I've been thinking about this for a while now but I've been approaching it from the opposite direction.

If we were attempting to put someone into some sort of Matrix like reality simulator but we lacked the technology to provide a perfect simulation what level of simulation would be 'good enough' that a human would consider it reality and be able to develop into something we could relate to?

If you gave someone the Helen Keller level of experience, but with reduced tactile sensation, how much could you reduce that touch sensation before they wouldn't be like us?