August 29, 2022 • 1hr 51min

Dr. Erich Jarvis: The Neuroscience of Speech, Language & Music

Huberman Lab

In this episode, Dr. Andrew Huberman interviews Dr. Erich Jarvis, a professor at Rockefeller University and investigator at the Howard Hughes Medical Institute. Dr. Jarvis studies the neurobiology of vocal learning, language, speech disorders, and the relationship between language, music, and movement. His work spans from molecular genetics to neural circuits to behavior, providing insights into the evolution and mechanisms of human speech and language. Dr. Jarvis brings a unique perspective, having trained as a dancer before becoming a neuroscientist. This background informs his research on the connections between movement, music, and language in the brain. The conversation covers a wide range of fascinating topics related to speech, language, and animal communication.

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Key Takeaways

Speech and language are closely intertwined in the brain, without a separate "language module". The speech production pathway contains the complex algorithms for spoken language.
Vocal learning - the ability to imitate sounds - is what makes human spoken language special and is rare in the animal kingdom. Only humans, some birds, and a few other species have this ability.
There are remarkable similarities between human and songbird brains in the circuits controlling vocal learning and language, down to the genes expressed.
The brain pathways for speech likely evolved from motor circuits controlling body movement. This explains why only vocal learning species can dance to a beat.
There is a critical period in childhood for optimal language learning. Learning multiple languages early makes it easier to learn additional languages later.
Reading activates speech circuits in the brain, even when done silently. Writing involves coordinating visual, speech, and hand motor circuits.
Singing and music may have evolved before language as a form of emotional communication. The right brain hemisphere is more involved in processing music.
Movement and dance can enhance cognitive function by engaging brain circuits adjacent to speech areas. Staying physically active is important for maintaining cognitive health.
New genomic technologies are revealing genetic changes associated with traits like vocal learning across species. This comparative approach provides insights into human language evolution.

Introduction

In this episode, Dr. Andrew Huberman interviews Dr. Erich Jarvis, a professor at Rockefeller University and investigator at the Howard Hughes Medical Institute. Dr. Jarvis studies the neurobiology of vocal learning, language, speech disorders, and the relationship between language, music, and movement. His work spans from molecular genetics to neural circuits to behavior, providing insights into the evolution and mechanisms of human speech and language.

Dr. Jarvis brings a unique perspective, having trained as a dancer before becoming a neuroscientist. This background informs his research on the connections between movement, music, and language in the brain. The conversation covers a wide range of fascinating topics related to speech, language, and animal communication.

Topics Discussed

Speech vs. Language and Animal Communication (8:01)

Dr. Jarvis explains that speech and language are closely intertwined in the brain, contrary to the idea of a separate "language module". The speech production pathway contains the complex algorithms for spoken language, while the auditory pathway handles speech perception.

He notes that some animals like dogs can understand human speech words, but can't produce them:

"Dogs can understand several hundred human speech words. Great apes, you can teach them for several thousand, but they can't say a word."

Key points:

Speech production and language comprehension involve overlapping brain circuits
Many animals can understand some human speech, but can't produce it
Gesturing with hands uses adjacent brain regions to speech areas

Vocal Learning and Evolution of Language (15:25)

Dr. Jarvis discusses vocal learning - the ability to imitate sounds - as the key feature that makes human language special. This trait is rare in the animal kingdom, found only in humans, some birds, and a few other species.

He explains that vocal learning likely evolved in humans sometime in the last 500,000 to 1 million years, with evidence that Neanderthals may have had spoken language as well.

Key points:

Vocal learning is rare but crucial for complex language
Evolved relatively recently in human ancestors
Neanderthals likely had some speech capabilities

Similarities Between Human and Songbird Brains (21:10)

The conversation turns to the remarkable similarities between human and songbird brains in the circuits controlling vocal learning and language. Dr. Jarvis explains that his research has found parallels in brain connectivity, function, and even gene expression between vocal learning birds and humans.

"Not only the actual circuitry and the connectivity are similar, but the underlying genes that are expressed in these brain regions in a specialized way, different from the rest of the brain, are also similar between humans and songbirds and parrots."

