Phase-Amplitude Markers of Synchrony and Noise: A Resting-State and TMS-EEG Study of Schizophrenia.

The electroencephalogram (EEG) of schizophrenia patients is known to exhibit a reduction of signal-to-noise ratio and of phase locking, as well as a facilitation of excitability, in response to a variety of external stimuli. Here, we demonstrate these effects in transcranial magnetic stimulation (TMS)-evoked potentials and in the resting-state EEG. To ensure veracity, we used 3 weekly sessions and analyzed both resting-state and TMS-EEG data.

Functional connectivity abnormalities during processing of predictive stimuli in patients with major depressive disorder.

The study investigated the underlying mechanisms associated with the ability of patients with major depressive disorder (MDD) to utilize predictive contextual information in order to facilitate detection of predictable versus random targets. To this end we evaluated EEG event-related functional connectivity during the processing of predictive stimuli in MDD and control subjects. A target detection task was used where targets were either preceded by randomized sequences of standards, or by sequences that included a predictive sequence.

A quantitative physical model of the TMS-induced discharge artifacts in EEG.

The combination of Transcranial Magnetic Stimulation (TMS) with Electroencephalography (EEG) exposes the brain's global response to localized and abrupt stimulations. However, large electric artifacts are induced in the EEG by the TMS, obscuring crucial stages of the brain's response. Artifact removal is commonly performed by data processing techniques.

Altered Brain Network Dynamics in Schizophrenia: A Cognitive Electroencephalography Study.

Background: Alterations in the dynamic coordination of widespread brain networks are proposed to underlie cognitive symptoms of schizophrenia. However, there is limited understanding of the temporal evolution of these networks and how they relate to cognitive impairment. The current study was designed to explore dynamic patterns of network connectivity underlying cognitive features of schizophrenia.

Hierarchy measurement for modeling network dynamics under directed attacks.

A fundamental issue in the dynamics of complex systems is the resilience of the network in response to targeted attacks. This paper explores the local dynamics of the network attack process by investigating the order of removal of the nodes that have maximal degree, and shows that this dynamic network response can be predicted from the graph's initial connectivity. We demonstrate numerically that the maximal degree M(τ) of the network at time step τ decays exponentially with τ via a topology-dependent exponent.

Connectivity maps based analysis of EEG for the advanced diagnosis of schizophrenia attributes.

This article presents a novel connectivity analysis method that is suitable for multi-node networks such as EEG, MEG or EcOG electrode recordings. Its diagnostic power and ability to interpret brain states in schizophrenia is demonstrated on a set of 50 subjects that constituted of 25 healthy and 25 diagnosed with schizophrenia and treated with medication. The method can also be used for the automatic detection of schizophrenia; it exhibits higher sensitivity than state-of-the-art methods with no false positives.

Schizophrenia detection and classification by advanced analysis of EEG recordings using a single electrode approach.

Electroencephalographic (EEG) analysis has emerged as a powerful tool for brain state interpretation and diagnosis, but not for the diagnosis of mental disorders; this may be explained by its low spatial resolution or depth sensitivity. This paper concerns the diagnosis of schizophrenia using EEG, which currently suffers from several cardinal problems: it heavily depends on assumptions, conditions and prior knowledge regarding the patient. Additionally, the diagnostic experiments take hours, and the accuracy of the analysis is low or unreliable.

The functional anatomy of schizophrenia: A dynamic causal modeling study of predictive coding.

This paper tests the hypothesis that patients with schizophrenia have a deficit in selectively attending to predictable events. We used dynamic causal modeling (DCM) of electrophysiological responses - to predictable and unpredictable visual targets - to quantify the effective connectivity within and between cortical sources in the visual hierarchy in 25 schizophrenia patients and 25 age-matched controls. We found evidence for marked differences between normal subjects and schizophrenia patients in the strength of extrinsic backward connections from higher hierarchical levels to lower levels within the visual system.

Local contextual processing in major depressive disorder.

Objective: The study investigated local contextual processing in patients with major depressive disorder (MDD). This was defined as the ability to utilize predictive contextual information to facilitate detection of predictable versus random targets.

Method: We recorded EEG in 15 MDD patients and 14 age-matched controls.

Rating of textual associations in organized and nonorganized sentences for the assessment of semantic networks in schizophrenia.

Background: Collins and Quillian ( Acta Psychol 1970;33:304-314) proposed that semantic representations in the human brain could have a "networklike" theoretical construct. Thought disorders in schizophrenia have been described as disturbances in the spread of activation within semantic networks. Semantic networks are typically evaluated indirectly via reaction times of priming tasks.

Somatosensory evoked potentials during a rubber-hand illusion in schizophrenia.

The rubber-hand illusion (RHI), an illusion in which tactile sensations are referred to a synthetic alien limb, is enhanced in schizophrenia patients. Somatosensory evoked responses of the illusion were compared between schizophrenia patients and normal control subjects. Schizophrenia patients had significant alterations in long latency evoked responses during the illusion.

