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Human Brain seems to procceses image data serially
Tekmage writes "Ever wonder how the brain processes image/vision data? According to this research, it does so in a more serial manner than parallel. " This has been one of those on-going debates since the 1960s, with the advent of machine vision, with this being the latest round in the battle between the two sides.
Does it really matter? Technology is still way behind being able to keep up with the processing power of the mind. top ten post?
Although I haven't read the article, I know Luck's work. He probably:
1) Used and eyetracker to make sure gaze was at the center of the display.
2) Made the objects large enough so that they could be identified in peripheral vision (remember: attention is not strictly coupled to the fovea. After all, you can watch someone out of 'the corner of your eye' as long as the eye is not making a saccade).
3) Used SSVEP to determine which item was being attended. SSVEP dislays items at different flicker frequencies. Deconvolve the frequencies, and you have the waveforms for different items. Subtract attend from unattend condition, and if you find a difference at that frequency, then you can pretty much conclude that they were paying attention.
4) What's flawed is the task: the task entices subject to process the items in parallel.
You are completely correct.
This article isn't about image processing per se, it's about attention - the selective subcognitive process by which we focus additional processing power on specific elements of perception. It's a vital, essential skill, and works in a variety of levels and situations.
Notice how you can always hear your name mentioned in a loud party, even though you otherwise can't make out a single conversation? Or how a tired mother can sleep through a storm, yet awaken to the quieter sound of her infant crying?
There's a sort of "thunk" procedure that works in these situations. What the studies you've cited show, as well as the one cited in the article, is just which tasks require this "thunk" and which do not.
The blood vessels in front of the photoreceptors supply blood (products) to the neurons in front of the photoreceptors, and are in fact, very sparse. The photoreceptors themselves are fed by the much more blood rich tissue BEHIND the receptors.
Will be slim to none, imho. "A serial process operating on parellel hardware." It seems likely that the comparison was a serial process because a line of cubes, one not the same, is not something you see regularly enough recognize in parellel -- "at a glance", like you do, for instances, faces. I'd bet that after enough repetitions, the mind's pattern matching would kick into action and operate vision in parellel. After all, how many of you still read letter-by-letter?
The conclusion to gain from this experiment is that computer vision systems need to be adaptive and learning. While it's probably not necessary to explicitly program every word into a computer reading system, sitting there and grinding away with OCR on a character-by-character basis is probably a waste of time. The difficulty is in feeding back the brain's (knowledge base's) identifier for a pattern (how do remember what the word "word" looks like well enough that you don't read it letter-by-letter?), determined after a serial examination of a given input, back to the parellel recognition system for training.
I think it's safe to dismiss the 1/10 of a second switch as specific to the situation. I can notice an interval a great deal smaller than that playing Half-Life, and so can you, I'd imagine.
-_Quinn
Reality Maintenance Group, Silver City Construction Co., Ltd.
i wish i had some of those. i would build a beowulf from them.
Yes.
Whilst I am not an expert in any of the science involved here, doesn't the instruction "probably red, but could be green" immediately make people search the red block first in detail and then the green one? Would this not influence the results?
Ho! Haha! Guard! Turn! Parry! Dodge! Spin! Ha! Thrust!
If you're really, really, lucky, your article will finally be accepted for publication a year after it was originally sent out (assuming it was conditionally accepted the first time pending revisions). Then, there is usually at least a one year publication lag from acceptance.
For example, in the June 1998 Journal of Experimental Psychology: Human Perception and Perforamance, the first four articles were first received on:
1/31/96
3/12/96
3/21/96
9/14/95
They were accepted on:
3/3/1997
3/4/1997
3/5/1997
3/5/1997
The research was probably completed anywhere from 1 month to 2 years before the article was first received (the authors might not have the time to right up the article imediately, or the article might have been rejected from another publication.).
So, even in peer-review journals, the experiments were usually performed at least 2 (minimum) years ago.
Just goes to show you how ridiculously out of date textbooks are!
But back to this article: the IEEE write-up was published this year, but we don't know when or where the original journal article was published (or did I overlook it?).
Visual processing is done in the retina and optic
nerve. Manipulating the processed data is done in
the brain. By the time the signal arrives at the
brain it has already been processed into data for
representing all the objects and characters being
viewed. All this experiment shows (besides limits
in the eyes field of view) is that the brain
evaluates objects serially, at least under some
conditions. I does not identify object serially.
Our brains are divided into at least 2 independent chunks - the left and the right side. These two sides are only connected by a fairly tenous collection of neurons known as the Corpus Callosum (there are a couple of other very small connections as well...).
People have actually had their corpus callosum severed - so-called "split brain" patients. In general, experiments with these people show that the two sides of the brain are largely independent - for instance if people are shown an object in such a manner that only one side of the brain can see it, then the other side of the brain is not aware of the position of this object. If the patient is then asked to reach for the object with the hand governed by the other side of the brain, they will try, but not know where the object is.
Doesn't this tend to suggest at least 2 independent "chunks", with the CC normally governing communication between these chunks?
To me, if the brain is really a large parallel machine, there's no reason why seperate threads of computation can't be going on in seperate parts of the brain - each taking up a small physical region of resources.
These threads could even communicate with each other fairly readily. There's really only problems when the two threads want the same resources.
This is backed up by experiment, too - Richard Feynmann did some very interesting experiments in keeping time. He found that without a watch, he could keep time very well....when he counted to 60, he _ALWAYS_ got 72 +- 1 seconds (or something like that).
The interesting thing is what happened when he tried to do other things while counting. The majority of tasks had absolutely no effect on the counting. A few tasks slowed or sped up the counting. And some tasks precluded counting - he couldn't count at all while doing these tasks.
(He also did some experiments to make sure he wasn't basing his counting on some internal physical clock like the heart beating or breathing - he counted while running up and down stairs. No change in the rate of counting.)
Now I admit that a fast-switching serial model would work just as well in explaining these results, but considering that the brain is demonstrably a parallel architecture, I think that the parallel model is a lot more elegant.
-Shane Stephens
In the psychological world, the belief of serialization by the brain is most often demonstrated with the following experiment. I do not have the specific reference of the experimenter but it can be found in any book on cognitive processes.
The subject is given a list of numbers to memorize. Then the experimenter asks the subject if a given number is in the list or not.
The results: The time taken to answer the question negatively is longer for longer lists. The theory is that the brain is sequentially (serially) looking through the list.
Visual processing is probably also serial but as pointed out, the fovea is quite small region so in order to find a feature on a picture, all the relevant parts of the picture must be passed over the fovea. For this reason, the experiment in this Slashdot item is probably not too useful.
I just had to point out this experiment because this is yet another Slashdot article that just pisses me off because there are so many arrogant posters that don't have a clue what they are talking about. These are the people that have qualitative comments like "Well, I can do xyz in parallel so I must be parallel, woohoo!" From a philosophical point of view, do you ever really know what your brain is doing? Our brain is what makes our perception of reality so it can mask it's own operations from us. Kinda like a stealth virus or malicious linux module. Even if we don't have a malicious brain hiding it's operations, when was the last time you could see each frame of a movie as it played at 24fps or 30fps? It sure looks like fluid motion doesn't it? How easily we can be tricked... So maybe the parallel processing in our brain is actually multiprogramming with a time quanta smaller than we can detect so as far as we can tell, it is perfect parallel processing.
I agree, but in the article, they sought to prove their serial theory by using examples of visual images. So they were justifying their serial theory by using serial input. See my comment/posting on the mono VCR.
Based on the way this experiment was setup (from what I could tell from the article), I don't think you can infer too much about how the brain processes visual information in general. What they measured was how the brain picked up a very specific detail on one of three objects. If the objects were spaced too far apart (for one example), then the brain would be forced to process each image separately (ie. serially) simply becuase the human field of vision isn't large enough to encompass each of the blocks.
I think that this study shows that it is possible for the brain to process image data serially in such a fashion that we perceive it as happening instantaneously, but it says nothing to exclude the possibility of the the brain's ability to process images in parallel.
I would be interested to see if they can create a setup which shows that for that certain test, the brain does deal with visual information in parallel. Based on my experience with having a brain (albeit a weak and puny one), my guess is no, but I still don't have confidence in a neurological study with only one type of test.
A fellow poster had said that the brain is parallel, becuase he can take a shower, and think about what to code after breakfast. This is true, however the article was more about image processing, rather then thought patterns.
