A short 9-page paper presents a model of conscious perception as a discrete process:
Time Slices: What Is the Duration of a Percept?
Abstract
We experience the world as a seamless stream of percepts. However, intriguing illusions and recent experiments suggest that the world is not continuously translated into conscious perception. Instead, perception seems to operate in a discrete manner, just like movies appear continuous although they consist of discrete images. To explain how the temporal resolution of human vision can be fast compared to sluggish conscious perception, we propose a novel conceptual framework in which features of objects, such as their color, are quasi-continuously and unconsciously analyzed with high temporal resolution. Like other features, temporal features, such as duration, are coded as quantitative labels. When unconscious processing is “completed,” all features are simultaneously rendered conscious at discrete moments in time, sometimes even hundreds of milliseconds after stimuli were presented.
(H/T J-Mac)
It’s difficult to avoid homuncular reasoning when reading this paper.
Makes me think something is wrong with the way we talk about consciousnesses.
50 years ago I assisted a professor who was researching subjective perceived colors. I don’t detect any progress made in the questions being asked.
I like this abstract. Its moving in the right direction. Yes illusions etc prove we do not see the world as it really is. We are not looking outside the window by way of eyes. Yes its being arranged within the skull what we perceive. However as a creationist i say again its not that complicated. Its simply we read, with our soul, our memory images. sight simply puts images upon the memory and we read it. Yet there can be a wee bit of editting where there is overload of info. So illusions. Thats why dreaming is exactly the same perception as when awake. There is no difference. Both are simply our souls reading the memory. Recent or old. Just cut out the middleman of the brain and it will work better on how humans perceive the world.
I have often thought about this. If we shoot an arrow across the sky, at any given instant, it is only in one discreet place. So what we see as it continuously moving sort of has to be formed in our brain, doesn’t it. We are watching a movie of stills, aren’t we, with each frame occurring at the speed of light?
So I find it hard to fully grasp what movement is. How is a moving arrow any different from a still arrow, other than the sort of trick it plays within our brain? The arrow is still always ever just in one place.
I wonder if this question is properly formed. The human perception system is composed of multiple modules, signals from each of which travel different distances along different sorts of neural media to reach the brain at different rates, and each signal source requires a certain amount of interpretive processing. It seems reasonable that there is a trade-off between the speed at which the perception can be composed, and the complexity and number of signal inputs involved to produce a more complete picture. The viewers often completely miss the guy in the gorilla suit because the perceptual speed required to accomplish the task of focus (counting passes) means extraneous inputs (like the gorilla) don’t have time for the processing power available to integrate.
So I don’t consider it matter of discrete or continuous perception, but a matter of perception density and processing power. The closer to instantaneous the perception needs to be, the more limited its scope. I envision the brain as having a sort of “prefetch queue” where perceptions are in a continuous process of being constructed while they are being sampled at whatever rate seems necessary.
I think this view assumes that time is granular and quantized; that there is a sort of “planck interval”, and the arrow is frozen in place for the duration of that interval. I’m not sure this is right or wrong, and I can’t offhand think of any way to make that determination. Certainly the fastest clocks current technology can construct tick many orders of magnitude too slowly to detect a time quantum.
Flint,
Well, any movement is an illusion, right. To the arrow, you are moving and it is staying still. So all movement we see has to be an illusion of some kind or another.
I’m not sure I follow that. I agree that you and the arrow have different frames of reference, since you are in different places and moving relative to one another. Exactly this sort of frame of reference issue is what caused people to believe earth was fixed and the universe was spinning around us. Relatively speaking, that’s as true as picking any other frame of reference, though some choices make calculations easier.
But I don’t see how this makes movement an illusion. I would say instead that the perception that anything is NOT moving is an illusion.
Well, when you see something moving, what do you think you are seeing?
What is the difference between an arrow hanging on the wall, as opposed to an arrow flying throw the air, other than your frame of reference? In both instances it can be said the arrow is standing still.
This is interesting…
Can you elaborate or link to some more, please?
There more to it, keiths…
I didn’t want to sidetrack your OP yesterday, but just as Flint already related to it, the concept of time (s) seems to be blurred between stimuli and percepts, at least in some experiments… There is no seemless stream of percepts with an arrow of forward time attached. Quite to the contrary.
When I get to the office, I will link it.
I’ve only skimmed it, but based on that I don’t have a problem with the ideas in this paper. On the surface, they seem compatible with GWS and Dennett’s MDM, both of which the author’s cite (although the Dennett’s cites are for a different purpose which I disagree with).
Also nice to see a cite to Friston and Predictive Processing, although it was merely in passing.
Although I am not sure what exactly he is referring to in this paper I agree with Keith that many neuroscientific papers, let along popularizations, slide into language which assumes a Cartesian theatre and so borders on dualism.
