On the membership plug-in, how can I associate a site role with an access level?

Is it possible to associate a site role with an access level?

I have 3 access levels - visitors, standard, premium.

When a user creates an account but does not subscribe to a membership plan, they get the default role which is 'subscriber'.

When a user subscribes to a membership (standard or premium), they should get the 'standard' role assigned to them.

How can I accomplish this?

Thanks!