indexing multiple subjects and then making multiple different lines for each subject?

Hello!

I have a for loop for two subjects where I am graphing their time series.

I want to 1) manually put and index certain time segments for sleep, e.g. lines = [30:35, 60:70] [10:20, 65:70].

and then 2) I want to use this index to plot two lines on each graph that have different values.

I've used the yline and then now the line function which works but I need it to be the sleep index instead:

lines = [30:35, 60:70] [10:20, 65:70]

for k = 1:length(subj)

        %plotting
        subplot(2,1,k); hold on
        plot(whole_ts{k}, detrend_ts{k}); hold on
        
        line([30,60],[y,y], 'LineWidth',8) %THIS IS THE LINE
        %yline(-15,'LineWidth',8)
        yl.Color = [.80 0 .40];
        ylim([-15 15])
       
end

this is along the lines of what I want:

lines = [30:35, 60:70] [10:20, 65:70]

for k = 1:length(subj)

        %plotting
        subplot(2,1,k); hold on
        plot(whole_ts{k}, detrend_ts{k}); hold on
        
        line(lines,[y,y], 'LineWidth',8) %THIS IS THE LINE
        %yline(-15,'LineWidth',8)
        yl.Color = [.80 0 .40];
        ylim([-15 15])
       
end

can anyone help me?

here is an example of what i want to do (the red line):