Essentials: Neuralink & Technologies to Enhance Human Brains | Dr. Matt MacDougall

Andrew Huberman opens the conversation by asking neurosurgeon and neuroscientist Dr. Matt MacDougall how he thinks about the brain as an organ. Huberman frames the question around a surgeon's habit of fixing and mending, and around the possibility of adding things to the brain "that don't exist there already."

MacDougall answers with a deliberately unglamorous picture. He describes the brain as a set of separate functional parts held together loosely. Because those parts are separable, damage to one can produce what he calls "very interesting failure modes."

The brain really is a collection of functional modules pinned together, duct taped together in this bone box attached to your head.

His example is a case from early in his training at UC San Diego. A very young man had just been in a car accident, and the team operated on him. MacDougall says that, as often happens in neurosurgery, they saved his life "potentially at the cost of quality of life." The patient woke with damage to both frontal lobes and essentially no impulse control. His 80-year-old recovery room nurse called the team back urgently. When they arrived, the patient pointed at her and said she wouldn't have sex with him. MacDougall concluded that the patient's frontal lobes were "gone." He judged that this person would never have "reasonable human behavior again," and called it one of the most tragic ways for a brain to malfunction.

He then widens the point. Everything the brain does comes out of the brain, and any part of it, or all of it, can go wrong. He lists hormone control, vision, sensation and muscle movement, from eye movement to moving a bicep. That makes brain surgery very high stakes. He balances this against the moments when a surgeon gets to "fix something that seems unfixable." He says that "Lazarus-like miracles" happen "not too uncommonly," and that this makes the career extremely satisfying.

When Huberman asks for an example of a satisfying experience, MacDougall describes a newer technique for a "reasonably small tumor" deep in the brain that is hard to reach. The traditional approach would mean cutting through a lot of healthy brain. It would disrupt many neurons and a lot of white matter, which he glosses as the wires connecting neurons.

How MacDougall describes the modern procedure: - The surgeon drills a two-millimeter hole in the skull. - A small fiber-optic cannula passes through the hole and connects to a laser. - The laser heats the tumor deep inside the brain while the patient is in an MRI scanner. - The team takes images about every second and monitors the temperature in real time. - The goal is a temperature that kills the tumor cells while hurting hardly any of the surrounding brain.

He says that "not uncommonly nowadays" a patient arrives with a tumor that would once have been catastrophic to operate on, and the tumor can be eliminated while leaving only a poke hole in the skin. He includes some sites once considered "totally inoperable": the brainstem, primary motor cortex, and primary verbal areas such as Broca's area. In those cases the expectation used to be either no operation or catastrophic damage. His claim is hedged, though. He says those patients "sometimes now" come out unscathed, not always. He also gives no numbers on outcomes or how often the procedure succeeds.

Huberman moves to MacDougall's role at Neuralink. He calls this an exciting time in which engineers "are starting to toss up big problems and go for it." He also offers his own view that Elon is "certainly among the best, if not the best" at going big. He asks about Neuralink's missions "to the extent that you are allowed." He suggests possible goals: understanding and augmenting the brain, or clinically repairing conditions in people who are suffering.