Beta
×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

"Microsaccades" Help To Refresh Your Field of View

Soulskill posted more than 5 years ago | from the adding-a-new-word-to-the-spellchecker dept.

Medicine 96

Ponca City, We love you writes with news of research from the Salk Institute into small, unconscious eye movements called "microsaccades," the purpose of which has been in question for many years. A recent study showed that those movements were essentially responsible for maintaining a coherent image for interpretation by the brain. They are also the cause of a famous optical illusion in which a still image appears to move. '"Because images on the retina fade from view if they are perfectly stabilized, the active generation of fixational eye movements by the central nervous system allows these movements to constantly shift the scene ever so slightly, thus refreshing the images on our retina and preventing us from going 'blind,'" explains Hafed. "When images begin to fade, the uncertainty about where to look increases the fluctuations in superior colliculus activity, triggering a microsaccade," adds Krauzlis.'"

cancel ×

96 comments

Sorry! There are no comments related to the filter you selected.

how is this new? (1, Interesting)

Anonymous Coward | more than 5 years ago | (#26864513)

I remember reading about this back in the 90s...so what is new here?

Re:how is this new? (4, Interesting)

ScrewMaster (602015) | more than 5 years ago | (#26864577)

I remember reading about this back in the 90s...so what is new here?

Nothing that I can tell. I was working as a software developer back in 1982 or so for a group of neuroscientists at a local university. One of the projects I worked on used a pair of glasses with infrared motion sensors on them to continuously track pupil movements. The idea was to monitor saccades for diagnostic purposes (they become exaggerated in, for example, people who habitually work in near-darkness ... like miners.) It was explained to me that it had been known since the sixties (if not earlier) that saccades were, at least in part, needed to avoid retinal fatigue. Early experiments were performed using a grain-of-wheat bulb literally glued to the eyeball. It was shown that when the image didn't move relative to the retina, it quickly became invisible.

It sounds like what these guys are doing is relating these involuntary eye movements to brain activity. That's interesting if not particularly novel: some of the people I worked for were doing this twenty-five years ago using EEGs. What's more interesting to me is that we're generally completely unaware of these eye movements, just as we're generally unaware of our blind spots. It's an impressive bit of (ahem) abstraction layering that the brain does for us.

Re:how is this new? (2, Insightful)

causality (777677) | more than 5 years ago | (#26864741)

Early experiments were performed using a grain-of-wheat bulb literally glued to the eyeball.

Am I the only one who shuddered a bit when I read this and thought about how it would feel to have a small object glued to the eyeball? I'm sure it was benign and performed by competent people who knew what they were doing ... but damn, that just sounds like a form of torture.

Re:how is this new? (1)

JustOK (667959) | more than 5 years ago | (#26864817)

It wasn't torture, just part of the search for Wobbles of Microsaccades, Duh!

Re:how is this new? (2, Interesting)

kylben (1008989) | more than 5 years ago | (#26865163)

Am I the only one who shuddered a bit when I read this and thought about how it would feel to have a small object glued to the eyeball?

Anybody who wore contact lenses back in the 80's knows just how it feels. Especially if you were lazy, in college, and/or drank alot...

Re:how is this new? (1)

anachronous diehard (1169155) | more than 5 years ago | (#26868681)

Early experiments were performed using a grain-of-wheat bulb literally glued to the eyeball.

I first saw this in a Life Magazine article published in the late 1940s or early 1950s. That experiment used a mirror glued to a contact lens, not to the eyeball.

The mirror shifted an image on a screen to negate the retinal image's movement caused by microsaccades. The mirror was better for detecting the eye's angular movement than a light bulb would have been.

Re:how is this new? (2, Interesting)

ScrewMaster (602015) | more than 5 years ago | (#26868743)

Early experiments were performed using a grain-of-wheat bulb literally glued to the eyeball.

I first saw this in a Life Magazine article published in the late 1940s or early 1950s. That experiment used a mirror glued to a contact lens, not to the eyeball.

The mirror shifted an image on a screen to negate the retinal image's movement caused by microsaccades. The mirror was better for detecting the eye's angular movement than a light bulb would have been.

Well, the experiment I read did indeed have a small lamp assembly glued to an eyeball. It's been a long time, but as I recall the experiment wasn't about monitoring eye motion, but to determine what happens when the retina is exposed to an unchanging image. The article mentioned the fact that rabbits are pretty much unable to see anything unless it's moving (something about a lot of the visual preprocessing being done in the rabbit's eye, not in the brain.)

Re:how is this new? (1)

Profane MuthaFucka (574406) | more than 5 years ago | (#26868731)

I shuddered a bit when I realized that these people discovered a way to make ordinary object invisible - a cloaking device. They just abandoned it when all it needed was a few small changes to make it practical.

Re:how is this new? (2, Interesting)

socha23 (1137849) | more than 5 years ago | (#26870879)

Peter Watts explores this subject (among many other interesting topics - including existence of free will, the chinese room, and the nature of empathy and sentience) in his newest book, 'Blindsight'. It's a pretty good read.

The book is available online here: http://www.rifters.com/real/Blindsight.htm [rifters.com] . It's published under Creative Commons license.

Re:how is this new? (4, Insightful)

ColdWetDog (752185) | more than 5 years ago | (#26864765)

It sounds like what these guys are doing is relating these involuntary eye movements to brain activity. That's interesting if not particularly novel: some of the people I worked for were doing this twenty-five years ago using EEGs.

Yes, however this research points to a particular part of the brain, the superior colliculus. That's interesting in a mapping sense. Perhaps not earth shattering, mind boggling interesting like a picture of the FSM, but interesting. Perhaps with better techniques, somebody will be able to tease the movements apart a bit better. As you alluded to in your post, sacchades are interesting from a clinical point of view. How about being able to manipulate microsacchades on a monitor and insert (evil-commercial-concept-or-product)? Your garden variety tinfoil goggles would be useless!

What's more interesting to me is that we're generally completely unaware of these eye movements, just as we're generally unaware of our blind spots. It's an impressive bit of (ahem) abstraction layering that the brain does for us.

