Why are we here? Are we alone in the universe? What is consciousness? Why do cat pictures go viral on Facebook? A satisfactory answer exists for exactly one of these questions—namely, the consciousness thing. And it explains what happens when you come back into your body in the morning.
The understanding comes from a long line of research by Francis Crick (of discoverer-of-DNA fame) and Christof Koch at the Allen Institute for Brain Science in Seattle. They started with a simple question: Is there one area of the brain that lights up during all the tasks of consciousness? If all these sensory and motor and cognitive things were circles of a Venn diagram, where would they overlap?
What they found is the claustrum, a one-millimeter-thick sheet of neurons that divides the hemispheres of the brain. All mammals have it. And it’s connected to all the major players in your skull, including the prefrontal cortex, auditory cortex, visual cortex, primary motor cortex, premotor cortex, and many other areas of functioning. So Crick and Koch went into people’s heads and zapped their claustrums to see if it would mess with their consciousness. Actually, they didn’t—due to troublesome things like ethics and morality, you can’t just fry people’s brains and see what happens. That is, outside of very special circumstances.
One of those circumstances is in the treatment of epilepsy. In epilepsy, an area of the brain misfires in a way that lets electricity “leak” into surrounding tissues, rebounding through the brain like a gunslinger’s bullet in a rib cage—sometimes with equally devastating consequences. To treat cases of severe and debilitating epilepsy, doctors explore inside the brains of conscious patients to discover the source of the problem, at which point they can sometimes cure or diminish symptoms by inserting a sophisticated electrical pacemaker. The thing is, epilepsy can live pretty much anywhere in the brain, and so discovering its source sometimes takes significant exploring.
That’s what Mohamad Koubeissi and colleagues did with a fifty-four-year-old with what they describe as “intractable epilepsy.” In a study published in Epilepsy and Behavior in 2014, they recount what happened during what’s called electrical stimulation mapping, when the surgeons just happened to be poking around her claustrum. “Stimulation of the claustral electrode reproducibly resulted in a complete arrest of volitional behavior, unresponsiveness, and amnesia without negative motor symptoms or mere aphasia,” they write. In English, this means that when Koubeissi zapped this woman’s claustrum, she became unconscious. When they turned off the juice, she was again immediately conscious. During brain mapping, patients usually read aloud or do some other kind of brain task that can show doctors how their prodding affects function. In this case, as Koubeissi introduced high-frequency electrical impulses into his patient’s claustrum (i.e., “frying”), she would stop reading and stop responding to her surgical team, and her body would gently slow into a state of deep relaxation. When the signals stopped, she would open her eyes and be able to continue reading.
In a Forbes article, Koubeissi called the claustrum the “sleep switch” and likened it to turning the key in a car’s ignition. The understanding of this difference between asleep and awake, conscious and unconscious, is still in its early stages, and opportunities to double-check the finding don’t come around so often. But here’s a cool part: now that we are beginning to understand the location and function of human consciousness, it might make it possible to not only understand the roots of our own consciousness but also replicate this consciousness. Knowing the difference between asleep and awake in your brain may make it possible for us to artificially create “awakeness.”
Tongue Slips
Outside the big switch of Consciousness with a capital C are those little slips of consciousness, like when you call your knowledgeable friend “a vast suppository of information.” Or when you turn spaghetti into pasketti. The first is called a malapropism (when you switch around meaning), and the second is a metathesis (when you switch around sounds). Listen for these today.