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Hallucinatory experiences can occur in both clinical and nonclinical groups. However, in previous studies of the general population, investigations of the cognitive mechanisms underlying hallucinatory experiences have yielded inconsistent results. We ran a large-scale preregistered multisite study, in which general-population participants (N = 1,394 across 11 data-collection sites and online) completed assessments of hallucinatory experiences, a measure of adverse childhood experiences, and four tasks: source memory, dichotic listening, backward digit span, and auditory signal detection. We found that hallucinatory experiences were associated with a higher false-alarm rate on the signal detection task and a greater number of reported adverse childhood experiences but not with any of the other cognitive measures employed. These findings are an important step in improving reproducibility in hallucinations research and suggest that the replicability of some findings regarding cognition in clinical samples needs to be investigated.
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Cognición , Alucinaciones , Percepción Auditiva , Humanos , Reproducibilidad de los ResultadosRESUMEN
In this study, we use separate eye-tracking measurements and functional magnetic resonance imaging to investigate the neuronal and behavioral response to painted portraits with direct versus averted gaze. We further explored modulatory effects of several painting characteristics (premodern vs modern period, influence of style and pictorial context). In the fMRI experiment, we show that the direct versus averted gaze elicited increased activation in lingual and inferior occipital and the fusiform face area, as well as in several areas involved in attentional and social cognitive processes, especially the theory of mind: angular gyrus/temporo-parietal junction, inferior frontal gyrus and dorsolateral prefrontal cortex. The additional eye-tracking experiment showed that participants spent more time viewing the portrait's eyes and mouth when the portrait's gaze was directed towards the observer. These results suggest that static and, in some cases, highly stylized depictions of human beings in artistic portraits elicit brain activation commensurate with the experience of being observed by a watchful intelligent being. They thus involve observers in implicit inferences of the painted subject's mental states and emotions. We further confirm the substantial influence of representational medium on brain activity.
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Atención/fisiología , Encéfalo/diagnóstico por imagen , Movimientos Oculares/fisiología , Fijación Ocular/fisiología , Pinturas , Percepción Social , Adulto , Encéfalo/fisiología , Mapeo Encefálico , Emociones/fisiología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
BACKGROUND: Visual word recognition is one of the central topics in cognitive psychology and cognitive neuroscience. Genetic factors are known to contribute to the visual word recognition, but no genes associated with this process have been identified so far. We studied the impact of the DRD2 C957T polymorphism on the efficiency of visual word recognition by measuring its neuronal correlates and behavioral parameters. Early (~200 ms) components of event-related potentials (ERP) were recorded during a lexical decision task. The DRD2 C957T polymorphism is thought to be associated with D2 receptor's availability and binding potential. Earlier studies have demonstrated the influence of this variation on perception and processing of verbal stimuli. The DRD2 C957T is also associated with schizophrenia, with the C allele being the risk allele. METHODS: Electroencephalogram, genetic, and behavioral data were collected from 96 healthy individuals (53.1% men). ERPs were recorded for words and pseudowords in implicit and explicit tasks. Two regions of interests in the left ventral temporal cortex, whose role in early visual word processing is well established, were selected for analysis. RESULTS: The results showed the main effect of the DRD2 C957T polymorphism on P200 amplitude. Carriers of the TT genotype had higher P200 amplitudes compared to subjects with schizophrenia risk C allele. Within-group comparisons demonstrated a better ability to adjust attention to orthographic stimuli depending on task demands and lexicality in the TT group. CONCLUSION: The results of the study suggest that the DRD2 C957T polymorphism modulates early stages of visual word recognition.
RESUMEN
Cognitive dysfunction is a common characteristic across a number of psychiatric conditions. With growing technological advances, application based cognitive remediation (cognitive apps) is becoming steadily popular due to its accessibility, ease of use and minimal interference with the activities of daily life. However, despite a number of benefits that application based cognitive training possesses, it is not clear, whether the utilisation of these apps is a reliable approach that can be recommended in clinical psychiatric practice in order to restore cognition. In the present review, we have analysed eleven applications which trained the cognitive domains of memory, attention, language, processing speed, executive function and perception with respect to the structure and function of the applications, duration of use and measuring and monitoring of user progress and assessed them, based on the published data, for efficacy in the general population and clinical subgroups of the population. We conclude that, given that there are differences between the apps, given that there is a difference between the general population using these apps and groups suffering pathological conditions using them, given that cognitive deficits are caused by different pathological processes in different illnesses and that different illnesses present with different ranges of deficits, it is not possible to make blanket recommendations for the use of the apps. Nor is there sufficient published evidence for any of the apps to be specifically recommended for cognitive remediation. More evidence, such as trials of specific apps in different conditions, trials of specific apps against therapist guided techniques and blind trials of different apps against each other are necessary before recommendations of particular apps for particular remedial treatments can be made. Nor can 'brain training' in normal populations be seen as preventing cognitive decline or be seen as proof that cognitive remediation can improve cognition in pathological groups. Our paper serves as a useful reference to what apps are available, how they compare, and what the published evidence is, with a view to planning further research.
