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Science

Man Can Change His Pupil Size On Command (livescience.com) 84

Posted by BeauHD from the unusual-talents dept.
An anonymous reader quotes a report from Live Science: A 23-year-old student in Germany can shrink and enlarge his pupils on demand, according to a new case report -- a feat that was previously thought to be impossible. Two tiny opposing muscles in the eye act as puppeteers of each pupil (the dark center of the eye), dilating or enlarging them in a dark environment to let in more light and constricting them in a bright environment to limit the amount of light that flows in. This process was thought to be completely automatic; when you step into a dark room, you don't have to consciously tell your pupils to change size. Pupils can also change size in response to other factors, such as increases in arousal. It was previously known that some people can change their pupil size at will, but by using indirect methods.

[N]o one thought it was possible to change pupil size by directly controlling it like a muscle -- that is, until a student of psychology at Ulm University in Germany contacted Strauch after taking one of his courses. (Strauch was previously a doctoral student at Ulm University). When he was about 15 or 16 years old, the young man -- identified in the case report by his initials, D.W. -- realized that he could change the size of his pupils. "I showed a friend that I can 'tremble' with my eyeballs, and he noticed that my pupils became small," D.W. told Strauch and his colleagues at Ulm University. But D.W. didn't notice that he had this ability until he played computer games for long periods of time. "Constricting the pupil feels like gripping, tensing something; making it larger feels like fully releasing, relaxing the eye," D.W. told the researchers.

Through a series of tests, the researchers confirmed that D.W. indeed had this ability -- and they found no indication that he was changing the size of his pupils indirectly. In one test, the researchers measured the electrical properties of the skin by applying voltage to test whether he was aroused by increased mental effort, which also might have increased his pupil size indirectly. Without using any indirect method, D.W. could dilate his pupils up to 0.09 inches (2.4 millimeters) in diameter and constrict them to 0.03 inches (0.88 mm) in diameter. What's more, even at the closest point an object can be for the eye to still see it in focus, in which the pupil is already "maximally" constricted, D.W. could voluntarily constrict his pupil even more. By doing this, D.W. improved his focus and could see objects clearly nearly two times closer to his face than he could if he wasn't controlling his pupil size. Using a type of brain scan known as functional magnetic resonance imaging (fMRI), the researchers found increased activation of certain parts of the brain involved in volition, or the ability to decide and do something out of free will. The researchers can't say for sure that D.W. was directly controlling his pupils, but from their many tests, they did not find any evidence that he was using indirect strategies. The findings were published in the International Journal of Psychophysiology.
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Man Can Change His Pupil Size On Command More

Man Can Change His Pupil Size On Command

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  • Hypnosis (Score:1, Insightful)

    by Narcocide ( 102829 )

    With clever use of hypnosis you can take over manual control of any previously assumed-to-be reflexive response in a target subject. I thought this was already a well-known scientific fact. With additional training the subject can learn to gain manual control themselves. This isn't a toy. This is really dangerous.

    • With clever use of hypnosis you can take over manual control of any previously assumed-to-be reflexive response in a target subject

      Any? Really? Source?

      I thought this was already a well-known scientific fact

      Whatever made you think that?

      • Re: (Score:3)

        by narcc ( 412956 )

        Hypnosis isn't silly stage magic. You've mistaken watching television for education. It's a real thing [apa.org].

        I thought this was already a well-known scientific fact

        Whatever made you think that?

        I suspect he got that idea from the decades of scientific research on the subject.

        It even has real clinical applications:
        Patterson, D. R., & Jensen, M. P. (2003). Hypnosis and clinical pain. Psychological Bulletin, 129(4), 495–521. https://doi.org/10.1037/0033-2... [doi.org]

        Really? Source?

        Can't use google scholar? He may have exaggerated with 'any', I don't know, but I'm not going to waste my afternoon on it. You ar

        • You're making an awful lot of assumptions about me. Especially for one interested in science.

