Immersion in Virtual Worlds

The worlds created using virtual reality technologies induce an illusion of reality that can be really powerful, as they play with various cognitive mechanisms associated with human perception and emotion. It is relatively easy to deceive our senses and feel ourselves in another place or in other bodies, which until recently could only be regarded as science fiction. Do we understand how our brains work in our interaction with virtual reality? Will the day come when we are unable to tell the difference between a real and a virtual environment?