[Eeglablist] draw ROI on time-frequency plot

[chista fn]

*Hi everyone,*

I am currently working on an ERP analysis project. for my time-frequency
analysis, I plot the ERSP image, with the help of the
EEGLAB function pop_newtimef and now I want to plot a square or
Ellipse shape in the region that marks my P300 ROI, for example, 300 to 500
ms.
I tried drawing it with the help of Matlab xline but it seems it is not
working, so I'm wondering if anyone can help me with this problem

Any help is appreciated. Thank you!