Our dreams are neural activity in our brain; there’s nothing special about them that doesn’t affect every other emotional or perceptual experience we have in our waking lives.
The big caveat is not the technology, but the fact that we still don’t really know the neural code; we still don’t know how conscious experience is encoded in the brain.
But one day, if we do understand what’s going on with the biology, and the technology exists, there’s no reason why we couldn’t download our consciousnesses onto a computer and live forever—or, alternately, share our dreams.
On a more philosophical level, your thought, and your dreams, are always embedded in your overall memory networks and life experiences. Besides the innocuous sense in which we communicate our dreams, there are at least two interesting senses of dream-sharing: to have the same dream (co-dreaming); and to view another’s dream, perhaps through advanced technology (dream-scanning).
On that view, dreaming is a fundamentally private (sleeping) experience that can only currently be shared through (waking) communication: the experience itself occurs in isolation.
On this alternative view, there is no fundamentally private experience behind our dream reports.
We predict that information one might gain from scanning the brains of sleeping people will only correlate very loosely with their dream reports because what people report dreaming is influenced by so many other factors, such as cultural norms and social expectations.