How do our brains adapt to control an extra body part?
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How hard was it to relearn? at first I'd try to move my toe and something else would move, it felt weird - but doctor's orders were essentially don't do anything for 3 months, bed rest and keep the leg raised - all the muscles turned to jelly ... then months of physio, in the pool and then in the gym - at that point, once I started moving stuff again my brain had adjusted - that muscle moves my foot, not my toe - I didn't have to do anything explicitly to make it change, it just did
I've been through enough learning cycles to appreciate this but this was a real hurdle for me when I was young because my default was to rely on systems and rules. Ironically as a swimmer my biggest breakthroughs in speed and technique as a teenager were intuition borne out through thousands of hours of repetition but it took me many many more years and a very good piano teacher to conceptualise the art of not conceptualising.
After a game, Lebron James can explain what happened in a play moment by moment for every player on the floor, and everything he was thinking and planning as the play developed. He’s done it in post game press conferences off the top of his head.
Granted he’s maybe the all time greatest, but it’s illustrative. He’s not thinking at all about how his body is going to do what it does. That’s completely automatic. He’s thinking a lot about the higher level strategy of the game.
I recently read a post about how Nadal gets an unfair stereotype of being brutish due to play style but from a young age in his post match interviews (in Spanish) we would refer to specific points in the match and give critical analysis for how he made adjustments etc.
In a way, it's way deeper than "subconscious". A large portion of the science behind CLA is based on Nikolai Bernstein's works from the 1930-s (the guy who coined the term "biomechanics"). He wrote about the hierarchical model of motor control, where 5 different systems (that evolutionary are completely different) must work in synergy to solve the movement problem.
There is a great book that explains the science behind CLA called "How we learn to move" by Rob Gray.
- was it legato?
- were you playing free from tension?
- was your tone even?
- were you in time?
Very rarely would he actually ever tell me anything. And whenever I'd ask for more or feedback he'd just loop back to the questions and ask if I was actually listening to myself play. It was a very frustrating start but eventually it all clicked what he was doing was teaching me to understand my own constraints and then also understand what are the outcomes I am aiming to achieve - if I can't hear how even my own touch is how will I ever play evenly.
Was the most valuable coaching I ever got and was probably life changing for me in terms of levelling up my ability to learn new things.
Prior to meeting him I held the belief there was a "perfect way to play" the piano and would occasionally peruse books and videos on the subject. Of course, as my teacher was keen to point out, no body is the same so how can two anatomically different pianists play with the same technique?
If you have small hands so much of the repertoire will be different vs if you have rach hands
> I held the belief there was a "perfect way to play" the piano
Yes, CLA is actively debunking the myth of a "perfect technique" which is very popular in sports. Like a coach/teacher is one who knows the "perfect" way, and their job is to make students repeat an exercise over and over again, fixing deviations from "perfect" technique. This couldn't be more wrong according to CLA.
Already mentioned Bernstein introduced the concept of "repetition without repetition", which claims that repetition is important in learning but for a different reason. Each attempt of a movement will have slightly different "inputs" - constraints – and thus can't have a single "perfect" technique that will work for all variations of inputs. Each repetition will be slightly different (hence "without repetition"), and the goal of the proper learning process is to give the body enough "input data" to _discover_ the proper movement solution.
It's important to note that "constraints" is a wide term here, and there are few classes of constraints. Task and goal given to the student are constraints, so the size of the hand or level of fatigue. Even environment temperature, mental state, and light conditions are constraints.
Another important concept in CLA is action-perception coupling rooted in James Gibson's theory of perception. This one was mindblowing to me when I first read it. In essence, the brain perceives the world not as a set of geometric objects but as "actionable" items. What you can do directly influences how you see the world. That has direct implications for learning as well – mastering any skill (including playing a musical instrument) is coupled with perception, as your body has to react to how it sees/hears the result of its own movements.
But the core of CLA as an educational philosophy lays in acknowledging that the actual learning still has to happen inside your nervous system. You can't really "teach" a skill, only facilitate a discovery inside the student's body.
It's really fascinating how it all works in practice. One related concept in motor skill acquisition science is the Method of Error Amplification (MAE). Let's say, golf players make a fundamental error of not shifting weight onto the back foot after swinging. Instead of giving them verbal instruction "Shift weight to the back foot", coach might do the opposite – ask them to move weight to the *front foot*. This will increase the error, which will amplify the signal in the nervous system and the body will react to it as it now feels "more wrong" by itself. It's not super clear to which types of errors MAE is applicable, but the research on MAE is fascinating.