          Yes, it was the "any" part that I thought was wildly overshooting, exacerbated by the claim that this was well know fact.

          I am fully aware og what hypnotism is.
          I haven haven't been denying anything.
          Keep your enemy-projections to yourself

  • He's been given great power... (Score:5, Funny)

    by h33t l4x0r ( 4107715 ) on Thursday September 02, 2021 @12:52AM (#61755389)
    I only hope he has the wisdom to wield it responsibly.

  • Not surprised (Score:5, Interesting)

    by getuid() ( 1305889 ) on Thursday September 02, 2021 @12:57AM (#61755395)

    I can move the skin on my head in a manner as to wiggle my ears. While not really a magician's trick, by far not everybody can do it.

    Also, this is how specific forms of Qi Gong and meditation work. You build bodily awareness to the point where you "know" of parts of your body (muscles, sensorics etc) that you normally wouldn't know about.

    For instance there's a specific muscle that enables men to pull their testicles back into their belly, so you can actually take a kick in the groin. Some of us have felt that muscle maybe 1-2 times in a lifetime (a female medicine student taught me that if someone caresses your upper inner thigh in a specific way, you may feel a very odd local twitch - that's said muscle twitching). Paying attention to that, practicing that, and strengthening that, you grow bettet ar doing it - surprise!

    Of course, once you've managed, there is tne issue of bringing your testicles out of your belly again. Many fail at this, and given that they die off if they stay at 37 degree Celaius, you have mere hours to learn that. I know 2nd hand that Hong Kong ER regularly receives advanced Kung Fu and Qi Gong masters who've managed the first part, but couldn't learn the 2nd part fast enough...

    In essence: keep practicing, it's your body and learning things is good. But it pays off to have a good teacher, and the ancient arts (Qi Gong, Yoga, Kung Fu) have plenty of useful practical experience. Still dangerous, though, so be careful. It's not magick. Use common sense.

    • James Bond - You Only Live Twice.

      • Man with the Golden Gun... Martial arts choreography by master Victor Kan Way Chit, student of Ip Man.

        • I'm fairly sure it's in the original Fleming book You Only Live Twice, are you saying it was moved to the Man with the Golden Gun for the movies (long time since I saw any of them)?

          • If you mean the scene with Roger Moore kicking a karate guy in the balls after twisting a sumo wrestler's "knickers", then yeah, it's in the Man with the Golden Gun.

            • I'm talking about this conversation from the book:

              Now, you know that, in men, the testicles, which until puberty have been held inside the body, are released by a particular muscle and descend between the legs?”

              “Yes.”

              “Well, the sumo wrestler will have been selected for his profession by the time of puberty. Perhaps because of his weight and strength, or perhaps because he comes of a sumo family. Well, by assiduously massaging those parts, he is able, after much practice, to c

    • Re: Not surprised (Score:4, Interesting)

      by aRTeeNLCH ( 6256058 ) on Thursday September 02, 2021 @08:32AM (#61756317)
      Actually, no, your balls don't die off at 37 degrees, just the sperm. On the martial arts practitioners ending up in hospital, link or it didn't happen.

      • On the martial arts practitioners ending up in hospital, link or it didn't happen.

        Why do you think I owe anything?

        Also, on another note: when you grow up, mummy and daddy are going to explain to you that not everything one knows necessarily has to come from the internet, and not everything that happened necessarily ends up on the internet.

        • So, no evidence to support your claim, only derision?

          That's how you *know* it's for real.

          • waah! He didn't spoon feed me!

            He didn't publish a paper on it, so why would there be links? Go and search for information about it yourself.

            Maybe your babysitter will do it for you, if you ask nicely?

          • I don't care if you "know it's for real".

            I have no skin in this. I'm not in the news business, fake, true, or otherwise.

          • Re: (Score:2)

            by narcc ( 412956 )

            only derision?

            That was more than your post deserved. Learn to use google.

