Plotting ERP standard dev. etc... in studies

[arnodelorme]

Add choice of option for plotting ERP

   Plot arithmetic means (trial average).    [X].   
        # Stanrdard Deviations.      +/-[0]
        # Std. error of the mean.     +/-[1]
  Else plot median []
        # PDF percentiles.        50 +/-[0]
  Else plot percentile of the distribution [ ___________ ]

https://sccn.ucsd.edu/wiki/Chapter_08:_Command_line_STUDY_functions

[arnodelorme]