Key points:

Similar brain circuits for vocal learning in humans and songbirds
Parallel gene expression patterns in these circuits
Mutations affecting speech in humans cause similar deficits in birds

Critical Periods for Language Learning (35:49)

Dr. Jarvis discusses critical periods for language learning, explaining why it's easier to learn languages as a child. He notes that the entire brain undergoes critical period development, but speech pathways have a particularly strong critical period effect.

Key points:

Children learn languages more easily due to greater brain plasticity
Learning multiple languages early makes it easier to learn more later
Adults can still learn new languages, but it's more challenging

Singing, Music, and Dance (47:32)

The discussion turns to the connections between language, singing, and dance. Dr. Jarvis explains his "motor theory of vocal learning origin" - that speech circuits evolved from motor circuits controlling body movement. This explains why only vocal learning species can dance to a beat.

"When speech evolved in humans and the equivalent behavior in parrots and songbirds, it required a very tight integration in the brain regions that can hear sound, with the brain regions that control your muscles for producing sound. And that tight auditory-motor integration, we argue, then contaminated the surrounding brain regions. And that contamination of the surrounding brain regions now allows us, humans, in particular, and parrots, to coordinate our muscle movements of the rest of the body with sound in the same way we do for speech sounds. So we're speaking with our bodies when we dance."

Key points:

Speech circuits evolved from motor circuits
Only vocal learning species can dance to a beat
Singing may have evolved before language for emotional communication

Reading, Writing, and Brain Circuits (1:09:35)

Dr. Jarvis explains how reading and writing engage multiple brain circuits, including speech areas. Even when reading silently, the speech production pathway is activated.

Writing involves coordinating visual, speech, and hand motor circuits. He notes that writing by hand may engage different neural processes compared to typing.

Key points:

Reading activates speech circuits even when silent
Writing coordinates multiple brain systems
Handwriting may engage neural processes differently than typing

Stuttering and Speech Disorders (1:20:58)

The conversation touches on stuttering and other speech disorders. Dr. Jarvis explains that damage or disruption to the basal ganglia is often involved in stuttering. He notes that behavioral therapies focusing on sensory-motor integration can help reduce stuttering.

Key points:

Basal ganglia disruption often involved in stuttering
Behavioral therapies can help reduce stuttering
Focus on controlling sensory input and motor output

Modern Language Evolution: Texting and Social Media (1:26:58)

Dr. Huberman and Dr. Jarvis discuss how modern communication technologies like texting and social media are impacting language use and brain function. Dr. Jarvis suggests that while these technologies change how we communicate, they are not necessarily decreasing language abilities:

"I think texting is not decreasing the speech prowess or the intellectual prowess of speech, it's converting it and using it a lot in a different way, in a way that may not be as rich in regular writing because you can only communicate so much nuance in short-term writing. But whatever is being done, you got people texting hours and hours and hours on the phone. So whatever, your thumb circuit is going to get pretty big, actually."

Key points:

Texting and social media are changing communication patterns
Not necessarily decreasing language abilities, but using them differently
Rapid communication can lead to less nuanced expression

Comparative Genomics and Language Evolution (1:40:21)

Dr. Jarvis discusses his work on comparative genomics, studying genetic changes associated with traits like vocal learning across species. This approach provides insights into human language evolution and the genetic basis of speech.

He explains the importance of having complete, high-quality genomes for many species to do this comparative work. Dr. Jarvis is involved in large-scale projects to sequence genomes of many species, including endangered ones.

Key points:

Comparative genomics reveals genetic changes associated with vocal learning
High-quality genomes needed for many species
Insights into human language evolution from animal genomics

Conclusion

This wide-ranging conversation between Dr. Huberman and Dr. Jarvis provides fascinating insights into the neurobiology and evolution of speech and language. By studying vocal learning in humans and animals, researchers are uncovering the neural circuits, genes, and evolutionary processes that gave rise to our remarkable capacity for complex communication.

The discussion highlights how seemingly disparate abilities like language, music, and dance are interconnected in the brain. It also touches on how modern technologies are impacting language use and the potential for genomic studies to further our understanding of human cognitive evolution.

Dr. Jarvis's unique background as both a dancer and neuroscientist brings an integrative perspective to this research, emphasizing the deep connections between movement, music, and language. His work demonstrates the value of comparative studies across species for gaining insights into human brain function and evolution.