Well and again, yes. Do you want to have to will your heart to beat faster when you go up a flight of stairs? What happens if you forget that detail. The automaticity of our bodies allows us to concentrate on important things.

Like Slashdot.

Re:how is this new? (1)

BronsCon (927697) | more than 5 years ago | (#26866291)

What's funny is, as I was concentrating on reading the last paragraph of your post, I was focusing on each word as I read it. Something seemed strange as I read, so I read it again, this time pausing for several seconds before moving to the next word.

Having already read the paragraph, I knew what it said. There was no sense of urgency in my mind, nothing to influence whatever part of my brain causes saccades to refresh my field of view so I could read the next word.

I could see each word very clearly when I first focused on it. By the time I moved my focus the the next word, I saw mostly gray.

Try it. Read this post a couple times, comprehend it, then focus on each word, individually, for several seconds.

Re:how is this new? (5, Funny)

ScrewMaster (602015) | more than 5 years ago | (#26868751)

What's funny is, as I was concentrating on reading the last paragraph of your post, I was focusing on each word as I read it. Something seemed strange as I read, so I read it again, this time pausing for several seconds before moving to the next word.

Having already read the paragraph, I knew what it said. There was no sense of urgency in my mind, nothing to influence whatever part of my brain causes saccades to refresh my field of view so I could read the next word.

I could see each word very clearly when I first focused on it. By the time I moved my focus the the next word, I saw mostly gray.

Try it. Read this post a couple times, comprehend it, then focus on each word, individually, for several seconds.

Funny, for an instant I thought your post had some actual content, but for some reason all I can see now is the word "fnord" repeated over and over.

Re:how is this new? (1)

BronsCon (927697) | more than 5 years ago | (#26868997)

Mod points please? +5 Fucking Epic.

Re:how is this new? (3, Informative)

jellie (949898) | more than 5 years ago | (#26865225)

That's interesting if not particularly novel: some of the people I worked for were doing this twenty-five years ago using EEGs.

The superior colliculus is fairly deep within the brain, so my guess is that they're using single-unit recording, which has been around for at least 30 years, to record from neurons. EEGs don't give readings at the neuronal level, anyway.

Re:how is this new? (2, Funny)

tomhudson (43916) | more than 5 years ago | (#26864643)

Ditto - but back in the 70's. What next - wide ties and lapels, bell-bottoms and flood pants, nehru jackets and peasant skirts, platform shoes and disco?

Well, what the heck, if you can't get bail-out money, at least get research grant money.

Re:how is this new? (1)

causality (777677) | more than 5 years ago | (#26864755)

Ditto - but back in the 70's. What next - wide ties and lapels, bell-bottoms and flood pants, nehru jackets and peasant skirts, platform shoes and disco?

Well, what the heck, if you can't get bail-out money, at least get research grant money.

You forgot the leisure suit. No grant money for you!

Stringy Eye Goop (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#26864649)

Recently I have been getting a lot of stringy eye goop, some of the strands are like 4 inches long! here is a picture of a days harvest [imageshack.us] that I have stored. Advice please?

Re:Stringy Eye Goop (0)

Anonymous Coward | more than 5 years ago | (#26864737)

If you're really asking and just trolling, go see an eye doctor. Looks like you have yourself a serious eye infection there.

Re:Stringy Eye Goop (0)

Anonymous Coward | more than 5 years ago | (#26864773)

do a barrel roll

Re:Stringy Eye Goop (0)

Anonymous Coward | more than 5 years ago | (#26865339)

Please post a video, or no free advise. (p.s. i am a doctor and I can help)

Re:how is this new? (4, Informative)

splodus (655932) | more than 5 years ago | (#26864815)

Saccadic movements have been understood for a very long time, and it has pretty much always been assumed that part of their 'function' was to prevent the Ganzfeld effect and to facilitate in the construction of a representation in the mind of a wider field of view. It has also been known for a long time that the superior colliculus and brain stem are involved in those movements.

This work has begun to identify highly specialised structures in the superior colliculus that seem to control the saccades, and that *has* furthered our understanding of this aspect of perception.

I'd be surprised if the researchers themselves believe that most people thought saccades were 'mere 'motor noise''. I think when Krauzlis says 'scientists have debated the function, if any, of these fixational eye movements' he's being a good scientist and making a statement that does not have to be qualified to be true.

The Real Reason Is Change Detection (3, Informative)

Louis Savain (65843) | more than 5 years ago | (#26865191)

Saccadic movements have been understood for a very long time, and it has pretty much always been assumed that part of their 'function' was to prevent the Ganzfeld effect and to facilitate in the construction of a representation in the mind of a wider field of view. It has also been known for a long time that the superior colliculus and brain stem are involved in those movements.

Yes but the real reason for microsaccades is that almost all the photoreceptors in the retina are designed to detect changes, such as the onset or offset of illumination. Unless there is change in the field of view, the sensors will not fire and the brain stops receiving visual signals. Indeed, retinal ganglion cells (RGC) use a center-surround arangement so that they can detect movement in many different directions. There must be a slight delay between the signals sent from the photoreceptors to the center and side cells in order for the RGC to fire. This is crucial for the detection of things like edges, lines, etc. The brain is primarily a massively parallel discrete signal processor. The precise timing of signals is crucial to its operation.

Re:how is this new? (1, Interesting)

Anonymous Coward | more than 5 years ago | (#26869659)

Saccades also provide oversampling, which increases resolution in the exact same manner an electrical A/D converter does.

Not new (1)

HEbGb (6544) | more than 5 years ago | (#26864535)

There is nothing new here; this has been well known for decades. People with vision difficulties also move their eyes more than those with perfect vision, for the same reasons. This isn't news.

Re:Not new (1)

oloron (1092167) | more than 5 years ago | (#26864557)

of course this is pertinent, Slashdot is losing its vision, and has to look at stories over and over again to keep from forgetting them, or is this just your first day here.... no wait UID too low... what is your excuse ;)

hmm
  captcha = speech
how ironic

Re:Not new (1)

ScrewMaster (602015) | more than 5 years ago | (#26864655)

... no wait UID too low... what is your excuse ;)

hmm captcha = speech how ironic

No kidding ... I wonder what happens if your UID goes negative. Do you simply cease to exist?

