Event-related theta synchronization predicts deficit in facial affect recognition in schizophrenia.

Growing evidence suggests that abnormalities in the synchronized oscillatory activity of neurons in schizophrenia may lead to impaired neural activation and temporal coding and thus lead to neurocognitive dysfunctions, such as deficits in facial affect recognition. To gain an insight into the neurobiological processes linked to facial affect recognition, we investigated both induced and evoked oscillatory activity by calculating the Event Related Spectral Perturbation (ERSP) and the Inter Trial Coherence (ITC) during facial affect recognition. Fearful and neutral faces as well as nonface patches were presented to 24 patients with schizophrenia and 24 matched healthy controls while EEG was recorded. The participants' task was to recognize facial expressions. Because previous findings with healthy controls showed that facial feature decoding was associated primarily with oscillatory activity in the theta band, we analyzed ERSP and ITC in this frequency band in the time interval of 140-200 ms, which corresponds to the N170 component. Event-related theta activity and phase-locking to facial expressions, but not to nonface patches, predicted emotion recognition performance in both controls and patients. Event-related changes in theta amplitude and phase-locking were found to be significantly weaker in patients compared with healthy controls, which is in line with previous investigations showing decreased neural synchronization in the low frequency bands in patients with schizophrenia. Neural synchrony is thought to underlie distributed information processing. Our results indicate a less effective functioning in the recognition process of facial features, which may contribute to a less effective social cognition in schizophrenia.

[From life events to symptoms of anxiety and depression: the role of dysfunctional attitudes and coping]. / Az életeseményektol a depressziós és szorongásos panaszokig: a diszfunkcionális attitudök és a megküzdés szerepe a patogenezis folyamatában.

UNLABELLED: The aim of the present study was a systematic path-analytical investigation between the effects of life events, dysfunctional attitudes and coping strategies in relation with the exhibited depressive and anxiety symptoms in patients with mental disorders. METHODS: Self-report data of 234 patients from our outpatient psychotherapy unit were analyzed. Life events, dysfunctional attitudes, coping strategies as well as symptoms of anxiety and depression were assessed by self-administerd questionnaires. Statistical methods included structural equation modelling, which enables the estimation of the magnitude and strength of individual variables within an overarching casual model, thus yielding a complex view on the possible processes underlying the development of the clinical symptoms of anxiety and depression. RESULTS: Our findings indicate that both the number of negative life events and their subjectively experienced intensity contributed to the increase of dysfunctional attitudes. The presence of dysfunctional attitudes decreased the use of problem-focused coping strategies and increased the use of emotion-focused coping strategies. The use of problem-focused coping decreased symptom occurrence and emotion-focused coping strategies increased the frequency of symptoms of anxiety and depression. Our findings suggest that dysfunctional need for achievement and perfectionism directly increase the probability of depressive symptom manifestation. The attitude of external locus of control showed a significant relationship with anxiety symptoms through emotion-focused coping strategies and directly as well. CONCLUSION: Restructuring dysfunctional attitudes and developing problem-focused coping strategies are an important part of psychotherapeutic interventions aiming to decrease anxiety and depressive symptoms.

Emotion-related visual mismatch responses in schizophrenia: impairments and correlations with emotion recognition.

BACKGROUND AND OBJECTIVES: Mismatch negativity (MMN) is an event-related potential (ERP) measure of preattentional sensory processing. While deficits in the auditory MMN are robust electrophysiological findings in schizophrenia, little is known about visual mismatch response and its association with social cognitive functions such as emotion recognition in schizophrenia. Our aim was to study the potential deficit in the visual mismatch response to unexpected facial emotions in schizophrenia and its association with emotion recognition impairments, and to localize the sources of the mismatch signals. EXPERIMENTAL DESIGN: The sample comprised 24 patients with schizophrenia and 24 healthy control subjects. Controls were matched individually to patients by gender, age, and education. ERPs were recorded using a high-density 128-channel BioSemi amplifier. Mismatch responses to happy and fearful faces were determined in 2 time windows over six regions of interest (ROIs). Emotion recognition performance and its association with the mismatch response were also investigated. PRINCIPAL OBSERVATIONS: Mismatch signals to both emotional conditions were significantly attenuated in patients compared to controls in central and temporal ROIs. Controls recognized emotions significantly better than patients. The association between overall emotion recognition performance and mismatch response to the happy condition was significant in the 250-360 ms time window in the central ROI. The estimated sources of the mismatch responses for both emotional conditions were localized in frontal regions, where patients showed significantly lower activity. CONCLUSIONS: Impaired generation of mismatch signals indicate insufficient automatic processing of emotions in patients with schizophrenia, which correlates strongly with decreased emotion recognition.

