Re: Where does the future of virtual reality lie?

Dear Mike,

You’re not the first person who thinks about such projects. It is indeed 
possible to stimulate some specific brain areas with small electrodes to 
produce different sensations. These experiments have mostly been done 
during surgical procedures made to relieve patients from symptoms like 
severe epilepsia. In these procedures, the patient is awake and a part of 
his/her brain is exposed, allowing the surgeon to stimulate the brain and 
the patient to report what s/he experiences. There are also non-invasive 
techniques such as transcranial stimulation that allows to stimulate the 
brain but they are less precise compared to microelectrodes.  Moreover, 
you may know that many brain areas are folded into sulcus while others lie 
in deeper parts of the brain. These regions are therefore extremely 
difficult to access even for neurosurgeons. All these considerations would 
pose serious technical problems to the development of programs like 
you’re thinking about. One other problem that is even more important is 
the following: we have no idea about how we could create the perception 
of a given object with the use of brain stimulation. Indeed, if you 
stimulate the visual part of the brain, you can elicit gross sensation of 
light or shadows in various parts of the visual field but you cannot 
create the perception of complex figures that you  have chosen in 
advance.  For example, suppose that you see a coloured bird that flies and 
makes sounds. The knowledge we have tends us to hypothesize that the form 
of the bird, it's colour, it's movement, it's location in the space and the 
sounds it makes are analysed in different brain areas in an extremely 
complex manner.  If one wishes to reproduce this image through brain 
stimulation, it would suppose that the exact pattern of excitation of 
nearly each brain cell during such experience is known and it is obviously 
not the case. Many people can easily be impressed by new computers and 
recent technological advances but often underestimate the brain’s 
complexity (which surpasses by far any artificial device) and sometimes 
overestimate our limited knowledge about how the brain works.

Since the idea of stimulating the brain to create virtual reality faces 
several problems and seems to me almost impossible, what seems more 
encouraging in the future is to stimulate senses rather than directly 
stimulating the areas of the brain. Suppose that you wish to create a 
virtual scene in which you see a bird flying. Well, the only thing you 
have to do is to send to your eyes exactly what they would receive if the 
bird was actually real. This could be possible with special goggles. If 
you’ve ever tried these new 3D movies, that’s what they do: sending to 
each eye a slightly different image as is the case in real life because 
eyes are spaced laterally from each other. That creates a vivid impression 
of depth when you actually look at a flat screen. This may be a starting 
point to create virtual environments although many problems remain to be 
solved.
I hope that helps,
Eric