Is a “Severance” Split Brain possible? How Are Memories Formed? Can Different Aspects of Personality Be Isolated Inside the Brain? Memory, Identity, and Neuroplasticity with David Eagleman

About this episode

Could your mind really be split in two? Can a chip in your brain divide your work life from your personal life?

Hosts astrophysicist and UCLA Professor Dr. Amy Mainzer and writer/producer Adam Sigel welcome back Stanford neuroscientist, author and creator of Inner Cosmos, David Eagleman, who also serves as a science consultant for Severance Season 3. Adam references the Hollywood development term "science-faction" to describe the show—a blend of fiction rooted heavily in real-world scientific possibilities. The core premise of the show explores the ultimate, extreme form of satirical work-life balance: surgically separating an individual's memories between their corporate life ("innies") and personal life ("outies").

How the Brain Processes Memory

To understand how a "severance chip" might function, Dr. Eagleman breaks down the fundamental mechanics of the human brain:

The Electrochemical System: The roughly 86 billion neurons in the brain fire electrical signals down axons, releasing chemicals to interact with neighboring cells.

Associative Neural Networks: Unlike computers, human memory functions as an interconnected web. Hearing a single word instantly triggers a vast, non-linear network of related memories, experiences, and references.

The Coalition of Memories: Debunking the "Grandmother Cell" (the idea that a single neuron holds a specific memory), memories are actually distributed across vast coalitions of millions of interconnected neurons working in unison.

The Mechanics of a "Severance Chip"

Dr. Eagleman, who consulted on the science for Severance Season 3, proposes a real-world hypothesis for how the fictional procedure could work. Rather than physically cutting parts of the brain, the chip would act as an electrical coding switch:

An implanted chip applies a distinct electrical code to the employee's active thoughts at work. The neurons marked with this specific "work code" only connect with a other work-tagged neurons, stopping their neural pathways from interacting. The show's elevator completely flushes active electrical patterns in the brain's short-term memory.

Split-Brains and Multiple Identities

The conversation shifts to historical precedents and the psychological toll of memory separation: Split-Brain Surgery (1960s treatment for severe epilepsy) is the severing the corpus callosum, the neural superhighway linking the brain's hemispheres which creates two separate consciousnesses in one body (sometimes causing Alien Hand Syndrome, where hands physically work against each other). Distributed Memory (The Ngram) says memories are not stored in a single, hard-drive-like location but are distributed holographically across the brain, providing evolutionary redundancy. Long-term memory is divided into separate, distinct networks and amnesia cases (such as Ansel Bourne or Jodie Roberts) demonstrate that someone can lose their autobiographical memory while keeping procedural skills.

Philosophical Implications: Who Are We?

Ultimately, Severance serves as a profound philosophical sandbox. Because human identity is entirely shaped by the sum of our accumulated memories, creating isolated memory pools effectively creates two distinct, living people inside one body. This separation poses a tragic human dilemma, exemplified by the main character, Mark, who uses the procedure to escape the heavy burden of grief over his deceased wife. While it successfully blocks his suffering for eight hours a day, it forces audiences to grapple with a haunting question: If you could wipe away your deepest suffering at the cost of your memories and your true identity, would you?

Follow Unobtainium Podcast!

Website: unobtainiumpodcast.com

Watch full episodes on https://www.youtube.com/@unobtainiumpod

Stay connected:

Instagram: @unobtainiumpod

TikTok: @unobtainiumpod

Bluesky: @unobtainiumpod.bsky.social

X: @unobtainiumpod

For David Eagleman:

Website: https://eagleman.com/

Instagram: https://instagram.com/davideagelman/?hl=en

X: https://x.com/davideagleman

Hosted on Acast. See acast.com/privacy for more information.