Scientists at UC Berkeley have achieved a major milestone in their quest to create a technology that would let us tap into our brain's imaging systems. They used functional Magnetic Resonance Imaging (fMRI) and computational models and they succeeded in decoding and reconstructing visual experiences of their test subjects.
The tests they ran had people watching a movie trailer. Then, they reconstructed the images using their new technology. While that's as far as they can do right now, it puts them one step closer to being able to tap into your dreams.
The more noble implications for this technology will allow some sort of understanding, and even communication with people who cannot communicate verbally. For example, stroke victims, and people in comas. Check out the source if you wanna learn more about how they achieved this great feat.