What Causes Stuttering & Treatment for Stutter | Dr. Erich Jarvis & Dr. Andrew Huberman
00:00:00.000 | What's being developed in terms of treatments for stutter?
00:00:05.360 | Yeah, so we actually accidentally came across stuttering in songbirds and we've published
00:00:13.000 | several papers on this to try to figure out the neurobiological basis.
00:00:16.520 | The first study we had was a brain area called the basal ganglia, the striatum part of the
00:00:23.340 | basal ganglia involved in coordinating movements, learning how to make movements when it was
00:00:29.000 | damaged in the speech-like pathway in these birds.
00:00:33.040 | What we found is that they started to stutter as the brain region recovered.
00:00:40.120 | And unlike humans, they actually recovered after three or four months.
00:00:45.480 | And why is that the case?
00:00:46.680 | Because bird brains undergoes new neurogenesis in a way that human or mammal brains don't.
00:00:53.720 | And it was the new neurons that were coming in into the circuit, but not quite, you know,
00:00:59.560 | with the right proper activity, was resulting in this stuttering in these birds.
00:01:06.340 | And after it was repaired, not exactly the old song came back after the repair, but still
00:01:11.840 | it recovered a lot better.
00:01:14.280 | And it's now known, they call this neurogenics stuttering in humans, with damage to the basal
00:01:21.520 | ganglia or some type of disruption to the basal ganglia at a young age also causes stuttering
00:01:27.480 | in humans.
00:01:28.620 | And even those who are born with stuttering, it's often the basal ganglia that's disrupted
00:01:36.400 | in some other brain circuit.
00:01:38.260 | And we think the speech part of the basal ganglia.
00:01:41.200 | Can adults who maintain a stutter from childhood repair that stutter?
00:01:46.060 | They can repair it with therapy, with learning how to speak slower, learning how to tap out
00:01:52.140 | a rhythm.
00:01:53.140 | And yeah, I'm not a speech pathologist, but I started reading this literature and talking
00:01:57.880 | to others that, you know, colleagues who actually study stuttering.
00:02:02.180 | So yes, there are ways to overcome the stuttering through, you know, behavioral therapy.
00:02:11.620 | And I think all of the tools out there have something to do with sensory motor integration.
00:02:19.740 | Controlling what you hear with what you output in a thoughtful, controlled way helps reduce
00:02:26.560 | the stuttering.
00:02:27.560 | There are a couple of examples from real life that I want to touch on.
00:02:30.300 | And one is somewhat facetious, but now I realize is a serious neurobiological issue.
00:02:38.100 | This meaning, I think, interesting, which is that every once in a while, I will have
00:02:43.380 | a conversation with somebody who says the last word of the sentence along with me.
00:02:48.820 | And it seems annoying in some instances.
00:02:52.620 | But I'm guessing this is just a breakthrough of the motor pattern, that they're hearing
00:02:56.020 | what I'm saying very well.
00:02:57.980 | So I'm going to interpret this kindly and think they're hearing what I'm saying.
00:03:01.820 | They're literally hearing it in their mind.
00:03:05.460 | And they're getting that low level electrical activity to their throat.
00:03:09.080 | And they're just joining me in the enunciation of what I'm saying, probably without realizing
00:03:15.780 | it.
00:03:16.780 | Can we assume that that might be the case?
00:03:17.980 | Well, I wouldn't be surprised.
00:03:19.940 | So that, you know, the motor theory of speech perception, where this idea originally came,
00:03:23.740 | what you hear is going through your speech circuit, and then also activating those muscles
00:03:29.260 | slightly.
00:03:31.180 | So yes, so one might argue, okay, is that speech circuit now interpreting what that
00:03:38.420 | person is speaking, now you listening to me, and is going to finish it off because it's
00:03:42.920 | already going through their brain, and they can predict it.
00:03:46.460 | That would be one theory.
00:03:48.660 | I don't think the verdict out there is no, but that's one.
00:03:51.620 | The other is synchronizing turn-taking in the conversation, where you're acknowledging
00:04:01.300 | that we understand each other by finishing off what I say, and it's almost like a social
00:04:08.300 | bonding kind of thing.
00:04:10.200 | The other could be, I want the person to shut up so I can speak as well and take that turn.
00:04:15.500 | And each pair of people have a rhythm to their conversation.
00:04:20.040 | And if you have somebody who's over-talkative versus under-talkative or vice versa, that
00:04:24.660 | rhythm can be lost in them finishing ideas and going back and forth.
00:04:28.580 | But I think having something to do with turn-taking as well makes a lot of sense.
00:04:33.860 | I have a colleague at Stanford who says that interruption is a sign of interest.
00:04:38.860 | I'm not sure that everyone agrees.
00:04:40.780 | I think it's highly contextual.
00:04:42.900 | But there is this form of a verbal nod of saying, or things of that sort.
00:04:48.140 | And there are many of these.
00:04:50.380 | And I'm often told by my audience that I interrupt my guests and things of that sort.
00:04:54.820 | Oftentimes I'll just get caught in the natural flow of the conversation.
00:04:58.580 | I think we've had pretty good turn-taking here, I hope.
00:05:01.780 | So far, so good.
00:05:02.780 | I feel that way.
00:05:03.780 | I'm glad you feel that way.
00:05:04.780 | Because especially in the context of a discussion about language, this seems important.
00:05:08.700 | [MUSIC PLAYING]