I love the concept of increasing the error - it definitely helps. Makes me think of reductio ad absurbum for the body. Do it more wrong to prove the opposite.
I totally get the idea of the learning having to come from the self and have held the belief that is why taichi and yoga use very poetic metaphors to describe their movements. This was a solution our extremely smart predecessors came up with to be prescriptive without being prescriptive to teach motor skills.
Just like my singing teacher telling me to stop thinking and just be a parrot and copy the pitch (which worked almost instantly)
I will definitely be digging into CLA thanks for sharing!
We don't see the chair as a 3D object, we see it as an affordance to sit (along with a wide windowsill or gym ball). The wall is a barrier for an elderly person, but an affordance to the parcour performer. The pole dancer perceives the lamp post very differently from the non-pole dancer. An experienced tennis player sees the ball in mid-air as much bigger than the newbie player. Fatigued hiker perceives the hill as much steeper than full-of-energy hiker. If an athlete is more capable, objects like a baseball or tennis ball, or basketball hoop look bigger.
Gibson's theory on affordances started with his 1979 book "The Ecological Approach to Visual Perception". My understanding is that it has some criticisms, but still considered as one of the leading theories in perception studies and is heavily used in the design community.
"Before I learned the art, a punch was just a punch, and a kick, just a kick. After I learned the art, a punch was no longer a punch, a kick, no longer a kick. Now that I understand the art, a punch is just a punch and a kick is just a kick."
As applicable to fighting as it is programming. You will see it in high level sports - athletes will do all kinds of unorthodox things from weird positions to eke out a result, because the result is all that matters.
When you try too hard to make the sound it doesn't really work.
But then after a while it just happens as you don't think about and are just speaking with natives.
What happened to your toe? Did you loose the capability to move it individually from the others?
I think my realization was that my brain didn't just do simple things, it did complex in many dimensions to adapt and fix things.
The same thing goes with your foot, and it goes way deeper than we realize. It's probably not that one muscle, it is ALL the muscles in the area working together to help you walk. I wouldn't be surprised if there are 50 muscles involved.
I understand it (especially then), but it's just crazy isn't it, that it actually works? Discovering/theorising and then prototyping some of this fundamental stuff and seeing that for the first time must have been absolutely incredible.
So I spent every waking moment looking for motions that I used to be able to do but which hurt when I started to do them, and slowly working those motions despite the pain.
At the followup to start physio, the surgeon did a quick range of motion check. His jaw literally dropped when I demonstrated that I had recovered 95% range of motion without pain, full flexibility. “You… don't have to come back.”
BTW most achilles breaks are dealt with my putting them in a boot to force the broken bits together and hope that they heal in place - in my case we knew it was damaged but it later broke and my GPs misdiagnosed it so it was broken for ~6 months before we realised
I can hike reasonable distances (multiple kilometres), running not so much a thing - I feel incredibly lucky I'm doing as well as I am
I'm very aware that if I break it again I'm probably screwed (and all I originally did was step in a hole, nothing strenuous) so I'm generally careful
Supposedly, it worked quite well - wearers got VERY good navigating with it and seemed to like the tech overall. Not sure why it disappeared - cost (it was probably made from pretty pricey tech for the time)? Weight ? battery life ?
Yes.
After 30 years of exclusively "joystick must be inverted Y" I got tired of being able to help other people play a tough spot of a game using their controller, and switched cold turkey. It took 2 - 3 weeks before I didn't randomly aim the wrong way, and 2 months to regain full accuracy.
Similar on the inverted scroll switch that Apple did when they married up scroll on iPad and Magic Trackpad. For several OS versions I stayed with the old way, then too many new users were a direction I couldn't handle, so switched. That switch took maybe 3 days to grok.
One of the weirder tricks you can do is hang upside from jungle gym or over the edge of a top bunk bed and "toss" a ball to your friend, which means you have to throw the ball "down" to them instead of toss it up. You can invert gravity much faster than you'd think!