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Trastornos del Conocimiento , Remediación Cognitiva , Cognición , Trastornos del Conocimiento/terapia , Humanos , MemoriaRESUMEN
The research is based on comparative analysis of 'Hinting Task', 'Faux Pas', and 'Reading the Mind in the Eyes' tests sensitivity in detection of Theory of Mind deficits. The study included 20 subjects with schizophrenia and schizophrenia spectrum disorders with the first episode of psychosis. Every subject performed the three proposed tests. It was shown that success rate of the three tests differed significantly. The non-verbal test 'Reading the Mind in the Eyes' caused the most difficulties. The success rate percentage of this test performance correlated negatively with the severity of psychopathological symptoms evaluated according to the PANSS scale. Thus, 'Reading the Mind in the Eyes' test is the most sensitive out of the three to Theory of Mind deficits detection, which may be used for diagnostic purposes.
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Trastornos del Conocimiento , Trastornos Psicóticos , Esquizofrenia , Teoría de la Mente , Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/terapia , Humanos , Pruebas Neuropsicológicas , Trastornos Psicóticos/diagnóstico , Esquizofrenia/diagnósticoRESUMEN
The recovery model of schizophrenia is central to the devlopment of community services for patients with schizophrenia. However often when applying the recovery model of psychosis, often formal identification of cognitive imparements is not carried out, nor are interventions to improve cognitive functioning offered in a targeted way. Here we discuss how these issues relate to each other and argue for the use of cognitive testing in order to elp recovery in schizophrenia.
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Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/terapia , Trastornos Psicóticos/psicología , Trastornos Psicóticos/terapia , Esquizofrenia/terapia , Psicología del Esquizofrénico , Trastornos del Conocimiento/psicología , Terapia Combinada , Humanos , Modelos Psicológicos , Pruebas NeuropsicológicasRESUMEN
It has been repeatedly shown that schizophrenia patients have immense alterations in goal-directed behaviour, social cognition, and social interactions, cognitive abilities that are presumably driven by the mirror neurons system (MNS). However, the neural bases of these deficits still remain unclear. Along with the task-related fMRI and EEG research tapping into the mirror neuron system, the characteristics of the resting state activity in the particular areas that encompass mirror neurons might be of interest as they obviously determine the baseline of the neuronal activity. Using resting state fMRI, we investigated resting state functional connectivity (FC) in four predefined brain structures, ROIs (inferior frontal gyrus, superior parietal lobule, premotor cortex and superior temporal gyrus), known for their mirror neurons activity, in 12 patients with first psychotic episode and 12 matched healthy individuals. As a specific hypothesis, based on the knowledge of the anatomical inputs of thalamus to all preselected ROIs, we have investigated the FC between thalamus and the ROIs. Of all ROIs included, seed-to-voxel connectivity analysis revealed significantly decreased FC only in left posterior superior temporal gyrus (STG) and the areas in visual cortex and cerebellum in patients as compared to controls. Using ROI-to-ROI analysis (thalamus and selected ROIs), we have found an increased FC of STG and bilateral thalamus whereas the FC of these areas was decreased in controls. Our results suggest that: (1) schizophrenia patients exhibit FC of STG which corresponds to the previously reported changes of superior temporal gyrus in schizophrenia and might contribute to the disturbances of specific functions, such as emotional processing or spatial awareness; (2) as the thalamus plays a pivotal role in the sensory gating, providing the filtering of the redundant stimulation, the observed hyperconnectivity between the thalami and the STGs in patients with schizophrenia might explain the sequential overload with sensory inputs that leads to the abnormal cognitive processing.