Quality of life and coping with schizophrenia symptoms.

The question addressed in this paper is whether different coping styles mediate the relationship between psychopathology and related distress and the quality of life (QOL) among patients with schizophrenia. In a cross-sectional design, 161 schizophrenia inpatients were comprehensively evaluated with standardized measures of QOL, psychopathology, psychological distress and coping styles. Correlations and regression analyses were performed to examine the relationship among parameters and to estimate the mediating effect of coping styles on QOL in the framework of a distress/protection model.

Subjective quality of life in severely mentally ill patients: a comparison of two instruments.

Although many quality of life (QOL) scales have been developed, comparison of specific QOL instruments is lacking. We compared the psychometric properties of two QOL measures in parallel samples of mentally disturbed and non-patient subjects. We simultaneously administered the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q) and self-report items of the Lancashire Quality of Life Profile (LQOLP) to 199 patients with severe mental disorders and 175 non-patients.

Assessing psychological distress in psychiatric patients: validation of the Talbieh Brief Distress Inventory.

The present study examined the psychometric properties of the Talbieh Brief Distress Inventory (TBDI), a 24-item self-report instrument used to measure psychological distress, for use in psychiatric patients. A case-control and partly longitudinal design was used to test the TBDI among 431 psychiatric outpatients and inpatients and 197 gender- and age-matched nonpatients. All respondents were interviewed using the ICD-10 Symptom Checklist, and patients additionally with psychopathology rating scales.

The impact of side-effects of antipsychotic agents on life satisfaction of schizophrenia patients: a naturalistic study.

This study compared the impact of side-effects of antipsychotic treatment, clinical and psychosocial factors on the subjective quality of life (QOL) of hospitalized patients. We surveyed 161 patients meeting DSM-IV criteria for schizophrenia stabilized on conventional and atypical antipsychotic drugs using standardized measures of adverse events, psychopathology, psychosocial variables, and perceived QOL. We found that patients with adverse events reported less satisfaction with life domains of subjective feelings and general activities than asymptomatic patients.

Phospholipid patterns of erythrocytes in schizophrenia: relationships to symptomatology.

The phospholipid composition of red blood cells (RBC) from 32 haloperidol-treated schizophrenic patients, classified according to the positive and negative syndrome scale (PANSS) as showing either predominantly positive or predominantly negative symptoms, was determined and compared with that of normal controls. While the levels of phosphatidylcholine and phosphatidylserine were similar in all three groups, sphingomyelin (SM) and phosphatidylethanolamine (PE) were, respectively, increased and decreased in RBCs of schizophrenic patients. In both patient groups, the SM/PE ratios correlated directly with the PANSS negative symptom scale scores and inversely with the positive symptom scale scores.

Gender differences in psychosocial risk factors for psychological distress among immigrants.

The reasons for a greater prevalence of psychological distress among women than men remain unknown. We sought to test two hypotheses that gender operates either as (1) a moderator or (2) a mediator between psychosocial risk factors and experienced distress. A cross-sectional community survey of 1,062 adult Russian-born Jewish immigrants to Israel was conducted.

Differences in quality of life domains and psychopathologic and psychosocial factors in psychiatric patients.

Background: Although treatment of severe mental disorders should strive to optimize quality of life (QOL) for the individual patient, little is known about variations in QOL domains and related psychopathologic and psychosocial factors in patients suffering from schizophrenia, schizoaffective disorder, and/or mood disorders. We hypothesized that QOL in severe mental disorder patients would have a more substantial relationship with psychosocial factors than with illness-associated factors.

Method: A case-control, cross-sectional design was used to examine QOL of 210 inpatients who met DSM-IV criteria for a severe mental disorder and who were consecutively admitted to closed, open, and rehabilitation wards.

Touch feel illusion in schizophrenic patients.

Background: The rubber hand illusion is a tactile sensation referred to as an alien limb. The illusion has been explained by a spurious reconciliation of visual and tactile inputs reflecting functional connectivity in the brain and was used to explore alterations of functional connectivity in schizophrenia.

Methods: The rubber hand illusion was achieved when two paintbrushes simultaneously stroke the hand of the subject hidden from vision by a screen, as well as an artificial hand placed in view of the subject.

Somatization in an immigrant population in Israel: a community survey of prevalence, risk factors, and help-seeking behavior.

Objective: Knowledge about the frequency, severity, and risk factors of somatization (somatic manifestations of psychological distress) among immigrants is limited. The authors examined somatic distress in an immigrant population in Israel, explored its relationship with psychological distress symptoms and health-care-seeking behavior, and determined its correlation with the length of residence in Israel.

Method: Two reliable and validated self-report questionnaires, the Brief Symptom Inventory and the Demographic Psychosocial Inventory, were administered in a cross-sectional community survey of 966 Jewish immigrants from the former Soviet Union who had arrived in Israel within the previous 30 months.