Vasco,
> First I wanted to check if this looks correct or if the reverse group comparison constrasts need to be added
The original script looks fine and you don't need to add those reversed versions because they are simply flipping the sign.
> Is there a way to run a single model with all of these effects or do I have to run separate ISC models (i.e. a model with all
> videos, as above; a model only with social videos; and a model for the socialvs.non-social).
You would have to create a separate model for each case.
Gang