Publications by authors named "Marco C G Merlo"

One of the main challenges for clinicians is to ensure that alcohol withdrawal treatment is the most effective possible after discharge. To address this issue, we designed a pilot study to investigate the efficacy of the rehabilitation treatment on the main stages of information processing, using an electroencephalographic method. This topic is of main importance as relapse rates after alcohol withdrawal treatment remain very high, indicating that established treatment methods are not fully effective in all patients in the long run.

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Background: The topic of false memory in schizophrenia has been well documented in earlier research contributions. To date, there is no study exploring the implications of specific neural networks during this phenomenon in patients suffering from schizophrenia.

Methods: We compared 17 patients suffering from psychosis (SCZ) to 33 healthy controls (HC) performing a verbal memory task designed to produce false memories, i.

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Working memory (WM) deficits constitute a core symptom of schizophrenia. Inadequacy of WM maintenance in schizophrenia has been reported to reflect abnormalities in the excitation/inhibition (E/I) balance between pyramidal neurons and parvalbumin basket cells, which may explain alterations of the dynamics of gamma and delta oscillations. To address this issue, we assessed event-related gamma (35-45 Hz) and delta (0.

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Differences in mental health (MH) of users of distinct psychoactive substances have been shown. Both substance use (SU) and MH in users are influenced by stressful life events. This study compared MH parameters in distinct groups of substance users and evaluated the impact of stress factors on these outcomes.

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The Ultimatum Game (UG) is a typical paradigm to investigate social decision-making. Although the behavior of humans in this task is already well established, the underlying brain processes remain poorly understood. Previous investigations using event-related potentials (ERPs) revealed three major components related to cognitive processes in participants engaged in the responder condition, the early ERP component P2, the feedback-related negativity (FRN) and a late positive wave (late positive component, LPC).

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Background: Schizophrenia has a core feature of cognitive dysfunctions. Since these deficits are predictive for patients' functional outcome, understanding their origin is of great importance to improve their daily lives. A specific component of the deficit involves social decision-making, which can be studied using the Ultimatum Game (UG).

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Gamma band oscillations participate in the temporal binding needed to synchronize cortical networks, involved in early sensory and short term memory processes. In earlier studies, alterations of these neurophysiological parameters have been found in psychotic disorders. To date no study has explored the temporal dynamics and signal complexity of gamma band oscillations in first episode psychosis (FEP).

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The present study contributes to the current debate about electrophysiological measurements of mental workload. Specifically, the allocation of attentional resources during different complexity levels of tasks and its changes over time are of great interest. Therefore, we investigated mental workload using tasks varying in difficulty during an auditory oddball target paradigm.

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The current study investigated the effectiveness of a group cognitive behavioral therapy for auditory verbal hallucinations (AVHs), the Voices Group. This consists of seven specific sessions. Forty-one participants with schizophrenic or schizoaffective disorders completed a battery of questionnaires.

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The 24-item Brief Psychiatric Rating Scale (BPRS, version 4.0) enables the rater to measure psychopathology severity. Still, little is known about the BPRS's reliability and validity outside of the psychosis spectrum.

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Background: Earlier contributions have documented significant changes in sensory, attention-related endogenous event-related potential (ERP) components and θ band oscillatory responses during working memory activation in patients with schizophrenia. In patients with first-episode psychosis, such studies are still scarce and mostly focused on auditory sensory processing. The present study aimed to explore whether subtle deficits of cortical activation are present in these patients before the decline of working memory performance.

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Neural resources subserving spatial processing in either egocentric or allocentric reference frames are, at least partly, dissociated. However, it is unclear whether these two types of representations are independent or whether they interact. We investigated this question using a learning transfer paradigm.

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Working memory (WM) impairments are core cognitive deficits in patients with schizophrenia linked to prefrontal cortical dysfunctions. Determining the differences between early phases of illness allows a better understanding of its course and constitutes an important guide for treatment. The present cross-sectional study examined differences of working memory functions between 33 first-episode and 29 chronic schizophrenic patients, as well as 64 healthy controls.

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In schizophrenic disorders, impairments in social functioning, neurocognition, and theory of mind (ToM) are frequently reported but little is known about the relationships between them. The aim of this study is twofold: (a) to compare neurocognition, social-functioning, and ToM in patients and controls and (b) to investigate whether impairments in these domains are related to psychiatric symptoms. Participants were 16 outpatients with schizophrenic disorders (DSM-IV), and 16 healthy controls.

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Objective: Patterns of successive saccades and fixations (scan paths) that are made while viewing images are often spatially restricted in schizophrenia, but the relation with cannabis-induced psychosis has not been examined. We used higher-order statistical methods to examine spatiotemporal characteristics of scan paths to determine whether viewing behaviour was distinguishable on a continuum.

Methods: Patients with early acute first-episode paranoid schizophrenia (SCH; n = 11), cannabis-induced psychosis (CIP; n = 6) and unaffected control subjects (n = 22) undertook a task requiring free viewing of facial, fractal and landscape images for 5 seconds while their eye movements were recorded.

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Background: The aim of this study was to examine differences in the improvement of clinical psychopathology and in fine motor functions at 2 doses of risperidone in first-episode, acutely psychotic patients.

Method: In a double-blind, fixed-dose study, 49 acutely psychotic, neuroleptic-naive patients who were admitted for the first time and who met DSM-IV criteria for schizophrenia, schizophreniform disorder, or schizoaffective disorder were randomly assigned to 2 or 4 mg/day of risperidone. Treatment efficacy was measured using the Brief Psychiatric Rating Scale, the Scale for the Assessment of Negative Symptoms, The Clinical Global Impressions scale, and the Social and Occupational Functioning Assessment Scale.

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