Looking at 4chan as an example, although in theory masked the discussions defaults to a specific and recognizable tone and specific ways of argumenting or joking.
Giving a mask gives you a new contextual facet of a person, but hardly the truth. Few are those who can even know the truth about themselves. I don't know if I do.
Perhaps it's more like give someone a mask and they will tell you their psychosis. Is the disinhibited mind properly functioning any more than a drunk person is their real self or a disinhibited muscle contributes the most to a person's presence?
"Man is least himself when he talks in his own person. Give him a mask, and he will tell you the truth - Oscar Wilde."