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Mapeo Encefálico , Encéfalo/fisiopatología , Imagen por Resonancia Magnética/métodos , Neuronas Espejo/fisiología , Vías Nerviosas/fisiopatología , Esquizofrenia/fisiopatología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Lóbulo Temporal/fisiopatología , Adulto JovenRESUMEN
Understanding the mechanisms involved in perception and conception of oneself is a fundamental psychological topic with high relevance for psychiatric and neurological issues, and it is one of the great challenges in neuroscientific research. The paradigmatic single-case study presented here aimed to investigate different components of self- and other-processes and to elucidate corresponding neurobiological underpinnings. An eminent professional opera singer with profound performance experience has undergone functional magnetic resonance imaging and was exposed to excerpts of Mozart arias, sung by herself or another singer. The results indicate a distinction between self- and other conditions in cortical midline structures, differentially involved in self-related and self-referential processing. This lends further support to the assumption of cortical midline structures being involved in the neural processing of self-specific stimuli and also confirms the power of single case studies as a research tool.
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Encéfalo/fisiología , Autoimagen , Anciano , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética , CantoRESUMEN
OBJECTIVE: Alpha activity in the electroencephalogram (EEG) is typically dominant during rest with closed eyes but suppressed by visual stimulation. Previous research has shown that alpha-blockade is less pronounced in schizophrenia patients compared to healthy individuals, but no studies have examined it in schizoaffective disorder. METHODS: A resting state EEG was used for the analysis of the alpha-reactivity between the eyes closed and the eyes opened conditions in overall (8 - 13 Hz), low (8 - 10 Hz) and high (10 - 13 Hz) alpha bands in three groups: schizophrenia patients (SC, n = 30), schizoaffective disorder (SA, n = 30), and healthy controls (HC, n = 36). All patients had their first psychotic episode and were receiving antipsychotic therapy. RESULTS: A significant decrease in alpha power was noted across all subjects from the eyes-closed to eyes-open condition, spanning all regions. Alpha reactivity over the posterior regions was lower in SC compared to HC within overall and high alpha. SA showed a trend towards reduced alpha reactivity compared to HC, especially evident over the left posterior region within the overall alpha. Alpha reactivity was more pronounced over the middle and right posterior regions of SA as compared to SC, particularly in the high alpha. Alpha reactivity in SC and SA patients was associated with various negative symptoms. CONCLUSIONS: Our findings imply distinct alterations in arousal mechanisms in SC and SA and their relation to negative symptomatology. Arousal is more preserved in SA. SIGNIFICANCE: This study is the first to compare the EEG features of arousal in SC and SA.
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Ritmo alfa , Electroencefalografía , Trastornos Psicóticos , Esquizofrenia , Humanos , Esquizofrenia/fisiopatología , Esquizofrenia/diagnóstico , Trastornos Psicóticos/fisiopatología , Trastornos Psicóticos/diagnóstico , Masculino , Femenino , Adulto , Ritmo alfa/fisiología , Electroencefalografía/métodos , Persona de Mediana Edad , Adulto Joven , Ojo/fisiopatologíaRESUMEN
BACKGROUND: Psychotic-like experiences (PLEs) are subtle, subclinical perturbations of perceptions and thoughts and are common in the general population. Their characterisation and unidimensionality are still debated. METHODS: This study was conducted by the Electronic-halluCinations-Like Experiences Cross-culTural International Consortium (E-CLECTIC) and aimed at measuring the Community Assessment of Psychic Experiences (CAPE) factorial structure across five European countries (Belgium; Czech Republic, Germany; Greece, and Spain) and testing the adequacy of the unidimensional polytomous Rasch model of the tool via Partial Credit Model (PCM) of the CAPE to detect people with a high risk for developing psychosis. RESULTS: The sample included 1461 participants from the general population. The factorial analysis confirmed the best fit for the bifactor implementation of the three-factor model, including the positive, negative and depressive dimensions and a general factor. Moreover, the unidimensional polytomous Rasch analysis confirmed that CAPE responses reflected one underlying psychosis proneness. CONCLUSIONS: The study proved that the CAPE measures a single latent dimension of psychosis-proneness. The CAPE might help locate and estimate psychosis risk and can be used as a screening tool in primary care settings/education settings.
