Recently, in the tony backyard of David Goyer’s Los Angeles home, scientists, philanthropists, screenwriters, and producers gathered to delve into the mystery of consciousness–Who are we? How do we become self-aware? Can we augment our consciousness by hacking our sensory receptors?

In partnership with the National Academy of Sciences, following the first event with creators of science-infused entertainment–including Dune, Arrival, and Black Panther–the participants came with more questions than answers.

Definitions of consciousness

David Eagleman, a neuroscientist, technologist, and author who teaches at Stanford, was a consultant on the television show Westworld and hosts the podcast Inner Cosmos. He and his wife, Dr. Sarah Eagleman, a translational neuroscientist studying electrical activity within the brain and implantable brain-computer interface (BCI) devices, gave presentations before fielding an array of questions.  

“How do you define consciousness?” said David, repeating a question from one of the sixty seated guests. “It’s a famously hard question. I think of [consciousness] as the thing that flickers to life when you wake up in the morning.”  

Consciousness has been defined in many ways by many scholars, but one basic way to describe it is the ability to have subjective experiences. How that happens, though, is anything but clear.

What it’s like to be a bat

“Most people think about [consciousness] as some sort of gradient,” said David. “But of course, other animals can have consciousness very different from ours. There’s a famous 1973 essay by Thomas Nagel, “What is it like to be a bat?”…There’s really no way for us to know.”

Our perception of the world is limited by our biology. Thousands of cell phone conversations pass through our bodies unnoticed every day. The visible spectrum of light, the colors we see, are just a sliver of the electromagnetic spectrum because humans don’t have the receptors to pick up a wider range. Other animals, such as snakes and honeybees, can perceive infrared or ultraviolet light.

Sarah Eagleman avoids eating octopuses because they’re so intelligent. “I choose the foods I eat based on how conscious I think they are,” said Sarah. “I would never touch octopi because of the complexity of their behavior that I ascribe a higher level of consciousness.” 

Radiohead

Many scholars assume that consciousness is entirely constructed by the brain. When the brain loses oxygen, gets damaged, or dies, that’s the end of consciousness.

But other theories of consciousness, both old and new, also have proponents. Panpsychism, the idea that consciousness is a fundamental property of reality and pervades the universe, has come into vogue among contemporary philosophers of mind. 

Along these lines, David offered an illustration of a “radio hypothesis.” If a primitive tribe who knows nothing about modern technology were to discover a radio in the bushes, they’d likely assume that the voices were created by the device itself.  They wouldn’t guess that there are invisible things called radio signals, transmitted from distant cities, traveling all around us, that the radio picks up. What if consciousness is similar—our brains are acting as receivers? 

From a neuroscientific perspective, consciousness involves brain activity, but its exact origin remains speculative. “For my two cents,” said David. “Our job is to try to figure out the material world first.”

Consciousness on the brain

“As far as we can tell, we’re the only species who has thrown ourselves headlong into this puzzle of trying to figure out our own programming language. It would be like your computer used its peripheral devices to take its cover off and point its camera at its circuitry trying to figure out on its own what makes it run. That’s the situation we’re in,” said David. “And what we found under the hood is the most complicated thing we’ve ever found in the universe.” 

The human brain has about 86 billion neurons, each as complex as a large, bustling city. Every neuron contains the entire human genome, traffics millions of proteins in very complicated cascades, and is connected to about 10,000 neighbors. “What you have is about 200 trillion connections in the brain. This is you. This is all your hopes, your dreams, your aspirations, the agony, the ecstasy—it’s all happening right here.”

Expanding consciousness of sense-ability

“One of the things I proposed some years ago is the PH model of evolution. That stands for potato head,” said David. The idea is that sensors like your eyes, ears, and nose are just plug-and-play, and the brain figures out whatever is plugged into it. “In other words, the brain is a general-purpose device.”  

David’s work on non-invasive sensory substitution technology allows people to “hear” through their skin via a wristband, or “see” with vibrations on their back from a small vest.  

“Imagine feeling the state of your microbiome or seeing the world in ultraviolet,” he said, adding there are limitless senses we can add to our conscious awareness. This perception expansion changes what we understand as human reality.  

Brain-computer interfaces

Electrodes have been put into people’s brains for years, helping with disabilities and more. Patients are controlling prosthetic limbs, using device telepathy to control a cursor on their computer screen and objects with their thoughts. There are retinal and cochlear implants that significantly improve people’s vision and hearing, and potential methods to combat PTSD. “I think it’s just a matter of time before people are controlling exoskeletons and robots and stuff like that. It’s an exciting time to be in the field,” said Sarah 

As BCIs become more integrated, they raise complex ethical questions about autonomy and identity. Movies such as Eternal Sunshine of the Spotless Mind and Inception come to mind. Although there is regulation, there is still a risk of bad actors hacking your brain, getting access to personal and neural data, and other security vulnerabilities, potentially compromising personal autonomy. While the promise of BCIs is great, so is the need for ethical oversight.

To sleep, perchance to dream

“Most of my career has been spent using tools to probe consciousness,” said Sarah, noting electrical systems in our brains change systematically as we fall asleep. Dreams, she explains, are the brain rehearsing what it experiences during the day, and all animals, even house flies, dream.

Because the brain has remarkable plasticity (the ability to change its structure and function), David suggests dreams might also protect the visual cortex from sensory takeover during the night. “The brain is locked in silence and darkness, relying on a few windows to the world…all the important stuff is in that silent kingdom.” Only 5% of the visual cortex’s input comes from the eyes; the rest is internal, which is why we can have rich visual experiences with our eyes closed. “That’s what dreams are at nighttime.”

The internal nature of consciousness also explains phenomena like Anton Syndrome, where blind individuals believe they can see, or phantom limb sensations. “Again, all of this is happening because the whole theater show is internal anyway,” said David.

What happens to consciousness during and after death? 

Experts report that during cardiac arrest, some individuals exhibit large-scale brain activity, potentially explaining the phenomenon of life flashing before one’s eyes. In other cases, brain activity gradually decreases, eventually becoming silent and flatlining as death occurs.

David emphasizes the importance of testing hypotheses regarding ancient wisdom traditions and consciousness. “We don’t just say, ‘A spiritual guru said something, so it’s true.’” Talking about the difference between life and death, “What’s very fascinating about it is it’s the same material, it’s the same neuron sitting there the moment before and the moment after death. It’s not that some energy has left, as far as we can tell, but instead, it’s this giant cascade of activity and things moving around that has ground to a halt, and that is what we call death.”

Consciousness, it seems, is a mystery still evolving.