ICA decomposition and component analysis Task 1 Run ICA Exercise... Task 2 Plot components Identify components Task 3 Plot component power Plot component ERP & erpimages Plot ERSP/Cross coherence Exercise... EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 1
ICA decomposition and component analysis Task 1 Run ICA Exercise... Task 2 Plot components Identify components Task 3 Plot component power Plot component ERP & erpimages Plot ERSP/Cross coherence Exercise... EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 2
Reject continuous data To prepare data for ICA, reject strange artifacts but keep stereotyped artifacts! Stereotyped eye blinks Strange EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 3
Independent Component Analysis x = scalp EEG W = unmixing matrix u = sources Channels W*x = u ICA Components Time x = W -1 *u u = sources Time W -1 (scalp projections) * EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 4
Runica/binica options Option Default Comments extended 0 1 is recommended to find sub-gaussians stop 1e-7 final weight change stop lrate determined too small too long from data too large wts blow up maxsteps 512 Should not need more? pca 0 or Decompose only a EEG.nbchan principal data subspace lrate,1e-3 maxsteps,750 extended,1 stop,1e-7 pca,50 EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 5
Runica Progress EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 6
Exercise Load dataset 'faces_3.set' from ' /data/' directory Reject noise from continuous or epoched data Run ICA EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 7
ICA decomposition and component analysis Task 1 Run ICA Exercise... Task 2 Plot components Identify components Task 3 Plot component power Plot component ERP & erpimages Plot ERSP/Cross coherence Exercise... EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 8
Plot ICA scalp maps EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 9
EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 10
Plot ICA scalp maps EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 11
Compare 'good' and 'bad' scalp maps EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 12
Scroll component activities Note: Activity like this, not separated by ICA, should be removed and ICA run again for better decomposition EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 13
Components Channels EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 14
Plot ICA component properties EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 15
Reviewing component properties EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 16
Component scalp maps/properties EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 17
EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 18
EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 19
EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 20
EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 21
EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 22
EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 23
Export ICA weights How can I apply these weights to other datasets? Only apply weights to same subject, same session data!! EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 24
Importing ICA weights EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 25
Imported weights EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 26
ICA decomposition and component analysis Task 1 Run ICA Exercise... Task 2 Plot components Identify components Task 3 Plot component power Plot component ERP & erpimages Plot ERSP/Cross coherence Exercise... EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 27
Plot component power EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 28
Component ERPs EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 29
Definition: The data envelope Data (all channels) Data Envelope (max min) EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 30
Component contributions to the dataset ERP EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 31
Component contribution to the dataset ERP Artifact Components! EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 32
ERP Image basics Trial 1 ERP Image Trial 2 Trial 3 by default, sorted by time-on-task (1 st trial, 2 nd trial,...) Trial 4 EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 33
ERP Image basics Trial 1: Trial 2:... EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 34
ERP Images: smoothing across trials EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 35
Component ERP Images EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 36
Plot IC ERSP EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 37
Plot IC cross coherence EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 38
Channel/IC statistics EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 39
Exercise Look at your component maps/activations Find components that contribute most to: Data power spectrum at 6 Hz The ERP between 100 and 500 ms -Remove noise components when plotting Plot and study different ERP images for these components Plot ERSP and/or IC cross coherence for selected ICs EEGLAB Workshop III, Nov 15-18, 2006, Singapore: Julie Onton Data Decomposition with ICA 40