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Psicometría , Trastornos Psicóticos , Humanos , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/psicología , Masculino , Femenino , Psicometría/normas , Adulto , Adulto Joven , Persona de Mediana Edad , Comparación Transcultural , Alemania , Europa (Continente) , Grecia , Bélgica , República Checa , España , Escalas de Valoración Psiquiátrica/normas , Alucinaciones/diagnóstico , Adolescente , Análisis FactorialRESUMEN
BACKGROUND: Low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) diminishes auditory hallucinations (AHs). The aims of our study were a) to assess the efficacy of LF-rTMS in a randomized, sham-controlled double-blind alignment, b) to identify the electrophysiological changes accompanying the LF-rTMS, and c) to identify the influence of LF-rTMS on brain functional connectivity (FC). METHODS: Nineteen schizophrenia patients with antipsychotic-resistant AHs were randomized to either active (n = 10) or sham (n = 9) LF-rTMS administered over the left temporo-parietal region for ten days. The clinical effect was assessed by the Auditory Hallucination Rating Scale (AHRS). The localization of the differences in electrical activity was identified by standardized low resolution brain electromagnetic tomography (sLORETA) and FC was measured by lagged phase synchronization. RESULTS: AHRS scores were significantly improved for patients receiving active rTMS compared to the sham (median reduction: 40 % vs 12 %; p = 0.01). sLORETA revealed a decrease of alpha-2, beta-1,-2 bands in the left hemisphere in the active group. Active rTMS led to a decrease of the lagged phase connectivity in beta bands originating in areas close to the site of stimulation, and to a prevailing increase of alpha-2 FC. No significant differences in current density or FC were observed in the sham group. LIMITATIONS: Limitations to our study included the small group sizes, and the disability of LORETA to assess subcortical neuronal activity. CONCLUSIONS: LF-rTMS attenuated AHs and induced a decrease of higher frequency bands on the left hemisphere. The FC changes support the assumption that LF-rTMS is linked to the modulation of cortico-cortical coupling.
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Esquizofrenia , Humanos , Electroencefalografía , Alucinaciones/terapia , Estimulación Magnética Transcraneal/métodos , Resultado del TratamientoRESUMEN
Recovery encompasses symptom remission and functional elements such as cognition, social functioning and quality of life. Personal recovery is also important in illness management to help the person stay on track with treatment and focus on activities unrelated to taking medication that maintain mental health. In the present study we aimed to identify neurocognitive functioning in two clinically stable groups of patients with personal recovery and non-recovered patients. The results showered generalized cognitive deficits in both groups while the non-recovery group was more impaired in verbal and visual memory, acoustic and tactile gnosis and neurodynamics and executing functioning. Interestingly the recovery group demonstrated lack of programming of actions and sufficient error monitoring and self-correction whereas the non-recovery group was significantly more impaired in all executive domains. The obtained results could be beneficial in identifying a target for psychosocial treatments and specifically cognitive remediation for patients with schizophrenia to facilitate the process of recovery.
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Antipsicóticos/uso terapéutico , Trastornos del Conocimiento/tratamiento farmacológico , Batería Neuropsicológica de Luria-Nebraska/estadística & datos numéricos , Trastornos Psicóticos/tratamiento farmacológico , Risperidona/uso terapéutico , Esquizofrenia/tratamiento farmacológico , Psicología del Esquizofrénico , Adulto , Nivel de Alerta/efectos de los fármacos , Atención/efectos de los fármacos , Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/psicología , Función Ejecutiva/efectos de los fármacos , Femenino , Humanos , Masculino , Solución de Problemas/efectos de los fármacos , Escalas de Valoración Psiquiátrica/estadística & datos numéricos , Psicometría , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/psicología , Esquizofrenia/diagnósticoRESUMEN
Faces and their aesthetic appreciation are a core element of social interaction. Although studies have been made on facial processing when looking at faces with different perspectives, a direct comparison of faces in the left to the right perspective is missing. Portraits in classical Western art indicate a preference of the left compared to the right perspective, but the neural underpinnings of such an asymmetry still have to be clarified. Using functional magnetic resonance imaging, the current study focuses on the processing of three-quarter faces seen with different perspectives. Seventeen participants were asked to passively look at photographs of six male and six female faces with a neutral expression; the photographs were taken from the left, right, and frontal perspectives while keeping their focus on the eyes. The results showed that specific brain areas were involved in processing the three-quarter faces in either symmetric or asymmetric ways. Viewing left and right three-quarter faces resulted in two mirror-like activations in the striate cortex corresponding to the symmetric layout of the left and right perspectives. Viewing the left face resulted additionally in an enhanced activation also in the left extrastriate cortex. The right perspective of male faces elicited a lower activation compared to other perspectives in face-selective areas of the brain. Our findings suggest that the preference of the left three-quarter face emerges already in the early visual pathway presumably prior to facial identification, emotional processing, and aesthetic appreciation. Our observations may have general importance in disentangling different neural components and processing stages in the spatiotemporal characteristics of artistic expressions.
