Inverted retina image correction by brain

[@jphb95]

An absolute legend! Thanks for all the help Dr Lee, these videos are golden

[@gblargg]

It's NOT inverted within the context of your head. There are no tiny gravity sensors in your retina denoting what is up and down. There is no up and down. It's just this mostly dark, mush place where an image is projected. It's only when we, from the outside of a person, ask what it would look like if we could see inside and what's projected. But it's because we are inverted with respect to the image, not the other way around. The neurons are wired to where each part of the image falls. Things that are above you cast light in a particular part of the retina, so that's where they get wired. The ground casts light in other parts of the retina, so that's where neurons for things being down. It's not like your brain has a retina pre-wired where the part near the top of your head is wired to be up, and part near the bottom of your head is wired to be down, and then it gets an image with things the opposite way.

[@cyrrender]

sources please? would like to look further into this

[@gblargg]

@@cyrrender It's a conceptual thing, stemming perhaps from the idea that there is a little person inside your head viewing things, and seeing the image upside-down. "Why would the brain flip the images perceived by your eyes?" discussion has some good answers.

[@gblargg]

@@cyrrender I found an interesting article, Illusions "Right-Side Up" that talks about perception of various things, and how some are tied to our sense of which way is up, and others aren't.

[@jslsa64]

Thank you Dr Lee!

[@noahpage7459]

Really cool demonstration

[@hectorportillo1906]

Excellent video! Thanks!

[@lordad872]

To be honesty I wanna try to do that prison glasses experiment

[@hgracern]

Wow, thanks. Then the cortex adds Color to the inverted image. 🎉

[@debigdogk9563]

Wonders of the eye 😀😀😀🙏🙏🙏 Thank you 🙏

[@khaledgowaily6818]

Thank you Dr Lee. I just wonder if in uncorrected hyperopes, the image is not inverted (because the focus is behind the retina).

[@d3ci.b3L]

My brain can't comprehend something. And maybe I'm not comprehending this correctly. But if the world is inverted upside down in the retina, then shouldn't up/down be opposite to where my eyes look? If my eye looks up, is not my retina seeing the bottom of the scene?

[@tomtroler]

1:09 that one got me up from the sleep

[@munazzasikandarsikandarkha7566]

Amazing!

[@gaylecheung3087]

Don’t ever remember having prison glasses because I was either too young or I totally locked it out of my conscious but I do remember to have a great kindergarten and up to great H3 I can remember I’m so used to go to see eye doctors on my life

[@lisanasanguino8794]

Ohh thanks

[@def6420]

but why does brain turn the image?

[@abhigyanganguly1988]

I'm very interested about this phenomenon. Could someone explain exactly how does the brain invert this image? Is it like applying the rotation matrix used in computer vision ? Or is it some other mechanism?

[@gblargg]

There is no inversion. Each neuron is connected to the appropriate part of the retina. Same for a camera sensor. There is no inversion. They're just wired so that the upper-left pixel corresponds to the proper image detecting element that corresponds to the things outside the camera on the upper-left side. The inversion is a characteristic of describing the setup from the perspective of someone outside the head/camera. Within the confines of the head/camera, there is no inversion (because there is nothing else to refer to, just the image inside it).

[@abhigyanganguly1988]

That's what I too thought at first, but there's a famous neuroscience experiment using inverted prism glasses. Wearing these glasses, the subject sees everything upside down, as he should. But after a period of time, (1-2 days), the brain turns everything back to normal. The glasses have no effect. It's called neural plasticity. So it's definitely more that an inverted connection

[@arh7897]

And you never really touched anything your whole life atom's