[HN Gopher] EEG Cat Ears (2018)
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       EEG Cat Ears (2018)
        
       Author : searchableguy
       Score  : 313 points
       Date   : 2022-03-02 11:15 UTC (11 hours ago)
        
 (HTM) web link (i2nk.co)
 (TXT) w3m dump (i2nk.co)
        
       | Nursie wrote:
       | Awesome project!
       | 
       | We had some neko-mimi's a few years ago but the ear clip broke
       | very quickly.
        
       | gg2222 wrote:
       | Here is a fun demonstration of the Necomimi cat ears that were
       | noted as reference material for the project.
       | 
       | https://youtu.be/fOrqZjvQ0JQ?t=527
       | 
       | Amazing work building your own btw!
        
         | Animats wrote:
         | Yes, it's a Necomimi clone. The big year for those was 2012.
         | They detect three mental states - idle/relaxed, attentive, and
         | surprised. I saw a group of cosplay girls wearing them at a
         | convention. Someone called out the name of one of the girls.
         | Her ears, and not the ears of the others, popped up. A review
         | reported someone playing a video game had their ears in the
         | "attentive" position while playing a level, and the ears would
         | droop between levels.
         | 
         | Good idea, but too bulky. It needed cosplay big hair to hide
         | the machinery. The big head-mounted box is mostly the 4 AAA
         | batteries. If someone revives this, the mechanism needs to be
         | about half the size and better fitted to a head.
         | 
         | The Nekomimi people also came out with a powered cat tail, but
         | that was a total flop.
        
       | KaiserPro wrote:
       | I do love a good write up. The concept and execution is great,
       | but what's most important is that they have shared the journey.
        
         | alexpotato wrote:
         | I was really impressed with the sketches. I always thought
         | those were more of an engineering "suggested best practice" but
         | this is a good reminder that a visual sketch can act as a
         | reference while also showing how pieces might fit together.
        
       | sebastianvoelkl wrote:
       | There was a really old version of this already 9 years ago*
       | *https://www.youtube.com/watch?v=hP8kVEvm6h8
        
         | resonious wrote:
         | Those exact ears were reference material for this project.
         | 
         | > I began by looking at the youtube concept video for the
         | necomimi brainwave-controlled ears. My intent wasn't to copy
         | their implementation, but I was curious what kind of motion
         | they had decided on.
        
         | snarfy wrote:
         | Neat. I bought a pair at PAX many years ago. Sadly they stopped
         | working after a week or so.
        
         | LoveMortuus wrote:
         | The ones that you linked are called Necomimi, I bought them and
         | they still work. The one thing that they should really improve
         | is the quality of the motors because they are extremely loud
         | which kind of defeats the point of having a mode which shows
         | you your meditation state and relaxed state. I wish someone
         | would make an update and improved version. Another thing that
         | bothered me is that it needs FOUR AAA batteries, which is good
         | from the environment point of view. But very bulky and kinda
         | annoying from the UX point of view.
         | 
         | The same company also made a tail, but I didn't have a chance
         | to test it nor did I buy it.
        
       | [deleted]
        
       | blobbers wrote:
       | A little surprising this isn't a kickstarter project partnered
       | with Neurosky.
       | 
       | I have a few of their headsets and I can never bring myself to
       | get around to doing much with them.
       | 
       | I should pull them out and give this a shot!
        
       | dmitrygr wrote:
       | Bought a similar thing a decade ago: https://www.necomimi.com/
        
       | phnofive wrote:
       | (2018)
       | 
       | Hoping for a v2 but couldn't find one.
        