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Mapeo Encefálico , Corteza Visual , Encéfalo/fisiología , Emociones/fisiología , Estética , Expresión Facial , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Estimulación Luminosa/métodos , Corteza Visual/fisiologíaRESUMEN
Cognitive deficit is a core feature of schizophrenia mostly grasping memory, psychomotor processing, attention, thinking, and executive functioning and is already present in the prodromal phase of the illness and is detected at the onset. Recent studies have been focused on the differentiation of cognitive functioning in relation to the diagnostic categories, which reveal cognitive heterogeneity in schizophrenia and schizophrenia spectrum disorders. The study demonstrated that along with changes in the clinical state, specifically, with reduction of psychopathological symptoms, patients with schizoaffective disorders show more positive dynamics with better chances to back up while in schizophrenia the cognitive dysfunction is more defined and less prone to improvement.
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Trastornos del Conocimiento/complicaciones , Cognición/efectos de los fármacos , Pruebas Neuropsicológicas/estadística & datos numéricos , Trastornos Psicóticos/complicaciones , Trastornos Psicóticos/tratamiento farmacológico , Análisis de Varianza , Trastornos del Conocimiento/psicología , Humanos , Escalas de Valoración Psiquiátrica , Esquizofrenia/complicaciones , Esquizofrenia/tratamiento farmacológico , Psicología del EsquizofrénicoRESUMEN
Hallucinatory experiences (HEs) can be pronounced in psychosis, but similar experiences also occur in nonclinical populations. Cognitive mechanisms hypothesized to underpin HEs include dysfunctional source monitoring, heightened signal detection, and impaired attentional processes. Using data from an international multisite study on non-clinical participants (N = 419), we described the overlap between two sets of variables - one measuring cognition and the other HEs - at the level of individual items. We used a three-step method to extract and examine item-specific signal, which is typically obscured when summary scores are analyzed using traditional methodologies. The three-step method involved: (1) constraining variance in cognition variables to that which is predictable from HE variables, followed by dimension reduction, (2) determining reliable HE items using split-halves and permutation tests, and (3) selecting cognition items for interpretation using a leave-one-out procedure followed by repetition of Steps 1 and 2. The results showed that the overlap between HEs and cognition variables can be conceptualized as bi-dimensional, with two distinct mechanisms emerging as candidates for separate pathways to the development of HEs: HEs involving perceptual distortions on one hand (including voices), underpinned by a low threshold for signal detection in cognition, and HEs involving sensory overload on the other hand, underpinned by reduced laterality in cognition. We propose that these two dimensions of HEs involving distortions/liberal signal detection, and sensation overload/reduced laterality may map onto psychosis-spectrum and dissociation-spectrum anomalous experiences, respectively.
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Alucinaciones , Trastornos Psicóticos , Atención , Cognición , Humanos , Análisis MultivarianteRESUMEN
The Early Intervention Centre (First episode clinic, FEC) that provides specific service programs to this particular target group of patients with early psychosis opened in November 2000 as a day clinic at the Moscow Research Institute of Psychiatry. To date, FEC programs consistent with the developed model have been established in 30 regions across Russia. 5-year follow-up data are available for 114 patients who received such care in the FEC. In more than 30% of cases complete remission was maintained over the 5 years. The number of relapses increased on the 2nd and 3rd years, but later decreased more than by one half. The relapses were mostly treated in day clinic or outpatient settings and did not require hospital admissions. More than 73% of the patients maintained their social achievements with no losses. By the end of the 5th year only 1/5 of the cases were formally recognized as unemployable due to psychiatric disability. Significantly better clinical and psychosocial outcomes have been shown in comparison with a control group of patients, treated in routine psychiatric services.
