The brain connections between our hands and tongues | Hacker News Reader

The brain connections between our hands and tongues

quantamagazine.org

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Andre Agassi noticed that Boris Becker's tongue gave away the direction in which he intended to serve [1].

"I started to realize he had this weird tick with his tongue," Agassi said. "I'm not kidding. He would go into his rocking motion, his same routine, and just as he was about to toss the ball, he would stick his tongue out. And it would either be right in the middle of his lip, or it'd be to the left corner of his lip.

[1] https://www.insider.com/andre-agassi-beat-boris-becker-watch...

Gestures are another vector in the hand-tongue highway. They are so interesting and I looked into it in a Cog Sci class. My writeup was so subpar compared to the research I did. I need to get back into it. Ended up being my favorite class as there was so much I did not know.

"“Adult speakers who are blind from birth also gesture when they talk, and these gestures resemble the gestures of sighted adults speaking the same language. This is quite interesting, since blind speakers cannot be learning these language-specific gestures by watching other speakers gesture,” [1]

Similar article [2]

A more 'official' paper: "People use gestures when they talk, but is this behaviour learned from watching others move their hands when talking? Individuals who are blind from birth never see such gestures and so have no model for gesturing. But here we show that congenitally blind speakers gesture despite their lack of a visual model, even when they speak to a blind listener. Gestures therefore require neither a model nor an observant partner." [3]

There are a lot of dance styles in India where gestures (hand/face/leg) are the principal means of story communication.

[1] https://news.uchicago.edu/story/blind-adults-gestures-resemb....

[2] https://www.thecut.com/2016/09/blind-people-gesture-like-sig...

[3] https://www.nature.com/articles/24300

....tennis players often shout as they smack the ball. And research shows that coupling hand movements with specific mouth movements, often with vocalization, shortens the reaction time needed to do both.

Perhaps this will help reduce my annoyance when watching a very vocal tennis match!

Even drummers using their four limbs tend to make weird faces or open their jaws wide while playing.

It should have something to do with dexterity, coordination and limb independence I believe. I can still play simple beats without making faces. But I wouldn't be able to play complex polyrhythms without making faces.

Or lift heavy weights.

Maybe routing commands just to the limbs becomes too complicated and the commands spill over to related routes.

Or maybe the brain is too busy with the limbs and relinquishes face control which starts acting on random signal flows.

You can see this in other situations, for example when you are in a high impact situation you stop caring about "how you look".

When I play guitar or mandolin my mouth often moves in some sort of way as if keeping time. I recorded a video one time and noticed it. Now I'm a little self-conscious about it but it's a bit relieving to hear it's pretty common / innate.

We evolve from animals that manipulate the world with their mouths and use their forelegs for locomotion. I'd expect that using hands to manipulate things would be in some way tied to our mouths, it's not surprising to me.

I recall a theory that we do it because of our arboreal lineage. When apes moved into the trees to get away from predators, they would often carry things in their mouth (using their tongue to hold them) so leaving their forelimbs free for tree swinging. Hence the connection - if the hands are occupied, the tongue comes out.

And also walking led to us feeding using our hands... we would just pick stuff up and stuff it into our mouth.

> We evolve from animals that manipulate the world with their mouths and use their forelegs for locomotion

Technically we didn't. One of our ancestor species did.

That makes me think of the Puppeteer aliens from Larry Niven's "Known Space" books: Three-legged creatures with the brain in their main body, and two "heads" on prehensile necks.

Each head has one eye--allowing them to simultaneously look in different directions or opposite sides of a nearby object--and they manipulate the world using their lips which have small nodules similar to fingertips.

Michael Jordan and Patrick Mahomes both stuck/stick their tongue out when making plays. Mahomes has said it's involuntary and he doesn't know he's doing it until he sees film later.

Truly, we are made in the image of god.

I'm not surprised, the tongue is probably the second most (or third most depending on how you count the hands) "touch interactive" body part we have. Nothing else apart from the hands is as dextrous. It feels fine details just like the hands do but also with added taste ability.

Actually, the tongue can feel finer details then hands/fingers can. It is not socially accepted, so mostly done in secret... But I am blind, and whenever I have to feel something very very tiny, the tongue is better then the finger(nails) can be.

Interesting, that actually makes a lot of sense. Be careful with capacitors!

said it a few days ago: there's an interesting connection between teeth, vestibular system and hip-flexors, which can lead to lower back pain - found it on youtube, there are a few vids on so called "postural restoration"

I have noticed that when babies are trying to figure out how you speak, they will often shove some or their hand in your mouth to try and feel where your tongue is and what it is doing. Perhaps it is that pathway opening in reverse?

I don't think that's what that is. It's just them touching everything.

I wonder is there has been some exaptation where something tongue related was co-opted along the way to make hands work, or vice-versa.

The tongue, jaw, and shoulder girdle are mechanically linked, and it would be surprising if their control wasn't coupled.

> Electrical stimulation of this same area triggers a monkey’s hand to make a grip motion while its mouth opens, and its hand moves to its mouth.

Fixed Action Pattern (?) which didn't quite go away.

Is this related to Central Pattern Generators?

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