Fearful face recognition in schizophrenia: an electrophysiological study.

BACKGROUND: Emotional expressions are important acts of communication, and impairment in facial emotion recognition has been shown to be related to impairments in social cognition in schizophrenia. We used an event-related potential (ERP) paradigm to identify and delineate the temporal characteristics in the electrophysiological cascade related to fearful facial affect processing in patients with schizophrenia as compared to healthy controls. METHODS: Twenty-four subjects with schizophrenia and 24 individually matched healthy controls participated in an emotion recognition task. Ekman faces displaying neutral and fearful facial expressions were used as stimuli. ERPs were recorded using a 128-channel EEG system. RESULTS: Based on the analysis of Global Field Power (GFP) in the 150-190 ms time window both groups differentiated between fearful and neutral faces. Schizophrenia patients showed an additional differential processing of fearful vs. neutral faces in the 330-450 ms time window, and this ERP effect correlated with psychopathology. CONCLUSIONS: Both patients and healthy controls differentiate fearful and neutral faces in early phases of emotion processing. Our results also indicate that schizophrenia patients show increased responsivity to fearful faces at a later processing stage. This could be related to the overrating of negative emotions, and the symptomatology associated with fear processing in patients with schizophrenia.

Processing of unattended facial emotions: a visual mismatch negativity study.

Facial emotions express our internal states and are fundamental in social interactions. Here we explore whether the repetition of unattended facial emotions builds up a predictive representation of frequently encountered emotions in the visual system. Participants (n=24) were presented peripherally with facial stimuli expressing emotions while they performed a visual detection task presented in the center of the visual field. Facial stimuli consisted of four faces of different identity, but expressed the same emotion (happy or fearful). Facial stimuli were presented in blocks of oddball sequence (standard emotion: p=0.9, deviant emotion: p=0.1). Event-related potentials (ERPs) to the same emotions were compared when the emotions were deviant and standard, respectively. We found visual mismatch negativity (vMMN) responses to unattended deviant emotions in the 170-360 ms post-stimulus range over bilateral occipito-temporal sites. Our results demonstrate that information about the emotional content of unattended faces presented at the periphery of the visual field is rapidly processed and stored in a predictive memory representation by the visual system. We also found evidence that differential processing of deviant fearful faces starts already at 70-120 ms after stimulus onset. This finding shows a 'negativity bias' under unattended conditions. Differential processing of fearful deviants were more pronounced in the right hemisphere in the 195-275 ms and 360-390 ms intervals, whereas processing of happy deviants evoked larger differential response in the left hemisphere in the 360-390 ms range, indicating differential hemispheric specialization for automatic processing of positive and negative affect.

[Gamma oscillation synchronization in schizophrenia--literature review]. / Gamma oszcilláció szinkronizáció szkizofréniában. Irodalmi összefoglaló.

INTRODUCTION: Gamma oscillation - as a basic operating mode of cortical networks - has received considerable interest in the the current EEG literature. Research in the field of gamma synchronization in schizophrenia has become the focus of psychiatry research in the past two decades, obtaining significant attention from the beginning, since the idea that a deficit in synchronization, especially in gamma oscillation synchronization might play a principal role in certain schizophrenia symptoms has emerged. METHODS: In our review we aim to provide a brief description of the theoretical background, as well as an overview of differences in gamma oscillation synchronization observed in patients with schizophrenia compared to healthy controls. In order to identify relevant articles, we used PubMed and Medline search engines. For the current paper we reviewed articles published between 1999-2009, which reported results of clinical studies. RESULTS: Consistent evidence for gamma synchronization deficit in both visual and acoustic modalities has been found in patients with schizophrenia as compared to healthy controls from most of the available studies, but the methodological heterogeneity observable in the field make the generalization of findings difficult. CONCLUSIONS: The alteration observed in gamma oscillations and synchrony in patients with schizophrenia might play an important role in the pathophysiology of the disease. The potential relevance of the topic with regard to clinical practice underlines the need for more research.

[Event-related potentials associated with error detection in adult ADHD--literature review]. / Eseményfüggô agyi potenciál eltérések felnôttkori ADHD-ban. Irodalmi áttekintés.

