Time-frequency: ERSP & ITC

In the GUI

1. Plot channel time frequency -- pop_newtimef()Channel number... ← 14
2. Sub epoch time limits [min max] (msec)
3. Frequency limits [min max] (Hz) or sequence ← 3 30
4. Baseline limits [min max] (msec) (0->pre-stim.) ← 0
5. Wavelet cycles [min max/fact] or sequence ← 3 0.8
6. Optional newtimef() arguments (see Help) ← 'winsize', 128
7. Plot Event Related Spectral PowerPlot Inter Trial CoherenceOk

Script

cz = find(strcmp({EEG.chanlocs.labels}, 'Cz'));
figure;
[ersp, itc, powbase, times, freqs] = pop_newtimef(EEG, 1, cz, ...
    [EEG.xmin EEG.xmax]*1000, [3 0.8], 'freqs', [3 30], 'winsize', 128, ...
    'baseline', 0, 'padratio', 1, 'plotphase', 'off');
itcMag = abs(itc);
fprintf('Frequencies %.1f to %.1f Hz, times %.0f to %.0f ms\n', ...
    freqs(1), freqs(end), times(1), times(end));
[maxItc, idx] = max(itcMag(:));
[fi, ti] = ind2sub(size(itcMag), idx);
fprintf('Max ITC %.2f at %.1f Hz, %.0f ms\n', maxItc, freqs(fi), times(ti));

Which value should I choose?

For your Methods

Event-related spectral perturbation and inter-trial coherence were computed at Cz with newtimef using Morlet wavelets whose number of cycles increased linearly from 3 at 3 Hz to 6 at 30 Hz, relative to a −500 to 0 ms prestimulus baseline (EEGLAB 2026.1).