Thank you for this great course! You, Steve and your team are doing a great job! I heard that the reason for having the retina kind of inside out is that the pigment epithelium is actually required to transform 11-trans retinal back to 11-cis form, so "used" molecules are transferred to the pigment epithelium and "refurbished" ones are transferred back to photoreceptors. Another function of the pigment epithelium is the garbage collection. Each disk in a row or a cone lives only for a few days, new disks push old ones towards pigment epithelium for utilization. So this seemingly bad architecture is actually a smart one :) Octopuses use another kind of photoreceptors called melanopsin, it isomerizes when a photon hits and then re-isomerizes when another photon hits, so it doesn't need the pigment epithelium's help. That’s why they can have another retina layout. There are some tradeoffs, I suppose. I find this explanation reasonable and very interesting. I got it from the course of Medical Neurobiology by Peggy Mason (University of Chicago), it’s available on youtube and I certainly recommend it.
This is the best explanation, of how eyeballs work, thank you so much, this was what I was asking for New year's 2020, vision not a virus. The iris, thanks again :)
"the reason they cross is because....left side... goes to the right". Basically "they cross because they cross". Maybe add that you'll explain *why* in later videos. Polarized light: Haidinger's brushes are subtle, but we do (usually subliminally) see differences in polarization. Enjoying this series so far.
What she's trying to say is not that "the nerves cross over because the nerves cross over," but "the nerves cross over because the information needs to cross over." The reason the information needs to cross over is because most of the _outputs_ cross back. This is because, at a very very early stage in development, the head twists around upside down, (this is during a period of time that the embryo is still essentially a tiny worm.) That's right... our heads really are all "on backwards," developmentally speaking. I think this happens before the notochord is developed, but I'm not sure, but the result is that a lot of things end up having to grow crossed over like this.
Thank you; it was very enjoyable to listen to! Curious question: If the photoreceptors work in 'continuous' mode, as you said (they hyperpolarize according to the number of photons received), how is the brightness information transmitted through the ganglia cells and toward the brain? I presume the brightness correlates with the firing frequency of the axons that go through the optical cords? Next question: is there a single axon per "pixel"? You said, there are about a million axons in the wire. Does that mean, technically speaking, that we have a resolution of 1 megapixel? Or is there some sort of multiplexing going on?
That is correct, the firing rate of the retinal ganglion cells (RGC) is proportional to brightness. Each RGC is polled over many photoreceptors, and each photoreceptor contributes to many RGCs, so there is massive multiplexing going on. Next video is on this exact topic, coming out tomorrow!
@@bingsbrain Thank you for the quick explanation. I roughly remember the retinal structures from the textbooks, but no one explained how information travels to the brain. It's great to learn from someone with such a passion for her work!
Night vision in particular varies a lot based on ancient genetic history. This is extremely complex and impacts relative sensitivity to blue light, and color constancy adjustment. Some people can see stars as different colors, where most cannot. This is likely either from Neanderthal or Denisovan adaptations to the winter dark conditions in northern latitudes and the heed to see in extremely low light conditions shifted strongly to blue light dominance, snd to still be able to distinguish color despite the distorted color spectrum and very low light levels.
I never thought biology was much fun, but this is pretty exciting because it's more like physics. And if light travels as a wave, some visual feedback loops must be doing something like a DFT to see specific colors and/or store visual memories, right? Or not. But signal processing is fun. That's cool that octopuses had backside illuminated sensors before Sony. In a dystopian future we'll be growing genetically engineered octopus eyes to install in space telescopes!
31:54 , wow, good! I thought that was because damage, thanks for letting me know it's normal. I subscribed and am going to start watching some of your other lectures. It's great how you were able to help fill in major gaps in my knowledge and correct a lot of the things I had wrong due to the oversimplification of teaching I received in my earlier school years.
That was very fascinating. Thank you very much for this Cristal clear explanation.❤ Would you mind to extend this topic in same detail to explain why we watch movies in ca. 24fps ?
At 6 minutes where your talking about the light spectrum , you said lower longer wavelength corresponds to a higher frequency . The shorter the wavelength, the higher the frequency is how the spectrum works.
There is another never resolved hypothesis about cone cells from 70 years ago that hypothesizes that the reason cone cells are cone shaped is that they also serve to act a lot like prisms, with different wavelengths being absorbed at different depths in the cones. This is in addition to. not instead of the tuned dyes (opsins) used by the cells.
and do we know if in the cortex outside is always same eye fibers and inside the other? so might be something about hiting back head result on one expecific eye being vague?