       | writegit wrote:
       | Super cool project and write up.
       | 
       | What's the state of EEG these days?
       | 
       | Last I interacted with one of these systems it seemed more like
       | confimation bias from noise.
       | 
       | Had a buddy who bought a "high end" headset, shaved his head to
       | "improve the signal", and it appeared for all intents and
       | purposes that it was mostly only reading concusive activity. He
       | would "show me it's working" by tapping on the exterior of the
       | sensors to get it to display a spike.
       | 
       | Conceptually these systems "make sense" to me, ie. the brain uses
       | electromagnetism to function so one should be able to
       | sense/manipulate those vectors, but an FMRI is MASSIVE and
       | requires a 1-3 Tesla electromagnet to get its fidelity, and even
       | then is only measuring blood flow and correlating that to brain
       | activity.
       | 
       | So what's the hope that a tiny sensor resting on your skin will
       | actually correspond to anything happening inside the brain?
        
         | ravi-delia wrote:
         | EEG studies are rife with issues, but there are a number of
         | very well replicated results. Obviously they do nothing to
         | localize an effect, but there are absolutely clear
         | correspondences between the readings of an EEG and at least
         | some cognitive activity.
         | 
         | Will you get that nice FMRI resolution? Absolutely not. But the
         | effects you do get are fascinating, and super weird.
         | 
         | Now that's the EEG I've seen in labs. Not sure if there is a
         | similarly good commercial offering.
        
         | caycep wrote:
         | the underlying concept of EEG hasn't changed since the initial
         | ones in 1929. Basically just electrodes trying to detect
         | whatever LFP (aggregate electrical potentials) comes across the
         | cranium. The clinical ones are considered a rough gauge of
         | brain activity, good enough to reliably detect large seizures
         | or a generalized slowing in patients who are delirious but that
         | is about it.
         | 
         | There's MEG which tries to do the same thing but using magnetic
         | detectors instead of scalp electrodes, but those systems are
         | large and unwieldy
         | 
         | In surgery, they do intracranial subdural electrodes which give
         | you better cortical LFP because the electrodes are almost
         | directly on top of the brain and not having to measure through
         | bone.
         | 
         | Then there are the single unit electrodes or things like the
         | Black Rock systems Utah array where thin probes penetrate the
         | brain into deeper structures but obviously have much more
         | special circumstances where they are able to be used.
        
         | SkittyDog wrote:
         | EEG and MRI are based on two completely different physical
         | measurements. They have nothing whatsoever to do with each
         | otyer, in terms of why they work. Medical EEG machines are very
         | small, and their size relative to MRI machines does not factor
         | into how effective the EEG is.
         | 
         | I mean, would you doubt that a stethescope can work, because
         | it's so much smaller than an MRI? No, that would be ridculous.
         | Same with your comparison vs EEGs.
         | 
         | Just read the WP articles on MRIs and EEGs. You'll understand
         | it.
        
           | writegit wrote:
           | Is this written from the perspective of experience with
           | contemporary EEG systems or wiki reading?
           | 
           | > They have nothing whatsoever to do with each otyer, in
           | terms of why they work.
           | 
           | I thought my comment made my knowledge of this explicit? Also
           | I was referring to FMRI.
           | 
           | >> and even then is only measuring blood flow and correlating
           | that to brain activity.
           | 
           | My question is about resolution. FMRIs are our best tools in
           | terms of brain activity when concerned about resolution.
           | 
           | A stethoscope can indirectly tell you if you have fluid in
           | your lungs, but "where" or "why" are far beyond the scope of
           | a stethoscope.
           | 
           | A direct comparison would be:                   stethoscope :
           | is water in lungs? :: EEG : is brain in skull?
           | 
           | One seems useful; the other, self-evident.
           | 
           | So, EEG, is it /still/ confirmation bias in its ability to
           | read/interpret signals in the brain?
           | 
           | Or has there been an appreciable development in EEG's
           | abilities/resolution/functionality?
        
