The Neuroscience of Avatar – could we really download our brains into a new body?

By Lauren Wagner

Thirteen years after the first Avatar movie came out in 2009, director James Cameron invites viewers to journey back to the faraway, lush exo-moon of Pandora with a sequel: Avatar: The Way of Water. To say that the franchise’s reprise has been successful is an understatement: the film raked in a billion dollars in the box office in its first two weeks alone. The 2022 follow-up film focuses less on the science fiction of avatar bodies and transfers of consciousness than the first installment, and more on the indigenous’ culture, spirituality, and unique relationship with the Pandoran biosphere. Nonetheless, as thousands of viewers re-watched the original film in late 2022 – Disney even re-released a remastered version of the original in theatres across the U.S. – the sequel’s recent debut reignited questions about the meaning of consciousness, memory, and what it means to be human on an alien world.

What is so captivating about this fantasy world? Sure, flying around on air and water dragons is exciting. However, at the same time, the Avatar franchise taps into a specific theme of science fiction that many have pondered. What would it be like to export one’s consciousness – thoughts, memory, and all – out of the confines of the human body, and experience the world with an entirely new anatomy? Is such a phenomenon even possible?

Set in the year 2154, the original Avatar movie follows a retired U.S. Marine soldier’s journey to the distant moon of Pandora, an earth-like world with diverse flora and fauna that includes an intelligent humanoid species known as the Na’vi. Although Pandora’s climate is suitable for human habitation, the moon’s poisonous atmosphere requires the human colonizers either to don oxygen masks when venturing outside, or to use lab-grown human-Na’vi hybrid bodies known as “avatars” as proxies during their expeditions. Each avatar body is grown from a mix of Na’vi and human DNA to be customized for one human operator. Newly grown avatar bodies are, presumably, a tabula rasa that closely mirrors its human’s physiology and genetics. In other words, the avatar body is a mostly-genetically-alien hybrid clone of a specific human, having reached maturity without any experiential input from its environment – a neural “blank slate” ready to be occupied by the driver.

In the world of Avatar, these hybrid bodies are operated using a “link bed” machine that remotely transmits neural signals from the human operator’s brain to the avatar’s brain. Although the films do not detail the mechanics of this neural link and how remote transmission is achieved, the process would likely require a complex network of many thousands of neural transceivers to be implanted at key locations throughout the avatar’s brain. These transceivers would be capable of recording sensory input from the avatar brain as its body interacts with the outside world, and subsequently relaying the information back to the human brain. At the same time, the link bed would need to pick up signals from the human driver’s motor cortex in order to stimulate the avatar brain’s corresponding motor centers, thus executing the driver’s planned actions.

With these mechanics, it is clear that the human operator does not “transfer” their conscious to the avatar body during each link session. Rather, the process is more akin to how we think of immersive virtual reality technology. The avatar body is used as a sort of biological prosthetic that bypasses the operator’s human body, which lays paralyzed, entranced in a dream-like state. The transceivers that control the remote body execute the driver’s neural commands for movement, while simultaneously transmitting sensory information back to the human body as the avatar interacts with the outside, alien world.

How would this “link” be possible? For starters, we know that electrical patterns throughout the brain oscillate at certain frequencies, depending on whether a person is awake, asleep or excited. This idea forms the basis for electroencephalography (EEG), a common neuroimaging technique. Synchronizing neuronal activity across the human and avatar brains so that they are, quite literally, “on the same wavelength” would likely require a process called brainwave entrainment. Using external stimuli, such as electrical current, magnetic stimulation (Herrmann et al., 2013), or even sound waves (Basu & Banerjee, 2022), researchers can induce shifts in the brain’s oscillations such that they lock onto a new frequency. Recent research suggests that neural entrainment could have applications for improving memory and attention (Basu & Banerjee, 2022) or even treating psychiatric conditions (Strüber & Herrmann, 2020). Perhaps in the far future, brainwave entrainment will also be the key to syncing up with your avatar body.

Once the human and avatar brains are synced, what technology would we need to operate a remote body? Such a technology would need to be capable of recording high-resolution, high-speed information from the human driver and relaying it to the remote transceivers embedded in the avatar brain, while simultaneously stimulating the human brain to convey information as the avatar interacts with the world. An early form of such technologies may exist today. Today’s functional near-infrared spectroscopy (fNIRS) imaging technology uses infrared light to non-invasively record brain activity with excellent temporal resolution (samples can be recorded up to 100 times per second), and spatial resolution superior to that of an EEG apparatus (about 1 cm²; Quaresima & Ferrari, 2016). However, fNIRS can only pick up activity near the surface of the brain’s cortex. This means that, with today’s non-invasive recording technology, neuronal activity in important deep-brain structures responsible for emotion, learning, and memory are off-limits.

To stimulate the human operator’s brain so that they are made aware of incoming signals from the avatar body, one might use a technique known as transcranial magnetic stimulation (TMS), which uses magnetism to induce electrical currents within the brain. Indeed, a growing number of researchers are beginning to use concurrent TMS-fNIRS (see (Curtin et al., 2019) for a review), showing that these two non-invasive recording and stimulation technologies can be reliably used at the same time. Although today’s noninvasive TMS technology can reach spatial resolution on the order of a few millimeters, typically only one brain structure receives stimulation in any given experiment. Moreover, like fNIRS, TMS can only penetrate to regions near the brain’s surface (Bolognini & Ro, 2010), leaving out many important structures. Newer techniques, such as focused ultrasound (FUS) technology, may be a promising stimulation approach in the coming decades with higher spatial resolution (~1mm) and the ability to penetrate to deep brain structures (Liu et al., 2022). However, given current technology, the fields of noninvasive brain imaging and stimulation will need some major technological advances before we see remote-controlled avatar bodies.

