ARMS; Alpha; Schizophrenia; Psychosis; ERP; FEP; EEG; Theta; neurocognition
Ramyead Avinash, Studerus Erich, Kometer Michael, Heitz Ulrike, Gschwandtner Ute, Fuhr Peter, Riecher-Rössler Anita (2016), Neural Oscillations in Antipsychotic-Naïve Patients with a First Psychotic Episode., in The world journal of biological psychiatry : the official journal of the World Federation of Societi
Ramyead Avinash, Studerus Erich, Kometer Michael, Uttinger Martina, Gschwandtner Ute, Fuhr Peter, Riecher-Rössler Anita (2015), Prediction of psychosis using neural oscillations and machine learning in neuroleptic-naïve at-risk patients., in The world journal of biological psychiatry : the official journal of the World Federation of Societi
Ramyead Avinash, Kometer Michael, Studerus Erich, Koranyi Susan, Ittig Sarah, Gschwandtner Ute, Fuhr Peter, Riecher-Rössler Anita (2014), Aberrant Current Source-Density and Lagged Phase Synchronization of Neural Oscillations as Markers for Emerging Psychosis., in Schizophrenia bulletin
, 41(4), 919-29.
Background: In the last 20 years, there has been a strongly increased interest in the early detection and treatment of psychosis. Despite the various potential “prodromes” that have been identified and have helped increased detection accuracy of those at-risk for developing psychoses, it is still not possible to predict the transition to psychosis with a sufficient accuracy. Although some electroencephalography (EEG) studies, based on basic power-spectral and event-related potential analyses, have been conducted in the field of early detection, neural oscillations and synchrony have been ignored.Objectives: To study:•the role of prefrontal theta oscillations in integrating and applying contextual information.•the contribution of phase-synchronization between the medial prefrontal cortex (mPFC) and the lateral prefrontal cortex (lPFC) to self-monitoring functioning. •the role of alpha oscillations in protecting against distractors, and its contribution to the formation of psychotic symptoms.Hypothesis:•At-risk mental state (ARMS) and first episode psychosis (FEP) patients are impaired in context-dependent learning and this impairment is associated with abnormal theta oscillations in the frontal lobe of the brain.•ARMS and FEP patients are impaired in a self-monitoring and this impairment is associated with a low synchronization of the theta band between the mPFC and lPFC.•ARMS and FEP patients are impaired in shielding working memory against distractorsand this impairment is associated with abnormal alpha oscillations in the occipito-parietal regions of the brain.Design and Methods: 20 healthy controls (HC), 20 ARMS and 20 FEP patients recruited through the Basel Früherkennung von Psychosen (FePsy) study will be tested by three EEG paradigms assessing context-dependent encoding, self-monitoring, and shielding against distractors. The EEG data will be analyzed by state-of-the-art methods, including LORETA, wavelets, connectivity and phase synchronicity analyses.Expected value of the project: This project could considerably advance our understanding of the role of alpha and theta oscillations in context-dependent encoding, self-monitoring, and protection against distraction in emerging psychosis. Furthermore, because HC, ARMS and FEP subjects will be compared, it could reveal whether disruptions in these oscillations and associated cognitive functions are diseases-stage dependent. This in turn could not only enhance our understanding of the pathophysiology of schizophrenic psychoses but also provide the ground for a more in-depth study that could potentially change the way we diagnose patients with emerging psychosis. This could reduce the duration of untreated illness and yield enhanced functional outcomes in these individuals.