Standard deviation of gaussian mask for drifting grating stimulus

I was wondering in what units the standard deviation of the gaussian mask for the drifting grating stimulus is given. Intuitively I would have thought it’s in dva, but then gratings of different widths, but with the same standard deviation should look the same (which they don’t), right? My next best guess is that it’s percentage of the stimulus width?
Any answer would be greatly appreciated.
Thanks a lot!
Benedict (German Primate Center)

Hi Benedict,

Please see this discussion for an explanation. (Adding this to the user manual is still on my to-do list!)

Chris Stawarz

Thanks Chris, that answered all my questions! Sorry for not looking properly first.