The point that the study was making is that the brain focuses on images one at a time. (really fast that it's a blur to the concious mind, but singularly nonetheless.) Think about it. You stare at a computer monitor, and a post-it-note you have stuck next to your monitor falls down. Your eyes detect the movement and send the signal to the brain. The brain in turn sends an impulse back to the eye muscles to rotate and focus on the movement. In this split second, you forget about the monitor and your attention is on the post-it-note. Then your brain receives the visual cue that it's "Just a Goddamn piece of paper" and clicks back over to the monitor.
But, since Thought patterns are processed in parallel, you can think of many things at once. While that post-it-note falls, you could be singing along to music that you are listening to on the radio. (AND, chances are you won't miss a beat when the post-it-note falls, and you're still singing. It's not severe enough to command the brain's full attention. If a car smashed through your wall, however, I'd bet you'd stop singing.)
-- Give him Head? Be a Beacon?
-- Give him Head? Be a Beacon? :P)
(If you can't figure out how to E-Mail me, Don't.
Agreed. If they simply had an array of black blocks with one white block and said, "Find the white block," or, say, "Does this array of blocks contain two green ones," you'd be able to do that *instantly*, because, as I understand it, you would be able to find the patterns in the scene and discover the anomalies (the white block, for example) in much more of a parallel fashion, which allows you to do it nearly instantaneously, whereas examining a green and a red block for a small "nick" (which would require a detailed examination, thus movement of the eyeball itself), requires much more detail.
.. then how come I'm 99% sure that I can read words instantaneously? That doesn't include understanding them; you seem to have to pump them through some kind of auditory circuit first and internally vocalize them, but I'm pretty damn sure that I read the words themselves nigh-on immediately.
:)
Now if only I could get around that road-block in the middle, but I guess the brain still has to break it up, digest it, and commit it to memory - which takes time.
As ever (and as with even the best computer architectures today), the problem appears to be the pipe between the processor and memory
Recognition and processing is parallel.
Understanding is serial.
Simon
Coming soon - pyrogyra
Much of this may have to do with the fact that human vision is not like a computer's vision. We don't get a nice rectangle of even pixels. We see best in a small area where are vision is focused. Move a few degrees out and vision (peripheral vision) rapidly degrades. This alone means that it is next to impossible to examine two things well at the same time.
I'd be very curious as to if they'd get similar results with sound experiments. I suspect not. I recall experiments in which people were fed different sound sources in each ear. Even when paying attention to one voice stream for some task, subjects still responded to their own names in the other voice stream. This implies that some level of cognitive processing is still going on for the stream supposedly being ignored.
The cake is a pie
I wonder how much influence the fact that we can only focus on one object at a time has on these findings.
I mean, if we can only look at the objects serially (and discriminating whether it has a nick or not i think requires "looking at" rather than "scanning" for one red block in a sea of greens), how do they expect us to process them in parallel?
I didn't see any data. How many people did they test? How did they determine if the thoughts were parallel or serial by watching N2PC?
The article was a good brief overview but had no links to the report itself.
BTW. Did it seem odd that the experiments were performed in 1994 but the article was just published? I wish I had 5 years to evaluate my findings and report back.
~Billkr
This is eye mechanics. The eye has higher resolution in the fovea, which is the only place likely to be able to find a nick on a block. (Also, the coor receptors necessary to differentiate between red and green concentrate in the fovea).
Thus the eye will saccade (move rapidly) from one spot to the next to get the object under study projected onto the fovea. Of course the brain will process them serially; the fovea can only point at one at a time.
Reading is a more realistic problem, where several words can fit onto the fovea at once. The question of whether we process those words in parallel or serial is not resolved by this study.
[
The article was rather pithy. I haven't read the original, but I know some of Steven's Lucks work. Here's how he might have done it:
1) How do you determine "what" is being looked at? Luck sometimes uses an ingeneous method called SSVEP (I dunno what it stands for). Basically, you occilate the different objects at different frequencies (requires a fast monitor and video card). Therefore, any brain waves occilating at those same frequencies must have been driven by those same stimuli.
2) How do you tell what is being attended? Attention, at least in early vision, appears to act like a gain control. Therefore, if you are paying attention to a certain object (at a certain frequency), then if the object is being attended, the brainwaves matching that frequency will be different in some way (compared to the "don't attend" control condition). If you don't find a difference, then you can assume they weren't attending (or weren't attending differently from the "don't attend" control condition).
3) How do you know where? Well, you can never be certain with ERPs, but they use a multi channel (128 electrode?) hair net. Unfortunately, it's not as simple as triangulating (you can never be certain how tissue densities might affect the signals), but you can at least get a crude idea (front, back, left, right).
I agree. We're massively parallel. All they proved is that there is a limit to our parallelism. Duh! I can only focus on so many details at once. I knew that without any brain-wave processing.
I already knew that when I read a book, I don't stare at the whole page until the text of the book sinks in. I read word after word. When I'm looking for a detail in a picture, I don't just stare at the picture until I find what I'm looking for. I scan small areas that look interesting until I can focus in on the area in question.
Time flies like an arrow. Fruit flies like a banana.
This is simply common sense. Wave your hand in front of a lamp (monitors don't work very well for this experiment). How do you see it? As one image after another; you don't see your hand in all possible positions at once.
Note that that's simply processing sensory data. The people who talk about spotting the red cube in a bunch of green ones are talking about something totally different: recognition. Even there, the brain picks the red cube out from the whole image; the reason the time to recognize the red cube doesn't depend on the number of total cubes is that you see the same size image, no matter how many cubes there are, and the red cube looks different enough from the green ones that it's easy to spot. It'd be like playing "Where's Waldo" in a situation where everyone else is wearing blue; no matter how many people there are you'll find Waldo in a second.
Still not convinced? Here's a simple experiment to try: play "Twinkle Twinkle Little Star" and Limp Bizkit's "Nookie" in your head simultaneously (those songs being chosen because they're totally different; feel free to substitute any other two songs that are sufficiently different), and try to concentrate on both at the same time (note: do this without actually saying the lyrics to either one; that's cheating). You can get pretty close, but I'll bet that you can't quite do it.
More than likely, the brain simply "multitasks" in a manner not unlike machines do today; it doesn't really run multiple processes at once but it can do a pretty convincing illusion. Since each area works somewhat independently of the others, you can get a bit of parallelism going. That's why you could sing the lyrics to one song while thinking of another; you've assigned a different area to each task. Put them in the same area (by not saying the lyrics to either one) and suddenly you can't do it.
So, cheer up. At least on this planet we're still top dog in terms of intelligence (your average U.S. politician notwithstanding).
What bothers me about the article is that it takes the stance of "The debate has always been which architecture is best. Now, since the human brain processes data serially, the debate is settled."
Since when was it established that the human way of processing things was the best for sure??? Very poor logic on their part (IMHO)
Werd.
This leads me to a question...
What framerate do our eyes capture? Or are they too analogue to measure? Obviously our brains can't take in an infinite amount of data, but is it a matter of skipping "frames", or just a loss of resolution?
For that matter, what is the framerate of reality? Personally I think it's infinite but I know there will be people who disagree with me. It partly depends on how you measure it.
Enquiring minds want to know.
I had a (somewhat) similar thought when I read the article.
;-)
I'm not cool enough to be able to speed read in parallel, but i'm pretty sure i can edit that way. For the last couple of years i've been able to look at a page of print, and my eyes will suddenly focus on a typo--it takes a second or two for my conscious mind to recognize what my eyes are focusing on is an error. Other people have mentioned the experiment of when given any number of green boxes, and one red box, that a person can find the red box in the same amount of time irregardless of how many green boxes there are. I believe that my high speed editing parlor trick is similar to this problem--over time my mind has become trained to recognize patterns of text as naturally as patterns of color.
If the "nick on the box" test was carried out for several months, possibly several years, the results might vary. Meaning, that over time the people would become more expert at noticing nicks on boxes and the brain might process the information on a higher symbolic level. I doubt that anyone would want to check for nicks on boxes for that long, but there must surely be a job similar to the experiment in manufacturing or processing. Some sort of quality control job where a person has to watch a line of goods go by that they check for defects. Testing if a person who has done a task like that for several years (and is actually good at it!) has trained their neural net to perform the task in a parallel manner would be interesting, and would give a broader view of the nature of the cognitive process. You would only need to find one person that could process image data this way and it would muddy the picture presented by the article.