Could you do a video on what could be happening in the brain to people who get blurry vision from covid? Is it the thalamus or cortex that is inflamed?
The black of the eye takes the light in, in this way - the white of the eye takes in the light like this I (together it is this+) and the collar of the eye hits both from every side possible
What is the reason the two wire cross over to the other side: the left to right side, and the right to the left side? Is it because the reason the wires cross over is to create more length and thus more time to transmit the signals to the back of the brain?
More time to transmit the signals would actually be a problem. The reason why is because very early in development, the head turns around upside down, (at this point in development, the face will be facing up, not "forwards," and thus, turning it around means turning it upside down, not turning it backwards. But ultimately, this makes the head backwards.) this happens before the notochord develops, so there's not a lot of structure to the organism, but a lot of the groundwork, the electrical potentials that tell organs where they need to be placed as they migrate during development, will be laid out across tissues. The body has to cross the signals from the eyes over for them to wind up in the same regions of the brain as the signals from the rest of the body --- left visual signals to where left sensory information is being collected, and right visual signals to where right sensory information is being collected. The evolutionary change that caused this happened sometime after our basal ancestor with arthropods, and you don't see this occur with arthropods during development. Their heads stay right side up. Edit: take some of this with a grain of salt, I may have gotten some detail wrong, but this is how I recall it.
@@peppermintgal4302 Fascinating! Have you followed the breakthrough research by Prof. Michael Levin with flatworms? His study on developmental bioelectricity: ways in which all cells connect in somatic electrical networks that store, process, and act on information to control large-scale body structure. His lab creates and employs tools to read and edit the bioelectric code that guides the proto-cognitive computations of the body, much as neuroscientists are learning to read and write the mental content of the brain. This is very similar to fetus' head turns around, upside down before the notochord develops with electrical potentials that tell where tissues to be located!
Quantum sensors, turns out that all of our senses, are quantum senses and our brain, the most bad ass quantum computer, that ever existed. (at least, on Earth, for the past couple of thousand years).
the reason why all animals (chordates ... ?) have this cumbersome design where brains control the opposite side of the body would be an interesting topic too. and why are there two brains in the first place.
Out of interest, how exactly are these lectures done? like the whole black screen, the images. I'm imagining all the graphics have transparent backgrounds and maybe she's on some green screen or something?
What I hate about lectures like this is that my brain quickly goes off on tangents. I'm 2 minutes in and I'm distracted by questions. Why does the visual information crossover like that? What evolutionary advantage could there be for that? When did this crossover occur? How many species share this crossover with us? Can we trace the genetic history of the brain feature? If so, how far back? What was the Earth like when this feature became dominant? If I couldn't pause this lecture, I would miss the next 3 or 4 minutes it. It always seems that each 5 minute slice of one lecture skips over information that could be expanded into another 2 hour lecture.
Just a min here.... Isn't it longer and shorter wave lengths / lower and higher frequencies....cause u went on to say lower wavelengths ah couple times or is that the actual descriptive phrase (lower wave length) ...I'm not not picking I'm just curious because Google is not what it use to be and neither is RUclips beings some people got their education from clips and videos alone
Great lecture, but the use of the inverted electromagnetic spectrum was an interesting choice. Is it a convention among the medical field or she just wanted to mess up with people? 🤣
An invaluable addition to understanding of temporal superposition Singularity-point relative-timing reciprocation-recirculation Apature of entangled sense-in-common cause-effect holography. Parallel coexistence time-timing sync-duration holography is superposition superspun around the Centre of Logarithmic Time Duration Timing, a self evident fact shown in this video, when you know to expect these wave-pulse-evolution arrangements of information processing.
Translated to human: This video explains a complex concept about how time and events are interconnected. It shows how time and timing can overlap and interact in a way that affects our understanding of cause and effect. Essentially, it highlights how different aspects of time sync up and influence each other, revealing patterns that are easier to recognize once you know what to look for. (So yes, dear comment reader, this above comment makes little sense)
Check out the Newly released Forever Devotional 401 + Verses (Psalm 119:105) Thy word is a lamp unto my feet and a light unto my path A Personal Devotional He has more to say… Using the Strongest Strong’s EXHAUSTIVE Concordance published by ZONDERVAN Because it has the littlest words in it. LIKE SAY SAID SAIDEST REMEMBER IF AT ALL AMONG… If it has a Number it has a Root Word that is the Spiritual Meaning of the Word and the way he Speaks to Us. Even up to the Number of Times a Word is Used The other way is the Letters of the Hebrew Words and there Meaning
this is the best :) feels less like a lecture and more like me listening to a friend infodump about a subject she loves. thank you for the education!
