David Eagleman: Stanford neuroscientist, best-selling author (Livewired), and science communicator. Founder of the former sensory-substitution company Neosensory and host of the Inner Cosmos podcast.
What this episode covers
Huberman and Eagleman explore neuroplasticity as the brain's defining trick: a half-baked brain that wires itself to its world and stays changeable when challenged. They cover how skills get burned from software into hardware, why seeking novelty keeps the aging brain plastic, and how neuromodulators like acetylcholine open windows for directed change. The conversation moves through memory and time perception (including Eagleman's freefall experiments showing slow-motion is a trick of memory density, not faster perception), false and malleable memories with implications for the legal system, the neuroscience of dreaming as defense of the visual cortex, and sensory substitution. It closes on the neuroscience of in-group/out-group bias, propaganda, dehumanization, and Eagleman's proposed tools for de-polarization.
Recommended on this episode
An Immense World
Ed Yong
“Ed Young wrote a book called An Immense World... for an animal lover like me, it's I found it really spectacular.”— Andrew Huberman
The guest's own work
Livewired
David Eagleman
“something that I wrote about in in my book Livewired about this, which is addiction is all about brain plasticity.”— David Eagleman
The Ulysses Contract
David Eagleman
“this is the topic of my next book. It's called the Ulisses Contract.”— David Eagleman
Empire of the Invisible
David Eagleman
“This is actually what my next next book is about. It's called Empire of the Invisible and it's about why we all believe our own internal models.”— David Eagleman
Neosensory wristband
Neosensory (David Eagleman)
“I built a wristband that captures sound and turns sound into patterns of vibration on the skin. This is for people who are deaf.”— David Eagleman
Also referenced (named, not recommended)
BrainPort
Wicab
“his research has continued with something called the brainport, which is again for blind people.”— David Eagleman
Big reveals from this episode
- Eagleman reveals his next book, The Ulysses Contract, on how we pre-commit to protect our future selves from bad behavior.
- His freefall experiments (dropping 23 people 150 feet) prove people do NOT perceive faster in life-threat; slow-motion is a memory illusion.
- Casually mentions he sold his company Neosensory about six months ago.
- Presents his theory that dreams exist to defend the visual cortex from being taken over by other senses during nightly darkness.
- Describes the hand-stabbing fMRI study showing empathy shrinks for out-groups, even with arbitrary coin-flip team labels.
- Reveals he has patented a social-media algorithm that de-polarizes by surfacing what people have in common first.
- Reveals he's making a documentary with comedian Craig Ferguson asking whether AI can be funny, touring a comedy robot through middle America.
Worth remembering
- Humans have roughly four times as much cortex as our nearest animal relatives; the cortex is a 'one-trick pony' defined by whatever you plug into it.
- Children raised bilingually or trilingually end up with lower vocabulary in each language simply due to less practice per language.
- The 'nun study' found some nuns had Alzheimer's pathology at death but no symptoms in life because they kept their brains constantly active.
- Parkinson's dopamine drugs caused some patients to become compulsive gamblers, now a labeled contraindication.
- Pixar founder Ed Catmull discovered he and most of his best animators are aphantasic - they can't picture images in their heads.
- In emergencies a secondary amygdala memory track records extra detail, making events feel like they took longer in hindsight.
- Blind users of the tongue-grid BrainPort can navigate obstacle courses and report it 'feels like sight.'
- Human infants spend about 50% of sleep in REM; more-plastic species get up to eight times more REM than precocial animals like cows.
- Elizabeth Phelps found 9/11 'flashbulb' memories drifted just as much as ordinary memories of the day before.
- Across history, governments run propaganda the same way: dehumanize the out-group (e.g. Tutsi called 'cockroaches') to switch off empathy circuits.