I bring it up because I wonder if this isn't the opposite of that. You come up with a technology aimed at healthy people, study how healthy people can adapt to using it, and maybe popularize it one day with healthy people. Because there are so many more people whose digits all work, it's a much broader audience. But once it's productionized and popular, I bet it'd probably do a lot of good for folks who'd need it.
Worse than the original curbs? Not in my experience.
In cases where this is not true, I’d challenge designers and engineers to find more novel designs that can genuinely be used by anyone and not cost too much inconvenience. This can sometimes mean starting from scratch and questioning our assumptions. Eg. Even the need for a curb-to-street indicator presupposes a street that is used by both big metal vehicles and pedestrians, whereas perhaps there’s a solution that means those paths never cross. Ie. More fundamental urban and transport design instead of band-aiding atop legacy systems.
Some obvious examples (even ignoring higher cost, since they are all also higher cost):
* Coloring for colorblind people is worse for people with normal vision.
* Large format type is cumbersome for people with normal vision.
* Traffic signals that are long enough for the elderly to cross cost everyone time every time they are used.
* Stalls in bathrooms suitable for disabled people means fewer stalls can fit.
* Ramps for wheelchairs require way more space than stairs and take much longer to traverse.
Again, I'm not saying we shouldn't do these things.
One rare downside is that all the people who only do gluten free as a fad don't really need to care about small amounts of gluten. So the 'gluten free' labelling aimed squarely at them can sometimes be rather misleading, ie some restaurants have gluten-light options but still label them as gluten free.
* But presumably not so enlightened as to transition the structure of government.
And he had a chapter about the automobile.
If you've ever had the chilling experience of a skid, the terrifying adrenaline surge during that second where it is clear the car is no longer under your control, you know the dude was onto something. The car is an extension of our bodies. An extra body part.
I had a very vivid experience while backpacking on acid: I fully comprehended the cyborg nature I had adopted by carrying all the resources necessary to sustain life on my person. The hose pumping water into the organs best suited to deal with it, the extra deployable shelter I had stashed away, the ability to isolate more water from harmful pathogens for continued sustenance, on-demand flame and vessel to cook foods that would otherwise be inedible/undigestable, etc.
Your cognitive processes reorganize themselves around those new affordances you've provided for yourself, and you can reasonably say you're thinking with those faculties and not merely of them.
Another instancee --
In my country growing up we didnt always have "blinkers" on our vehicles (light motorbikes, scooters, bicycles) -- so it was common to use "hand signals" to indicate your intention to turn right or left. I once did "hand signal" when WALKING along a corridor and had to turn right into another corridor / aisle.
When I go out for a walk on the street, I have to fight the urge to wave when I see a Jeep.
They put a sensor band around the forearm and used machine learning to interpret the electrical signals the brain was sending.
They were able to interpret intent to move before actual movement. they apparently had a perfect keyboard, but you didn't have to actually move your fingers.
What was interesting is that one of the guys working there had figured out how to have a third arm.
can't find the article. this is close:
https://www.theverge.com/2018/6/6/17433516/ctrl-labs-brain-c...
I can’t easily find the original research (somewhere in the 1990s), but several hackers and artists have rebuilt or rediscovered the idea.
See for example https://blinry.org/compass-belt/
I never finished the project, but love this idea!
Have you thought about trying something similar using Android? Taking the compass and doing small short vibration blips, you can also pair them with sound and light for testing or reinforcing it. Although I can imagine that the compass is not very accurate and the vibration control on Android is probably all over the place in terms of consistency between devices. But being able to have it as something compact that you probably already carry around could make it real-life useful.
I can imagine it being an assistance when it's in your pocket and it passively keeps feeding you the blips, you could use the proximity detection to make it only do that when in your pocket, for instance.
As a touch sense extension it seems intuitive to adapt - but feeling it more like a sound or colors, less as vibration then.. ?
What about inducted solution - like a matrix of nanocoils calibrated to/messing with nearby neurons electrical levels to provide super precise feedback - or to feel it maybe like different keys being focused to press by mm movements ? ( reverse keyboard ?? )
Or even put an array of car parking proximity sensors into that hat. https://www.kit.edu/kit/english/pi_2016_003_feeling-spaces-w...