Remote-operated bodies are not the only brain-based phenomenon proposed in the Avatar movies. At the end of the first film, protagonist Jake Sully has his human consciousness permanently transferred into his Na’vi avatar body using the vast neurological network that connects organisms throughout Pandora’s biosphere. Sully, a paraplegic previously wounded in combat on Earth, has his full physical abilities permanently restored thanks to this new, alien body. But, is it true that Sully’s consciousness has been transferred to this new form? Or, has an entirely new consciousness been awakened?

Central to this question is the idea of mind-body dualism, which says that the mind and the body are fundamentally separate entities — that a human’s consciousness can be unyoked from the body that houses it. This concept dates back to ancient Greek philosophy, and the debate between dualism and its counterpart, monism, has been contentious ever since. Although the idea of a soul separate from the body is pivotal to many schools of spiritualism and religion, contemporary neuroscientists are typically trained to take a monistic view of the brain: that is, they view behaviors, emotions, and consciousness as “emergent phenomena” that arise directly from the gray and white matter inside of your skull.

If we make the widespread assumption that a person’s consciousness is not distinct from their nervous system, but rather emerges directly from it, then it is safe to conclude that this “consciousness transfer” was not really a transfer at all. Instead, the human Jake Sully actually dies as the Na’vi Sully awakes. What is really happening here is that the avatar body – with a distinct brain trained over hundreds of hours of use to contain a duplicate of Sully’s memories, knowledge, personality, and muscle memory – is finally activated. It is not the original Sully anymore. It’s an autonomous copy.

This idea is developed slightly further in the sequel film, where the main antagonist is unexpectedly revived in a new avatar body that has been “imprinted” with a copy of the original character’s brain – the neural analog of making a backup of your computer’s hard drive and plugging it into a new computer.

Mapping the brain’s every connection and synapse – of which there are an estimated 10¹⁴ (Bostram, 1998), equivalent to about 12.5 terabytes of information – is an unthinkable task given current technology. Indeed, some researchers, like Dr. Eve Marder, have spent decades studying the dynamics of just a few dozen neurons in model organisms like the humble lobster (Nassim, 2018). In April 2019, one laboratory at the Allen Institute for Brain Science successfully mapped all of the neuronal connections contained in one cubic millimeter of mouse brain (DeWeerdt, 2019). With 100,000 neurons and one billion synapses to capture, the lab’s microscopes were imaging brain slices nonstop for five months. To think that we would be able to copy an entire human brain non-invasively in the next century, although not impossible, is overwhelmingly improbable. And then, there is the entirely separate hurdle of copying all of that information onto the newly-grown avatar brain.

Overall, the second installment in the Avatar franchise provokes some fascinating questions about neuroscience and the meaning of consciousness. Even though we are far from being able to experience the world through a new body, or download our personalities into a new brain, Avatar gives us the opportunity to consider where we are now, where we’re going, and what it would take to get to Pandora.

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Written by Lauren Wagner

Illustrated by Federica Raguseo

Edited by Chris Gabriel, Anastasiia Gryshyna, Zoe Dobler

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References
Basu, S., & Banerjee, B. (2022). Potential of binaural beats intervention for improving memory and attention: Insights from meta-analysis and systematic review. Psychological Research. https://doi.org/10.1007/s00426-022-01706-7

Bolognini, N., & Ro, T. (2010). Transcranial Magnetic Stimulation: Disrupting Neural Activity to Alter and Assess Brain Function. Journal of Neuroscience, 30(29), 9647–9650. https://doi.org/10.1523/JNEUROSCI.1990-10.2010

Bostrom, N. (1998). How long before superintelligence?. International Journal of Futures Studies, 2. https://nickbostrom.com/superintelligence

Curtin, A., Tong, S., Sun, J., Wang, J., Onaral, B., & Ayaz, H. (2019). A Systematic Review of Integrated Functional Near-Infrared Spectroscopy (fNIRS) and Transcranial Magnetic Stimulation (TMS) Studies. Frontiers in Neuroscience, 13. https://www.frontiersin.org/articles/10.3389/fnins.2019.00084

DeWeerdt, S. (2019). How to map the brain. Nature, 571(7766), S6–S8. https://doi.org/10.1038/d41586-019-02208-0

Herrmann, C., Rach, S., Neuling, T., & Strüber, D. (2013). Transcranial alternating current stimulation: A review of the underlying mechanisms and modulation of cognitive processes. Frontiers in Human Neuroscience, 7. https://www.frontiersin.org/articles/10.3389/fnhum.2013.00279

Liu, X., Qiu, F., Hou, L., & Wang, X. (2022). Review of Noninvasive or Minimally Invasive Deep Brain Stimulation. Frontiers in Behavioral Neuroscience, 15, 820017. https://doi.org/10.3389/fnbeh.2021.820017

Nassim, C. (2018). Lessons from the Lobster: Eve Marder’s Work in Neuroscience. MIT press.

Quaresima, V., & Ferrari, M. (2019). Functional near-infrared spectroscopy (fNIRS) for assessing cerebral cortex function during human behavior in natural/social situations: a concise review. Organizational Research Methods, 22(1), 46-68. https://doi.org/10.1177/1094428116658959

Strüber, D., & Herrmann, C. S. (2020). Modulation of gamma oscillations as a possible therapeutic tool for neuropsychiatric diseases: A review and perspective. International Journal of Psychophysiology, 152, 15–25. https://doi.org/10.1016/j.ijpsycho.2020.03.003