        • Well, it's too late for me to grow up, but I happen to have met quite a few martial arts practitioners from Hong Kong, and none of them have ever mentioned a problem with their balls... Also, I know from someone who trained (well, tried) that technique that if you manage to get your testicles up (he could only do it with use of his hands, not with just a muscle), it's easy to massage them down, or just jump a bit and they'll drop back down.
          A quick search confirms that if the testicles are typically in the

          • I've never trained that specific teqnique myself, so I don't know the details. What you're describing sounds reasonable, namely that they could/should fall out on the average person.

            But not everybody's body is the same, I was told of people who had kidneys displaced by more than 10 cm, people who had nostrils so narrow that they could only breathe through the mouth, children that still had their testicles up their bellies by the age of 18 etc (usually they slide out ans never go back before puberty).

            It's no

            • As my link explains, the cases that need operating upon are not those that start out normally and mess around. It's not a holy grail amongst Kung Fu practitioners to be able to do that, because it just places the testicles in the lower abdomen, where they will be fully impacted by a front kick or low punch. So statistically you may have a point, if enough people try it. I just pointed out it would be very uncommon.

              • It's not a holy grail amongst Kung Fu practitioners to be able to do that, because it just places the testicles in the lower abdomen, where they will be fully impacted by a front kick or low punch.

                That, and the fact that a kick in the groin causes enough damage even without testicles there to break the shock (just ask any girl who's received one)... confirms that me practicing different defenses was a better idea.

                However, there are techniques to mitigate a lot of the impact of abdomen shock energy with regard to inner organs. I don't know where this leaves the testicles in the long run, though. Again, never practiced that part.

              • BTW thanks for sharing the link.

    • You can also learn to manually control the focus (not pupil diameter) of your eyes.

      That's my superpower. I can pick up most prescription eyeglasses, tweak my eyes to match, and see fine. :/

    • Re: (Score:1)

      by vivian ( 156520 )

      I think I'd rather master kicking the other guy in the nuts first...

      • I think I'd rather master kicking the other guy in the nuts first...

        Having trained martial arts since I was a teenager... yep. That's pretty much what you should be practicing -- figuratively speaking :-) Even with testicles safely tucked in, there's a lot of damage that can be done by a kick to the groin. Just ask any girl having accidentally received one.

        However, on a more serious note (although probably off-topic, so feel free to ignore): if you're looking for self-defense capabilities, kicking the nuts isn't what you should be primarily practicing. Yes, it works if you

        • Re: (Score:1)

          by vivian ( 156520 )

          My Tae Kwon Do Instructor had a little bit of advice I am sure he got from some sage - "never kill when you can maim, never main when you can hurt, never hurt when you can hold".

          Basically always de-escalate any response where possible - and if you can, talk your way out of a situation. Failing that, haul ass and get out of there if you can do so safely, with combat being the last resort. At that point, even if you win you have already lost because there will be repercussions - damage to yourself, even if on

          • Ok, so this turns into a Martial Arts thread now... ;-)

            Basically always de-escalate any response where possible - and if you can, talk your way out of a situation.

            Yes, essentially true. Remember that even if you're better, winning is sometimes a bad move. What's somebody's life worth, even a mug's? Would you kill someone for $2000? Would you beat them into ER? Yet that's exactly what happens when you "defend" your laptop or your wallet because a mug on the street wants to have it.

            Yet there are situations where running away with a bruised ego isn't an option: sometimes you need defend others - children, spouse, or

        • Thanks for the write-up. I have two daughters, teenagers now, and when they came home from school I really had to explain that that's not something to do for fun. I've been at the receiving end (without cause, girl got challenged and I was the first guy to show up), and I do recall that I would have been perfectly capable of doing all kinds of things, I was just to confused and stuck in the thought "girls shouldn't be hit". So you don't necessarily stop someone...

          • Yes, pretty much this.

            The go-to "I need to hurt the other guy, easily" move I teach is: hammering fist on the collar bone to break it. Even in tough guys it only takes about 7-8 kg of force at most, a teenage girl can easily do it. Then, once it's broken (there may even be an open wound) put you finger on/inside the wound and squeeze.