ANOMALOUS ANTICIPATORY BRAIN ACTIVATION PRECEDING EXPOSURE OF EMOTIONAL AND NEUTRAL PICTURES
Dick J. Bierman and H. Steven Scholte
University of Amsterdam, Roetersstraat 15, 1018 WB Amsterdam, Netherlands
Abstract “The present study examined the neural substrates of anticipation in conjunction with functional magnetic resonance imaging (fMRI). Ten subjects were scanned while 48 pictures were presented. Each stimulus sequence started with the 4.2 seconds presentation of a fixation point before and during which the anticipation was measured. After the exposure of the stimulus picture which lasted also 4.2 second there was a period of 8.4 seconds during which the subject was supposed to recover from the stimulus presentation. It is found that large parts of the visual cortex do show larger activity after emotional stimuli than after calm. All brain regions that show a difference have also a response on calms except for regions that are at or near the amygdala. Here violent and erotic stimuli do generate a response but the response on calm stimuli is flat. Anticipatory effects tend to influence baseline values and hence influence the response values. This might be a problem if the subject is guessing the upcoming stimulus condition correctly but with proper randomization this is theoretically impossible. Great care was taken to randomize stimulus conditions with replacement while using different pictures for each stimulus presentation . Results suggest that, in spite of proper randomization, anticipatory activation preceding emotional stimuli is larger than the anticipatory activation preceding neutral stimuli. For the male subjects this appeared before the erotic stimuli while for the female both erotic and violent stimuli produced this anomalous effect. Possible normal explanations of this apparent anomaly, also called ‘presentiment’, are discussed. Most notably the possibility that this effect is just a result of ‘fishing’ for the right analysis out of many possible analyses. Exploratory results are presented dealing with differential effects in the responses to emotional stimuli and calm visual stimuli.’
https://www.quantumconsciousness.org/sites/default/files/presentiment_0.pdf
I’d encourage all interested to read the full text, which includes MRI pictures of the brain that “lights up before the stimuli appears on the screens”…
Interesting, J-Mac.
That’s 18 years old, and has subsequently been debunked.
That’s exactly like your “vaccine overload” tale.
At least these authors had enough class to note that their results could be merely the result of data fishing.
By James Randi! And Michael Shermer.
Oh, no no no no, phoodoo!
It was debunked by the professional cherry picker, as shown on the picture…
That’s why no links, just meaningless words…
J-Mac,
Jock thinks its SUPER hard to claim a study is worthless. But he took a course on it at a skeptics weekend retreat.
He must be from The Alzhe Club because he forgot who he claimed to be at TSZ… 😉 If he can’t google something then he thinks it doesn’t exist…
He is a waste of time…
phoodoo,
If you don’t know what the problem is… you can almost certainly follow the money…
Something I learned from the paper: The wagon wheel illusion (in which the wheel appears to be turning backwards) can be induced “in real life” even when the illumination is constant.
I’ve never seen it under those conditions, but I’ll start looking for it.
MRI scans
Heavens, no. What a silly idea.
I am referring to articles by neuroscientists published in real journals, such as Frontiers in Human Neuroscience (multiple hits), Perspectives on Psychological Science, and in Nature Neuroscience.
You are talking about a paper from a 2002 PSI conference in Japan.
But with your excellent research skills, you already knew that, right?
And again, I draw your attention to the sentence in the abstract you quoted
If I didn’t know better, I would say that Bierman was trolling you guys…
😉
My wife is a radiologist… Today these tests can be replicated much, much easier than say 20 years ago…
Interesting fact, if tangential: people who feel they lack control over their lives are likely to believe in pre-cognition.
In other news, Republicans scare easily.
J-Mac,
Your reply is a non sequitur. I’m talking about the paper that’s the topic of the OP.
I confess, I sort of made it up because it seemed implied in the “frozen arrow” which itself is a way of expressing Zeno’s paradox. However, a few google searches indicate that while both relativity and quantum mechanics view time as continuous, certain problems in quantum theory are easier to express if time is discrete.
What is this? Did you write this yourself? Did you just pluck random letters off the the internet?
Are you trying to plagiarize someone perhaps? What the hells going on here?
Nobody noticed… 😊
I think some have heard it more than once from me that in quantum mechanics time, or the arrow of time, is blurred…Same may apply to space… as proven by many experiments, including the one I linked earlier on “time flying backwards”…
Many people hate the results because they’ve shaken the fundamentals of physics, relativly and reality…
I look at it from another point of view… If space in quantum mechanics means nothing, then quantum entanglement can be easily explained… particles can travel faster than the speed of light… etc.
If that’s the case, the universe may not be as old as some would like it to be, or, they need it to be…😊
Can you imagine what would happen if light from the “edge of the universe” could travel faster than the “constant speed of light”, say with the same speed as the entanglement?
Sorry mate…
The paper seems to take for granted that postdiction is incompatible with continuous models of perception, but I don’t see why. As long as postdiction happens before the perceptual information is committed to consciousness, it shouldn’t matter whether the stream is continuous or not, as far as I can tell.
Their reasoning isn’t spelled out in the paper. I’ll take a look at a couple of the references to see if I can figure it out.
The mind boggles.
I have not read the paper in detail, but my first thought would be that there is a need to sample because there is a processing time associated with the input and output ends of the perceive-act-perceive loop?
