Why it's so hard to get rid of fear in the first place
Traditionally, people with phobias, PTSD, and other fear-related disorders have been treated by exposure therapy. Exposure therapy involves confronting the thing that terrifies you most, again and again, until you learn to deal with it.
For example, if you have a phobia of cockroaches, your first session might involve talking with a counselor about the hairy-legged, glossy brown spawns of Satan. Next, you might sit in the same room as a dead roach (gross). Finally, you'd work up to holding a live one (vomit). The experience can be unpleasant, for obvious reasons.
That's why this new technique -- called decoded neurofeedback, or DecNef -- is so revolutionary. It overwrites subjects' fear memories without requiring them to consciously experience fear or the terrifying object itself. "When referring to fear reduction effect, then yes, our results suggest that it can be achieved without physical presentation (i.e., awareness)," Dr. Koizumi wrote in an email.
In short, you don't have to see a roach for DecNef to work. You don't even have to think about a roach.