When I was a very small child, I was fascinated by the sensation of different body parts - the way touching each finger in turn compares to the next, and the way the opposite side has a similar range of sensations. It feels like I know exactly how it would feel to have a sixth, seventh finger in sequence with the others. I imagine that having a second right arm grafted below my current one would have the 'right' but 'lower' feeling and I could use it immediately. But there's no way to test whether this is just a childish imagining that has stayed with me.
IANAD, but I wonder what it would feel like to control it with the palmaris longus [0] instead. From what I understand, it doesn't really have an important role (14% of people don't even have it), and it's close to the skin, so an EMG could pick it up. It's also closer to the fingers, so it might be more intuitive to learn to repurpose it.
I remember that learning how to drive a car was actually quite difficult, but by now, even rental cars seem like an extension of my body that I can control mostly unconsciously. (Operating vehicles while entirely unconscious: not recommended)
There's even a name for it when you just appear to teleport down the road:
But a few embrace the clunkiness and make it a gameplay mechanic.
I found it quite easy to move blocks around, more complex tasks with more fine control was a bit harder but possible with even a limited amount of time. The only time I struggled was when trying to do anything with the thumb while walking on a treadmill - which should be expected when controlling a device with your toes!
Of course it doesn't follow that a lack of emojis is sufficient to create nuanced and intelligent conversation but said type of people also believes HN is tangibly different from Reddit.
Surely you're talking about something besides randomly putting redundant pictures in-line with your posts?
They'd probably have a great time...
Looks like a wingding to me, let’s just have it maybe.
https://emojipedia.org/watch says it's from 1993 Unicode 1.1
But the other emojis from that group seem to mostly not work.
Makes me wonder maybe brain adapts faster when you add something, and it takes longer to adapt for loss? Also maybe finger took longer time as there are more nerves there?
I'm thinking about cameras connected to a network where a server computer performs as the central hub for information and control. The set of cameras are mounted on drones or something and you have to control the drones (since artificial intelligence is still a tricky problem to solve).
The problem to solve is getting over not just control but constantly receiving new information types and pathways. Instead of the photo receptors in the human eyeballs, you now have in addition to your old eyes digital information from an array of cameras. You have the drones for taking the cameras with you everywhere you go. A whole lot of new stuff gets dumped on you and you're now basically undergoing physical therapy for a new organism or species.
Maybe twitching your tongue becomes a new daily occurrence? Or how about some hand signals forming to trigger indexed movements (a mapping between signals and output responses stored in the networked system's central database)? This is maybe how commands are sent. And that means you need an increase in power production for supporting the new infrastructure of your new lifestyle. And it will look like a gross hack in the end. Not that clean and sleek looking stuff you see in the movies. I guess pioneering is rough and rugged like that?
Sending commands is the easy part. But reading information, on top of the baseline of daily living, seems to create an information overload situation, yes? Because how to do remote control if you can't see what it is that you're remotely controlling? It's not simple like flying an RC drone. It's augmentation of all aspects of RC drone flying.
Of course it's not the same as it's a machine, not a living animal your are communicating with.
But so much it feels like it becomes an extension of your body and you just move by pure thought.
Similar to using a game controller I guess but more of a whole body experience.
the difference between an animal and an instrument is in the expression of intent that is parsed by another being. the sensors interpreted by a computer are a feedback mechanism more like a thermostat or ABS, but now with AI we're starting to challenge our understanding of those differences.
The horses react with puzzlement if you are not trained to a similar level - if you are a junior rider, expert horses are incompatible.
"A good horse" is actually one that matches your level, or is only slightly above, whatever that may currently be.
Note that Teitelman eventually gave up on getting machines to DWIM, and scratched that itch by doing dog agility instead.
(the most indirect control I've seen was someone from the local extension program, mounted on horseback, whistling to his dogs in order to instruct them to herd a flock of geese in slaloms/eights around a set of traffic cones. Roping horses still need to be doing their jobs even after their rider has left the saddle and is on foot to tie/doctor the roped critter.)
Holding cell phones!
I bet you can picture it too. That third thumb and fingers capture the phone leaving your standard thumb to input text with ease.
Different parts of the brain can be adapted to serve different purposes. For people who are blind or deaf, these regions of the brain will likely be adapted to serve different purposes.
"Bionic 3rd thumb: The future of human augmentation | Hard Reset"
I don't have a tail, but I can almost "feel" or visualise the commands I would send down my spine to make it move side to side.
So you got told up front? Doesn’t sound very misleading