Simply EEGLAB

AMICA & Picard

Station 4 · Lesson 7 · EEGLAB 2026.1

In the GUI

  1. FileManage EEGLAB extensions
  2. ToolsDecompose data by ICAICA algorithm to use (click to select)Infomax picard.mCommandline options (See help messages) 'maxiter', 500, 'mode', 'standard'
  3. PlotComponent mapsIn 2-DOK runica
  4. ToolsRun AMICA
  5. In File:# PCA Dims.: eeglab_data.fdt

Script

EEG_ica = pop_eegfiltnew(EEG, 'locutoff', 1);
expectedRank = EEG_ica.nbchan - numel(badChans) - 1;
tic;
EEG_runica = pop_runica(EEG_ica, 'icatype', 'runica', 'extended', 1);
tRunica = toc;
tic;
EEG_picard = pop_runica(EEG_ica, 'icatype', 'picard', 'maxiter', 500, ...
    'mode', 'standard', 'pca', expectedRank);
tPicard = toc;
fprintf('runica: %.0f s, %d components\n', tRunica, size(EEG_runica.icaweights, 1));
fprintf('Picard: %.0f s, %d components\n', tPicard, size(EEG_picard.icaweights, 1));
pop_topoplot(EEG_runica, 0, 1:10);
pop_topoplot(EEG_picard, 0, 1:10);

Which value should I choose?

runica (extended Infomax)PicardAMICA
Comes with EEGLABYes, the defaultNo, an extensionNo, an extension
Speed, as EEGLAB labels itThe defaultFastICA picard.m (fastest)AMICA (slowest; best)
What it givesOne ICA modelA plain Infomax (not extended) or FastICA solution, reached fasterOne or more ICA models
Rankpop_runica tries to detect itPass 'pca' yourselfSet the number of components to keep yourself
When to choose itMost studies, and everything on this roadmapMany datasets, or many channels, when time mattersWhen you want the slowest, most careful decomposition and have the time

Check

  • The algorithm appears
  • The number of components
  • The maps are similar
  • You noted the time

For your Methods

Independent component analysis was computed with Picard (Infomax mode, maximum 500 iterations; picard plugin [version], EEGLAB 2026.1; [31] components after PCA reduction to the data rank) on a copy of the data high-pass filtered at 1 Hz, and the resulting weights were applied to the 0.1 Hz high-pass filtered data.

Full lesson: https://simplyeeglab.pages.dev/en/lesson/amica-picard/

Content license: CC BY-NC-SA 4.0 · MIT (code)

An independent learning site, not affiliated with EEGLAB or SCCN.