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Conducta Cooperativa , Comunicación Interdisciplinaria , Grupo de Atención al Paciente , Trastornos Psicóticos/rehabilitación , Rehabilitación Vocacional , Adulto , Antipsicóticos/uso terapéutico , Terapia Familiar/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Cooperación del Paciente , Educación del Paciente como Asunto/métodos , Solución de Problemas , Estudios Prospectivos , Psicoterapia/métodos , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/psicología , Federación de Rusia , Ajuste Social , Adulto JovenRESUMEN
Cognitive deficit is present in most of schizophrenia cases and even better explains functional outcomes then positive and negative symptoms. There have been less consensus regarding the long-term course of cognitive functioning after onset of the illness. In our study we used a neuropsychological test battery based on Luria`s systematic approach in testing of patients at their first episode of schizophrenia and schizophrenia spectrum disorders and during 5-year follow-up. The results indicated that patients with various types of course of schizophrenia and schizophrenia spectrum disorders and hence, good and poor outcomes demonstrated different patterns of dynamic of cognitive decline during the follow-up.
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Trastornos del Conocimiento/diagnóstico , Batería Neuropsicológica de Luria-Nebraska , Esquizofrenia/diagnóstico , Psicología del Esquizofrénico , Adulto , Enfermedad Crónica , Trastornos del Conocimiento/psicología , Trastornos del Conocimiento/terapia , Depresión/diagnóstico , Depresión/psicología , Depresión/terapia , Femenino , Estudios de Seguimiento , Humanos , Masculino , Pronóstico , Escalas de Valoración Psiquiátrica , Esquizofrenia/terapia , Ajuste Social , Apoyo SocialRESUMEN
We identified a potential neurophysiological marker for processing of verbal cues in paranoid schizophrenia: high desynchronization in the beta-2 band in the right parietal area for meaningless cues, and no synchronization differences in the beta-2 and gamma bands in the left prefrontal area pointing to deficient categorization of the stimuli.
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Esquizofrenia Paranoide , Semántica , Señales (Psicología) , Electroencefalografía , Emociones , HumanosRESUMEN
BACKGROUND: EEG mu rhythm suppression is assessed in experiments on the execution, observation and imagination of movements. It is utilised for studying of actions, language, empathy in healthy individuals and preservation of sensorimotor system functions in patients with schizophrenia and autism spectrum disorders. While EEG alpha and mu rhythms are recorded in the same frequency range (8-13â¯Hz), their specification becomes a serious issue. THE NEW METHOD: is based on the spatial and functional characteristics of the mu wave, which are: (1) the mu rhythm is located over the sensorimotor cortex; (2) it desynchronises during movement processing and does not respond on the eyes opening. In EEG recordings, we analysed the mu rhythm under conditions with eyes opened and eyes closed (baseline), and during a motor imagery task with eyes closed. EEG recordings were processed by principal component analysis (PCA). RESULTS: The analysis of EEG data with the proposed approach revealed the maximum spectral power of mu rhythm localised in the sensorimotor areas. During motor imagery, mu rhythm was suppressed more in frontal and central sites than in occipital sites, whereas alpha rhythm was suppressed more in parietal and occipital sites. Mu rhythm desynchronization in sensorimotor sites during motor imagery was greater than alpha rhythm desynchronization. The proposed method enabled EEG mu rhythm separation from its mix with alpha rhythm. CONCLUSIONS: EEG mu rhythm separation with the proposed method satisfies its classical definition.
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Ritmo alfa , Electroencefalografía , Humanos , Imaginación , Movimiento , Análisis de Componente PrincipalRESUMEN
Background: Schizophrenia is often characterized by a general disruption of self-processing and self-demarcation. Previous studies have shown that self-monitoring and sense of agency (SoA, i.e., the ability to recognize one's own actions correctly) are altered in schizophrenia patients. However, research findings are inconclusive in regards to how SoA alterations are linked to clinical symptoms and their severity, or cognitive factors. Methods: In a longitudinal study, we examined 161 first-episode schizophrenia patients and 154 controls with a continuous-report SoA task and a control task testing general cognitive/sensorimotor processes. Clinical symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS). Results: In comparison to controls, patients performed worse in terms of recognition of self-produced movements even when controlling for confounding factors. Patients' SoA score correlated with the severity of PANSS-derived "Disorganized" symptoms and with a priori defined symptoms related to self-disturbances. In the follow-up, the changes in the two subscales were significantly associated with the change in SoA performance. Conclusion: We corroborated previous findings of altered SoA already in the early stage of schizophrenia. Decreased ability to recognize self-produced actions was associated with the severity of symptoms in two complementary domains: self-disturbances and disorganization. While the involvement of the former might indicate impairment in self-monitoring, the latter suggests the role of higher cognitive processes such as information updating or cognitive flexibility. The SoA alterations in schizophrenia are associated, at least partially, with the intensity of respective symptoms in a state-dependent manner.