Who knows, maybe people in Iowa are just more proned to seeing things serially than other humans
no, seems fine to me, what problems are you having?
Satan, oscillate my metallic sonatas.
It seems like a remarkable conclusion. I don't believe that they have really put enough detail into the article to judge it correctly. I make the claim that vision cannot be entirely serial, I play an arcade game called House of the Dead in two player mode by myself, and having played this for some time now, I have little or no difficulty maintaining accurate aim from both guns on varying targets on the screen.
While it may well be true that the highest level of vision is serial, this particular level of vision must be quite tightly defined, for, going back to the House of the Dead example, I always shoot for the head, which is by no means just a simple object recognition in such a game.
I suspect more research really needs to be done in the area, and more importantly, that conclusions need to be very accurately defined, rather than making such broad statements.
You can't win a fight.
To me, if the brain is really a large parallel machine, there's no reason why seperate threads of computation can't be going on in seperate parts of the brain - each taking up a small physical region of resources.
I agree, but I wouldn't consider these "threads" to be cognitive in nature. A person's immediate attention is always focused only on one item at a time. Try examining one object while describing another. Your mind has to switch back and forth to be able to do both "simultaneously."
In response to the "so this makes serial processers better" line of thought, it should be pointed out that it takes many parallel human braiin processors to get an accurate image descripion.
Think about trying to describe a thief you saw running down the street. You saw that he was tall and wearing a hat, someone else saw that he had a mustache, etc. Add more processors required to compensate for the uncertainty in the data from any single one, and you've got a system that doesn't look so serial anymore.
It's obvious that more than one human is required for an accurate description. They haven't proven anything in the serial vs. parallel debate!
-- First post (by a female living in a state that begins with M and does not end in a vowel with a birthday that falls
But obviously something is doing enough processing to tell the difference between your name and some other random word.
The cake is a pie
It is extremely difficult to tell what the scientists found based on the article. For example, "..it processes information serially, even though the underlying neural hardware is operating in parallel."
It would seem from this statement that they are considering part of the brain 'hardware', while other parts not. This seems like fragile reasoning as last I checked it consists of neurons and glial cells (okay, throw in some blood and ions as well).
I am going to make an assumption that they are referring to a person's attention when talking about the 'other part of the brain' -- that is, the brain takes the entire scene in all at once (this we know happens), but can only attend to one particular part of the scene at a time.
This is not a new discovery. In fact it was pointed out quite a while ago by William James. He describes concsiousness as the process of selecting what to pay attention to. That is, we can only really pay attention to one task at a time, but the brain takes in a whole lot. James is usually right.
Looking later in the article: "Luck and Woodman discovered that the brain turned its attention from one block to the next at intervals of about 1/10th second." Thus it would seem instead of describing how we view the world, they are rather describing the rate at which we attend to physically seen objects.
I would suspect that they could do a similiar experiment with sound, taste, etc. I have not seen any mention to factors such as rate that they eye can move at (as mentioned by a previous post), or even how far apart objects were.
Finally they a measure a brainwave without giving a good reason to pay attention to that brain wave. It reminds me of a joke I read once: "A scientist wants to figure out what makes an insect concious. He theorizes it must be the legs [okay, not smartest person]. He takes one leg off. It appears that the insect cannot make decisions as well as before. He continues in this fashion until the insect can no longer walk, and thus make a concious decision where to move."
In reality it is very difficult to probe the brain. Taking EEGs only gets weak signals off the top of the brain, and cannot measure other impotrant parts of the brain. Other measuring tools such as a PET or CAT scan operate a large intervals, not giving an overall picture of the brain (from what I've been told they can only image something like every 5 minutes). Imagine a system that is totally chaotic, except that normalizes for large amounts of time. Of course you will sometimes get images of it doing 'abnormal' behavior, but all an average is done (as they do for all PET and CAT scans for studies), and it will appear as though it very predictable.
People have known for years that some visual processes occur in parallel, because they take constant time regardless of the amount of input. For example, if I ask you to pick one red square out of a scattering of many green squares, the time required does not depend on the number of squares. Other tasks require times proportional to the number of objects. For example, finding one red square in a scattering of red circles, green circles, and green squares, is a task requiring time proportional to the number of items you have to sort through. Everybody assumes that this is a serial process. All this has been known for years-- the description of the tasks that can be done in parallel, and hence the properties of the hardware that computes them, was pretty much settled in the late '80s.
No doubt the research reported in this article is important for some reason, because I saw the technical paper it was based on in the most recent issue of Nature, which is a pretty major journal. Unfortunately I don't have it with me, so I can't read the paper and tell you why it is important. Certainly it's not just the fact that some kinds of visual perception are serial.
LOL!
/. a while back, there was an article saying the human brain has *built-in multitasking hardware*... Thus letting you chew gum and walk down the street (or in my case, writing this, watching tv, and typing)
Although, I think I've heard of similar stories before, and there are always followed by the obligatory post:
If you see a fellow user going blue because WinNT has crashed, poke both eyes, twist the nose, and grab ears and shake simultaneously to restart. >G
Seriously, on
I start breakfast, and then take a shower while the water boils or whatnot. While taking a shower, I often think of what I'm going to code after breakfast. I would consider that to be "multi-tasking".
Now, here's another thing - how many times do you wake up in the morning with an answer to a complex coding problem? For me - it's *alot*. I find the answers just float in from dimension X into my head. That's parallel processing - part of my brain solved the problem while the other part handled something completely different without either part being aware of what the other was doing.
I think the debate is rather moot - we can do both. If you want to argue over the sematics, you can do so. But when I think of the brain, I think of it as a complex signals processor.
What I mean is, when you see something, it's translated into a signal, which is run through a series of filters and comparisons to tell you what you're seeing. This is also why you don't have an exact copy of what you saw - your brain only stores the "most significant bits" necessary to duplicate the signal. Some brains are better than others about reconstructing the signal. If you don't have all of the signal, your brain fudges it with values from similar experiences (or your values/beliefs). And if you have no signal at all, you post as an Anonymous Coward.
So my point is - it can be both. Infact, look at how society is structured - into clusters of people (brains?) that work in parallel on a project until completion (teamwork). Minimal communication. Why wouldn't your own brain be wired in a similar fashion - with dozens, if not hundreds, of semi-autonomous agents working towards the same goal?
--
If you get a decent look at someone, a competent sketch artist can get a very accurate picture out of you.
I mean, really, do people think at all before they post? And to the moderator who thinks this drivel is insightful - please...
Shaun
i'm #1
Maybe you should ask a split-brain patient what it feels like to be multi-threaded. From what I understand, they are usually unaware of it.
Read the methodology... He was working in a highly controlled lab setting & told the subjects to find the block with the dent in it, & that it was probably the red block, but it might be the green block...
/in this situation/ people are going to look AT the red block, THEN look at the Green block, then the black block(s). & I could have told him that in less than the 5 years it apparantly took him to analyze the data.
duhh. I could have told him that
Peripheral vision is by nature less accurate than direct & if you're going to test direct field of vision, OF COURSE you can't hit the details of all blocks all at once.
If the experiment were to ask HOW MANY green or red blocks there were (& having ~3), then track & analyze the respective eye movements, we'd be reading a sweeping generalization how vision processing happens in parallel.
But there are many speed readers who are able to assimilate entire pages at a time. This seems to be a type of parallel processing.
As far as I know, speed reading is done serially as well, skipping quite a bit of the text and mentally filling in the blanks. As a result, the actual comprehension of speed readers is usually lower than normal readers. Can anyone verify this?
Also, certain compositions are considered poor because they lead your eye off the image. For instance, if two line-like shapes would converge outside the image, your eye will be drawn to the point of convergence.
This all happens very quickly, and unconsciously.
I don't think this would work if your vision system digested images all at once, in parallel.
Interesting view, but isn't the use of 'intelligence' here a bit overrated? what is your definition of intelligence? What and how do these 'entities' 'live' for? And what about animals? They are non-human intelligence too :)
"Which came first, the chicken or the egg? ;) "
(Schoolchildren in Kansas, cover your eyes)
I would have to say the egg, since the ancestors of what we now know as a chicken would at some point not be chickens. However, said ancestors would have laid an egg containing a mutant offspring which we now know as a chicken. Therefore, the egg came first.
