Objective: Independent component analysis (ICA) can disentangle multi-channel electroencephalogram (EEG) signals into a number of artifacts and brain-related signals. However, the identification and interpretation of independent components is time-consuming and involves subjective decision making. We developed and evaluated a semi-automatic tool designed for clustering independent components from different subjects and/or EEG recordings.
Methods: CORRMAP is an open-source EEGLAB plug-in, based on the correlation of ICA inverse weights, and finds independent components that are similar to a user-defined template. Component similarity is measured using a correlation procedure that selects components that pass a threshold. The threshold can be either user-defined or determined automatically. CORRMAP clustering performance was evaluated by comparing it with the performance of 11 users from different laboratories familiar with ICA.
Results: For eye-related artifacts, a very high degree of overlap between users (phi>0.80), and between users and CORRMAP (phi>0.80) was observed. Lower degrees of association were found for heartbeat artifact components, between users (phi<0.70), and between users and CORRMAP (phi<0.65).
Conclusions: These results demonstrate that CORRMAP provides an efficient, convenient and objective way of clustering independent components.
Significance: CORRMAP helps to efficiently use ICA for the removal EEG artifacts.
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http://dx.doi.org/10.1016/j.clinph.2009.01.015 | DOI Listing |
Brain Imaging Behav
January 2025
Key Laboratory of Adolescent Cyberpsychology and Behavior (Ministry of Education), Wuhan, China.
Bipolar disorder (BD) is a complex psychiatric condition marked by significant mood fluctuations that deeply affect quality of life. Understanding the neural mechanisms underlying BD is critical for improving diagnostic accuracy and developing more effective treatments. This study utilized resting-state functional magnetic resonance imaging (rs-fMRI) to investigate functional connectivity within the ventral and dorsal attention networks in 52 patients with BD and 51 healthy controls.
View Article and Find Full Text PDFJ Opt Soc Am A Opt Image Sci Vis
August 2024
A criterion for the characterization of the retardance effects produced by depolarizing and nondepolarizing linear media on interacting light is established based on Mueller matrices algebra. A consistent general description of retardance properties is performed by means of a serial decomposition of the Mueller matrix into three components, namely an element that encompasses the enpolarizing and depolarizing properties sandwiched by two elliptical retarders containing complete and decoupled information on retardance. The inherent ambiguity derived from the coincident formal structure of rotation matrices and circular retarders is removed though the introduction of the entrance and exit intrinsic reference frames, leading to the concepts of the intrinsic entrance and exit linear retarders, which are defined from the Mueller matrix itself and that are independent of the laboratory reference frames used to represent the incident and emerging polarized light beams, respectively.
View Article and Find Full Text PDFJ Opt Soc Am A Opt Image Sci Vis
August 2024
A three-dimensional (3D) waveguide model is applied in extreme ultraviolet (EUV) lithography simulations. The 3D waveguide model is equivalent to rigorous coupled-wave analysis, but fewer field components are used to solve Maxwell's equations. The 3D waveguide model uses two components of vector potential, and , corresponding to the two polarizations.
View Article and Find Full Text PDFCochrane Database Syst Rev
January 2025
Department of Pharmacy Practice, University of Connecticut, Storrs, CT 06269, USA.
Background: Guideline-recommended strategies to interrupt chronic anticoagulation with warfarin or direct oral anticoagulants (DOAC) during the perioperative period of cardiac implantable electronic device (CIED) surgery differ worldwide. There is uncertainty concerning the benefits and harms of interrupted and uninterrupted anticoagulation in patients undergoing CIED surgery.
Objectives: To assess the benefits and harms of interrupted anticoagulation (IAC) with either warfarin or DOAC in the perioperative period of CIED surgery versus uninterrupted anticoagulation (UAC), with or without heparin bridging, during an equivalent time frame, for CIED surgery.
Nano Lett
January 2025
Department of Electrical & Systems Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States.
Dielectric metasurfaces have emerged as an unprecedented platform for precise wavefront manipulation at subwavelength scales with nearly zero loss. When aiming at dynamic applications such as AR/VR and LiDAR, high-quality factor (high-Q) phase gradient metasurfaces have emerged as a way to boost weak light-material interactions in flat-optical components. However, resonant features are naturally tied to polarization, limiting devices to operating on a single polarization state, which reduces the efficiency and adaptability of wave-shaping.
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