Dr. Erich Jarvis

Thank you.

There really isn't such a sharp distinction.

Let me tell you how some people think of it now, that there's a separate language module in the brain that has all the algorithms and computations that influence the speech pathway on how to produce sound and the auditory pathway on how to perceive and interpret it for speech or for, you know, sound that we call speech.

I don't think there is any good evidence for a separate language module.

Instead, there is a speech production pathway that's controlling our larynx, controlling our jaw muscles, that has built within it all the complex algorithms for spoken language.

And there's the auditory pathway that has built within it all the complex algorithms for understanding speech.

not separate from a language module.

And this speech production pathway is specialized to humans and parrots and songbirds, whereas this auditory perception pathway is more ubiquitous amongst the animal kingdom.

And this is why dogs can understand sit, siente se, come here boy, get the ball, and so forth.

Dogs can understand several hundred human speech words.

Great apes, you can teach them for several thousand, but they can't say a word.

Right.

So next to the brain regions that are controlling spoken language are the brain regions for gesturing with the hands.

And that hand parallel pathway has also complex algorithms that we can utilize.

And some species are more advanced in these circuits, whether it's sound or gesturing with hands, and some are less advanced.

Humans are the most advanced at spoken language.

but not necessarily as big a difference at gestural language compared to some other species.

So as you and I are talking here today and people who are listening but can't see us, we're actually gesturing with our hands as we talk without knowing it or doing it unconsciously.

And if we were talking on a telephone, I would have one hand here and I'd be gesturing with the other hand without even you seeing me, right?

And so why is that?