QED.
MrCreosote Meow!Thump!Meow!Thump!Meow!Thump! "You're right! There isn't enough room to swing a cat in here!"
I know this is off topic, but I find it amazing how the brain "stores" music. For example, we can recognise a piece of music even if it is played faster, at a different pitch, with different instruments or even if other music/noise is occurring at the same time. Some people may also be able to recognise music played backwards. Also, a person may also be able to recognise a tune if the relative height of the pitches are shown visually.
Just me wondering at the capabilities of the brain :)
Call me new-agey, but I'm concerned that such experiments do not include 'enlightened masters' as subjects or controls. Surely the fact that an 'enlightened' mind is capable of processing sensory data without recourse to symbols would have some bearing on the outcome of this kind of experiment. The theory being that such a 'natural mind' has no need to compile its data in a common area for sorting and comparison, instead relying on more parallel processes to get the job done.
Yeah, I'm a Mac programmer. You got a problem with that?
-- thinkyhead software and media
According to my understanding of the subject, this is not true. High speed photography has demonstrated that vision occurs as discrete (serial) episodes called saccades. The choice of focal point is not based on higher level processing in the visual cortex, but rather is controlled by the Superior Colliculus (sp?) which is not part of the cortex. In fact, from what I've been told by researchers in the area of neurobiology, a human subject's eyes will repeatably focus on the same points in an image when presented at different times. Typically, edges and corners might be favored. Each such episode takes on the order of 50 or 100 msec, and input from a field of view about the focus point is fed into the visual cortex. Apparently, it is at the higher levels of processing that we turn these discrete, serial, images into a smooth, fuzzy view of the world about us.
It's a hot topic in neurobiology and really quite neat to learn about.
Cheers. Sapphire.
-- This is not a signature.
You measure voltage changes on the scalp. Because of the poor conductivity of the skull, potential changes are heavily smoothed, so that sometimes you have trouble even differentiating between two hemispheres. Information content of such measures is very limited: no matter what kind of processing you do, or how many electrodes you use, you will basically measure mass activity (over 10^5 neurons) simultaneuously.
The sad thing is that we don't have anything radically better available. Magnetoencephalography measures magnetic fields with superconducting SQUID devices and is marginally better than EEG. Then there is functional MRI, but it's time resolution is not milliseconds but more like hundreds or thousands of milliseconds. And it measures blood flow.
Now somebody has measured one ERP in one task, and claims that the brain, or visual processing is serial in general. What bull**it.
depends if you have one rock in your head or lots of corn in your butt
Try a random fractal terrain ceiling like the sprayed-on fiber stuff. Makes for some interesting patterns.
Works much better with fluorescent than incandescent (strobe effect)
It seems that by placing the blocks on opposite sides of the board (left and right), looking at the left block would elicit a higher amount of activity in the right side of the brain while examining the right block would fire up the left side. I believe these differences were what they were looking for. If the subject were able to examine both blocks in parallel, the two halves of the brain would work simultaneously. The experiment showed a 1/10th second or so difference that was always right -> left, indicating that they focused their attention on the left block followed by the right.
The article didn't really explain this, though, so this is just my educated guess.
This is good inspiration for those seeking to create artificial life and to a lesser degree, artificial intelligence.
nevermind, i found you.
Cool .....
For example (assuming a guy audience), can you talk with someone while you're watching the TV? I can't. Most women can.
I know, and it drives me bloody insane!
Berlin-- http://www.berlin-consortium.org
DNA just wants to be free...
now THAT impresses me.
This is probably down to learning. i went to an "open plan" junior school. there was always lots of commotion. later in life, (senior school, university etc) it was always possible to study with all sorts of commotion going on around me, whereas my peers had problems with the slightest distraction.
;)
btw, just to be pedantic, all our brains are equally evolved.. some just work better than others
in conclusion, peoples's efficacy at "multi-tasking" may well be based on the environment they grew up in.
I worked at an Air Force lab in the Human Resources department where they were doing cognitive and experimental psychological testing (in order to develop better ways of training pilots, or whatever). I would sometimes have discussions with my "mentor" (I was an intern - programming though), about human visual processing. One stream of thought was that one had to first /mentally construct/ an object before it could be recognized/identified/percieved. The other stream of thought said it was at a much lower level, just past the point of stimulation in eye cones and rods, where the image was constructed before the brain ever "thought" about it. I forget the names of the two streams of thought. Anyway, it seems to me that this article is at a much higher cognitive level. If you are /asking/ the subject to do something, you have given them a goal, and a reason to premeditate a process to solve the goal. All humans (in this case), chose to move their attention serially from cube to cube. This is far from saying that they could only "percieve" or "recognize" the cubes on a serial basis. They probably sat down and saw a whole bunch of cubes (parallel), and then /decided/ to examine them serially. It seems very fishy to me to conclude that the brain therefore processes the images serially. What if the test material wasn't graphical? What if it was just a multiple choice problem? Of course you'd examine the possible solutions /serially/...you wouldn't be able to examine them /all/ at once, and if you did, you'd do a pretty bad job of evaluating them.
It's 10 PM. Do you know if you're un-American?
A commercial entity (a corporation) 'lives' for profit, for example. This explains why a corporation comprised of basically decent, moral human beings can routinely commit immoral acts. The whole is more than the sum of its parts.
IMHO the only way to stop corporations from behaving immorally is to structure them in such a way that the individual moral decisions of the employees are not stifled as they are in a traditional corporate structure. What structure would work best, I don't know, but the Internet doesn't seem to be any better (see recent slashdot story on computer ethics).
I'm a guy. I can watch something on TV and have a conversation at the same time. I can also play videogames and have a conversation at the same time. At one point, I was able to tune in on two separate conversations, and had the ability to fully interact with both people. It all depends on how much attention you have free. Believe me, anyone can do it, it's just a matter of training yourself to free the extra attention. As for all these people who say that "no, there's no way vision is in serial" - sorry folks. Parallellism is a "neat" idea, but there are some tasks that are better done in serial. There is a law of computing that states that all else being equal, a 50MHz processor will always crunch data faster than two 25MHz processors of the same type, because even the most parallell problem will require at least a small amount of serial processing.
I'm no neurophysiologist but it seems that reguarding a neuron as a mere switch may be understating their function. Perhaps massively understating it.
License: By reading this you are agreeing that you agree with me.
Did anyone catch some little blurb, probably from Science News, that showed that the distribution of the different color-sensing cones is essentially random, yet when we look at, say a red wall, we see a uniform red wall...
Maybe the brain does a lot of serial processing of data from the optic nerve, but the optic nerve and retina also do a lot of signal processing in and of themselves.
I would rather think that we have lots of parallel/simultaneous subprocesses that are pipelined serially...
Student: "Is it a wave or a particle?"
Physics Buddha: "Yes."
We humans have developed organizational intelligence. Groups of human brains, hooked up with the appropriate networking, can themselves become an alien intelligence, as different from human intelligence as human behavior is from cellular behavior.
For a long time, this has been mostly the province of corporations and governments. Ever wonder why such entities often lack common sense? It's because they are made up of humans, but aren't human. Congress is a group of over 400 humans; it doesn't act as a human, but can be modeled as an intelligent, alien being.
Today, we have the Internet. On a smaller scale, we have Slashdot-style phenomena. These are virtually those "Beowulf clusters of human brains". It is just another alien intelligence.
The big difference between the Internet and government/corporate organizations is in the interhuman connectivity. In governments and corporations, the governing layers are codified into a bureaucracy. This causes specific people to act as chokepoints, and that in turn limits the number of people that can interact effectively. On the Internet, the governing layers are a lot less codified. This requires a lot more data filtering at the various nodes (humans)--spam and similar phenomena travel better across the Internet than through your office--and a lot more bandwidth. But the Internet is all about bandwidth.
Bureaucracies are alien intelligences made of humans. Internet communities are alien intelligences made of humans. They are different species of alien, and they are fighting each other.
Why are bureaucracies afraid of internet communities, and vice versa? The answer is easy to see if you stop thinking in terms of humans. The bureaucracies are seeing a brand new type of intelligence. The "Linux community" is a perfect example. Over the course of eight years, this thing has gotten Microsoft, one of the Lords of Bureaucracy, frightened. A race war of organizational intelligences is brewing, if not already being fought.
