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Science

It's Surprisingly Hard To Notice When Moving Objects Change 140

Posted by Soulskill
from the sorry-officer-the-traffic-light-was-swinging-in-the-wind dept.
An anonymous reader writes "Scientists at Harvard have found that people are remarkably bad at noticing when moving objects change in brightness, color, size, or shape. In a paper published yesterday (PDF) in Current Biology, the researchers present a new visual illusion that 'causes objects that had once been obviously dynamic to suddenly appear static.' The finding has implications for everything from video game design to the training of pilots."
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It's Surprisingly Hard To Notice When Moving Objects Change

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  • Slight of hand (Score:4, Interesting)

    by Anonymous Coward on Friday January 07, 2011 @07:44PM (#34799054)

    I think this was fairly well known (at least intuitively) by magicians. As long as you keep your hands moving, people can't tell what you are doing with them.

  • by Monkeedude1212 (1560403) on Friday January 07, 2011 @07:45PM (#34799064) Journal

    Our eyes are trained to do a whole lot of quick thinking and estimates before sending the raw data to our brain. This is one of the many reasons why simply hooking a camera up to the optic nerve doesn't quite produce the desired results - though our brains seem to be super-learning computers able to interact with almost any other kind of Input - Output, given enough time for trial and error.

    I imagine our Eyes are trained to generalize the colour it sees and focus on the appearance of motion, because thats usually more important and relevant to survival, and our eyes are just like technology: Limited bandwidth.

    You might call it a defect, I might think of it as evolutionary design.

  • Re:Slight of hand (Score:5, Interesting)

    by PopeRatzo (965947) * on Friday January 07, 2011 @07:56PM (#34799192) Homepage Journal

    I think this was fairly well known (at least intuitively) by magicians. As long as you keep your hands moving, people can't tell what you are doing with them.

    Sleights of Mind: What the Neuroscience of Magic Reveals about Our Everyday Deceptions by Stephen L. Macknick and Susana Martinez-Conde.

    I saw this book at the Bucktown branch of the Chicago Public Library earlier today in the "New Non-fiction" section. I took it out but haven't had the chance to crack it yet. It looks like it speaks directly to your point.

    This is from the blurb:

    Stephen Macknik and Susana Martinez-Conde, the founders of the exciting new discipline of neuromagic, have convinced some of the world's greatest magicians to allow scientists to study their techniques for tricking the brain. This book is the result of the authors' yearlong, world-wide exploration of magic and how its principles apply to our behavior. Magic tricks fool us because humans have hardwired processes of attention and awareness that are hackable—a good magician uses your mind's own intrinsic properties against you in a form of mental jujitsu.

    Now magic can reveal how our brains work in everyday situations. For instance, if you've ever bought an expensive item you'd sworn you'd never buy, the salesperson was probably a master at creating the "illusion of choice," a core technique of magic. The implications of neuromagic go beyond illuminating our behavior; early research points to new approaches for everything from the diagnosis of autism to marketing techniques and education. Sleights of Mind makes neuroscience fun and accessible by unveiling the key connections between magic and the mind.

  • by RyanFenton (230700) on Friday January 07, 2011 @07:56PM (#34799196)

    Switching something when it is in the middle of fast movement is the basis of all kinds of slight of hand tricks. There's just a certain state where the mind identifies something just as a blurb of overlapping color, rather than anything processed meaningfully, and you can freely swap it with a similar item without any notice. Mix in basic misdirection, and you can fool almost anyone's expectations. It's also why you kind of have to learn to juggle by feel & pattern rather than just sight - because the hand really does have to be faster than the (mind's ability to process information from the) eye to keep up with the pattern.

    Ryan Fenton

  • by k2backhoe (1092067) on Friday January 07, 2011 @09:14PM (#34800172)
    The reef squid has the ability to quickly change colors and patterns on it's body, and seems to signal other squids in this fashion (as well as for camouflage). I wonder if they would be fooled by this illusion or if their neural optics are wired very differently than ours. It would be challenging to try to create an objective test that you could do with them.
  • by PlaneShaper (1830294) on Friday January 07, 2011 @09:36PM (#34800352)

    I won't necessarily claim to be one here, since anyone can claim anything on the internet. But I wonder how well experienced MTI analysts (http://en.wikipedia.org/wiki/Moving_target_indication) would perform against these videos. Quite literally, it is the job of an MTI analyst to distinguish coherent from non-coherent changes across a vast number of moving dots displaying all sorts of crazy behaviors.

    Additionally, I would prefer to see this experiment run under different conditions, such as having the videos begin with dots in apparent motion for many seconds, then having them stop moving. I do think the results of the experiment are damaged by having the motion segment (3 secs) be significantly shorter than the non-motion segment (5 secs) and always happening after the eyes and brain have adjusted to the lack of apparent motion.

    I think another big problem with the videos provided is that the motion segment alters direction 9 times (counting first and last) within a short window -- this may not result in the human mind having difficulty seeing change in moving objects, but a difficulty in adjusting the perspective of the total scene to something observing rapid fluxuation in velocity. (I.E. The circle constantly rotates back and forth, preventing the brain from "getting used to" the scene, whereas when the dots are stationary and only changing in specific property, they remain in this configuration for a much longer period of time).

    It's a interesting topic, but research could have focused more on overall configuration of how viewers were presented with the experiment. There isn't enough information present to draw an accurate conclusion from these observed results.

  • Re:stupid scientists (Score:5, Interesting)

    by suchow (1972574) on Saturday January 08, 2011 @12:07AM (#34801370)

    hi, stupid scientist #1 here. (i'm one of the authors of the paper.) you're right, it would be nice to have a flash app that lets you change the speed of rotation. sadly, i programmed everything in MATLAB and I don't know flash. (and hey, didn't our overlord already pronounce flash dead?) on that note, if anyone knows flash and wants to program this up into an interactive demo, send me a message, i'm sure we could work something out.

    but you're in luck, my friend. the demo works even if you pick up the screen and rock it back and forth, and i have a movie (link below) with no motion. you can loop the video and whirl the computer around all you'd like, at various speeds.

    here's the movie [jwsu.ch].

    as an aside, the first experiment in the paper in a speed manipulation. (spoiler alert.) the fast the ring rotates, the slower the dots seem to change.

  • Culture Bias? (Score:4, Interesting)

    by Arterion (941661) on Saturday January 08, 2011 @03:37AM (#34802244)

    I'd like to see if there's a culture bias to this. Get someone from a very non-westernized culture and ask what they see. They're regularly not fooled by these kinds of "illusions":

    Which line is longer:

    >----------

    Their eyes just aren't trained to see geometry the same way as westerners who are faced with tons of man-made things everyday.

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