Essentials: The Neuroscience of Speech, Language & Music | Dr. Erich Jarvis
Dr. Erich Jarvis, a professor at Rockefeller University and HHMI investigator, discusses the neurobiology of speech and language. He explains the brain circuits and genes underlying vocal learning, the rarity of this ability in animals, and how movement and dance can preserve cognitive function across a lifetime.
Deep Dive Analysis
16 Topic Outline
Speech vs. Language and Brain Pathways
Gesture, Hand Movement, and Speech Evolution
Innate vs. Learned Vocalizations
Evolution of Spoken Language and Neanderthals
Birdsong and Human Speech Brain Circuit Parallels
Hummingbirds and Complex Trait Evolution
Critical Periods and Innate Predisposition to Learn
Pidgin Language and Cultural-Genetic Convergence
Genes Specialized in Speech Circuits
Critical Period for Language Learning and Multilingualism
Music, Emotion, and Semantic vs. Affective Communication
Facial Expression and Speech Circuitry
Written Language and Neural Pathways
Stuttering: Basal Ganglia and Neurobiological Basis
Texting and Language Evolution
Movement, Dancing, and Singing for Cognitive Health
5 Key Concepts
Vocal Learning
The rare ability among vertebrates to imitate sounds, distinguishing learned vocal communication (like human speech or birdsong) from innate sounds (like crying or barking) that most species produce reflexively.
Critical Period
A specific developmental window during which the brain is optimally primed for learning certain skills, such as language. After this period, learning becomes significantly harder as brain circuits solidify.
Semantic Communication
Communication that conveys specific meaning or information, such as the abstract concepts expressed in human spoken language. It contrasts with affective communication, which primarily conveys emotional content.
Affective Communication
Communication primarily focused on conveying emotional feelings or states, such as a courtship song or a territorial defense call. It uses the same brain circuits as semantic communication but in different ways.
Neuroplasticity
The brain's ability to reorganize itself by forming new neural connections throughout life. Genes specialized in speech circuits are involved in neuroplasticity, making these circuits more flexible for complex learning.
8 Questions Answered
There isn't a sharp distinction; instead of a separate 'language module,' there's a speech production pathway with built-in algorithms for spoken language and an auditory pathway for understanding it. The production pathway is specialized in humans and some birds, while the auditory pathway is more ubiquitous.
Brain regions controlling hand gestures are directly adjacent to those controlling spoken language, suggesting an evolutionary relationship where speech pathways may have evolved from body movement pathways. Humans gesture unconsciously while speaking, and different languages come with learned sets of gestures.
Based on genomic data from living humans and hominid fossils (Neanderthals, Denisovans), it's believed that spoken language has been present in human ancestors for at least 500,000 to a million years, as they possessed similar gene sequences involved in learned vocal communication.
The entire brain undergoes a critical period of development in childhood, making it easier to acquire new knowledge and skills, including language. The brain solidifies circuits with what is learned as a child, and while adults can learn, it requires more effort.
Yes, it's a common finding that multilingual children maintain a greater ability to produce different sounds (phonemes) that are used across various languages. This broader phonetic repertoire makes it easier to adapt to and learn additional languages later in life.
When reading, the visual signal goes to the visual cortex, then to the speech production pathway (Broca's area) where one silently 'speaks' the words. This signal is then sent to the auditory pathway to 'hear' it in one's head, and finally, the hand motor areas translate it into a visual signal on paper for writing, involving at least four brain circuits.
Stuttering is often linked to damage or disruption in the basal ganglia, particularly the speech-related part, which is involved in coordinating and learning movements. This has been observed in both humans (neurogenic stuttering) and in songbirds with targeted brain damage.
Texting allows for rapid communication and enhances the brain circuits involved in 'thumb' movement, much like a muscle that gets stronger with exercise. While it may not be as rich in nuance as regular writing, it is not necessarily decreasing speech or intellectual prowess but rather converting and utilizing brain circuits in a different way.
3 Actionable Insights
1. Maintain Cognitive Health Through Movement
Engage in consistent physical movement like dancing, walking, or running, and practice speech or singing. This keeps brain circuits active, helps maintain muscle tone, and preserves cognitive function into old age.
2. Leverage Childhood for Language Learning
Recognize that childhood is a critical period for language acquisition due to the brain’s heightened plasticity. Learning multiple languages as a child can make it easier to acquire new languages later in life by maintaining a broader range of phoneme production abilities.
3. Enhance Communication with Gestures
Understand that gesturing with hands is deeply linked to speech production pathways in the brain. Incorporating gestures can enhance communication, as they share evolutionary roots and neural connections with spoken language.
6 Key Quotes
I think that the brain pathways that control speech evolved out of the brain pathways that control body movement, all right?
Dr. Erich Jarvis
Most vertebrate species vocalize, but most of them are producing innate sounds that they're born with... And only a few species have learned vocal communication, the ability to imitate sounds. And that is what makes spoken language special.
Dr. Erich Jarvis
So by turning it off, you got to gain a function for speech, right?
Dr. Erich Jarvis
I think learning how to produce speech is a more complex learning ability than say learning how to walk or, or learning how to do tricks and jumps and so forth that dogs do.
Dr. Erich Jarvis
So the left in us humans is more dominant for speech, but the right has a more balance for singing or processing musical sounds as opposed to processing speech.
Dr. Erich Jarvis
If you want to stay cognitively intact into your old age, you better be moving and you better be doing it consistently, whether it's dancing, walking, running, and also practicing speech, oratory speech and so forth, or singing is controlling the brain circuits that are moving your facial musculature. And it's going to keep your cognitive circuits also in tune.
Dr. Erich Jarvis