            Fight is instantly over, works equally for men and women. Not likely to end up in anyone's death, not likely to end up in lasting damage once it heals.

            It also serves as a good

    • Re: (Score:2)

      by ed1park ( 100777 )

      So what do they do to cause the testicles to descend?

      • Honestly I have no idea.

        If I were to guess, I'd say it's probably a combination of creating pressure in the lower abdomen (just "pushing"? squeezing middle diaphragma and pelvic floor?) and relaxing specific muscles of the lower abdomen. It probably also depends from person to person how difficul that actually is - testicle size and the holes they have to fit through etc. Maybe those ending up in ER are just cases of bad luck?...

        I've never trained this specifically, although I've been practicing Qi Gong for

      • Or if you mean the hospitals? It was my understanding that they do it by surgery.

    • Maybe the reason they can't fall out is because the area around is swollen due to being kicked during practice? That or a muscle spasm due to the unusual stress; similar to when you start practicing the split; the muscles aren't used to being in such position so they send a signal to the brain indicating damage(causing pain) once you get used to it, you can do the split easily. Don't do it too fast or you will smash your nuts.

      • Maybe the reason they can't fall out is because the area around is swollen due to being kicked during practice?

        Maybe, but I'd be surprised if everyone who did this went immediately over to target practice... as being the target :-) Kicks in the groin hurt even if your nuts are not in the way.

        But I have no idea how often that happens, and to what kind of people (I have this information from my teachers, who learned Kung Fu and TCM in HK during the 80s and, 90s, but he didn't do into details). But your take is interesting though. Maybe some of them rush too early into demonstration of their abilities?...

    • and given that they die off if they stay at 37 degree Celaius,

      Your balls don't die at 37 degrees.

      Treat the rest of this post as bullshit as much as this claim.

  • Teachers aren't allowed to be alone in the classroom with only one pupil nowadays.

  • I have had retina surgery involving laser treatment and injection of an anesthetic behind the eye. It resulted in a minor complication whereby the nerve that controls the muscles of the pupil and lens is damaged.

    This nerve then regenerates and as there are about 10x more nerve fibers normally controlling the lens then there are controlling the pupil some of then regenerated abbarently (connecting focus nerves to the pupil). That makes that I can somewhat control my pupil by simulating looking near or far.

    It

  • just control your pupils like a human would.

  • There's a novel by Larry Niven called 'A Gift From Earth' about a fellow named Matthew Keller who has the ability to control the pupils of _other_ peoples' eyes, making them less or more interested in him (effectively giving him an odd sort of invisibility). He also doesn't realize that he has the ability, and had, up to the point he learned of his ability, always had trouble with women, because his own fear would instinctively make a woman's pupils smaller, making her move on to someone else. Keller uses h

    • Re: (Score:2)

      by PPH ( 736903 )

      I'm not sure it works the other way around. Being aroused or interested in someone results in pupil dilation. But dilating one's pupils doesn't make somebody more interested in someone else.

      I know a lady who has strangely large pupils. She is continually bothered by guys who read that the wrong way when she meets them. I've also seen this with people that have very dark irises. I jokingly suggested to one lad that she needed to have blue tinted contacts made with little pin-prick pupils. So as to convey th

  • Mine used to change predictively (Score:5, Interesting)

    by jddj ( 1085169 ) on Thursday September 02, 2021 @04:22AM (#61755729) Journal

    I used to work an animation stand (a Marron 1600, if you're hip to it), which meant I'd regularly put my left eye up to its very bright eyepiece, while my right eye faced the black aluminum of the camera body in the darkened room. (You don't close your other eye in this situation, because it's not really seeing much of anything, it isn't bright over there, and you might be looking often, and for a long time. Scrunching one eyelid for a half hour kinda hurts).