Is this the end of humanity and the beginning of organizational intelligence? Hardly. We have been living with bureaucracies since the Pharoahs, possibly before. But just the knowledge that there are inhuman intelligences out there helps you to better understand them, and to better interact with them.
--The basis of all love is respect
Why follow nature's mistake? Just because our meatware is too limited to process stuff in parallel doesn't mean that a computer couldn't. The question should be are we going to make the machines see like us, or see BETTER than us. I'm all for having the machines do things better than us whenever possible.
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
There has to be exceptions to this theory that the brain is serial. I can think of one example, though it is not an every day one:
It is said that Leonardo Da Vinci was able to write with both hands at the same time and in a different language with each hand. This may be somewhat of a myth and is far from provable, but if it is true than I would think that the brain has to be parallel.
I agree with one poster who said something about the brain being able to change from parallel to serial. Sometimes I find myself barely able to concentrate on any one thought, and other times I am able to think of several things at the same time (As in read a newspaper or do schoolwork while listening to the radio or carrying on a conversation).
"A great deal of intelligence can be invested in ignorance when the need for illusion is deep." --Saul Belloe
Though on the flip side of the coin, without using anything but your peripheral vision, try to count the number (or even color) of major items on the desk in front of you.
Though if they are in a pattern, you don't, which is interesting in and of itself. We don't have to count the dots every time a die comes up six.
The cake is a pie
I imagine that this is a serial experiment in itself because of how the mind works: trial and error (or the scientific method).
or:
for (i=0,i < blocks, i++)
if (block[i] == red) || (block[i] == green) {
if (block[i] == nicked) {
item.pick(block[i])
}
}
}
I don't believe this proves that the brain processes images serially - just experimentation data.
--onyx--
Right -- but that's just pattern recognition (something that is done in parallel), and not a cognitive analysis. You eventually just "know" that that pattern of 6 dots is, well, 6 dots.
They narrow it down to two blocks which are at opposite ends of the table. They then tell you it's most likely one of them. Then they are surprised by the results that everyone analyzed them in serial not parallel. Duh! If it were me, clearly I would look at the most likely one first then if not, the other one would have to be it QED. Also, there would be no use at all in looking at the ones in the middle. Design an experiment to only allow one result and guess what? You will get it. Is this the Mindcraft school of psychiatry?
and first
http://server.whatever/path/whatever.asp::$DATA
if it's not patched against that exploit
consists of two functionally independent, hierarchical stages: An early, pre-attentive stage that operates without capacity limitation and in parallel across the entire visual field, followed by a later, attentive limited-capacity stage that can deal with only one item (or at best a few items) at a time. When items pass from the first to the second stage of processing, these items are considered to be selected. (Theeuwes 1993, p. 97f, original italics)
Now wether or not this researcher is refering to the first or second stage is not clear from the article. As the reasearch had the subjects looking for a red or green block with a nick in it, I assume he is not making a claim about the first stage. This stage has always been considered parallel and he would have to prove it is not with a single feature task, not a multiple one like he used. However, from the tone of the article and the quote, it seem that he IS making this claim.
If the author is making the claim that single feature detection is serial, I feel that his experiment will be soundly ripped apart by most Psychological researchers as we have a large convincing body of evidence that this stage is parallel. If he is not making this claim, then he really wasn't adding anything new to the scientific body because we already KNEW that the second stage was serial.
Click here for more info JT
I wonder if this is due to nature or nurture? I have some blind friends that seem to process things in parallel. They arrive at the correct solution to complex serial problems without being able to explain how they got there, drives me nuts!
On the other hand simple things that I take for granted like how a small 3D model can represent a larger 3D environment seem difficult for them.
Thought it might have something to do with the way that young children learn to use their vision. Objects at a distance appear smaller, but then appear larger (over time) if the object approaches.
Cognitive science has many mysteries. or is this philosophy?
I realize this is barely worth a 1, but...
Just because our input(s) may be serial, and just because we only have one CPU, doesn't mean we cant have many processes going on at once.
Most of the evidence people in here have presented to argue against the serial processing theory sounds a lot more like multitasking, or perhaps even closer to threading. Though you have two threads going at once, say each focused on one item, you can't process each thread better than one at a time. Then occasionally you can put both threads in a wait state while you start another thread to process the results.
Also keep in mind that a lot of what we might perceive to indicate parallel processing is actually being done by recognized behavior analysis, which was burnt into us during our very early years.
We're also great at filtering, so that we can store one image or sound, but only focus on certain aspects of it. Later we may recall other aspects that we weren't paying attention to.
Can you tell me what flavors make up the flavor of Coca-Cola (without looking it up the same place I did)? Can you perceive a taste in parallel and pick out each part? Maybe you can take in a sample of data, filter it for one taste, take another sample, filter it a different way... but thats about it.
Same with musical chords -- this is purely a serial observation which we need to filter in order to pull out different bits, ond only by filtering out other sounds which we recognize. Often the best we can do is pattern-match one chord with the sound of the same chord we have heard before. Can even a trained ear recognize each note of a chord it hasn't heard before?
Okay, I don't have a degree or a research paper to back this up (I wish I did), but neither do most of you.
With a one-track mind,
Terrorists can attack freedom, but only Congress can destroy it.
It is hardly interesting to find out that individuals look at objects serially, which seems to be what the described experiment determined. Contrary to the stated conclusions, neuroanatomical evidence from animals and humans clearly shows massive parrallelism as visual information travels from the retina to optical cortex and beyond. This is nothing like "machine vision" where an input array or sensor is "scanned" to yield a serial data stream. Consider this: To imitate the human retina a photosensitive array would have to have a wire from each sensor (rod or cone) to make up the "optic nerve". So, to even get the resolution of a simple digital camera would require millions of connections . . . and that doesn't even begin to address the problem of what you do with the data coming from all those wires. Nobody who has studied visual science (I have a Ph.D. in it) is going to be very impressed with this work.
My wife handles electronic background noise MUCH better than I can. She can talk on the phone with a TV playing at normal volume in the same room. She can even sleep with the TV on. I can't handle ANY of that. I'm either watching TV or the darn thing is OFF because I'm doing something else.
I've had to explain to her several times that my brain is not as evolved as hers. Therefore, if the TV is on, no talking. If you want to talk, turn the TV off. If you forget, you have no right to yell at me for watching the news while you're trying to get my opinion on whether or not we should have dinner with the Andersons next Friday.
(Moderator -- I know what you're thinking. You're thinking, "Is he off topic?" In all the excitement, I kind of forgot myself. But since the main thread IS about mental multitasking, and since this post IS anecdotal information about the topic, and since I am an Anonymous Coward who already has 0 points, and since you only have so many points to use, you have to ask yourself a question -- "Do I want to waste my points on this guy?" Well, do ya?)
first bitzzatch!
Mmmh, apparently the guys made it to Nature, so bow to my masters. Yet, I never trust people who try to assimilate the human brain to a machine, at least not to one that we yet know of.
Culture is so influent. It's so obvious to me that one would scan one object at a time when searching an array of items for a tiny detail.
That's the way you're told to read, for example, albeit differently among different cultures.
In languages using phonetic alphabets, one's told to scan letter by letter and wait for a space, then put the letter in a string and possibly check with one's linguistic database for matches.
If you're playing pool, however, and you're watching your ball go, you're paying attention to a lot more 'events' at a time. You follow the ball's path, estimate its direction before it bounces on other balls (and often I get to picture its course and 'draw' it on my current 'view'). But you'll find yourself also keeping record of what color the first ball you hit was, which balls are possibly heading straight into the holes and which are not, and so forth.
Again, play tennis and your eyes/brain will be analyzing ball speed, course, estimating the bounce and checking if the ball lands out... it happens often that you're aware that the balls out but move and hit it anyway. That's because orders to your muscles have already been sent, but it also means that your brain has both ruled the ball out and estimated its path. One of the two has probably occurred before the other, but it might probably be because the two processes were indipendent yet not equally difficult to 'compute'.
