How does brain render imagined scenes?

KKRT

Veteran
Its fairly know how brain register the world we see through our eyes. Its simple, it works like encoding in digital video by registering signal changes.
Rendering memories should work similarly to how video works too, so just by reconstructing images and playing it back.

But how does it render images it hasnt seen or imagine things that do not exist?
From technology standpoint we know two ways to reconstruct/simulate world:
A) By approximated technique like ones used in real-time rendering
B) By physical simulation, many combined with some A), because we dont know algorithms for everything.

A) Should not work at all for brains, because it would give us false image.
B) Seems unlikely, because even though brain has tons of computation capabilities, it doesnt know how everything should be simulated.

The only logical answer would be some kind of 3D images reconstruction and modification in real-time, but this still doesnt explain how brain would be able to simulate things like fluid dynamics for example.

So, anyone knows some good research about this topic? It seems interesting, especially in context of future rendering technique that are not based on A) and B) examples.
 
Last edited by a moderator:
My very uneducated guess is that our brain dos a mix of photoshoping stuff we have already seen into something that only exists in our imagination. It also probably does a very lousy job at it, but it tells itself you are seeing what you want to imagine to be seeing and you end up believing your own deception.
 
My very uneducated guess is that our brain dos a mix of photoshoping stuff we have already seen into something that only exists in our imagination. It also probably does a very lousy job at it, but it tells itself you are seeing what you want to imagine to be seeing and you end up believing your own deception.

I'm not talking about situation like You wake up and think 'omg i dreamt about this awesome space travel' etc and You barely remember any details.
I'm talking about situations were You have really detailed dreams and full body presence in them. I have them frequently and everything in them behave like it should, even though many of those dreams are in places i've never been or never seen.
I had even dream recently when i looked at grass and laughed that it moves like in Crysis 3, which looked unnaturally in a dream to me! [yeah, i'm strange :)]
The only thing that i didnt observe, is how shadows behave in my dreams, i dont remember any moment that would somehow require me to focus on it, but i'm pretty sure the image would be distracting to me if they werent lifelike.

We also wouldnt have art without brain ability to make abstract things, which some make or does not make sense physically.
Nikola Tesla had an ability to imagine and construct whole machines in his head.

3D images reconstruction and modification seem like logical way to go, but it does not explain everything, like life like physics or ability to make up physics.
 
Grossly simplified, it should be a sort of re-usal of the vision "pipeline".

When we see things, the eyes feed sensed data to the retina which is then filtered, interpreted and stored.

Imagination should work more or less the same, except that the eyes are "bypassed". So the various stages in the vision pipeline are fed with stimuli directly, from memory maybe. But what feeds what and how is more a question of how each individual's brain is wired.

There was really a fascinating video on TED about old people who have poor sight may have an interesting disorder: they sometimes start to see geometrical figures super-imposed to what other people normally see. Or children, or cartoons. The reason is that thouse areas in the brain were getting switched on intensively & erratically and the brain interprets these as visual input.

The example was given to prove it is possible to bypass the normal visual "pipeline".
 
I'm not talking about situation like You wake up and think 'omg i dreamt about this awesome space travel' etc and You barely remember any details.
I'm talking about situations were You have really detailed dreams and full body presence in them. I have them frequently and everything in them behave like it should, even though many of those dreams are in places i've never been or never seen.
I had even dream recently when i looked at grass and laughed that it moves like in Crysis 3, which looked unnaturally in a dream to me! [yeah, i'm strange :)]
The only thing that i didnt observe, is how shadows behave in my dreams, i dont remember any moment that would somehow require me to focus on it, but i'm pretty sure the image would be distracting to me if they werent lifelike.

I routinely have very realistic lucid dreams and I've done the same thing :).

Except I have checked out the shadows and they are very very good. Actually the lighting in general is better than anything I've seen in a videogame.

I have noticed though that if I'm walking down a street that seems completely normal, if I stop and focus on a street sign or something it is complete gibberish until I "decide" what it should say.
 
