by the presence of dissocial behavior as operationalized in the DAPP-BQ dimensional model.