ICA Example

Abstraction: Infomax ICA separates brain and artifact sources from 100-channel EEG data

Key points:

• Demonstrates infomax ICA separating 100 independent components from 100-channel EEG recorded during a visual/auditory event-related task (Onton & Makeig 2006).
• Nearby scalp electrodes record highly similar mixtures of brain and non-brain activity; ICA components are temporally distinct (maximally independent) even when their scalp maps overlap.
• Example shows separation of eye-blink artifacts (IC1, IC3 capturing different blink phases), frontal theta (IC4, IC7), ECG artifact, EMG artifact, and posterior alpha bursts (IC5, IC98).
• Phase-locked (averaged ERP) and phase-incoherent activity within a single IC are dramatically different, illustrating that the trial average poorly summarizes unaveraged IC dynamics.

Connections: Ucsd Sccn · Independent Component Analysis · Eeg · Signal Processing

Source: http://sccn.ucsd.edu/~scott/ica_example.html