Re:Not new (1)

Bangmaker (1420175) | more than 5 years ago | (#26864569)

Some people reading this now were not actually functionally living in the '90s

Re:Not new (1)

ScrewMaster (602015) | more than 5 years ago | (#26864665)

Some people reading this now were not actually functionally living in the '90s

Well, if they were not functioning when they were alive in the 90's, what decade were they functioning in, then?

Now it all makes sense! (1, Funny)

Anonymous Coward | more than 5 years ago | (#26864981)

News for nerds, stuff that matters, replacement for a failing school system.

Slashdot, just like a good video streaming protocol, must send a background stream of image updates about science and knowledge, filling in all the missing pieces of static, known stuff for the lossy observers, while also trying to selectively send some content that is actually new and different.

Re:Not new (1)

osu-neko (2604) | more than 5 years ago | (#26869759)

Um, if the research was about the existence of or the reasons for these movements, you'd be right, it wouldn't be news. Those are things that have been known for decades.

If you actually read the article, you'd see what's new here. It's not anything that's been well known for decades, or even strongly suspected for decades.

Peoplew with eyes are deviuous (0)

Anonymous Coward | more than 5 years ago | (#26864539)

What? Nobody will believe it if it is on the internet. The internet is full of liars and pervaricators who tell the not truth ever. I think you would be better off eating tacoes. If my vagina was here it would be a hot rod of a wiz bang time! Hooray for the VAGUS NERVE!

The illusions don't work for me (1)

Reivec (607341) | more than 5 years ago | (#26864565)

I tested both illusions on the link provided in the summary and neither one had the effect on me that was claimed. What would that imply?

I tried them multiple times shifting my focus to different aspects of the image than directed just to see if it had any effect and it was no different.

Re:The illusions don't work for me (2, Interesting)

More_Cowbell (957742) | more than 5 years ago | (#26864653)

Perhaps your eyes aren't perfectly in sync? My brother had this as a child (one eye would wander around while the other was looking straight ahead. The doctors 'cured' it by having him wear an eye patch for a while to strengthen the weak eye. He looks fine but he's never been able to see 3D images or movies.

Re:The illusions don't work for me (4, Informative)

thermian (1267986) | more than 5 years ago | (#26864673)

I tested both illusions on the link provided in the summary and neither one had the effect on me that was claimed. What would that imply?

I tried them multiple times shifting my focus to different aspects of the image than directed just to see if it had any effect and it was no different.

Optical illusions don't work for everyone.

As an undergrad I had to sit through tests involving optical illusions for the psychology students, and in my case lots of the illusions didn't work. That got me excused from further tests, because they didn't want to make their precious stats go funny by including cases like mine (and about three other people in the class I recall).

Its not that unusual.

Re:The illusions don't work for me (1)

qw0ntum (831414) | more than 5 years ago | (#26864837)

To be fair some are harder to see than others; I had to try a couple times for this one. I was showing the circle and dot one to a friend and I had to coach him through part of it; he saw it eventually but I don't think he got how intently he needed to stare at the red dot. I don't doubt some illusions don't affect some people though.

Anyway, my contribution to this thread: http://allpsych.com/opticalillusions/images/jesus.jpg [allpsych.com]

Stare at that for thirty seconds or so then look at a blank wall and blink a couple times.

Re:The illusions don't work for me (2, Funny)

SGDarkKnight (253157) | more than 5 years ago | (#26865195)

Stare at that for thirty seconds or so then look at a blank wall and blink a couple times.

Damn you! why couldn't you have provided a link like that to a sweedish swimsuit model instead... now i got this bearded freak who looks somewhat familiar to me, i think his name is Buddy... something....

Re:The illusions don't work for me (1, Funny)

Anonymous Coward | more than 5 years ago | (#26865571)

Are you dumb or what?
It is RMS!!

Re:The illusions don't work for me (4, Insightful)

causality (777677) | more than 5 years ago | (#26864911)

As an undergrad I had to sit through tests involving optical illusions for the psychology students, and in my case lots of the illusions didn't work. That got me excused from further tests, because they didn't want to make their precious stats go funny by including cases like mine (and about three other people in the class I recall).

That sounds like they are not very concerned about the accuracy of their stats. You mentioned that this was a type of test. What's the point of running a test if you have pre-determined the outcome? That is more properly called (by them, not you) a demonstration.

While the optical illusion tests you describe are probably not terribly important in the scheme of things, I mention this because it's surprising how many important things are handled this way. It's to the point that whenever I see a purportedly scientific study, my first question is "who funded it?"

Re:The illusions don't work for me (0)

Anonymous Coward | more than 5 years ago | (#26865015)

I call BS.

If you don't notice the illusions, you are either a liar or dull-witted.

The illusions are closely tied to how your brain is wired. If you really don't see them, your brain isn't functioning normally.

Granted, there are some poorly presented illusions, but these generally don't propagate because they don't work well for anyone, or they require a lot of special conditions and work to notice. (e.g. The Magic Eye posters).

Re:The illusions don't work for me (1)

causality (777677) | more than 5 years ago | (#26865223)

I call BS.

If you don't notice the illusions, you are either a liar or dull-witted.

The illusions are closely tied to how your brain is wired. If you really don't see them, your brain isn't functioning normally.

Granted, there are some poorly presented illusions, but these generally don't propagate because they don't work well for anyone, or they require a lot of special conditions and work to notice. (e.g. The Magic Eye posters).

Many of them are strongly influenced by stress (eustress and distress) or the lack thereof. There's also a significant component of vision that is "learned" or interpretive, as evidenced by people who were blind for a long period of time and later had their sight restored only to find that it was confusing and amorphous because they had to "re-learn" how to see. To the degree that illusions depend on reaching the limitations of perception, I would not be the least bit surprised if it turned out that some people manage those limitations and learn to overcome them or compensate for them better than others.

