Week 08: Electroencephalography (EEG)
Methods in Human Neuroimaging — NBL 425/625Electroencephalography provides millisecond-level temporal resolution of macroscopic neural dynamics directly from scalp electrodes. This week examines the biophysical origin of scalp potentials in aligned cortical pyramidal cells, classical frequency bands, Event-Related Potentials (ERPs), and artifact decontamination.
Interactive Demos & Activities
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Interactive Multi-Channel EEG & Artifact Simulator
Switch between canonical brainwave bands (Delta, Theta, Alpha, Beta, Gamma) across Frontal (Fp1), Central (Cz), and Occipital (O1) channels. Test realistic artifact injection buttons for Eye Blinks (EOG) and Jaw Clenching (EMG).
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Local Field Potential (LFP) Population Simulator
Explore how 150 individual pyramidal neurons summate: asynchronous firing causes phase cancellation, while rhythmic synchrony generates high-amplitude oscillations and seizure hypersynchrony.
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Hodgkin-Huxley Action Potential Simulator
Investigate the voltage-gated $Na^+$ and $K^+$ channel dynamics that govern neuronal excitability and establish the membrane potentials measured by electrophysiological tools.
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EEG Modality Card Game
Test your mastery of the International 10-20 electrode system, frequency bands, differential amplifiers, and clinical neurology applications.
Topics Covered
- Biophysical Origin of Scalp Potentials: Open-field geometry of layer V cortical pyramidal neurons, dipolar postsynaptic potentials (PSPs) vs. quadrupolar action potentials.
- The Volume Conduction Problem: Signal blurring through cerebrospinal fluid, the high electrical resistivity of the skull, and spatial resolution limits.
- ERP Analysis & Frequency Decomposition: Time-locked trial averaging (P300, N400), Fast Fourier Transforms (FFT), time-frequency wavelets, and independent component analysis (ICA) for artifact removal.