Receptacles with isolated grounds are still grounded. The ground is isolated from the grounding system downstream of the panel. For example, if you install a receptacle to a metal receptacle box you tap from another circuit, the grounds are common to all outlets on that circuit through the boxes and wiring. An isolated ground receptacle has insulators on the ears which insulates (isolates) the receptacle from the box. The receptacle is then grounded by the green wire attached to the screw on the receptacle and the wire is run directly to the ground bus of the panel and does not join any other circuit grounds.
If you use romex wire and plastic boxes, the ground scheme is almost the same. Since the plastic box is non-conductive, you are required to ground the green wire to the receptacle screw. If that circuit happens to be dedicated to that receptacle, it becomes an "isolated ground" receptacle by default.
If you use romex wire and plastic boxes, the ground scheme is almost the same. Since the plastic box is non-conductive, you are required to ground the green wire to the receptacle screw. If that circuit happens to be dedicated to that receptacle, it becomes an "isolated ground" receptacle by default.