As a young graduate student, I was fascinated with the idea that someday we, as scientists, would figure out a way to read signals in the brain with enough resolution to be able to operate computer interfaces directly with our brains. The computer interface helmet in James P. Hogan's The Genesis Machine and the immersive virtual reality in Real-time Interrupt were just the type of brain-to-machine interface that inspired me to enter the field of neurophysiology. Much more recently, Mary Lou Jepsen, former CEO at Intel, Google[X] and more ( https:///about-us ), suggests that one of her patents may even go a step further and provide machine-assisted telepathy in the form of sensors embedded into a wearable hat. Unfortunately, the biggest hurdle in brain-to-machine or brain-to-computer interfacing (commonly referred to as BCI) is the ability to pick up signals from deep inside the brain. EEG signals from the brain surface are easy. Memory signals from hippocampus, and deeper are much harder to separate from background. What we need is some good way to look inside the brain and be able to decipher the activity that corresponds to specific thoughts and intentions.
Most of our books have call numbers and subject terms, but a small portion of them (about 1/6 at present) do not have call numbers, and a lot of our fiction books (and some of our more obscure nonfiction) do not have subject headings. Rare books, children's books, and old popular fiction that's no longer popular are more likely not to have a these things, compared to other kinds of books. You can look for books without call numbers or subject terms in our author and title listings, however. In physical libraries, books have only one call number, which determines where they get shelved. In theory, it should be possible to assign multiple call numbers to online books, so that they can be found under multiple topics in the "virtual shelves". As a practical matter, though, we can only support one call number per book at present. We try to choose ones that put books in their most relevant category. For more precise categorization, try our subject term browsing .