What’s the EEG package? The link to JuliaHub doesn’t find the package (not your fault, this is auto-generated by Discourse) and Google doesn’t seem to help.
Anyway your plot looks like a Plots plot, and also looks like it’s just a single plot with five lines in? I don’t know EEGs at all but to me it looks like every series has just been normalized and then plotted with an offset, so something like:
p = plot(ylabel = "Amplitude (uV)", xlabel = "Time (s)", yticks = (1:5, ["F5", "O1", "F6", "TP8", "O2"]));
for (i, s) in enumerate(series)
plot!(1:length(s), i .+ (s .- mean(s)) ./ 1.5 * std(s), label = "")
end
current()
produces:

Where the 1.5 factor in the normalization effectively scales the vertical distance between the lines.
Now this feels somewhat hacky and to me it seems a bit weird to have an axis with a label that suggests some sort of numerical scale(uV) but then also have “categorical” labels, but maybe this is a standard plot in the field of EEG analysis?