Either way, I think the knee-jerk urge to accuse someone of being a liar or of being dull-witted because their experience is not like yours is unnecessary. It seems to arise out of a lack of appreciation for the complexity and variability of this issue. The GP did indicate that he was in a small minority and that most other students involved did experience these illusions. I'm not sure what more you want.

Re:The illusions don't work for me (1)

thermian (1267986) | more than 5 years ago | (#26865299)

The GP did indicate that he was in a small minority and that most other students involved did experience these illusions. I'm not sure what more you want.

The supervising lecturer said it was likely because I, and at least one other person (I didn't hear him talk to everyone), had sight defects, My left eye looks minutelly to the left when I look straight forward. Its enough to disrupt distance judgement, but otherwise pretty trivial.

Apparently that, or other minor sight defects are enough to nix some optical illusions.

Re:The illusions don't work for me (0)

Anonymous Coward | more than 5 years ago | (#26866137)

Slight defects may possibly be to blame, but since there is a wide variation of illusions, only a few are likely to be impacted, barring catastrophic failure of your sight (i.e. blindness).

For example, if you claim to fail to see several illusions based on different effects, it becomes quite clear where the problem is.

Re:The illusions don't work for me (1)

causality (777677) | more than 5 years ago | (#26866553)

The GP did indicate that he was in a small minority and that most other students involved did experience these illusions. I'm not sure what more you want.

The supervising lecturer said it was likely because I, and at least one other person (I didn't hear him talk to everyone), had sight defects, My left eye looks minutelly to the left when I look straight forward. Its enough to disrupt distance judgement, but otherwise pretty trivial.

Apparently that, or other minor sight defects are enough to nix some optical illusions.

I wonder if maybe having such a visual defect has caused you to practice how to compensate for it. Maybe not consciously or deliberately compensate for it, but just by living your life and using your eyes during your day-to-day activities. You mention distance judgment as one thing that this can disrupt. If you can still drive a car or play sports or things like that which do require distance judgment, that might confirm my little hypothesis.

Another reply by an AC [slashdot.org] says this:

Slight defects may possibly be to blame, but since there is a wide variation of illusions, only a few are likely to be impacted, barring catastrophic failure of your sight (i.e. blindness).

My idea is that if your visual defect has caused you (i.e. your brain) to compensate by processing the raw data from your eyes in a different way, I'd expect it to do so all of the time as a sort of default mode rather than have one mode for perceptions that the defect influences and a second mode for everything else. This may impact illusions of all sorts and not just the ones that bear any relation to the defect. Of course, I am definitely not an optometrist so this is just speculation based on inductive reasoning, but I think it's interesting all the same.

Re:The illusions don't work for me (0)

Anonymous Coward | more than 5 years ago | (#26867403)

As an undergrad I had to sit through tests involving optical illusions for the psychology students, and in my case lots of the illusions didn't work.

The husband of a woman I worked with was getting his degree in geomorphology at UC Berkeley. When he got to the part where they taught terrain analysis using stereo aerial photos, he couldn't see the 3D effect. His prof was going to fail him. He got credit for the class by pointing out that stereoscopic vision was not listed in the catalog as a prerequisite for the course. Apparently it was only in this context that stereo vision failed him -- he otherwise had normal depth perception for all other activities.

I myself have extreme difficulty seeing the desired effect in those fuzzy-looking pictures where you're intended to focus on a point farther away than the picture. You're supposed to see a separate foreground plus background elements through cutouts in the foreground. In effect, you have to go slightly wall-eyed. I can't do that well, but, since I can voluntarily cross my eyes, I can still see the effect, but only for a couple of seconds at a time.

I can still recall the moment I first discovered what the stereo effect was all about. A friend had given me a training text for aerial photo interpretation. It included a series of pairs of extremely simplified topographic images and a stand with two lenses arranged so that each eye saw only one image of the pair.

I was looking at an image of a volcanic crater and had to slightly defocus my eyes. I jumped back from the glasses when it appeared as if the paper suddenly crumpled up toward my face. It all came together in an instant. Since that time, I've gotten much better at looking at stereo pairs. I can occasionally see the effect if I just position myself at the right distance from them, but sometimes I have to put the edge of my hand or a piece of paper up to my nose to fully separate the two images.

One other startling experience I had with the viewing glasses was when I picked up a book on named "Terrain Analysis" from my local library. I positioned the glasses on a page which showed a tarn -- the round lake that forms in a cirque, which is the pit left at the source of a glacier after the glacier has completely melted away. As I looked at it and the effect kicked in, I had a sudden sinking feeling because it looked as though I were viewing it from some thousand feet above the surface, with no support.

Obviously I don't spend a lot of time in helicopters with big bubbles that let you see downwards.

It is not an optical illusion ..... (2, Funny)

daryl_and_daryl (1005065) | more than 5 years ago | (#26864879)

It just looks like one

Re:The illusions don't work for me (3, Funny)

kylben (1008989) | more than 5 years ago | (#26865213)

I tested both illusions on the link provided in the summary and neither one had the effect on me that was claimed.

If at first you don't saccade...

Re:The illusions don't work for me (0)

Anonymous Coward | more than 5 years ago | (#26866403)

Maybe your vision is based on movement?

Re:The illusions don't work for me (1)

Verteiron (224042) | more than 5 years ago | (#26866757)

They only work for me with my glasses on. With them off, even when I move into the range where I can focus on them (4 inches from the screen or so) the illusions don't work. Only with my glasses on can I see the effects.

I don't know that's especially necessary? (1)

drinkypoo (153816) | more than 5 years ago | (#26864585)

You think that's the world, you're seeing? No, you're seeing a representation of it constructed by your mind. The only time you need to see something is when it's moving (or when you're moving in relation to it.) Otherwise it still looks pretty much like it did the last time you looked at it. On the other hand, if something is moving and your eye is damaged, or your brain wants more information about it, then it should need the information. Not that I know more about what this guy is talking about than he does or anything, but I guess what I'm clumsily doing is asking whether that's necessary for sight, or just a byproduct?

