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.
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.
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.
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.
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.
>>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.
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.
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.
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!
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..
> 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.
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.
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?
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.
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.
>> 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.
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.
Stick you fingers in the space between your ear and your head, and you can feel the muscles moving there. That should really help with building a mind-muscle connection since it’s hard to get feedback otherwise.
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
The daughter of a friend of mine (just a grade-school-aged child at the time) demonstrated for me how she could hold one eye completely fixed (staring straight ahead) and move the other eye independently, turning it outwards as far as she could had she been moving both eyes. The motion of the eye being moved was very smooth and deliberate. I found it absolutely fascinating and baffling. How does one even discover they have such an ability?
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.
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?
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.
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.
"Confirmation bias" seems overly harsh. EEG does actually measure brain activity and it's certainly useful for some clinical/research tasks--if you don't mess it up (which is very easy to do). The trick is that you have to play to its strengths, which involve measuring large-scale activity patterns, like sleep (or epilepsy). If you want to measure something very localized, you need another technique (ideally with a hole in the skull).
In fact, I'd say that there is no overall "best" tool.
fMRI has the best (non-invasive) spatial resolution, but since it relies on blood flow, the temporal resolution is sluggish.
EEG has great temporal resolution, but even with fancy source-reconstruction techniques, the spatial resolution is very poor. It's certainly useful for some things, especially those related to global "state" factors. It's also very portable--if you can control EMI and movement artifacts.
MEG is something of dark horse: very good temporal resolution, and the spatial resolution often good--mostly. Since it relies on detecting magnetic fields, it cannot detect neural (electrical) activity that is radial to it. The other big drawback is that it required a large and expensive system with cryogenically-cooled superconducting detectors. However, the newer OPM detectors are cheaper and work at room temp, so more real-world things are possible.
fNIRS, PAT, and ultrasound seem like they might be good in some applications too.
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.
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.
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.
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.
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.
Protip: press the End key, then Home, and only then read the article to avoid everything moving and fading before your eyes the whole time. If it were an article with one or two pictures this would have been just a pet peeve, but here it's actively annoying because you are constantly scrolling and waiting for animations.
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.
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.
