it is an external impulse -- analagous to a flashing light
that is perceived, much like an encrypted credit card purchase online . . . and reassembled by various mechanisms that ARE within the brain
conscousness is external -- the coding for taking the encrypted stimuli IS, though, housed within the brain
which is why many assume conscousness is "based there"
but the memory itself is external . . . and to tap into these memories
you can't "use your mind"