Re:I don't know that's especially necessary? (1)

morgan_greywolf (835522) | more than 5 years ago | (#26864803)

You think that's the world, you're seeing? No, you're seeing a representation of it constructed by your mind.

That's how all your senses work. The sensory signals are nothing until interpreted by the brain. Your brain literally does not know the difference between what it perceives through the senses vs. what is playing back in your 'minds eye' through memory. Remembering what an apple looks like and seeing an apple produces the exact same synaptic patterns in the brain.

As far as your postulation about needing to see only movement, I can kind of see your point, though not totally. Evolutionarily speaking, we traded the ability to see well in the dark for extended color perception during the day.

Cats, for example, can see very well in the dark. Their eyes are tuned for detecting movement -- good for hunting. This is why cats are easily amused by laser pointer or a toy on a string, for instance.

Our eyes seem to be more tuned for a broader range of tasks. Probably related to our hunter/gatherer phase. Probably a bit more for the gathering than the hunting, actually.

Re:I don't know that's especially necessary? (1)

drinkypoo (153816) | more than 5 years ago | (#26865585)

That's how all your senses work.

Granted. I was just being snarky. In fact, all your senses are just input for your current world-representation. And... so is memory. But then, memory is little-understood anyway. But it's interesting how some half-forgotten memory can manifest itself in your waking life and interfere with your perceptions.

Re:I don't know that's especially necessary? (1)

noidentity (188756) | more than 5 years ago | (#26864895)

You think that's the world, you're seeing?

No, you're seeing a representation of it constructed by your mind.

So, you think that's the representation of the world you're seeing?

Re:I don't know that's especially necessary? (1)

causality (777677) | more than 5 years ago | (#26864993)

You think that's the world, you're seeing? No, you're seeing a representation of it constructed by your mind.

This reminds me of a section from The Book of Lies by Aleister Crowley (of all people):

A red rose absorbs all colours but red; red is therefore
the one colour that it is not.
This Law, Reason, Time, Space, all Limitation blinds
us to the Truth.
All that we know of Man, Nature, God, is just that
which they are not; it is that which they throw off
as repungnant.

I can't say I subscribe to much of anything that the man believed, but I found the parallel to be interesting.

By the way, nice sig.

Ok, so... (1)

AnonGCB (1398517) | more than 5 years ago | (#26864781)

Can we finally get some specs on life, such as Refresh rate and resolution?

Re:Ok, so... (1)

JustOK (667959) | more than 5 years ago | (#26864831)

Its only a beta. Have to wait for the final release.

Re:Ok, so... (1, Insightful)

PPH (736903) | more than 5 years ago | (#26864917)

Slashdotters' field of view is 1280x1024pixels. Anything outside of that is extraneous noise.

Re:Ok, so... (1)

poopdeville (841677) | more than 5 years ago | (#26864935)

Pff. 1920 x 1200

Re:Ok, so... (1)

ters a-zA-Z0-9$_.+!* (1177175) | more than 5 years ago | (#26869287)

i only see in 1024 x 768 you insensitive clod

You can test this yourself (3, Interesting)

Mprx (82435) | more than 5 years ago | (#26864805)

If you can perfectly relax your eyes you can watch the image fade. Color fades before lightness, and eventually the whole image is just noisy gray. It's easiest if there's nothing visually interesting in your field of vision so you don't accidentally look at something and move your eyes.

Re:You can test this yourself (0)

Anonymous Coward | more than 5 years ago | (#26864881)

If I perfectly relax my eyes, I'd fall asleep.

Re:You can test this yourself (2, Interesting)

Mprx (82435) | more than 5 years ago | (#26864941)

The trick is basically to fall asleep without sleeping, as I assume microsaccades are not present during deep sleep. When I was a kid there was an "astral projection" fad in my school, and people would pass around books about it and try to learn the technique. It doesn't actually work, but you can learn to "shut down" parts of your brain while maintaining consciousness. As the article says, microsaccades are not motor noise, so you can learn to stop them. You can learn to consciously control lots of supposedly unconscious body processes, eg. you can make one hand hotter than the other, or change your heart rate at will. This kind of "body hacking" is the truth behind "ki" and other mystical things.

Re:You can test this yourself (1)

Anynomous Coward (841063) | more than 5 years ago | (#26866253)

True enough.

Years ago I found out how to control the muscles that cause hiccups. While I still can be caught off guard by hiccups, at least I can stop them instantly.

Other stuff I found out how to do:
- decide which eye to use as the dominant eye
- change focus of left and right eye independently
- decouple focus from convergence
- rotate an eye slightly around the Z axis.
- make tinnitus disappear (that's a big one)

Still working on:
- moving left and right eyes independently
- visualizing arbitrary mental images in total darkness

Re:You can test this yourself (1)

geekboy642 (799087) | more than 5 years ago | (#26869691)

I sometimes get hiccups lasting for 8+ hours. Please, by all that's holy and good, share your technique for killing them!

Re:You can test this yourself (1)

Anynomous Coward (841063) | more than 5 years ago | (#26875623)

Poor you !

What worked for me is the realization that hiccups are basically a cramped inhalation, driven by the same muscles you use to breathe. Once I knew this it was easy to get to control them.

Alas, I don't know how to teach the technique.

Re:You can test this yourself (1)

Mprx (82435) | more than 5 years ago | (#26881023)

Pure speculation on my part, but I'd start by studying the anatomy of the muscles involved. I'd then attempt to contract them in isolation from other muscles, feeling the muscles as well as possible, both with my hands and trying to interpret the movement directly, and attempting to identify the muscles that actually did contract. I'd then attempt to contract surrounding muscles, and isolate those are well as possible too. It may not be possible to 100% isolate the individual muscles, but I'd expect to gain some control over them. Then I'd attempt to relax the hiccup muscles in isolation, using the feeling of the muscle contracted as a reference, like you would in progressive muscle relaxation. No guarantees that it will work, but the starting point for all these body tricks is gaining awareness of what your body is really doing.

