This clicked with me when I watched The Brain with David Eagleman [1] on BBC a little while ago. I've always know there is a disconnect between reality and what you interpret but the way he described it stuck. Note this is my layman's way of describing how I understand it.
Firstly your eyes are not connected directly to your "brain". You don't see what is in front of you.
Your eyes write a rough scan of elements of what is in front of you to a "frame buffer". Your brain looks at this "frame buffer" and interprets what it thinks you are seeing. At this stage it can fill in blanks and do all sorts of manipulations to make it look smooth and complete.
What can also happen is your brain can write to this "frame buffer", this is indistinguishable from the information the eyes have put there. This is pretty much how psychosis works - those monsters/spiders/people/objects seem as real as if they are there.
When you realize your previous approximation leads to a discontinuous function after new data arrives, just roll back your instruction pointer as well as your perception of time.
This ability to retroactively error-correct without affecting perceived continuity could also be affording our brains a greater margin of error.
Maybe, but then it turns out that your brain's cache isn't rolled back when you mispredict, and you have to close your eyes for ten seconds after looking at anything secret until another few hundred generations of evolution fix the bug.
It seems our biological neural networks, probably, aren't all that different from the ones we write. In their 'scope' they basically do just enough, for us to function. Beyond that, evolution probably started to optimise other things.
"Just enough" would mean being able to agree upon whether the object being seen was a danger (say a wild animal, an enemy tribe) or not (a friendly tribe). This goes deep enough for us to agree upon facial expressions and the like.
Interestingly, the 'lack of agreement' would theoretically be impossible to detect, because for consensus, we would achieve "eventual consistency" of conclusions - thereby reforming the neural pathways of all individuals.
My father was a photographer and over the decades he worked with many other photographers in his darkroom (this was in the era of chemical photography). After several hundred occasions when he and another photographer were looking at a print under the color balancer, he realized they were literally seeing different colors. My father, who was scientifically inclined, eventually worked out the average variation, which I want to say was two clicks on the projector, but I’d need to check to find out what that actually meant in terms of frequencies. It’s a small variation, but it was certainly real. Remember, these were all professionals with years of skill at judging color.
I watched a program on PBS back in the mid 80's about San Fransisco and the Haight Asbury Free clinic.
They were speaking with a doctor about "acid casualties" LSD. What the doctor said was really interesting.
People who have flashbacks get scared thinking their brain is fried, and it's usually triggered by something visual. The patients have visual "abnormalities" and it scares them into thinking a new acid trip will start. In reality what LSD, Mushrooms, Peyote, etc. can do is strip away all the adaptations in the visual system. He said in most cultures that use psychedelics they usually talk about cleansing, or stripping away when using psychedelics, and with the visual system it's a true statement.
When he went on to say was that when we are born our visual system is like a blank downloadable computer, and as we grow, the visual part of our brain is making adaptations based on what it knows vs what is 'senses'. He said that due to small eye movements the sensing would jiggle, especially in our peripheral vision, but we learn the the world doesn't jiggle, so the visual system makes sure that stable items don't jiggle. Tons of adaptations take place, depending on our lives and experiences some of us have more adaptions than others.
Sometimes when taking psychedelics all those adaptations get stripped out, or only some get stripped out, leaving people with the untrained system, and that untrained system doesn't present things in the same way. Colors don't look the same, sometimes things in the peripheral vision jiggle or move, moving our heads quickly while quickly moving our eyes can cause 'trails'. All indications that our visual system has had some adaptations erased.
The doctor said that eventually over time things get usually restored to normal. However he said for colors, it's interesting because for people that grew up in a different area of the country and had their color perception set at that location, they sometimes find the when wipe out the adaptions and reset things the colors sometimes don't matched. Depending on where they grew up vs where the adaptations get reset the color of the sunlight can be different, and that will alert the color adaptation.
9 might be okay if the effect size is large enough. (If the study was pre-registered there should have been a power analysis to determine the sample size given the hypothesized effect size.)
The article and its associated paper did not really engage me. Perhaps I am missing something.
However, I was reminded of something that I learned when taking drama lessons as a teenager, and which I have used as a teacher. Our attention of an object (such as another human) oscillates from eye to eye. However, it is biased to one eye. Generally this is the one on the opposite site to our writing norm (i.e. left handed = right eyed). If you really want to hold a scene when being filmed, look unwaveringly out of the eye that is nearest the camera. It will feel unnatural, but look dam cool on the screen. Look carefully... you can see Laurence Olivier and others doing precisely this.
As a teacher I use it in class to hold attention. But it’s best effect is on the screen.
Do you have a link with a video or a visual explanation? I dont get what looking unwaveringly out of the eye closest to the camera means - what does it mean to look out of one eye?
He tell a bunch of actors to always 'pick an eye' when in front of a camera. What Michel Cain does not say is that some actors prefer looking out of their 'handed' eye, believing it to have more impact.
As a demo of 'handedness' in eyes, try this experiment:
1. Hold one finger around one foot in front of your face. Hold the other at arms length. Whilst try to look out of both eyes, ensure that the fingers are visually aligned with each other. This will be difficult, as the images from each eye will not correspond.
2. Slowly open and close one eye. Then do the same with the other. The slow blink from one eye (eye A) will not affect the correspondence of the fingers, whilst the slow blink from the other (eye B) will.
The reason is that eye B is adjusting itself to match eye A.
He does mention choosing which of his own eyes to look out of, but when he says "pick an eye" he's clearly talking about picking one of the other person's eyes to look at. That's also clearly the source of the flicking back and forth that he talks about (and demonstrates).
> Our attention of an object (such as another human) oscillates from eye to eye.
