# Brain Science Paper Explained Model credits \(Sketchfab\): “Human brain, Cerebrum & Brainstem” by FrankJohansson, via Sketchfab \(https://sketchfab\.com/3d\-models/0aa0e33c5c854d1bab7bac9e1c7acaec\)\. CC\-BY\-4\.0: https://creativecommons\.org/licenses/by/4\.0/ Prepared for Jig; static geometry/material conversion\. By greenlig Topic: Human Body & Medicine [Open the interactive Jig](https://ask.jig.com/j/XkAvyl0bowxc) ## Guide ### 1. Fifteen times a second A new study listened to hundreds of brain cells at once while monkeys looked at faces\. It found that the brain keeps flipping between what is seen and what goes unseen, about 15 times every second\. Drag anywhere to turn the scene\. Hesse, Lanfranchi, McGrory, Shi, Engel and Tsao, UC Berkeley and Princeton\. Posted October 2026 as a preprint, not yet peer reviewed\. ### 2. The oldest open question Only some of your brain's work ever reaches awareness\. The rest happens without you noticing\. For decades scientists have hunted for the place where conscious seeing lives: the front of the brain, or the back? No region has shown a clean signal of what we actually see\. Consciousness here means conscious access: which information you can notice and report\. ### 3. One face for each eye Show one face to one eye\. A second or two later, flash a different face to the other eye\. You now see only the new face, even though the first is still on its screen\. The picture stays fixed while the experience changes, which is exactly what researchers need\. This trick is called binocular flash suppression\. Fourteen volunteers confirmed it: after the flash they mostly saw the new face\. ### 4. Listening to face cells Two rhesus monkeys watched the same displays\. Thin probes called Neuropixels recorded hundreds of neurons at once in face patches, small regions full of cells that fire for faces\. The probes reached the side of the brain, called inferotemporal cortex, and the front, called prefrontal cortex\. Shown here on a human brain\. A monkey brain is smaller, with face patches in similar places\. ### 5. The blurry average Averaged over time, face cells preferred the seen face only weakly, and they still carried the hidden one\. Rebuild a face from that average and you get a blend of both faces that matches neither\. This puzzle had stood for years\. The faces are rebuilt from cell activity, because face cells respond to measurable features such as eye spacing and face shape\. ### 6. Slice time thin The team cut the activity into slices of 10 milliseconds, one hundredth of a second each\. For every slice they asked which face the cells looked like\. The answer flipped back and forth, about 15 times per second\. Slow time down to watch the flips\. At real speed the flips blur together, just like the old averages\. ### 7. Two faces taking turns Rebuild a face from only the seen slices and you get the seen face\. Rebuild it from the hidden slices and you get the hidden face, sharp and clear\. The same cells swap what they stand for, holding each state for about 60 milliseconds\. What we perceive switches far more slowly\. In classic rivalry, perception changes about once every two seconds\. ### 8. A stronger beat for the seen The two states are not mirror images\. In seen moments, cells respond a little more strongly to the face, so the seen state can be told apart from the hidden one\. The front of the brain showed the same back\-and\-forth pattern\. That small extra strength explains why the old averages still leaned slightly toward the seen face\. ### 9. Not where, but when Consciousness may depend less on where activity happens and more on when\. The brain seems to give the seen picture and the hidden one their own slices of time\. That could help explain how things we never notice still nudge our attention and feelings\. One new study in two monkeys\. Other labs will need to repeat it before it is settled\.