Re:You can test this yourself (2, Interesting)

matthewncohen (1166231) | more than 5 years ago | (#26864977)

As a long-time meditator I can absolutely attest to this. It does not always happen, but there are certain states of relaxation in which my eyes stop doing this and whatever is in my field of vision becomes gray/green blurry outlines or eventually nothing at all until I move.

Re:You can test this yourself (1)

finity (535067) | more than 5 years ago | (#26864999)

I've never experienced it to that extreme, but definitely know what you're talking about. Standing at "attention" is really boring, and it gets slightly more interesting if you can make everything turn kinda gray. I can always still see whatever is directly in front of my eyes, but everything else fades out.

Re:You can test this yourself (1)

ehud42 (314607) | more than 5 years ago | (#26865173)

Cool! I have been able to do this for many years - especially when I'm tired. I remember in an intro-psych course many years ago the professor showing some kind of image and discussing how people see. I believe it was either the 'count the dots in a grid' illusion or the test your eyes for some disease simple grid image (if the lines are not straight you have a visual problem). Anyway, I asked what it meant when the image faded - as I was tired that day in class, I was able to hold still enough to have the image fade to gray. Seems that was not a normal question - lots of students laughed and the prof made some back handed comment possibly regarding potential substance abuse and that is was not possible for people to hold their eyes still enough.

I always assumed it was simply a stimulus refresh issue, like when you wear something (watch / glasses) and after awhile you can no longer feel it. This is the first time I have ever heard someone actually mention that it happens with eyes.

Conceptual confusions (0)

Anonymous Coward | more than 5 years ago | (#26864819)

Yet again - conceptual confusions abound (in linked articles and comments). The brain does not 'interpret' anything. A person can 'interpret', a brain cannot.

Re:Conceptual confusions (0)

Anonymous Coward | more than 5 years ago | (#26865671)

Yet again - conceptual confusions abound (in linked articles and comments). The brain does not 'interpret' anything. A person can 'interpret', a brain cannot.

Well, honestly my brain is having a hard time interpreting your remark.

Are we talking about the same? (1)

Teun (17872) | more than 5 years ago | (#26864827)

I noticed that rapid eye movement already years ago.

Until now I couldn't quite explain it, say there was this tall blond passing by my eyes would continuesly wander.
Was it some large brunette it wouldn't happen but once only, even though I've always liked dark haired women best.

But this study finally explains it, the big broad doesn't get lost from vision as easily as the slim blonde!
Thanks for nature!

Unconscious eye movement (1, Funny)

Anonymous Coward | more than 5 years ago | (#26864841)

Finally, a viable excuse...
"Yes, I keep glancing at your tits. Nope, sorry, I'm afraid I can't stop unconscious eye movements"

If this bothers you... (0)

Anonymous Coward | more than 5 years ago | (#26864903)

Simply enable vsync and triple buffering.

DRAM refresh and Jurassic Park (1)

mlwmohawk (801821) | more than 5 years ago | (#26865019)

All I can think of is DRAM. You need to keep refreshing the memory by re-addressing it and recharging the cells. By moving the eye, you are just refreshing the pixels.

I am also reminded by the probably nonsensical warning to "hold still" because the T-REX's vision was based on movement. It seems our vision is also based on movement, except we supply the movement with our eyes.

Re:DRAM refresh and Jurassic Park (1)

Dahamma (304068) | more than 5 years ago | (#26865509)

If you are going to use an electronics analogy, I think a better one would be anti-burn in technology in modern plasma TVs. They can periodically shift the image on screen by tiny incremental amounts not detectable to the eye, which lessens the amount of time any one pixel will be fixed on one color.

killing fields (1)

onionlee (836083) | more than 5 years ago | (#26865063)

might this be the cause of those people who lose their sight after having especially traumatic experiences?

Perception (1)

Nicolay77 (258497) | more than 5 years ago | (#26865255)

Martinez-Conde still doesn't know exactly how microsaccades create the false perception of motion.

Aliasing at the retinal level ??

Increases effective resolution too... (1)

spectecjr (31235) | more than 5 years ago | (#26865271)

What I find amazing is that no-one seems to have figured out that it also increases effectives resolution too. And is probably involved in focusing.

Actually... (1)

wanax (46819) | more than 5 years ago | (#26865477)

Michele Rucci's lab figured out a while back that microsaccades improve our perception of high spatial frequency stimuli.. here's the article. [nature.com]

Re:Actually... (1)

spectecjr (31235) | more than 5 years ago | (#26869959)

Michele Rucci's lab figured out a while back that microsaccades improve our perception of high spatial frequency stimuli..

Thanks for the link :)

The thing that gets me is, surely this is obvious? The receptors on the retina are arranged in a poisson distribution (random, no receptors closer to each other than a certain limit). As long as the microsaccades are roughly 1/2 the poisson distance in any direction, this should at least lead to a doubling of the resolution of the signal achieved, averaged over time. If the brain keeps track of the distances moved, you get even higher resolutions (although my guess is that for bandwidth reasons, the microsaccades are 1/2 the poisson distance or less; that way there's really no bookkeeping necessary).

Re:Actually... (1)

wanax (46819) | more than 5 years ago | (#26877749)

I think the main reason that it's not obvious is that the structure of the retina is quite a bit more complex than you make it out to be. First of all, there is essentially an exponential fall-off of receptor density as we move away from the fovea. Secondly, there are several horizontal channels in the lamina of the retina that aggregate receptor inputs in an center-surround manner (eg. on-center, off surround, off center, on surround)- and these horizontal channels are of differing lengths.

So it's not such an easy question of which, if any, are the privileged pieces of the circuit, or which, if spatial areas of the retina are privileged, since there are multiple spatial scales in the former, and spatial frequency gradients in the latter.

There are also some complications about time averaging. The retina has both on and off channels - on channels have fast temporal response to increased light, then their activity decays back to 'base', while off channels have the opposite transient response. So you have asymmetric temporal responses between the channels (which is one of the reasons you have center-surround processing). You also have the detail that most neurons in the retina don't spike, they communicate using membrane potentials rather than action potentials (spikes) - and the temporal resolution of many of these channels is still not fully understood.

