For the first time in over a decade, a new Star Wars film is upon us, and if you’re like the staff of Knowing Neurons, your nucleus accumbens is firing off A monoamine neurotransmitter. Dopamine is involved in many b... as fast as it can! Oh, what’s that you say? Lightsabers, Star Destroyers, and the Force have nothing to do with neurons, action potentials, and brain waves? Ah … I find your lack of faith disturbing.
Heads up! There are spoilers to come for Episodes I – VI, but not for the new J.J. Abrams film.
Our journey begins in the carbon freeze chamber on Bespin. Much to our horror, space pirate and reluctant hero Han Solo has been frozen in carbonite by the evil Lord Vader. Though alive, Han persists in a state of suspended animation until he is rescued in the next film. Is carbonite real? Could we freeze Harrison Ford in real life?
The chemical suffix –ite indicates an anion formed with oxygen. In the case of carbonite, this would refer to the ion CO22-. Being a charged particle, carbonite would not be stable as a pure substance; rather, it would need to be dissolved in solution or bound to another ion as a salt. But fear not, future Sith Lords. The same malicious feat of freezing Captain Solo could be achieved with liquid nitrogen. Nitrogen, which composes 80% of our air, condenses into a liquid at a chilly -320°F. In our universe, liquid nitrogen is used for cryonics, the process of preserving living organisms at extremely cold temperatures. Because cold temperatures stall the chemical reactions that decompose the body after death, a dying person could theoretically preserve his or her body indefinitely. The body may then be thawed out in the distant future after medicine finds a cure for the patient. In fact, cryonics already exists as a private industry today! Because of the expenses of freezing an entire body for decades (or centuries), many individuals opt to have only their heads frozen. This preserves the brain and all of its rich synaptic connections that encode not only memory, but arguably the nuanced personality of the individual. A considerable challenge of cryonics is ensuring that ice crystals, which lyse cells, do not form during or after the freezing process. While a human being has yet to be revived from cryonic preservation, goldfish frozen in liquid nitrogen have been effortlessly brought “back to life.”
So, would Captain Solo survive the freezing process? Nobody really knows. But as with any scientific experiment, statistical inference would be needed to learn more. In The Empire Strikes Back, Vader freezes Han as a test to see if Luke Skywalker can be successfully frozen alive and brought before the Emperor. While a great Sith Lord, Vader may not be such a great scientist (no, please don’t Force choke me!). Freezing Han is really a case study demonstrating only that it is possible to survive the carbon freezing without saying anything about the probability of survival. For all know, Han’s case could be one in a million!
Later, near the end of The Empire Strikes Back, Luke loses his hand in a lightsaber duel with Vader. Thanks to cybernetics, he later receives a perfectly human-looking prosthetic hand, which he controls with his mind! We also see in the prequels that Luke’s father has many prosthetic limbs. At the time Empire was filmed, functional prosthetic limbs were pure science fiction. But today, thanks to the wonders of biomedical engineering, prosthetic limbs are reality. Last year, Les Baugh became the first bilateral arm amputee to control his Modular Prosthetic Limbs just by thinking about the movements. This remarkable engineering feat from a team at John Hopkins has gone even further, as they collaborate with DARPA to build the “Luke Arm,” officially called the DEKA Arm System. This FDA approved arm can make even more realistic and complicated movements, which will hopefully improve quality of life for amputees.
So how can thoughts operate machines? Electrical signals from the brain are read by a computer using a brain-computer interface (BCI). These computers acquire brain signals, analyze them, translate them into commands, and relay these commands to an output device, such as a robotic arm. Recent studies found that monkeys, whose brain signals are analyzed passively through the scalp using a technology called electroencephalography (Electroencephalogram, a technique that places electrodes on ...), can easily accept mechanical arms as their own, using them to grab and eat food. In the not so distant future, BCIs might also be able to receive sensory feedback, sending information from the arm to the brain. This would give the user a sense of proprioception as well as touch, allowing for faster reaction rates and skilled interaction with the outside world.
In the original Star Wars film, Darth Vader warns the crew of the Death Star that technology is “insignificant next to the power of the Force.” While the Force is a fictional concept, some practices of the Jedi, including meditation, are real. During his furious lightsaber duel with Darth Maul in The Phantom Menace, Jedi master Qui-Gon Jinn takes a break to peacefully meditate as an energy field comes down between the two opponents. How does meditation affect the brain? What benefits does it have for cognitive processes such as attention and focus?
Zen practitioners, who have extensive experience with meditation, show powerful alpha oscillations in EEG recordings. Alpha is a brain wave with a frequency of 8 to 12 cycles per second, and it is observed during quiet relaxation, especially over visual brain regions when the eyes are closed. In individuals inexperienced in meditation, alpha oscillations are interrupted by distracting stimuli, such as loud noises. Experienced meditators, however, show alpha oscillations that are relatively robust to distracting stimuli. Moreover, the amplitude and spatial extent of alpha oscillations over the scalp is greater in experienced Zen meditators.
But sitting several feet away from a dangerous Sith Lord, why is blocking out one’s environment preferable to a state of hypervigilance? As it turns out, meditation-naive individuals show less and less disruption of alpha oscillations as the distracting stimulus is repeated, a phenomenon known as habituation, suggesting lessened awareness of the environment. By contrast, experienced meditators do not habituate, showing a rather modest disturbance of alpha oscillations each time the stimulus is repeated. It seems that meditation allows for both inner focus and sustained awareness of the environment, a balance that can be described as a blurring of the self with the environment.
While the Star Wars universe is often described as space fantasy, it is fun to consider which elements are grounded in real science. When The Force Awakens opens this weekend, see if you can identify which aspects of the movie relate to the brain and medicine! Grab your popcorn, get your dopamine fix, and may the Force be with you!
Buzsaki, Gyorgy. Rhythms of the Brain. Oxford University Press, 2006.
Resnik, L., Klinger, S. L., & Etter, K. (2014). The DEKA Arm: its features, functionality, and evolution during the Veterans Affairs Study to optimize the DEKA Arm. Prosthetics and Orthotics International, 38(6), 492–504. http://doi.org/10.1177/0309364613506913