Bruce,
How does postdiction fit into that? The authors pin the problem specifically on postdiction:
I was focussing on the continuous part which you also mentioned. But I guess I missed your point.
It’s either this or dark energy is toast…but then 3 Nobel Prize winners are toast too…And, the Copernican Principle could be toast too…again…lol
What do you prefer?
Einstein’s relativity or the Copernican Principle? 😉
There’s probably the third option you are not going to like either…🤣
Evidence so far suggests that the Hubble constant isn’t as constant as once thought. Measurements based on the very early universe conflict with measurements based on current observation and the CMB. The difference is large enough for cosmologists to suspect that they are missing something important, but they don’t know what it is. Certainly I don’t either.
So I think it would be foolish of me or anyone else to take an uninformed guess based on personal preference, especially religious preference. I do see a critical difference between the scientific and the religious mindset, though. The scientist’s reaction is like “oh boy, a mystery to solve, let’s put together some testable hypotheses and see if we can learn anything”. The religious reaction is “obviously goddidit, and we can only laugh at those atheist scientists who refuse to see the obvious.”
Interesting paper.
Both my wife and myself have had vivid precognitive dreams that we have related to each other on waking. I tend to gloss over the contents of any memorable dreams I have but my wife goes into great detail on the few occasions she does tell me about a dream she has had.
In relation to perception there is much more to “time” than anything that can be measured “objectively”. Experiential time is not a continuum, we should all be aware that it passes in discrete units.
Out of interest has anyone here had any experience time slowing down during a traumatic event?
Of course it won’t surprise anyone who has read my past posts when I say that both Steiner and Goethe would have agreed that our sense perceptions are discrete and disjointed. It is by the means of thinking that continuity is restored.
It is because of our bodily organisation that our perceptions are disjointed but it is the process of thinking that gives us the potential to experience reality in its true continuity.
Ahh… so, what is the problem exactly? Let’s see if you know…or more so, if your bias will allow to cough it up, if you are able to google it…😉
Whose religious preference? Yours or mine?
I think you’d have a chance to prove this very soon…😉
As I said it above…it remains to be seen, or, proven in your case…
I don’t mind that at all…
I disagree with this, but I have a problem when scientists insist on proving preconceived notions when the evidence is pointing against it, such as is the case with the implications of the Hubble Constant, the Copernican Principle, relativly and the story goes on…
Best way to test precognition is to write it down an get it notarized. Maybe photograph the document with a phone camera that records the time and place.
Otherwise, pfffftttt.
Can you reveal some details? I assume you are not married to your identical twin? 😉
Many people often have a feeling that an long, few hours sleep, with or without dreems, lasted few minutes… I can certainly relate to these experiences…
Yup.
I may have missed those…
Yes that would be the best way to provide evidence for third parties. But those that have the experience may not require such evidence and may be content with the experience as it stands.
CharlieM:
But then you need to take confirmation bias into account. Dreams that appear to come true are more memorable than those that don’t. This can lead you to believe that it happens more often than it does in reality.
CharlieM:
Interestingly (and ironically), the wagon wheel illusion provides some of the best evidence that visual perception is not discrete.
Here’s the abstract of a paper that makes that case:
Kline, K., Holcombe, A. O., & Eagleman, D. M. (2004). Illusory motion reversal is caused by rivalry, not by perceptual snapshots of the visual field. Vision Research, 44(23), 2653–2658. doi:10.1016/j.visres.2004.05.030
My most memorable dream involved a large airliner crashing into houses just before the Lockerbie disaster. And I would say my wife’s one involved a man on a bycycle and Ferrero Rocher chocolates.
We’re proof that opposites attract 🙂
Yes, that’s what I was referring to. We have no experience of time during dreamless sleep.
Me too 🙂
I can’t remember myself if I’ve quoted anything of relevance from them.
I’ve had very few dreams where I’ve made any connection to upcoming events. I can’t make head nor tail of the vast majority of them. Those few that I have had occurred just prior to the actual events. Any vivid dreams that my wife has she usually insists that I listen to her account of them just after she wakes up so that they are fresh in her memory.
I was being a bit ambiguous in saying that sense perceptions are discrete. They are discrete in that sight is distinct from hearing.
But whether or not our senses give us disconnected impressions, we have the ability to understand them in a unified way. Consider the spoken language. We receive the sound as a stream of syllables but we don’t “hear” each individually. We hear meaningful words and sentences. In reducing the sounds to strings of syllables the meaning is lost. Understanding comes with being able to grasp the whole in context. Because of the way we learn and remember we don’t always have to build up a picture of what we see. We can know immediately what the entity in front of us is.
So IMO visual perception is a dynamic process. Even a close look at our eyes demonstrates this with their constant saccades and microsaccades during vision. Motion is fundamental to our perceptions.
My brother is friends with really good tennis players.
The best returners in the game claim the can see the ball coming at them after the serve of 150 mph or 250 km/h and react…
How could it be even possible, when conventional neural firings are considered?