             | SkittyDog wrote:
             | I'm not an expert. I did some undergraduate courses in
             | neuroscience, and one of those covered how various
             | instruments work, including MRI, EEG, and a few others. I
             | would invite anyone with a better education to correct any
             | errors they can identify in what I've said.
             | 
             | And yes I DID just refresh myself on those WP articles I
             | mentioned :-) and they seemed pretty well written, to me.
             | 
             | I also owned a NeuroSky a while back, and IMHO it was not
             | very useful... But that's because it was a toy, not a
             | medical device. Same underlying measurement principles, but
             | very different in terms of actual operation.
             | 
             | One of the main differences is that medical devices are
             | always attached to _bare skin_ with _conductive gel_
             | applied under the sensor. Also, medical devices have more
             | sensors. This vastly improves the signal quality, as
             | compared to the toy devices.
             | 
             | In research work, medical EEGs have been successfully
             | controlling computers for several decades, long before
             | NeuroSky or the Necomini ears came to market.
             | 
             | Tl;Dr, you don't need an FMRI to control a computer... EEGs
             | work fine, but none of the existing EEG toys have been
             | particularly well designed in that regard.
        
         | pedalpete wrote:
         | We're building an eeg device for sleep, and work with a
         | colleague who is on the Emotiv team, so I've got a bit of
         | experience.
         | 
         | The state of BCI is improving, but one of the challenges is for
         | many of the things we'd want to do, you need electrodes placed
         | in areas that have hair. There are flexible sensors that can
         | find their way through hair, but as somebody with thick curly
         | hair, they are not fit for everyone yet. Then there is movement
         | that also needs to be considered for many of these devices.
         | 
         | This is why something like Muse headband used for meditation is
         | a good starting point. You are placing the electrodes on areas
         | that don't have hair, and the use case is while being still, so
         | you have consistent contact without movement.
         | 
         | At my start-up (https://soundmind.co) we're using forehead
         | mounted electrodes which measure your brain waves during sleep,
         | and we use sound to improve sleep performance. So like Muse
         | (which you can also use during sleep, but does not yet provide
         | stim), we benefit from measuring very small signals when you
         | are mostly still.
         | 
         | I think if we were walking down the street with our headband
         | trying to control cat ears, you'd get lots of EEG artifacts due
         | to movement of the electrodes.
         | 
         | My 2 cents.
        
       | svnpenn wrote:
       | Site does not work at all without JavaScript, I just get a
       | completely white page.
        
         | jd24 wrote:
         | Yeah, because the guy is animating in every image for some
         | reason
        
       | actionfromafar wrote:
       | Very cool! This triggered another idea - our ears already can
       | move a slight bit by its own muscles. Can't we read these muscle
       | movements, and amplify them by controlling the servo Cat Ears in
       | sync? Might be easier to learn to control, maybe.
        
         | JKCalhoun wrote:
         | I was thinking perhaps add a pair of microphones to the headset
         | and have the ears react to loud sounds -- attempt to angle
         | towards the source of the loud sound.
         | 
         | Mux that in with the neural input.
        
         | yoz-y wrote:
         | It would be a better control mechanism. NeuroSky (the headset
         | used here) is only good as an eye blink detector and even at
         | that it's not great. EEG reading on the forehead, without gel
         | is always really bad because there are no obviously
         | interpretable signals (frontal cortex is way more complex than,
         | say motor regions or the occipital nerve), the skin is tougher
         | due to no hair, and is way too much muscle interference.
         | 
         | Something with two electrodes behind ears (or wherever the
         | muscles responsible for moving ears are) could be even used as
         | a tool to train to move your (human) ears.
        
           | musingsole wrote:
           | The Muse 2 headset has ear and forehead sensors. I'm not too
           | up on EEG, but I'd believed the ear sensors were just for
           | grounding/baselining what's read from the forehead.
           | 
           | Blink detection at least is pretty robust when I've played
           | with it.
           | 
           | https://choosemuse.com/muse-2/
        
             | yoz-y wrote:
             | yeah, ear sensors are for a ground and a reference, to be
             | able to remove noise from the EEG (basically you are trying
             | to have a channel which has no EEG)
             | 
             | Muse is more or less couple of neurosky's glued together.
             | With multiple sensors you can at least get to know which
             | eye blinked, extract stuff like raised eyebrows and such.
             | But dry electrodes on the forehead will never really give
             | any good EEG results.
             | 
             | There was a paper when somebody managed to get P300 working
             | with neurosky, but they needed to average something like a
             | 1000 trials. This is tens of minutes of looking at a
             | flashing screen.
        