Bottom line, I'd say that the 'attention area' capable of being processed is small, so you're naturally prone to shift from one point to another because of the limited 'screen' you have. Yet, if details aren't too tiny, and don't require great resolution, like balls moving, a broader scope is enough to let you observe them all and analyze them more or less in a parallel fashion...
marco baciarello
Hmm... how much of the serial processing debate is affected by the fact that most humans can only focus our attention on only one thing at a time, really, for details? Sure, there are peripheral triggers around the "attention space", but since we don't have eyes like chameleons, we're kind of stuck to some sort of parallel processing of serially-gathered detail information.
Ever wonder why chickens and pigeons do that "head thing" when they walk? Part of it is due to the latency they have in the rate of how fast their eyes focus (which is probably related to how fast their brains absorb detail). They keep their head steady until they have to move it to give their eyes a chance to focus...
Interesting question. Ask someone else, but this
might help.
Film (you know, that old fashioned stuff that you
used to head about projecting movies) goes at
24 frames per second, because any slower and
the human eye sees the flicker. Why isn't 24
frames good enough for video games? Because
the monitor is also flickering. When you have
a flicker on top of a flicker, you get problems
that you've probably seen.
Of course, that's a real half-assed answer for
you. Subliminal images are much shorter than
1/24th of a second, and we're pretty sure that
some part of our visual system picks them up.
Furthermore, the whole system is influenced by
all sorts of strange things. Ever get in a crash
or a fight, and remember seeing things in slow
motion? That was adrenaline at work, overclocking
your whole body including your brain. Even
And of course, in the end, I don't think that
the way human vision works could really be described in terms of frames/second. There's
even things like compression going on.
I hope someone posts a real answer...
Who moderates the meta-moderators?
The brain is a _shock absorber_ for the body.
The answer to this riddle is simple.
I need a computer with infinite storage capacity.
One that is able to recall data that is years old instantly. It must be able to perfectly sort all data that is received at the same time.
I need every piece of data cross referenced to every other piece of old, new, or current data. I need hashes performed faster than light on this information.
It must contain an extremely low power consumption level. It must be available 24x7x365+1/4 days.
It must contain it's own power supply system.
It must be able to reason on the data from above and last but not least....
....it must be portable!
The answer is the mind.
The mind is _definately_ a parallel processor. You take in data simultaneously. You can export data simultaneously. The only limiting factor here is the availibilty of a state of awareness. To what extent are you _awake_.
The mind is a separate entity from the brain. A state of mind is just that. It is an idea about, position or situation that the mind is experiencing. It is not possible to have a state of brain other than life or death. Surely not active. All the brain does is buffer the shock received to the transportation system.
The mind is what heals the body. The mind is what damages the body.
The mind is the end all be all of everything.
A small charge somewhere in front of what you perceive to be are your eyes is you. You are the mind. You are not your body. Your are not your hands.
Your body refers to something you possess.
Your hands are something that is connected to your body. So on and so forth.
You are a separate entity from anything else.
You are an alien being that is not known to most humans. You possess the body as a transportation system. It is your symbiotic host until it dies.
You will then find a new one to occupy. This will happen for eternity. It has always been like this.
The matrix has you....
Is this really a surprise? My two eyes do not act independently, so the bottleneck in parallel processing seems to be the eyes. Maybe the brain could handle parallel vision (the article says the brain does do some things in parallel), but with only one 'eye set' is this really a surprising result?
wow, i wonder how the brain can shift rapidly so fast from one object to another. it is awe-inspiring. and the fact is that each one of us has one in our heads is nice :)
Does this mean I should be designing by brain plug to interface to USB instead of the parallel port?
They have certainly demonstrated that when they tell test subjects what order to look in, they get them looking from one block to the other rapidly, but they didn't really prove a causal relationship. I think that 1/10 of a second is more than enough time to look from one object to another conciously. We do it all of the time when driving or playing video games. They didn't really show that it was impossible to process visual stimuli in parallel, just that in this case (with the leading instructions) that there was observed to be no sign of parallel processing. I'm not sure that this doesn't contradict the work done by Renshaw, where he demonstrated that humans can process many times more data than could be processed serially. He trained people to be able to read pages of text in one blink. What do you all think? Tony (who's to lazy to look up his password)
Specifically, I'm wondering if they bothered to vary the overall width of the landscape to rule out the effect of the eye's limited ability to focus on more than one object in a large field of view.
I've done work in this area. This class of experiment is known as visual search in the psychophysics literature. The situation is much more complex than suggested by the article. There are many previous peer-reviewed publications and experiments involving combinatorial stimuli that demonstrate parallel processing is also possible in visual search tasks. Human visual processing for object recognition is not necessarily either serial or parallel; in certain tasks it can even be both.
Signed, Permanent AC 4116f92680bf8d52139bb47815005a96
Seems obvious.. how can you"look" at all the blocks at once. AC
perhaps this will help us answer the lifelong question, is food god? We shall never know, and thats why we have faith.
I suspect that the article is talking about very high level cognitive processes. But it's clear that heck of a lot of parallel preprocessing has to happen upfront! Before you can shift your attention from one object to another, you have to recognize that object regardless of how it is oriented, what the lighting conditions are, what the background is and so on. They aren't saying that this is all serial.
But to me, those higher processes have less to do with vision and more to do with reasoning. I might experience one thought after another concerning some object, but I still see all the objects in front of me.
I read the article and i think that the reason we do this is because of how the eye's work. We can only focus in on 1 thing at a time. I have a hard time grabbing something out of my 3 degree central vision(i just spilled some water on myself why i was typing) Anyway if we had some weird phased array of eyes where we could see things in their true 3 dimensions and not an illusion, then it would work. i've rambled enough Napalm4u's account was eaten by Slashdot!
Surely this is just further confirmation of what gestalt pyshcologists determined in the 19th century ? that we only pay attention to a small part of our visual field at any given time. The only new aspect seems to be the neurological confirmation of what was alread known through psychological experiment.
Also, its not the image processing that is serial. We've known for some time that that is parallel - large parts of visual cortex recognise lines at different angles, changes in color, etc, using what are quite close to standard image processing algorithms.
Now now, we all know that food is the true god of this earth, and we should stop the mindless blabber about this whole 'computer' thing. I make it my personal mission on this earth to spread the true message of the food, myself playing the role of Jesus.
The test seems more like it studies the method we use to examine things, which I would consider a behavioral trait, and not an indication of how the brain is working.
Just because I look at each block in order doesn't mean thats how I think about those blocks.
Somthing can be procssed parallel with only one
processer.
Well I guess that kills the "But can we run Beowulf on it?" question...
knowing that the brain processes images serially should give food for thought into some of the visuals lsd usage produces. Is anyone seriously studying why the little black dots on drop-down ceiling tiles start swimming around after a couple hundred micrograms, and does it have anything to do with the fact that it takes me a tenth of a second to switch from looking at one dot to the next? Incidentally, that article on eetimes wasn't the pinacle of scientific journalism... is there a more primary, cited document involving the research?
Dammn, brains must be faster than I thought if they really process images serially. It really needs only tens of a second to recognize someone...
As the article notes ... this serial processing happens faster than the conscious mind can interpret and as such the difference between serial and parallel visual processing causes little difference in perception. It would be very interesting to see the processes involved in translating these serial images to memory and the crossover to parallel neural pathways.
The raw image data is of course handled in an extremely parallel fashion, but the cognitive process involved, identifying patterns and discriminating between one object and another, is serial.
This really shouldn't be that big of a surprise. Try watching two or more moving objects simultaneously, and pay attention to how you do it. Your attention ends up being focused on one item at a time, albeit relatively quickly (depending on how fast you think and how much caffeine you've had).
Though I basically agree with their findings, I'm not too thrilled about how this experiment was set up. They basically *forced* the participants to think serially by placing both of the suspect blocks on opposite ends of the board (yes, I know that's really the only way they could reliably determine which item was being focused on and when). The eye ball itself isn't capable of doing a detailed analysis of imagery except in the very small area in the direct center of its field of view. It's only logical for the participant to immediately identify the different colors peripherally (and perhaps even in parallel -- the experiment never delved into this part) and then concentrate a detailed glance first on one block, then on the other. Biologically, it had to happen that way. Their eyes couldn't have efficiently made the same analysis in a parallel fashion.
"We are the first research group to show definitively that the human brain processes images serially-paying attention to only one object at a time and shifting rapidly from object to object"
now my question is, might this not have to do with the human's eyes and focusing on one object at a time and switching between multiple images quickly to try to bring them into focus as simultaneously and seamlessly as possible?