This is teaching from the future. Thank you so much Doctor :))
Clear explanation. Good diagrams. Why aren't there more RUclips videos like this?
Thank you :-)
The tip of looking slightly away given at minute 31:43 is often applied instinctively when looking at something in a very dark room.
I've always done that to locate objects in the dark. It's not often talked about.
Thank you for this great course! You, Steve and your team are doing a great job!
I heard that the reason for having the retina kind of inside out is that the pigment epithelium is actually required to transform 11-trans retinal back to 11-cis form, so "used" molecules are transferred to the pigment epithelium and "refurbished" ones are transferred back to photoreceptors. Another function of the pigment epithelium is the garbage collection. Each disk in a row or a cone lives only for a few days, new disks push old ones towards pigment epithelium for utilization. So this seemingly bad architecture is actually a smart one :)
Octopuses use another kind of photoreceptors called melanopsin, it isomerizes when a photon hits and then re-isomerizes when another photon hits, so it doesn't need the pigment epithelium's help. That’s why they can have another retina layout. There are some tradeoffs, I suppose.
I find this explanation reasonable and very interesting. I got it from the course of Medical Neurobiology by Peggy Mason (University of Chicago), it’s available on youtube and I certainly recommend it.
10.5 Photoreceptors ruclips.net/video/pMu8z844KYk/видео.htmlsi=7anT43T3z2snBRKY
10.8 Non-perceptual Visual Functions ruclips.net/video/prtJ0oPubjU/видео.htmlsi=izOruw0151blovpO&t=212
Wow. Fabulous density of information. Thanks very much. I am sharing this broadly.
That shipibo dress is (and suits you) beatiful! And your lecturing is too 👏
Fascinating!
This presentation style is unbelievably good. It’s inspiring me to try and make my presentations look like this
This is the best explanation, of how eyeballs work, thank you so much, this was what I was asking for New year's 2020, vision not a virus. The iris, thanks again :)
This is amazing, I'm so happy I stumbled upon your channel!
I'm ok that the first episode I'm seeing is episode 17 :D Now I'll loop back to the start. Nice summary. Good diagrams and explanations!
Enjoyable lecture, even by the standards of a RUclips entertainment video it was enjoyable too. Thanks :)
Great review lecture! Subscribed!
You realy teaching very amazingly and very clear and very very easy way and fantastic way ❤
Thank you again for an awesome lecture!
Best video I've seen so far ❤
Beautiful lecture! Great job 😊
love this content, looking forward to more! you got my sub
Absolutely fascinating
Great videos. Thanks so much for the great content. You're an amazing scientist and lecturer. I'm looking forward to the lectures on the motor system.
Thanks. Great explanation. I have a slightly better understanding then before.
I have a lot to think about.
Excelent presentation. 👍
"the reason they cross is because....left side... goes to the right". Basically "they cross because they cross". Maybe add that you'll explain *why* in later videos.
Polarized light: Haidinger's brushes are subtle, but we do (usually subliminally) see differences in polarization.
Enjoying this series so far.
ruclips.net/video/uahs9NqMGGo/видео.htmlsi=0YpUnT_eVBx3sXbI
What she's trying to say is not that "the nerves cross over because the nerves cross over," but "the nerves cross over because the information needs to cross over." The reason the information needs to cross over is because most of the _outputs_ cross back. This is because, at a very very early stage in development, the head twists around upside down, (this is during a period of time that the embryo is still essentially a tiny worm.) That's right... our heads really are all "on backwards," developmentally speaking. I think this happens before the notochord is developed, but I'm not sure, but the result is that a lot of things end up having to grow crossed over like this.
I can't wait for the next video
9:22 what I order (that is what I see) vrs what gets delivered (by my eye phone - as in the phone cameras), are always two totally different things
What an amazing video sis
🌍 Excellent🌎
👀🥇👀
Presentation,
Synchronous
2 the subject.
Thanks 💚 Prof.
Bing wen Brunton
You're pioneer
In Video quality
& teaching .
🌍🥇🌎.
Perfect .
Thank you sir!
You've gotten my sub good video seriously
Thank you, quite interesting
You are really cool!! Great video!
Pretty, smart 🎉
Thank you! Bravo! 😮😊❤
Thank you; it was very enjoyable to listen to! Curious question: If the photoreceptors work in 'continuous' mode, as you said (they hyperpolarize according to the number of photons received), how is the brightness information transmitted through the ganglia cells and toward the brain? I presume the brightness correlates with the firing frequency of the axons that go through the optical cords? Next question: is there a single axon per "pixel"? You said, there are about a million axons in the wire. Does that mean, technically speaking, that we have a resolution of 1 megapixel? Or is there some sort of multiplexing going on?