INTRODUCTION: According to a recent assessment the prevalence of adult attention-deficit/hyperactivity disorder (ADHD) was 1.5% in the Hungarian adult population (1), which is in line with previous results indicating that ADHD is a disorder of high prevalence. The core symptoms, including the attention deficit, the hyperactivity and impulsivity are all characteristics that have a significant impact on cognitive functions. Our review focuses on event-related potentials of patients suffering from adult ADHD. With information gained from electrophysiological measurement, our goal is to give an overview of the process leading to a functional impairment based on the available literature. METHOD: PubMed and Medline search engines were used in order to identify all relevant articles, published between 1993 and 2010. For the purpose of the current paper we reviewed publications summarizing results of clinical studies. RESULTS: With regard to evoked potentials reflecting early sensorial information processing a significant difference between ADHD and control subjects was detected in the auditory N2 and P2, and visual N2 components. The P300 component, which is independent of modality, was significantly lower in ADHD patients compared to the control group. Similar results were reported with regard to error related negativity (ERN). CONCLUSION: Since electrophysiological research investigating event-related evoked potientials in adults suffering from ADHD have come to the focus of scientific interest only recently, the amount of literature available is relatively limited. Considering that all three core symptoms of the disorder have a significant impact on both information processing and on concomitant cognitive functions, patients with ADHD should be divided into subgroups based on their neuropsychologically measured dominant symptoms.

[Facial emotion recognition in schizophrenia: an electrophysiological review]. / Erzelmi arcfelismerés szkizofréniában: Mi és hol csúszik félre? Elektrofizológiai àttekintès.

Deficits in social cognition in schizophrenia have been shown to be among the main factors predicting functional impairment. Facial emotion perception is a basic component of social cognition and other higher-level social cognitive processes. In our review we aim to give an overview of findings investigating the electrophysiological correlates of facial emotion recognition, and summarize previous findings relating to the nature of the deficit in schizophrenia as compared to healthy controls. Disentangling early and late components of emotion processing as indexed by event-related brain potentials allows for a better understanding of whether impairment of facial emotion processing is due to deficits in the early structural encoding of faces, or whether it is related to later deficits associated with the encoding of the emotional content. Findings in the field of social cognition in schizophrenia are of both clinical and pharmacological importance, as on one side they carry the potential to improve cognitive therapeutic interventions, and on the other to develop targets aiming at the improvement of social deficits in schizophrenia.

Pharmacotherapy of adult attention deficit hyperactivity disorder (ADHD): a meta-analysis.

Our objective was to conduct a meta-analysis of therapeutic efficacy of pharmacological treatment of adult ADHD based on data from controlled clinical trials. We used the search engines PubMed and Medline to identify relevant clinical trials. Short-term studies with double-blind parallel-group design were selected for the analysis. Altogether, we identified 11 trials that met the criteria, and investigated a total of 1991 subjects, 694 and 1297 of whom were treated with placebo or active medication, respectively. In order to pool efficacy data from studies with different characteristics, including different number of participants, different trial duration and measures of efficacy, the statistical effect sizes for each study had to be calculated. Our findings showed that the pooled effect size across all treatments was in the medium-to-high range (Cohen's d=0.65, p<0.0001 vs. placebo), and the effect size for stimulants (Cohen's d=0.67, p<0.0001 vs. placebo) was somewhat higher than for non-stimulant medications (Cohen's d=0.59, p<0.0001 vs. placebo). The current database of controlled trials for adult ADHD is relatively small, and does not include data for many of the potentially important agents. In addition, effect-size estimates for different classes of medications (i.e. stimulant and non-stimulant medications) were based on separate studies; head-to-head comparisons of various agents are severely lacking. Nonetheless, results of this meta-analysis across all ADHD medications in adult subjects demonstrated statistically significant and clinically robust improvement in symptom severity compared to placebo treatment.

[The relationship between cognition and functional outcome in schizophrenia]. / A szkizofréniában tapasztalható kognitív deficit osszefüggése a mindennapi funkcióképességgel.

Schizophrenia is associated with poor functional outcome, which has been shown to be associated with cognitive impairment, a core feature of the illness. The aim of the present study is to provide an overview of measurements of cognitive deficit and everyday functioning in schizophrenia. The authors demonstrate that cognitive impairment is a predictor of subsequent functional outcome measures by reviewing the relevant cross-sectional and longitudinal studies. Furthermore, models proposing intermediate variables that may provide a link between cognition and functional outcome are discussed. Such mediator variables are social cognition and functional capacity. Future avenues of research on cognition and functional outcome in schizophrenia are outlined, as there is considerable interest in finding treatments to improve cognition in schizophrenia. Improvements in cognitive deficits are expected to lead to benefits in the everyday functioning of the patients.