"It was important that we knew the order in which they paid attention to the colored objects, because the N2PC works by correlating the brain waves coming from each side of the brain over many statistical trials, so we had to always have them search in the same order"
He acknowledges that the brain is paying attention to certain objects based on color in a certain order, but attributes this to the brain and not to the input device. I'm going to make a crude analogy which will probably get shot down, but if you can think of a better one, please post it. It's like taking a mono VCR hooked up to mono speakers VS a mono VCR hooked up to a surround sound speakers. You know it's able to process the info better, but it can't because of the input device's shortcomings.
It seems totally intuitive. The only news here is that they've got documented data to back up intuition.
... And sage, and rosemary... "
:)
We can only focus on one thing at one time, therefore we can only handle one visual input. I'd venture the guess that all our I/O is serial - with quite a bit of DMA capability thrown in.
We can tune in on a single conversation in a room full of people, and switch focus from one to another, but it's real hard to keep track of more than that. We remember music sequencially, but unless we're well trained in music, we can not correctly conceptualize chord structures.
We become completely oblivious to the goings-on when we watch (and listen to) TV. We have a difficult time separating olfactory inputs - so we process those serially as well. "What is that? Lemon?
The only sense that seems parallel to me is the tactile. Though, since tactile input is the summation of very many single (bit) neurons, the parallelism we experience is probably the result of a lot of preprocessing of stimuli in the sensory nervous system and the spinal chord.
The neat thing is when we tune all the senses into the same stream of data. Remember last Christmas? The scent of the cooking goose, the sound of the Grandma Got Run Over By A Raindeer, the blinking of those damned lights and the itchy wool sweater..
With all of the senses delivering a variety of data that shares the same conceptual context, the imprint of the event is more powerful than if the serial stimuli from the different senses were reporting on events that we know are not related. This is probably why we remember better those times when all our senses are firing in parallel on the same concepts.
I'd venture the guess that as this research progresses, we will learn that we manage some pseudo-parallelism in our input processing through a similar mechanizm that we rely on for memory. Chunking, was it?
For example, if shown a group of objects, we can visually process them based on similarity (i.e. they're all read, square, whatever) so we notice more than if they were all distinctly different. Then we get lost in the volume of data that we have to take it.
As with the chunking that takes place when trying to remember more that the 7 (avg) simple items, finding commonality among the items we try to process sensually, makes it possible for us to more more data through our inputs. Sort of a lossy compression really.
-- What you do today will cost you a day of your life.
Although my background isn't in neuro or such, this seems to be a questionable experiment. If I'm looking for a detail in a image (a nick on a block) I will examine each block sequentially, and look for the feature. If it's a big nick, it may not take long, but if it's small, I can certainly tell that I'm examining each block.
On the other hand, does this experiment actually indicate that the brain is _interpreting_ a scene serially? (That's a tree, that's grass, that's an anvil dropping on my head) Or just processing a task serially? (Where is the oak tree?)
I guess the artical didn't really give enough information; perhaps the experiment was more than indicated.
But then again, what do I know.
#include "standard_disclaimer.h"
I have always believed/heard (anyone have some scientific info on this?) that men and women interpret data differently. For example (assuming a guy audience), can you talk with someone while you're watching the TV? I can't. Most women can.
Whuzzup with that?
BTW, can you watch the telly while talking on the phone? (Not me!)
...Williams James (and his buddy Wundt) got it 95% right on their first try.
BTW: Machine vision? Bah! It's all psychology and neurology...and Steven Luck is a neuropsycholgist.
Oh, yes, I forgot to get to what the correct answer is: both. Subunits (retina and V1 are good examples) work in parallel, while the units tend to communicate in a more serial fashion. Even there, it's not cut and dried (cascade model, etc.).
Of course, turning back to Luck's work (I'm assuming he used ssvep, where the different objects are presented at different occilating frequencies so that you can deconvolve the erp signals and determine which object is being attended), if you give someone a serial task (such as a difficult discrimination), they will perform in a serial manner.
Now if Luck would have asked subjects to try to determine if two spatial seperate items matched, then we might get somewhere (the task can be done in serial or parallel, but it might entice people to attempt to do it in parallel).
Oh, yeah: you ignored the Kramer and Hahn (Psychological Science, 1995) splitting-the-beam article [which is basically the experiment I suggested above]. Explain that, Slashdotters!
Otherwise, this is the same ol' parallel-serial debate that is rehashed every 3 months on Slashdot. Yawn.
BTW: Why are you quoting an IEEE publication as the authority on human vision?
How does this experiment they mentioned (N2PC?) help them know serial vs parallel? All that does (according to the article) is let them know which side of the brain is doing the work.
How does that let them draw their conclusion (that object recognition is serial)? And while I'm asking questions: how did they manage to know which brain activity was the stuff they were interested in, rather than some housekeeping-type function (breathing, heart rate, etc).
-- Baffled
--Mark
Hmm... So, I wonder what would happen if we somehow tapped into our brains, formed a collective, and created some sort of Beuwolf cluster... Isn't this the internet? Take all those "Serial" minds and make 'em useful. -Duranos
a better sig would normally be here. -blah-
Now we're one step closer to robots taking over the world! no!!
Hmm... it seems kinda dubious to me, highly dependent on what the experimentors were asking the subjects to do. how big was the nick in the block? could it be seen eaqsily through peripheral vision, or did you have to look directly at the block to see it? Visual resolution is roughly inversely proportional to distance from the center of the field of view. It could be that te feature being looked for could not have been noticed unless the subject looked directly at hte block for a split second.
Same reason why "Where's Waldo " puzzles are difficult sometimes...the amount of resolution required is only available at the center of he field of view, so you have to scan sequentially instead of just percieving at first glance.
This only proves (if it proves anything) that the brain is time-shared in the initial stage of analyzing visual information. The article says that the brain switches focus about every 0.1 second. But remember that the consciousness has a 0.5 second "lag" that gets masked by some reality-defying neural algorithms to get the "real-time" effect. And there is reason to belive that parts of the brain is far too complicated to be described as "parallel" or "serial" (eg. holographic theories).
What i really want to know is whether it uses a monolithic or microkernel architecture...
"Bernoulli was wrong. X proves that you can fill a vacuum, yet still it sucks." - Dennis Ritchie
So are they saying that the brain processes different tasks in paralell, but everything in each task in serial? Thats just weird!
Which came first, the chicken or the egg? ;)
Seriously, though, this does sound right, considering the fact that people tend to have difficulty focusing on more than one thing at a time. The old adage about chewing gum and walking for some folk. :)
But I wonder, is this serial processing due to the need to comprehend in a temporal fashion though?
If we processed visually in parallel, then our concept of time would be blurred, would it not? Or am I just not getting enough sleep and swapping my attention between this screen and the second screen in an attempt to get work done hampering my ability to understand?
Who knows. :p
- Wing
- Reap the fires of the soul.
- Harvest the passion of life.
- Wing
- Reap the fires of the soul.
- Harvest the passion of life.
Redmond, Wash. Wed. September 8 1999.
Microsoft today announced Windows for Neurones, the brand new Microsoft operating system for life critical operations. No release date has been set yet, but Microsoft hope to have a release version on the shelves by the fall of 2000.
It is thought that Microsoft have been working on this product for several years, early alpha versions of which can still apparently be seen in institutions around the US. "We had problems with the initial cooperative multitasking that we tried. Processes would sometimes end up in a loop, and not release the processor for other tasks." an insider said. "The results of these early tests can be seen as high up as ex-president Ronald Reagan. He was an early alpha tester, but developed problems. Unfortunately, the uninstall wasn't available then."
Microsoft site several advantages to using the OS:
1. Your brain is no longer dependant on old proprietry systems, some of them as old as several million years! We've learnt a lot in all those years. Windows for Neurones (sometimes referred to as Windows Neurones Technology, or just WinNT,) uses such modern features as pre-emtive multitasking, and virtual memory.
2. Your brain can now use cheap, off the shelve productivity software. Studies have shown that a lot of people have to have productivity tools (calanders, addressbooks etc.) as external programs or peripherals. WinNT has all this built in. It is also easy to use, "it's as if it knows what you are thinking," an insider said.
