Research from Boston University and ATR Computational Neuroscience Laboratories, Kyoto, Japan recently demonstrated that through a person's visual cortex, researchers could use "decoded functional MRI to induce brain activity patterns to macth a previously known target state and thereby improve performance on visual tasks. The most interesting part of their research found that the test subjects were learning, without being aware that they were learning.
Think of the implications. Aside from learning Kung Fu, you could download textbooks directly into your brain, without having to read them. Goodbye exams! On a more serious note, this research could be used to help rehabilitating stroke victims (the ones that survive thrombolysis anyway) by modifying brain patterns to match healthy subjects. The possibilities are truly mind boggling.