Simply EEGLAB

Exporting results for papers & stats software

Station 8 · Lesson 8 · EEGLAB 2026.1

In the GUI

StudyPlot channel measuresSelect design: image onlyPz
ParamsPlot ERPsTime range (ms) [low high]OkPlot ERPs 150 250

Script

names = {STUDY.changrp.name};
chans = names(ismember(lower(names), {'fz', 'pz'}));
win = [150 250];   % window fixed before looking at the data (Thorpe et al., 1996)
d = 3;             % design 'image only': every participant appears in both conditions
subjects = STUDY.design(d).cases.value;
conds = STUDY.design(d).variable(1).value;
rows = {};
for c = 1:numel(chans)
    [STUDY, erp, times] = std_readdata(STUDY, ALLEEG, 'channels', chans(c), 'design', d, 'datatype', 'erp');
    inWin = times >= win(1) & times <= win(2);
    for k = 1:numel(conds)
        if size(erp{k}, 2) ~= numel(subjects)
            error('Condition %s does not hold every participant', conds{k});
        end
        amp = mean(erp{k}(inWin, :), 1);   % one mean amplitude per participant
        for s = 1:numel(subjects)
            info = STUDY.datasetinfo(strcmp({STUDY.datasetinfo.subject}, subjects{s}));
            rows(end+1, :) = {subjects{s}, info(1).group, conds{k}, chans{c}, double(amp(s))};
        end
    end
end
T = cell2table(rows, 'VariableNames', {'subject', 'gender', 'condition', 'channel', 'mean_uV'});
csvFile = fullfile(studyDir, 'erp_150_250_mean.csv');
writetable(T, csvFile);
fprintf('%d rows written to %s\n', height(T), csvFile);
disp(T(1:4, :));
for k = 1:numel(conds)
    sel = strcmpi(T.channel, 'Pz') & strcmp(T.condition, conds{k});
    fprintf('Pz %s: mean %.2f uV over %d participants\n', conds{k}, mean(T.mean_uV(sel)), nnz(sel));
end

Which value should I choose?

Choice	In this lesson	When to change it
Measure	Mean amplitude in a window	Peak amplitude and latency are noisier for single participants. If you need them, see the ERPLAB amplitude and latency lesson.
Window	150 to 250 ms: the start from Thorpe et al. (1996), the end a choice for this lesson	From your question or earlier studies, fixed before you look. Never from the group plot of the same data.
Channels	Fz and Pz	The channels named in your hypothesis. Averaging a few neighboring channels gives a more stable value than one channel.
Design	3, all participants in both conditions	Any design, but then each cell holds only some participants: `setinds` (the seventh output of `std_readdata`) gives the dataset numbers in each cell, and the participant names are in `STUDY.datasetinfo(setinds{c}).subject`.
Format	CSV, long format	Wide format for SPSS. Use `writetable(T, 'file.xlsx')` if you need Excel.

For your Methods

For each participant and image category, the mean ERP amplitude from [150] to [250] ms was extracted at [Fz] and [Pz] (std_readdata, EEGLAB 2026.1; window chosen a priori from [Thorpe et al., 1996]) and exported for analysis in [software and version].

In the GUI

Script

Which value should I choose?

For your Methods

More