I thought I understood this at first but with a bit more thought I realised I didn't. You can change the angle between your eyes' directions (i.e. you can cross your eyes rather than them always being totally parallel), so when you focus on single object they are both directly pointing at it simultaneously. Even if your attention is oscillating between them, there's no reason why this would be observable to an outside observer (or camera).
Is it possible you're thinking of looking at someone else's eyes? In that case there are really two objects to look at - the other person's two eyes - so your attention does indeed oscilate in a visible way. But it's not which of your eyes (that you're looking out of) that's varying - it's which of their eyes (that you're looking toward) that's varying.
On a slightly different but related topic, check this out: from Alfred Yarbus, 'Eye movements and vision'. Springer; 2013 Nov 11. p.107
"The drift of the axes of the eyes was first discovered, and on the whole correctly described, by Dodge (1907). He considered that there is no constant point of fixation and suggested the term 'fixation field."
Subsequently, nearly all authors studying eye movements confirmed the presence of drifting movements of the eyes (Glezer and Tsukkerman, 1961)."
I did a bit of work on a project that examined the difference between the way that artists and laymen look at images. For this we used eye trackers. This is where I first saw how restless normal eye movement is. The figures in that chapter and preceding it bear this out.
So... attention drifts from one eye to the other, though one eye is dominant, and defines the 'pan' angle of the other. In addition, generally the eyes scan points within an object rather than look directly at the object as a whole. As someone who teaching drawing (and therefore perhaps analytical looking) this was an 'eye opener'.
My understanding is that you only have a relatively small area in the center of your vision where you get a clear image. And so your eye moves back and forth so rapidly that you can't tell without slow motion, sort of scanning in the environment into a 3d map.
So maybe some of the variability is in that mapping circuitry.
Is there an expert who could explain what's novel here ?
The layman summary seems to imply specialists are surprised that people judge distance differently which seem crazy to me. I mean we have known for decades that vision is the result of a complex process involving different parts of the visual system and that people results on tasks involving mainly vision (and coordination admittedly) vary.
The scientists are trying to determine why we judge distance differently, and found that each individual will consistently have problems with particular areas in their field of sight.
They think this is a result of various imperfections forming when your eyes connected to your brain.
Not only that, Kant himself structured the idea of the world outside our field of experience in a critique of pure reason. Since then the idea that our experience is a perfect one and that all our ideas come from our experience has been questioned.
This is why when the interviewed said "We assume our perception is a perfect reflection of the physical world around us" it was really strange for me. Only those unaware of hundreds of years of advance in philosophy assume that. And this highlights possibly a field that is very much lacking in science, the critique of thought itself.
> Only those unaware of hundreds of years of advance in philosophy assume that
So then, nearly all children, and most of your average working-class people? Seems to me the author was just tailoring the piece for a layperson audience, which is kinda the default writing approach.
I would say even a lot of very educated people, despite maybe having read about these topics, will still feel and act as if what they are perceiving is reality itself.
I'm actually very surprised to see so many comments here dismissing the article as something almost obvious.
> “We assume our perception is a perfect reflection of the physical world around us, but this study shows that each of us has a unique visual fingerprint,”
I don’t think anyone makes that assumption. I think most people know we don’t actually “see” the physical world, our eyes receive electrical signals from photons and our brain interprets those signals and for lack of a better word we hallucinate the physical world (in the form of the visual light spectrum).
By its very nature, from a common sense point of view photons don’t hit our eyes at the same time or the same angle; therefore, electric impulses will be different reflected Differently in our hallucinations. And even if 2 people had the same distance/angle, there are sometimes other issues differentiating our hallucinations, just one example being color blindness, where for various reasons one person hallucinates different colors than another based on the same electric impulses from photons. Even without color blindness this happens regularly (think of the blue/white dress vs black/gold viral photo a few years back)
I think many educated people cognitively "know" this, or at least have heard it from somewhere. But I also think that the majority of people, educated or not, don't feel this in their actual lived experience. Your brain does a good job of telling you that what you see is what is.
Anecdotally I've always perceived that dress as blue/brown from the very beginning and I can't "switch" my vision to perceive it otherwise. It's incomprehensible to me that someone can see it as blue/white or even worse as black/gold :)
I don't want to trigger another thread about this old image, but I will point out that there are significant differences in monitor gamut and gamma across devices. Some cheap laptop LCDs crush blacks and whites significantly if you aren't looking at perpendicular dead center.
It is for this reason that using light blue or light yellow backgrounds to demarcate ads is sinister -- one can A/B test their marker into literal invisibility for many users.
I'm an amateur photographer and have got quite good monitors that I calibrate regularly :) But I've got trained sight, especially for color balance because of that - I can see people faces greenish when they stand under a tree in a sunny day so that's that.
On the flipside, I've experienced the dress thing before the dress itself - for me, it was entirely the difference between being used to sunlight vs indoor light. If I was currently used to the brighter sunlight I'd see it one way, after adjusting to indoor blue-r light I'd see it the other way.
After realizing that cause, I was able to change how I viewed the dress willingly.
Firstly your eyes are not connected directly to your "brain". You don't see what is in front of you.
Your eyes write a rough scan of elements of what is in front of you to a "frame buffer". Your brain looks at this "frame buffer" and interprets what it thinks you are seeing. At this stage it can fill in blanks and do all sorts of manipulations to make it look smooth and complete.
What can also happen is your brain can write to this "frame buffer", this is indistinguishable from the information the eyes have put there. This is pretty much how psychosis works - those monsters/spiders/people/objects seem as real as if they are there.
[1] https://www.bbc.co.uk/programmes/b06yjrdp