Some people have expressed concerns over the scalability of the new WinNT. While older systems (such as AT&T Metabolism Control and HP Coordination) have exploited the natural parallism in the typical brain, WinNT's new visual system appears to process data in a serial fashion, limiting the ability to exploit the brain's parallel capabilities.
"Rubbish," said a MS insider, "It has been shown in independent studies that our approach is upto 300% faster in processing visual data, for example." he said, quoting a recent study by Mindcraft Inc., a service-oriented, independent test lab. The visual aspects of the OS, what the person sees, has been controversial in recent discussions.
Existing OS providers in this critical industry also slam WinNT's reliability, based on test observations. "We have systems with a mean time before critical failure of 100+ years. I don't understand why anyone would want to upgrade. While brains running our OS consume ~20% of the bodies metabolic rate, we estimate WinNT brains to use upto 30% of the bodies metabolic rate, as it has no power saving facilities. Existing systems have the ability to sleep, saving power, but I've heard WinNT can keep you up all night. This can cause real problems." said a rival brain OS provider. Even if people think the visual aspects are better, which is debatable, a nice visual interface is a waste of time if your heart stops beating! Some things are simply more important than good visuals.
Microsoft refused to release licensing details, but it is said not be following the recent trend of open source software, and open API's and protocols. It is said to include a new licensing agent, called 'Paranoia', which prevents third parties from getting too close and examining it's workings, or 'reverse engineering' as it is known.
With training you can change the way you visually process information. For example, you can look at a dot on a page and without counting it know there is one dot. You can add dots and train yourself to identify the number of dots. Two rows of three dots is immediately identified as 6. I believe Houdini was able to train himself to read 52 dots by sight. I think this is more about pattern recognition than serial processing. Perhaps we should examine if pattern recognition is serial or parallel... Sorry, too lazy to log in... ten.knilrevlis@wkcuhc
It's often been said and proven that people try to create things in their own image... whether it be physical, mechanical or ideological. Perhaps we're on the right track to having a technological replicant of a human brain.
In a human eye all data collected on the left side of each eye is sent to the left part of the brain and vice versa. Thus, due to the mirroring of the image done in the lens, the right half of the brain process the left half of what is placed before you.
Now... IF the subject has to keep his eyes straight ahead isn't it likely that it takes some concentration and effort to discern details (nicked block or not) in an area removed from the focalpoint?
Would this not provoke serial behaviour even if the decoding itself was done in paralell?
If you are staring blankly at say, your computer
monitor, you would be viewin it serially.
If you are staring at your computer monitor at
savory JPEGS, it would be digitally, with your
digit in your hand.
The above post is an editorial, the poster cannot and will not be held responsible for all or in part for it's contents
I agree, the experiment seemed rather contrived. I would think that some other form of experiment would need to be done to give more insight into this process. Say, you see the same picture of blocks but you have to select which block is "red" for instance (a random red block). I would imagine (I'm not a cognitive scientist by any means) that that sort of information would be processed in parallel. When looking for a particular color, I wouldn't think a person look at each block individually. I seem to remember something about the way the brain processess color, especially the color red...hmm... :)
In any case, more experiments should be done before making statements such as the article is making. IMHO anyways...
Ribo
I wear pants.
So we got a bug here. Ya see, my system doesn't remember who you are, yet you think you are logged in. This could be because you are using a crappy browser. Or are behind a firewall or proxy or something that is stripping cookies. DON'T DO THAT! If you think none of these are the problem, please send me your browser version, nickname, uid, platform, and any other details that seem relavant. I'm trying to sort this out and not having much luck. Optionally, you might not have actually ever logged in, so you might want to Try Doing That instead!
All im using is squid, all cookies are working.
Rob, fix your perl code, and use C like real men.
I can't wait for a 1.1.x human body ;)
I knew this.
Serial, Parallel? Hell I'm thinking more like USB!!! FIRST POST BABY YEA!!!
I seem to remember from long ago that the switching time for neurons is the same as that for mechanical relays .. on the order of milliseconds. Such low switching time makes it impossible for vision to be operating in anything other than a massively parallel manner.
Given this, the article will have to do better than just state `vision is serial' w/o specifying how that is possible when using slow neurons.
Joe
I might have thought of it differently:
Most of the imaging rods and cones are concentrated in the center allowing greater detail, so would it make sense that we are used to looking at one thing at a time, and changing focus on different items. I see much greater detail when looking at something directly and might say I process things serially. One thing at a time. This does not seem true when driving for long periods of time when tunnel vision and eye movement seems to be comotose.
First post :P
Serial lines are always easier to read than parrallel lines... i wonder if it's possible to do tempest on the brain?
-whydna
Sounds to me like they happened to choose a task that needs to be done in parallel. I don't think it makes sense to say "the visual system works serially, not in parallel" -- obviously it does both, depending on the task in question.
A straight quote from the article:
"Luck was able to use N2PC to identify whether a person was processing visual signals one at a time or simultaneously. "
Bummer of a name for a probability doctor, eh?
+&x
Blood vessels are placed on the inner surface of the retina, thus further blocking the light and degrading performance.
I agree. Simply because the human has arisen to become the dominant form of life on the planet, what does this have to bear on the overall scheme of intellegince?
Let's see, out of how many billions of species over a few billion years have we come to dominate so totally (unless the Ants have nukes we don't know about)? My guess it has something to do with our brains, and how they work. Hands are pretty cool (read my thoughts) but I have to assume (unless you live in Kansas) that your brain helped them along to their current level of dexterity at some point (perhaps your parents chose white collar jobs?).
If machines can and do someday become intellligent, and do indeed surpass human intelligence,
it'll be 'cause we want them too. I'll leave it at that.
Read my sig, and you'll see where I fall on the debate.
+&x
It seems to me that the serial processing of visual information may simply be nothing more than a learned behaviour.
The most comon form of visual information requiring cognitive reasoning is written text.
And this is read serially, from left to right and top to bottom (at least English is).
But there are many speed readers who are able to assimilate entire pages at a time. This seems to be a type of parallel processing.
I wonder how these people would do when tested in similar conditions to those mentioned in the study.
The majority of people are not speed readers, and they process information the old fashioned way (serially). This would in turn be transferred to the method they would use to process other serial information. Certainly, the test performed in the study proves nothing that a word search couldn't.
Some people can just stare at a word search and be able to pick out words.
The only thing that the study proved was the people PREFER to use the serial method of visual congition.. Probably because that is what they are conditioned to do, or because they haven't learned how to do it in parallel.
This sort of stuffhas been going on for a while.
I remember an article somewhere (SciAm?) that
showed a visual intelligence test based on
looking at two images of a twisted 3-d pipe
and deciding if the second was a rotated version
of the first.
The decision time was roughly proportional to
the angle of the rotation of the two models.
I thought that result was kinda kool at time
time.
-- cary
This isn't all that surprising. It has long been known that trying to do two "similar" tasks is very difficult. It is very hard to sing while reading, for example, so in that sense, the brain does have units that are serial. However, there is quite a bit of parallism in that you can fairly easily do disimilar tasks. Examining blocks while singing, for example. In that respect, the brain is somewhat like a modern CPU. A small set of discrete, basically serial devices that can operate in parallel. (A gross oversimplification, but a good analogy, I think.)
At a low level (at the neuron level) we already know that the brain has to be massively parallel. The best proof of this is that it takes about 100 milliseconds for a neuron to respond to a signal. Obviously you couldn't do much with a serial algorithm at that speed.
The cake is a pie
They only seem to have performed an expt. with these colored blocks, but a valid expt. needs to have a control sample or control group to contrast the results. The article doesn't mention any.
Also, they seem to loaded the dice by telling the subjects that the red block, then green block, then the black blocks were most likely to have the notch. Anybody would naturally proceed in that order to look at the blocks (which coincidentally happens to be sequential). This hardly constitutes fair conditions for an observational expt.
I think the whole things is generally oversimplified. Simply obtaining data about which *side* of the brain waves are coming from to jump to conclusions that the brain internally processes visual info. sequentially like a CPU is quite a leap. The internal operations of the brain are pretty complex, and I don't think such simple conclusions can be drawn. For instance, the left side of the brain handles right side physiological processes. And BTW, the processing center for sight is located in the back of the brain at the middle (which is why a severe injury there can cause blindness). Since the region is in the center, it may make it all the more difficult to figure out which visual side it could be processing.
L.
So...what does this article have to do with processing human brains?