    I came to figure out that my left pupil would contract, not from the bright light of the eyepiece, but just before I got there, in a learned behavior. There was no registration of very bright light in the dark and then adjustment, at least after It'd started doing this. It was about the correct - uh, setting? - immediately. The right pupil stayed dilated appropriately to the dark room.

    I confirmed this with a few experiments with a mirror once I realized it was happening.

    Thought it was pretty cool. Haven't used one of those cameras in over 25 years, so I'm guessing that behavior has faded away by now.

  • I can flex some muscles in my face and close off my nasal passages. I learned to do it as a child, about the same time I practiced raising one eyebrow (at a time, I can do either) in the mirror. I know lots of people who can raise one eyebrow, but literally nobody else who can shut off their nose.

  • I would expect with nearly 8 billion people on the planet, that there is going to be someone who is wired a bit off where they can control a normally involuntary muscles. We have people who can control their heart rate, wiggle their ears, detail controls of parts of their digestion system. While the eyes are rather closely wired to the brain, with 8 billion people on the planet there can always be an odd ball, with an odd cross connection.
    It is kinda how evolution works, a random trait pops up, it either

  • big pupils means exitement and are used as an effect in movies. I watched Possession (1981) lately and in some rational/serious scenes theyre smaller. In excessive scenes, theyre bigger. That was good visible in a movie theater.

    • That could have been one of the "indirect strategies" mentioned. Many acting methods have the actor put themselves in the mindstate of the part they're playing, so they might artificially be in a state of fear or arousal to dilate their pupils.

  • Weird Flex, but okay
  • Is when is the new ABBA album coming out?
    https://news.yahoo.com/swedish... [yahoo.com]

  • Pro tip (Score:5, Informative)

    by Ecuador ( 740021 ) on Thursday September 02, 2021 @10:13AM (#61756751) Homepage

    When you get up in the middle of the night to go to the loo but don't want to switch on the bedroom light and wake up your partner, while at the same time not wee all over the place, close one of your eyes when you get to the loo and switch on the light. Then, returning to the bedroom, open your other eye and you have kept it fully dilated and can see in the dark.

  • I thought everyone could do this. . .

  • An article from 5 years ago.
    https://www.bbc.com/future/art... [bbc.com]
    They don't mention doing the change on command for the scientist, but I'm guessing some could.

    There seem to be a lot of learned experiences to dilate the pupil, so this guy was more aware than most when it happened and made it a learned muscle movement.

  • New for nerds, stuff that matters.

  • Lots and lots.... (Score:3)

    by rew ( 6140 ) <r.e.wolff@BitWizard.nl> on Friday September 03, 2021 @07:16AM (#61759081) Homepage

    lots and lots of muscles are operated "on automatic" by your brain.

    It is just that most people don't practice to operate them that they are not able to do so on demand.

    I have a friend who has a lazy eye. He says that he feels the focusing action of his eye, so he can gauge distances that way. Moving ears, breasts or nostrils is something that some people can do. In some cases the muscle is no longer there (evolution didn't find it important) but in most cases it is just that you've never felt the need to control that muscle.

    As an example of that you can learn to use muscles that (most of you) haven't really been able to control until today....

    Spread out the fingers of one hand. Now group them into a group of three and a single lonely finger. Now move one finger so that there are two groups of two. Now move onre more finger so that you're in the toher 3+1 configuration. Try not to move other fingers while doing this.

    It is taxing for the mind to try to do this. The younger you are the easier you'll learn. Practise this for two weeks 5 hours a day and you will be able to do it pretty fluently., Way better than what you did just now.

  • Lots of people can change pupil size, at least in a minor way. Who decided it could not be done?
    No wonder "science" is not always thought of as a "real" thing like - astrology.

  • Slashdot articles are rife with obscure acronyms that the editor doesn't bother to expand, yet in this case they thought it necessary to explain that the pupil is "the dark center of the eye".

    Honestly, it's as if the editors think we're a bunch of geeks who know everything about technology but are completely unfamiliar with human beings. Oh, wait...

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