I'm talking about situations were You have really detailed dreams and full body presence in them. I have them frequently and everything in them behave like it should, even though many of those dreams are in places i've never been or never seen.
Not all of the rendering may be on line ... by which I mean is that you remember them to be very detailed, but some of that might only be painted in when you try to recall the dream.
 
I have noticed though that if I'm walking down a street that seems completely normal, if I stop and focus on a street sign or something it is complete gibberish until I "decide" what it should say.

And an instant later you're in an attic or a boring office and struggle to get to the vivid street or lush paradise again. duh!

So many times I was also in great mood, thoughts and something, but move in the bed (slightly or not) and then lose it. Never can quite remember it but damn it was awesome and serenity inspiring.
So I think dreams are really only possible to the fullest extent when we're dreaming, at which point we're essentially paralyzed. (In the classic paradoxal sleep at least)
It's like that bodily function was made so we don't get detuned easily when dreaming.

Oh, that was texture loading you experienced?
 
Oh, that was texture loading you experienced?

Homerdog's brain rendering on Unreal Engine 3 confirmed :p

----
Not all of the rendering may be on line ... by which I mean is that you remember them to be very detailed, but some of that might only be painted in when you try to recall the dream.

Its different for me, i dont really remember full dreams far down the line, but i'm completely aware of everything while i'm dreaming. And after i wake up, i remember most of it, its just fading away with every minute ;\

And about details, i feel and see things like snowflakes dropping on my arm and seeing it melting for example :)

---
There was really a fascinating video on TED about old people who have poor sight may have an interesting disorder: they sometimes start to see geometrical figures super-imposed to what other people normally see. Or children, or cartoons. The reason is that thouse areas in the brain were getting switched on intensively & erratically and the brain interprets these as visual input.

Can You find it and link it? Seem interesting.

--
@kyetech
Thanks, i'll check it later.
 
really detailed dreams and full body presence in them. I

that kind of dream is one of the best type of dream i ever experienced but super bad for resting. after having a dream so real, i always feels exhausted in the morning :/

how do you regularly get that type of dream?
i usually draw some imaginary symbol in my palm for a few secs before sleeping, but it not always works.

Edit:
for unknown reason, all my detailed dream have very bad draw distance. Its like PS2 game where there's always those dark fog far away. Something like this:

http://www.youtube.com/watch?v=pjAsBdrECl8#t=1071
 
that kind of dream is one of the best type of dream i ever experienced but super bad for resting. after having a dream so real, i always feels exhausted in the morning :/

how do you regularly get that type of dream?
i usually draw some imaginary symbol in my palm for a few secs before sleeping, but it not always works.

Edit:
for unknown reason, all my detailed dream have very bad draw distance. Its like PS2 game where there's always those dark fog far away. Something like this:

http://www.youtube.com/watch?v=pjAsBdrECl8#t=1071

Nah, i dont feel exhausted at all. Actually i'm pretty sure that every dream i have is like that, but how i'm 'conscious' in them probably depends in what sleep phase i am. The lower phase of the dream, the less control i have over my body in dreams. For example if i'm almost awake, i have much worse motors skills in a dream - running is very hard and feels very strange, talking too.

I just have those dreams. I tried in the past some lucid dreams techniques to gain ability to fully control the dream or just to better remember it, but it was not that fun to do in the long run.

About draw distance, it definitely can happen to have lower 'visibility', but its type of dream or situation. For example in a dream about week ago, i was near the forest and saw carpet bombing of a city in the background.
 
Just to give another pick about how sick my dreams are.

Few days ago i had a dream where i was on a big ship. The dream was similar in progress as Groundhog Day or Edge of Tomorrow. Basically i had to manipulate and do stuff on a ship to safe a crew and a ship from several dangerous situations happening in similar time. If i failed, sequence would start from the beginning, but i remember what i did wrong.
I dont remember all the hazards, but one was storm with enormous waves, second was an assassination attempt on one of the crew members.
To save the ship from the big waves i had to convince captain that he is amazing steerman and able to do it.
For assassination one, i had to make a tactical team and find a killer. In one sequence of trying to safe a crew member, i remember, i got shot in the head.

Yeah, i'm fucked up, i know ;)
The day when we will be able to record our dream, will be the end of non-interactive media.
 
Back
Top