Herff et. al. demonstrate in "Brain-to-text: decoding spoken phrases from phone representations in the brain" a brain-to-text system to map intracranial electrocorticographic recordings to text.
I've been looking for literature attempting to go the other direction, text-to-brain, but have not had much luck finding anything on Springer, Google Scholar, and related services.
For someone in the know, what's the current state of the text-to-brain problem?
We don't have a well tested or accepted model of how specific items are encoded in the cortex, so text to brain is still far off. However, it is possible to send information to the brain.
Ramirez et al. 2013. Creating a False Memory in the Hippocampus
This study (in mice) involved creating a false sense of fear associated with a particular context. This implanted information is much higher level than just text, but it is still information.
pretty simple: through direct electromagnetic stimulation of photoreceptors in the retina in patterns corresponding to letter shapes, transduced through layers of processing there, passed through the optic nerve to the lgn of the thalamus and from there to visual cortex, eventually you get a complete neural representation of the text. alternatively, you could use direct stimulation of the chochlea via pressure waves in the ear canal transduced by the bones of the inner ear. the auditory cortex will then do most of the heavy lifting.
seriously, though, that paper's achievement was pretty limited: "With 10 words in the dictionary, 75% of all words are recognized correctly." That is just over 3 bits of information being conveyed. And that is after training the classifier.
Training the brain to classify direct inputs is at about the same level of a few bits. www.nature.com/articles/srep01319
see What research has been done on brain-to-brain interfaces?
