Sigmund Freud once asked the question: "Where does a thought go when it's forgotten?" The human mind is perhaps the most valuable, high-tech machine in the known universe. An infinitely complex maze of neurons and transmitters build a supercomputer hidden within each person with enough capacity to power the miracle of human consciousness and thought.

Our thoughts were once believed to be mysterious in origin and spiritual in nature, however new developments in technology mean that our most personal qualities may soon be something tangible, and even something digitalized.

Facebook is leading the charge. The global tech conglomerate is investing into research on interfaces between brain and machine that will allow thoughts created within the brain to be directly picked up and translated into words, without the need for any form of speech or external communication. The vision is grand.

Facebook in an announcement last month stated:"Imagine a world where all the knowledge, fun, and utility of today's smartphones were instantly accessible and completely hands-free. Where you could spend quality time with the people who matter most in your life, whenever you want, no matter where in the world you happen to be. And where you could connect with others in a meaningful way, regardless of external distractions, geographic constraints, and even physical disabilities and limitations."

The short-term goal however of Facebook is to aid patients with paralysis by enabling the interface to decode brain signals so they will be able to speak out their thoughts without so much as a wink or twitch of a muscle. This already would be a huge step forward because current techniques, such as electroencephalography are extremely slow, sometimes taking up to 70 minutes to painstakingly type out a single sentence. For patients incapacitated by neurological diseases, their longing for the gift of easy social communication is intense; something most of us take for granted.

Facebook is making decent progress. Patients in studies at the University of California San Francisco have had their thoughts decoded before they are spoken out loud with up to 61 percent accuracy.

Elon Musk's tech startup Neuralink is also keen to accelerate the development of this new technology, with significant progress being made. In an announcement also made last month, the unusually secretive company announced that a monkey had been able to control a computer with its brain in studies, and that advancements in the types of "threads" connecting the machine to the brain had been made, allowing a higher transfer of data through up to 3,072 electrodes, each thinner than a hair, attached to the brain.

Neuralink is also researching improving the medical procedure, with trials set to take place into using a laser to penetrate the skull, instead of drills.

Musk, the maverick Tesla and SpaceX CEO, has undoubtedly got a strong vision, and Neuralink hopes to have its very first human patient by the end of this year.

It is not yet clear however, just how many years off this fanciful future is for the rest of the population. It is hard to imagine such a leap of technology and change to the way in which we interact with electronic devices, even with the advent of mainstream touchscreen devices. Plugging our brains directly into such devices may seem like a big step. A far cry off from a steel hip replacement, boundaries between man and machine may soon be blurred in the most personal of ways. It seems that such a revolutionary technology involving our thoughts is the most difficult notion for our brains to imagine.