I think the reason that your insight isn't obvious, is because it's very difficult to translate that insight into a form that's understood by those expert in the anatomy and physiology so they can tell you whether your assumptions are consistent with the data.

Re:Actually... (1)

spectecjr (31235) | more than 5 years ago | (#26883777)

I think the main reason that it's not obvious is that the structure of the retina is quite a bit more complex than you make it out to be. First of all, there is essentially an exponential fall-off of receptor density as we move away from the fovea. Secondly, there are several horizontal channels in the lamina of the retina that aggregate receptor inputs in an center-surround manner (eg. on-center, off surround, off center, on surround)- and these horizontal channels are of differing lengths.

So it's not such an easy question of which, if any, are the privileged pieces of the circuit, or which, if spatial areas of the retina are privileged, since there are multiple spatial scales in the former, and spatial frequency gradients in the latter.

There are also some complications about time averaging. The retina has both on and off channels - on channels have fast temporal response to increased light, then their activity decays back to 'base', while off channels have the opposite transient response. So you have asymmetric temporal responses between the channels (which is one of the reasons you have center-surround processing). You also have the detail that most neurons in the retina don't spike, they communicate using membrane potentials rather than action potentials (spikes) - and the temporal resolution of many of these channels is still not fully understood.

I think the reason that your insight isn't obvious, is because it's very difficult to translate that insight into a form that's understood by those expert in the anatomy and physiology so they can tell you whether your assumptions are consistent with the data.

Actually, if the center-surround system has the on & off channels spike, then during a microsaccade, any crossing of the boundary should cause a fast-spike. If the motion is known, then the difference in time between the activation of the "on" channel and the activation of the "off" channel (as the edge crosses the boundary) should give a finer-resolution location of the edge.

Membrane potentials make sense in terms of color processing; we already know that color is a lower-bandwidth channel. It's also fuzzy and separate from edge recognition (I know this from... er... some experiments I did on myself involving... oh heck, pretty damn pure MDMA). So if the edge recognition triggers hit, they respond strongly to the extant color data (which is diffuse), and assume the gross color of the area pretty strongly. It seems that even in the fovea, color fills in pretty wildly - which is consistent with a membrane potential action. Also, that kind of slow response should be related to exposure control.

[My specific test case here: Reflected light of varying colors on a blank white surface. The edge-recognition triggers were misfiring, giving something that looked akin to a rolling segmented LCD text display. The color of the phantom text assumed the very light, diffuse and even color across the white surface as a strong, vivid primary color. I'm pretty certain that colors data is not spatially tightly encoded; edges are used to trigger the association of the two.

Other things I noticed during that experience were eigenfaces - apparently when the facial recognition system breaks down and you look at someone, all you get is eigenfaces - or at least the low & high frequency recognition systems go out of sync leading to something that looks a lot like them.

Another thing I noticed was that feature detection is rather interesting. Gross-feature detection is separate from texture-determination. It's kind of like the way GPU's paint a scene; you have the Z-buffer which provides depth, and then you have gross features (triangles in the case of a GPU), and then the actual texture of the surfaces themselves. When the texture system misfires, you get interesting effects, including something that looked like lots of little white bubbles mapped onto the surface, to something that looked like a rolling set of five-pointed stars and linear ridges rolling across the surface.

Anyway... that's a total aside. Anyone involved in that kind of research should at least try a little of that stuff... it's relatively safe, and to an even mildly trained eye will provide a lot of insight in how the processing systems work]

this is creepy (1)

sleepy_sanchez (1301981) | more than 5 years ago | (#26865463)

I kept seeing the phantom of the white background when I looked off the screen. It's like a watermark. Is that the illusion?

WTF? We all knew about this in the 1970s (2, Informative)

dpbsmith (263124) | more than 5 years ago | (#26866153)

Stabilized images on the retina fade. Microsaccades prevent it from happening. I actually think I read an article about this in Scientific American in the 1960s. Certainly I encountered it in a perceptual psychology course I took in the 1970s.

As for illusions like the Enigma illusion, we were told that caused by small eye movements, amplified by a moire effect between the image and the afterimage. Maybe that was only the professor's guess, and the new study did something to pin it down, but it's not a very new idea.

Hello Gordon Freeman... (1)

Samah (729132) | more than 5 years ago | (#26866195)

I read that as "microcascades" and was expecting to see headcrabs in TFA. I was sorely disappointed. :(

Interesting the way scientific discoveries reoccur (0)

Qbertino (265505) | more than 5 years ago | (#26866271)

I was 13, in the 7th grade at my school back in 1983 and I can clearly remember, as if it had happend today, the way our teacher described this phenomenon in biology and how the scientists examining it discovered the effects the prevention of these micromovements of the eye have on the visual perception of things. He also specifically described the blinding of the retina once an eyeball is held fix by small suction-cups.

Ever so often I encounter this, that things people have discovered decades or even a century or longer ago are rediscovered and sold as brand new insights into a specific field. Has any of you guys noticed the same thing? I'd suppose so. Strange isn't it? Does the scientific community need this sort of thing in order to 'stay important' - kinda like fashion fads reoccuring every 25 years or so?

Re:Interesting the way scientific discoveries reoc (1)

osu-neko (2604) | more than 5 years ago | (#26869737)

Actually, all that means is you read the inaccurate summary too well and didn't read the actual article carefully enough. (What's new here has nothing to do with anything you just said, and is not something anyone knew about back in 1983.)

What's new here has absolutely nothing to do with the fact that these movements occur, nor anything to do with their purpose, which has also been well understood for decades. What's new here is the pinpointing (or at least narrowing down) of the mechanism (or at least the area of the brain) that generates and controls these movements, and it's not where a lot of people thought it was.

I doubt a 7th grade class on the subject would have even touched on these details. Do you remember them discussing the various brain regions involved in the different parts of visual perception?