That is correct, the firing rate of the retinal ganglion cells (RGC) is proportional to brightness. Each RGC is polled over many photoreceptors, and each photoreceptor contributes to many RGCs, so there is massive multiplexing going on. Next video is on this exact topic, coming out tomorrow!
@@bingsbrain Thank you for the quick explanation. I roughly remember the retinal structures from the textbooks, but no one explained how information travels to the brain. It's great to learn from someone with such a passion for her work!
Would love to hear you do a podcast with Dr Jack Kruse
Night vision in particular varies a lot based on ancient genetic history. This is extremely complex and impacts relative sensitivity to blue light, and color constancy adjustment. Some people can see stars as different colors, where most cannot. This is likely either from Neanderthal or Denisovan adaptations to the winter dark conditions in northern latitudes and the heed to see in extremely low light conditions shifted strongly to blue light dominance, snd to still be able to distinguish color despite the distorted color spectrum and very low light levels.
I never thought biology was much fun, but this is pretty exciting because it's more like physics. And if light travels as a wave, some visual feedback loops must be doing something like a DFT to see specific colors and/or store visual memories, right? Or not. But signal processing is fun. That's cool that octopuses had backside illuminated sensors before Sony. In a dystopian future we'll be growing genetically engineered octopus eyes to install in space telescopes!
31:54 , wow, good! I thought that was because damage, thanks for letting me know it's normal.
I subscribed and am going to start watching some of your other lectures.
It's great how you were able to help fill in major gaps in my knowledge and correct a lot of the things I had wrong due to the oversimplification of teaching I received in my earlier school years.
That was very fascinating. Thank you very much for this Cristal clear explanation.❤
Would you mind to extend this topic in same detail to explain why we watch movies in ca. 24fps ?
Doctor i would like to more about foveal vision, peripheral vision. How to use foveal vision and peripheral vision...
At 6 minutes where your talking about the light spectrum , you said lower longer wavelength corresponds to a higher frequency . The shorter the wavelength, the higher the frequency is how the spectrum works.
There is another never resolved hypothesis about cone cells from 70 years ago that hypothesizes that the reason cone cells are cone shaped is that they also serve to act a lot like prisms, with different wavelengths being absorbed at different depths in the cones. This is in addition to. not instead of the tuned dyes (opsins) used by the cells.
Visual perception cloud not get off of the outfit very beautiful. 😍
and do we know if in the cortex outside is always same eye fibers and inside the other? so might be something about hiting back head result on one expecific eye being vague?
Gotta thank Eigensteve. We get another great teacher online. 😂
I believe it's the shorter the wavelength is the geater the frequency.?
Why do the “cables” cross? Does comparative anatomy suggest possible reasons as to how this came about?
Could you do a video on what could be happening in the brain to people who get blurry vision from covid? Is it the thalamus or cortex that is inflamed?
Isn't it just what you see < go tro the eyes like - and the brain gives
The black of the eye takes the light in, in this way - the white of the eye takes in the light like this I (together it is this+) and the collar of the eye hits both from every side possible
And the brain fils up the gaps
To clear up what you r looking at
that was so so good i didnt pick up my phone once lol
What is the reason the two wire cross over to the other side: the left to right side, and the right to the left side? Is it because the reason the wires cross over is to create more length and thus more time to transmit the signals to the back of the brain?
More time to transmit the signals would actually be a problem. The reason why is because very early in development, the head turns around upside down, (at this point in development, the face will be facing up, not "forwards," and thus, turning it around means turning it upside down, not turning it backwards. But ultimately, this makes the head backwards.) this happens before the notochord develops, so there's not a lot of structure to the organism, but a lot of the groundwork, the electrical potentials that tell organs where they need to be placed as they migrate during development, will be laid out across tissues. The body has to cross the signals from the eyes over for them to wind up in the same regions of the brain as the signals from the rest of the body --- left visual signals to where left sensory information is being collected, and right visual signals to where right sensory information is being collected.
The evolutionary change that caused this happened sometime after our basal ancestor with arthropods, and you don't see this occur with arthropods during development. Their heads stay right side up.
Edit: take some of this with a grain of salt, I may have gotten some detail wrong, but this is how I recall it.
@@peppermintgal4302 Fascinating! Have you followed the breakthrough research by Prof. Michael Levin with flatworms? His study on developmental bioelectricity: ways in which all cells connect in somatic electrical networks that store, process, and act on information to control large-scale body structure. His lab creates and employs tools to read and edit the bioelectric code that guides the proto-cognitive computations of the body, much as neuroscientists are learning to read and write the mental content of the brain. This is very similar to fetus' head turns around, upside down before the notochord develops with electrical potentials that tell where tissues to be located!
