EEG-correlated fMRI of human alpha activity
Autor: | Karsten Krakow, Evelyn Eger, Christine Preibisch, Afraim Salek-Haddadi, Helmut Laufs, A. Beyerle, Andreas Kleinschmidt |
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Rok vydání: | 2003 |
Předmět: |
Adult
Male Cognitive Neuroscience Electroencephalography Statistical parametric mapping EEG-fMRI Signal Imaging Three-Dimensional Oxygen Consumption Nuclear magnetic resonance Reference Values Functional neuroimaging Parietal Lobe Image Processing Computer-Assisted medicine Humans Computer vision Mathematical Computing Cerebral Cortex Brain Mapping Artifact (error) Fourier Analysis medicine.diagnostic_test business.industry Signal Processing Computer-Assisted Magnetic Resonance Imaging Frontal Lobe Alpha Rhythm Neurology Female Wakefulness Artificial intelligence Psychology Functional magnetic resonance imaging business psychological phenomena and processes |
Zdroj: | NeuroImage. 19:1463-1476 |
ISSN: | 1053-8119 |
Popis: | Electroencephalography-correlated functional magnetic resonance imaging (EEG/fMRI) can be used to identify blood oxygen level-dependent (BOLD) signal changes associated with both physiological and pathological EEG events. Here, we implemented continuous and simultaneous EEG/fMRI to identify BOLD signal changes related to spontaneous power fluctuations in the alpha rhythm (8-12 Hz), the dominant EEG pattern during relaxed wakefulness. Thirty-two channels of EEG were recorded in 10 subjects during eyes-closed rest inside a 1.5-T magnet resonance (MR) scanner using an MR-compatible EEG recording system. Functional scanning by echoplanar imaging covered almost the entire cerebrum every 4 s. Off-line MRI artifact subtraction software was applied to obtain continuous EEG data during fMRI acquisition. The average alpha power over 1-s epochs was derived at several electrode positions using a Fast Fourier Transform. The power time course was then convolved with a canonical hemodynamic response function, down-sampled, and used for statistical parametric mapping of associated signal changes in the image time series. At all electrode positions studied, a strong negative correlation of parietal and frontal cortical activity with alpha power was found. Conversely, only sparse and nonsystematic positive correlation was detected. The relevance of these findings is discussed in view of the current theories on the generation and significance of the alpha rhythm and the related functional neuroimaging findings. |
Databáze: | OpenAIRE |
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