Go to the Source and the water is Sweeter (2, Informative)

Magdalene (263144) | more than 5 years ago | (#26866811)

The article in Wired seems to be a 'dumbed down for public consumption' version of an article that appeared in Scientific American in August 2007. The original was authored by Dr Susana Martinez-Conde and Dr Stephen L Macknik, and referred to a study they had completed in 2006. There is a preview available here:

http://www.sciam.com/article.cfm?id=windows-on-the-mind [sciam.com]

unfortunately one would have to pay for the whole article as they are a subscription magazine. But the proof is in the preview, and if anyone should want more, I would encourage them to go to their local library and find the magazine there. The article in Scientific American is much more educational.

I'm pretty sure we've known about this for awhile (1)

purduephotog (218304) | more than 5 years ago | (#26866987)

... at least in my field.

It's been awhile since it's come up but it takes 7 of those little vibrations (if memory serves- I can ask the expert) to register the j-curve for the minimum contrast detection in the standard observer.

Useful for image refresh calculations :)

Does this change Sponge-Worthy ... (1)

cavehobbit (652751) | more than 5 years ago | (#26868279)

into a negative term or is it still positive?

'Damn, whatever that guy gave me last week seems to be sponge-worthy, better go to the clinic'

'course, it'd go for guys too now...

'Damn girl, you're so hot you're Sponge-Worthy!'

Yes, it's quite old (1)

DynaSoar (714234) | more than 5 years ago | (#26869389)

Blindness can be induced by paralyzing the ocular muscles and immobilizing the head. This was done decades ago using curare. If the visual field remains constant, there is a loss of visual contrast until everything greys out. With practice this can be done by forcing the eyes to remain focused on a point. The visual system detects edges via saccades, movement or both, and fills in the remainder via a combination of detection and heuristic recognition. The process description and references are in Karl Pribram's book "Brain and Perception" (the same book erroneously blamed for the "holography" ridiculousity). We used a similar technique on rats in his lab to negate visual input while measuring whisker input, the bottom line of which was to show the calculation process in both to be very similar.

The old SciAm article others mention was probably "What The Frog's Eye Tells The Frog's Brain", which describes that the frog detects motion by remaining still so that the visual field blanks, and waiting for motion to cross the visual field and so become visible. If the visual system was always detecting everything, it would run slower and the frog would be less able to react quickly and snatch the flying insect out of the air with its tongue.

The article summary is wrong in that saccades have been understood for years. TFA is a novel contribution in the sense that it describes the process of illusory motion. Yet this is not entirely novel since it is a variation of the spinning room illusion familiar to anyone who's tried to lay down after too much to drink, as well as the 'waterfall illusion' wherein things appear to be moving upward after having watched a waterfall for some time.

But the "maintaining a coherent image" stuff? 50 years old. Karl took the curare trip himself in the 50s. Luckily he had the foresight to use a ventilator also. Curare paralyzes the diaphragm as well.

Red Dot Blue Circle (1)

Drunken_Piper (1232578) | more than 5 years ago | (#26872685)

I focused on the dot without issue, but when the blue circle disappeared I found it harder to focus on the dot. Does anybody else experience this?

Human Super-resolution (1)

ubergeek65536 (862868) | more than 5 years ago | (#26875079)

I had assumed that type of eye movement allowed the brain to apply a super-resolution filter. Since the eye has a limited number of rods and cones and the eyes lens isn't perfect, it would allow the brain take multiple images and average to get a more detailed image. http://en.wikipedia.org/wiki/Super-resolution [wikipedia.org]

Practical Application? (1)

rikkers (13038) | more than 5 years ago | (#26877267)

Though knowing what part of the brain is responsible for this feat is a great revelation, it has been known that eye movement helps us to filter the noise and false images generated by our all too imperfect visual system.

With movement our brain tests repeatedly our rods and cones to verify that what they see is actually in front of us and not due to various things like the blood flowing through our retina, or the attenuation of a single or group of rods or cones with respect to others. After such eye movements, if a rod or cone still registers the same value then the brain can filter it out as not being real, or at least part of a smooth blank space (which probably gets ignored as well).

I am wondering if this can be applied to modern cameras, which seem to have problems with image noise. Instead of employing small sensor movements to reduce camera shake, perhaps they could be used to move the sensor in a predetermined path, one in which the final image could be calculated from. It would seem that if such a calculation of the resultant image could be done, then a much better image could be the result.

Voice of Fire (0)

Anonymous Coward | more than 5 years ago | (#26878109)

That' anomaly of vision is exploited in the above painting.

Not new, but still fascinating (1)

breakpoint8088 (793374) | more than 5 years ago | (#26880125)

Without looking at the paper in detail (things to do today, I'm afraid) I'd have to agree that this doesn't sound like anything new. I worked in video compression about, oh, ten years ago, and I remember it being explained to me as already fairly well established that:

1. The eye makes tiny, constant movements referred to as "tremor".

2. While the iris reacts to total constant light levels over time, the rods, cones, and optic nerve work to transfer transition data, primarily, to the visual cortex-- like other nerve activity, steady-state levels are of lesser importance than transitions, and seem to be processed slower.

3. If a sharp edge or feature is focused on the retina, tremor will cause rods and cones to move onto and off of that edge or feature, causing a sort of pulse train for the optic nerve and visual cortex.

4. This seems to account for things like conflicting results when early graphics researchers were trying to figure out the minimum acceptable frame rate for a flight simulator: We detect motion of edges and large objects at extremely high rates (I have heard 120-160 frames/sec equivalents), color (at all) at lower rates, texture features at even lower rates, and so on. This is why 24 frames per second can be either adequate or jarring, depending on what's in the scene and how things are moving.

One thing to share for sure, though: the physiology and related science of visual perception is absolutely, positively fascinating. Utterly rewarding stuff to read about-- you'll see it everywhere, once you learn some. Anybody the least bit interested in optics or graphics-- programmers, photographers, and videographers, sure, but even gamers-- should get a kick out of studying perception.
Check for New Comments
Slashdot Login

Need an Account?

Forgot your password?

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>