Simply EEGLAB
ERP image
Station 7 · Lesson 3 · EEGLAB 2026.1
In the GUI
- PlotChannel ERP image
- Channel
...Pz - Smoothing
1 - Time limits (ms)
-200 800 - Plot scalp mapPlot ERPPlot colorbarOk
- PlotChannel ERP image
- Smoothing
10 - Epoch-sorting field
latency - Event type(s)
rt - Event time range
0 1000 - RescaleAlignOk
no - AlignTime limits (ms)Ok
Inf
Script
EEG = pop_loadset('D1_epochs_clean.set', pwd);
chan = find(strcmp({EEG.chanlocs.labels}, 'Pz'));
rt = eeg_getepochevent(EEG, 'type', {'rt'}, 'timewin', [0 1000]);
fprintf('%d of %d epochs have a response, median RT %.0f ms\n', ...
sum(~isnan(rt)), EEG.trials, median(rt, 'omitnan'));
figure; pop_erpimage(EEG, 1, chan, [], 'Pz', 1, 1, {}, [], '', ...
'erp', 'on', 'cbar', 'on', 'limits', [-200 800], ...
'topo', {chan EEG.chanlocs EEG.chaninfo});
figure; pop_erpimage(EEG, 1, chan, [], 'Pz sorted by RT', 10, 1, {'rt'}, [0 1000], 'latency', ...
'erp', 'on', 'cbar', 'on', 'limits', [-200 800], ...
'topo', {chan EEG.chanlocs EEG.chaninfo});
figure; pop_erpimage(EEG, 1, chan, [], 'Pz aligned to response', 10, 1, {'rt'}, [0 1000], 'latency', ...
'align', Inf, 'erp', 'on', 'cbar', 'on', ...
'topo', {chan EEG.chanlocs EEG.chaninfo});Which value should I choose?
| Setting | Value |
|---|---|
| Smoothing | 1 for a first look, then 5 to 10 |
| Event time range | 0 1000 for D1 |
| Channel | Pz for a late positive component, POz or Oz for alpha |
| Color limits (see Help) | Empty (the default) or a fraction such as 0.9 |
| Downsampling | 1 |
| Align | Empty, or Inf to view from the response side |
For your Methods
Single-trial ERP images at Pz were sorted by reaction time and smoothed with a 10-trial moving average (pop_erpimage, EEGLAB 2026.1); [N] epochs without a response between 0 and 1000 ms were excluded from the image.