Things Your Brain Does Without Asking Your Permission

You spend roughly forty minutes of every day functionally blind and have never noticed. Your brain deletes your own nose from your vision permanently. And a scanner can predict which hand you'll use several seconds before you know you've decided. Here are 10 ways your brain edits reality before showing it to you. Your eyes move in jerks called saccades three to four times a second — over 150,000 a day — and vision is suppressed during each one, with the gap stitched shut using post-movement imagery; chronostasis, the stopped-clock illusion this produces, was described in Nature in 2001 by Kielan Yarrow and colleagues at University College London. Each eye has a blind spot where the optic nerve exits the retina, roughly the size of nine full moons, which the visual cortex fills in by sampling surrounding texture — Edme Mariotte discovered it in 1660. The fusiform face area, identified by Nancy Kanwisher's team at MIT in 1997, produces a face-detection signal around 170 milliseconds after exposure and triggers on two dots and a line, which is why the Viking 1 orbiter's 1976 image of a Cydonia mesa appeared to show a human face. During REM sleep the brainstem floods motor neurons with glycine and GABA, producing paralysis; failures in one direction cause REM sleep behaviour disorder and in the other cause sleep paralysis, experienced at least once by roughly 8% of people. Hypnic jerks affect around 60 to 70% of people, with the falling sensation constructed retroactively to explain a twitch that already occurred. Colin Cherry named the cocktail party effect at Imperial College London in 1953, and Neville Moray's 1959 experiment found around a third of participants detected their own name in a supposedly ignored audio channel while retaining nothing else from it. In 2012, Jennifer Hames and colleagues at Florida State University surveyed 431 students in the Journal of Affective Disorders and found the urge to jump from high places is common among people with no suicidal ideation, proposing it results from misreading one's own safety response. Daniel Simons and Christopher Chabris found in 1999 that roughly half of viewers counting basketball passes fail to see a person in a gorilla suit, and in 2013 Trafton Drew's team found 20 of 24 radiologists missed a gorilla embedded in lung CT scans. In 2008, John-Dylan Haynes and colleagues at the Max Planck Institute in Leipzig reported in Nature Neuroscience that fMRI patterns predicted a button-press choice up to seven seconds before awareness, at around 60% accuracy. And Michael Gazzaniga and Joseph LeDoux's split-brain work in the 1970s revealed an "interpreter" in the left hemisphere that confidently invents explanations for actions it has no information about. ⏱️ CHAPTERS 0:00 — Number 10: The Missing Forty Minutes 1:25 — Number 9: The Hole In Your Vision 2:45 — Number 8: The Face In The Toast 4:05 — Number 7: The Nightly Paralysis 5:25 — Number 6: The Falling 6:40 — Number 5: Your Name Across A Room 7:55 — Number 4: The Call Of The Void 9:15 — Number 3: The Gorilla You Didn't See 10:35 — Number 2: The Seven Second Head Start 11:55 — Number 1: The Liar In Your Left Hemisphere 13:15 — Outro ❓ QUESTIONS THIS VIDEO ANSWERS What are saccades? Are you blind while your eyes move? What is chronostasis? Why does a clock's second hand seem to freeze? Where is the blind spot in your eye? Why can't you see your own blind spot? Why don't you see your own nose? Why do we see faces in objects? What is the fusiform face area? What was the Face on Mars? Why are you paralysed during sleep? What is REM sleep behaviour disorder? What causes sleep paralysis? What is a hypnic jerk? Why do you feel like you're falling as you fall asleep? What is the cocktail party effect? Why do you hear your name in a noisy room? What is the call of the void? Does the urge to jump mean you're suicidal? What was the invisible gorilla experiment? Did radiologists miss a gorilla in a scan? Can brain scans predict your decisions? What did the Haynes 2008 study find? What is the left hemisphere interpreter? What did split-brain experiments reveal? 🔔 Subscribe for more countdown explainers like this one. 💬 Which one bothers you most? 👇 #Neuroscience #Psychology #Brain