               | daef wrote:
               | I just found https://alexandre.barachant.org/blog/2017/02
               | /05/P300-with-mu...
        
         | nonrandomstring wrote:
         | I sat behind a girl at school whose ears would involuntarily
         | move. Like quite a _lot_! Like a dog. It freaked everyone right
         | out.
        
         | caycep wrote:
         | honestly, looking at the devices and not seeing the EEG traces,
         | I half suspect that a lot of the input is already muscle
         | artifact. Even w/ dedicated medical EEG w/ the fancy electrodes
         | and conducting goop, it's plagued w/ a ton of eyelid/scalp
         | muscle artifact.
        
         | anfractuosity wrote:
         | I saw something where someone tried to do that -
         | https://hackaday.com/2020/01/02/assistive-technolgy-switch-i...
         | 
         | It seems to use a type of camera to measure movement in the
         | ear.
        
         | gambiting wrote:
         | >>our ears already can move a slight bit by its own muscles.
         | 
         | Not everyone can do that though. My wife can easily twitch her
         | ears by just thinking about it, I cannot no matter how hard I
         | try - it's just like there is no nerve link to whatever is
         | there.
        
           | praptak wrote:
           | I only discovered how to move my ears when I was like 8 years
           | old. This suggests the nerves are there, just very non-
           | obvious to control.
        
             | rstarast wrote:
             | I think I learned how to move my ears once I started
             | wearing glasses -- at some point I was able to actively
             | move them up and down my nose a little through ear
             | movement.
        
             | totetsu wrote:
             | What does it feel like? Smiling without the smile?
        
               | praptak wrote:
               | A bit hard to describe (how would you describe what
               | moving your arm feels like?)
               | 
               | I'd say a bit like raising my eyebrows, but the "tension"
               | is behind the ears.
        
               | webmaven wrote:
               | _> I 'd say a bit like raising my eyebrows, but the
               | "tension" is behind the ears._
               | 
               | For me the tension is pretty far back, basically halfway
               | to the back of my head on either side, and covers a
               | vaguely oblong patch that is about 1.5 square inches.
        
               | totetsu wrote:
               | Okay if I raise my eyebrows my ears come along for the
               | ride.. but I can move my eyebrows without the ears if I
               | think of it as moving my forehead.. so to isolate the
               | ears only I need to lock the eyebrows at max up or down
               | and try and wiggle them and see how it feels..
        
               | praptak wrote:
               | Yeah, maybe start with trying to move your forehead and
               | the whole scalp.
        
               | user_7832 wrote:
               | Do you have (loose) spectacles? If yes, you can try to
               | make the spectacles move back and forth (moving back
               | requires flexing the muscle, spectacles moved front is
               | the "natural" position). If not, maybe take a friend's
               | pair? Lol just kidding, just use sunglasses.
               | 
               | Honestly it's not some major movement and I only have 1
               | degree of motion properly under control - I'm sure
               | there's more that I can't. It's not a very significant
               | thing irl.
        
               | zellyn wrote:
               | This is the first time in my 46 years that I've had any
               | success voluntarily controlling ear muscles. Amazing!
               | Every few minutes I'm able to wiggle my glasses _very_
               | slightly, and then lost it completely after a few
               | wiggles!
        
           | goodpoint wrote:
           | The nerves are there. You "just" need to discover them.
        
             | gambiting wrote:
             | I mean, I've been trying for 30 years of my life and
             | haven't been able to, so yeah, no idea how you'd go about
             | it.
        
