We arrive at the final chapter, which surveys some topics that could influence widespread VR usage in the future, but are currently in a research and development stage. Sections 13.1 and 13.2 cover the forgotten senses. Earlier in this book, we covered vision, hearing, and balance (vestibular) senses, which leaves touch, smell, and taste. Section 13.1 covers touch, or more generally, the somatosensory system. This includes physiology, perception, and engineering technology that stimulates the somatosensory system. Section 13.2 covers the two chemical senses, smell and taste, along with attempts to engineer ‘‘displays’’ for them. Section 13.3 discusses how robots are used for telepresence and how they may ultimately become our surrogate selves through which the real world can be explored with a VR interface. Just like there are avatars in a virtual world (Section 10.4 ), the robot becomes a kind of physical avatar in the real world. Finally, Section 13.4 discusses steps toward the ultimate level of human augmentation and interaction: Brain-machine interfaces.