Quantum sensors, turns out that all of our senses, are quantum senses and our brain, the most bad ass quantum computer, that ever existed. (at least, on Earth, for the past couple of thousand years).
What controls the eyebrows? are they crosswired or wired laterally?
I just have a question. Can some people see light differently therefore see things of light by the way their eyes perceive light
the reason why all animals (chordates ... ?) have this cumbersome design where brains control the opposite side of the body would be an interesting topic too. and why are there two brains in the first place.
Out of interest, how exactly are these lectures done? like the whole black screen, the images. I'm imagining all the graphics have transparent backgrounds and maybe she's on some green screen or something?
This is tiny section of my human biology class
More than meets the eye....
💖💖💖💖
When you said rodopsin going from a cis configuration to a trans configuration really triggered me
Lmfaoooo
What I hate about lectures like this is that my brain quickly goes off on tangents. I'm 2 minutes in and I'm distracted by questions.
Why does the visual information crossover like that? What evolutionary advantage could there be for that? When did this crossover occur? How many species share this crossover with us? Can we trace the genetic history of the brain feature? If so, how far back? What was the Earth like when this feature became dominant?
If I couldn't pause this lecture, I would miss the next 3 or 4 minutes it.
It always seems that each 5 minute slice of one lecture skips over information that could be expanded into another 2 hour lecture.
Just a min here.... Isn't it longer and shorter wave lengths / lower and higher frequencies....cause u went on to say lower wavelengths ah couple times or is that the actual descriptive phrase (lower wave length) ...I'm not not picking I'm just curious because Google is not what it use to be and neither is RUclips beings some people got their education from clips and videos alone
the so-called "optic nerve" is a tract within the brain.
Dziękuję ❤, poproszę o dodanie języka Polskiego
S.i./ Ai
Please don't stop this. Teach us neuroscience and data science for neuroscience in a systemic manner please doctor.
👀
👍
Transparent Aluminum TM...
Oh no. Not another Brunton. I’m already running out of free time 😭😭
Great lecture, but the use of the inverted electromagnetic spectrum was an interesting choice. Is it a convention among the medical field or she just wanted to mess up with people? 🤣
Miy difucil omita eso en ribits
i wonder which motor or process system starts working when the field and retina agrees that her dress is see through😜
Excellent information than you!
i wish you had more visibility
I'm so glad I found your channel 😫...could you please branch more in the medical field and more clinically thank you sooo much
She's not a clinical neuroscientist so I wouldn't expect that
An invaluable addition to understanding of temporal superposition Singularity-point relative-timing reciprocation-recirculation Apature of entangled sense-in-common cause-effect holography.
Parallel coexistence time-timing sync-duration holography is superposition superspun around the Centre of Logarithmic Time Duration Timing, a self evident fact shown in this video, when you know to expect these wave-pulse-evolution arrangements of information processing.
Translated to human:
This video explains a complex concept about how time and events are interconnected. It shows how time and timing can overlap and interact in a way that affects our understanding of cause and effect. Essentially, it highlights how different aspects of time sync up and influence each other, revealing patterns that are easier to recognize once you know what to look for.
(So yes, dear comment reader, this above comment makes little sense)
You look really good
Your American husband is very lucky.
lateral geniculate nucleus
☮️🦇☯️🇨🇳✝️🌌
Too many commercials that are also too long.
Okay
@@jayg6138 I'm sorry, this comment wasn't meant for you.
Check out the Newly released Forever Devotional 401 + Verses (Psalm 119:105) Thy word is a lamp unto my feet and a light unto my path
A Personal Devotional
He has more to say…
Using the Strongest Strong’s EXHAUSTIVE Concordance published by ZONDERVAN
Because it has the littlest words in it. LIKE SAY SAID SAIDEST REMEMBER IF AT ALL AMONG…
If it has a Number it has a Root Word that is the Spiritual Meaning of the Word and the way he Speaks to Us. Even up to the Number of Times a Word is Used
The other way is the Letters of the Hebrew Words and there Meaning
Is the speaker an AI?
No,
Moore Sarah Clark Sandra Lopez Kenneth
Would knowledge be different if no language were used
😂😢
I'm so fuckkkkk confused
😐 the light goes through the signal wiring before the light receptors, seems like poor design... major L for evolution
It’s not true person
Amazing lecture! you got yourself a new student🫡
I wonder why im thinking about 10gb optical cables….