Update 'README.md'

README.md

@@ -5,6 +5,6 @@ All of the preprocessed data is available in the “Data" folder. There you can
 
 You can generate most of the figures in the paper by downloading the Data folder and the MatlabScripts folder, adding both folders to your Matlab path, and running the scripts in the MatlabScripts folder “3_Figures” — particularly “MainFigures.m”, as well as the scripts in “AdditionalFigures.”
 
-You'll want to change the pathname in "MatlabScripts/HelperFunctions/ottBari2020_root.m" to the folder that contains the Data folder.
+If you get error messages, they're likely related to pathname. You'll want to change the pathname in "MatlabScripts/HelperFunctions/ottBari2020_root.m" to the folder that contains the Data folder as well as the pathname for the behavior files for the "opto" AdditionalFigures scripts.
 
 Code will be updated at https://github.com/djottenheimer/VP_RPE_2020