               | deredede wrote:
               | I spent hours in front of a mirror a decade ago until I
               | was able to move my left ear. Lots of trying to move
               | things that either did nothing or made me clench my jaw
               | or close my eyes, before eventually "feeling" my ear, and
               | then a whole lot more of that before seing it move. It
               | was exhausting, and even though I have a faint
               | consciousness of the corresponding muscles in my right
               | ear --- I have no desire to spend that time and energy
               | again.
        
               | robbedpeter wrote:
               | It makes sense for actors to do that type of thing, or
               | maybe martial artists seeking to discipline every part of
               | their body, but the time needed is too high for what's
               | mostly a party trick for regular people.
               | 
               | Then again, maybe it gets easier with other muscles as
               | you practice and master more things - could it help
               | overall coordination, maybe improve typing speed or
               | balance?
        
               | robbedpeter wrote:
               | There are individuals who are more adept with their toes
               | than most people are with their hands, using their feet
               | to paint, draw, write, play music, and so on. It's a
               | repeated phenomenon, demonstrating neural plasticity in a
               | great way.
               | 
               | Such abilities are latent in all of us, differences in
               | brain function that paralyze or confuse any part of the
               | body are very rare.
               | 
               | You, too, can pull off an arched eyebrow like The Rock,
               | do ear wiggles, crazy eye rolls, and more. Getting good
               | at it seems to be a matter of methodical practice.
        
               | gambiting wrote:
               | >> Getting good at it seems to be a matter of methodical
               | practice.
               | 
               | Yes, but I can practice moving my eyebrows to achieve
               | mastery, because I know how to move them at least a
               | little bit. With my ears, I literally cannot - no matter
               | how hard I think about it or how much I strain, they just
               | won't move. So how can you practice something that you
               | cannot do at all? Just "try harder"? I feel like that's
               | like telling someone with no legs to practice walking.
        
               | robbedpeter wrote:
               | Maybe tiny shocks like with a tens system, or a pinch,
               | used to jolt your nerves into recognizing the location? I
               | had a lot of trouble with my eyebrow arching, but
               | eventually got it by poking it with a straw or pushing it
               | around with my finger.
               | 
               | Or maybe there's a genetic component, like tongue
               | rolling. The nerves and muscles are there, no sensation
               | seems to be lost, they're just arranged a bit different.
               | 
               | Kinda cool how something trivial can go into these weird
               | rabbit holes, anyway.
        
               | goodpoint wrote:
               | We instinctively "try" and discover our motor control as
               | babies, depending on how much feedback we get the
               | movement.
               | 
               | Unsurprisingly, hands are very popular.
               | 
               | Other things like proprioception of our backs and general
               | posture can go unnoticed even as adults. I.e. it takes
               | careful focus and training to [re]learn how and what to
               | move.
        
             | ioseph wrote:
             | So I can wiggle my ears but only sometimes, right now I can
             | move my left but not the right, other times it's the right
             | but most of time I can't and it's like the nerve is
             | missing. It's usually something I notice when I'm relaxed
             | and horizontal
        
           | amelius wrote:
           | Probably similar to how tongue rolling is genenic.
        
       | mysterydip wrote:
       | Really extensive write-up, very informative.
        
       | TruthWillHurt wrote:
       | Nice project, but obviously from the single electrode and its
       | placement, the only EEG signal you'll get is eye-movement
       | artifacts...
        
       | Mashimo wrote:
       | Dang, that 3D printer needs some calibrating :D The first layer
       | looks horrible (Or it's very old)
        
         | pilotneko wrote:
         | It's a Makerbot cupcake, which is pretty old by this point (~10
         | years). One of the first "affordable" 3D printers.
         | 
         | https://makerbot.fandom.com/wiki/Cupcake
        
       | snvzz wrote:
       | Actually readable not dynamically loading archived version:
       | 
       | https://archive.is/Axsy4
        
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       (page generated 2022-03-02 23:00 UTC)