Published October 2022 on YouTube

Dr. Eddie Chang: The Science of Learning & Speaking Languages | Huberman Lab Podcast #95

1. Dr. Eddie Chang, Speech & Language

Dr. Eddie Chang, a world expert in neuroscience and neurosurgery, discusses critical periods for language learning, the brain's control of speech and language, and his groundbreaking work in allowing people with locked-in syndrome to communicate through AI devices. He also touches on the ketogenic diet, bioengineering, and the future of augmenting the human brain.+

2. Health and Sleep Insights

Health Insights:Andrew shares insights on how Levels and Eight Sleep have helped him understand the impact of food, exercise, and sleep on his health. He discusses how Levels' continuous glucose monitor helped him predict how certain foods affect his energy levels and hormones. He also talks about how Eight Sleep's smart mattress cover helped him sleep deeply by cooling his body temperature at specific times.+
Enhancing Sleep:Andrew discusses the importance of sleep and how Eight Sleep can enhance not just your sleep, but all aspects of your life. He also talks about the benefits of regular blood work and how Inside Tracker can help you interpret your data and make positive changes for your health.+

3. Brain Plasticity

Brain Plasticity:Eddie shares his work with Mike Merznick on studying how the brain organizes in response to sound patterns in rodents and how the natural environment shapes the structure of the brain. The experiment of raising rat pups in continuous white noise that masked environmental sounds is discussed as it relates to neuroplasticity and brain development.+
Brain's Sensitivity:Eddie explains the critical period or sensitive period in brain development and how it is affected by environmental sounds. He discusses how the brain's sensitivity to sounds can be influenced by the environment and how it can impact speech and language development.+

4. White Noise and Infant Sleep

Eddie and Andrew discuss the use of white noise machines for infants and the potential impact on their auditory system and brain development. While studies have not been done on the effects of white noise on infant sleep, research on rodents suggests that continuous exposure to white noise may slow down brain maturation. Eddie suggests using more natural sounds to soothe infants instead of white noise.+

5. Neurobiology of Speech

Neurobiology of Speech:Eddie Chang, a neurosurgeon, talks about his work on the neurobiology of speech and language. He discusses the different brain areas that control speech and language and how they differ in humans compared to other species. He also talks about his experience with awake brain surgeries and mapping out language.+
Brain Mapping:Eddie Chang explains how brain mapping is used in awake brain surgery to protect critical areas of the brain while accomplishing the mission of getting seizures under control or removing brain tumors. By stimulating different parts of the brain, they can determine which areas are related to language, talking, and movements of the body. The brain mapping process can even shut down someone's ability to talk altogether, reminding us of the extraordinary and precise nature of the brain.+

6. Emotion; Anxiety & Epilepsy

Emotional Responses:Andrew and Eddie discuss how certain speech patterns and brain areas can evoke emotional responses, such as anxiety or relaxation. They explore the functions of different brain nodes and how stimulating them can affect our emotions.+
Seizures and Anxiety:Eddie shares a story about a young woman who was misdiagnosed with anxiety disorder for several years, when in fact she had underlying seizures and epilepsy activating a part of her brain that evokes anxious feelings. The only way to prove this was by putting electrodes into her brain and associating the electrical activity with her symptoms.+

7. Treating Epilepsy

Eddie explains that while many people with epilepsy can control their seizures with medication, about a third of people cannot. For those individuals, neurosurgery may be an option to remove or stimulate the affected part of the brain. However, surgery is not always a viable solution for everyone and may depend on the specific area of the brain affected.+

8. Ketogenic Diet & Epilepsy

Eddie and Andrew discuss the benefits of the ketogenic diet for treating epilepsy, particularly in children, and how it can also be beneficial for some adults. They also touch on the potential benefits for people with Alzheimer's, as a shift to an alternate fuel source can sometimes make people feel better.+

9. AG1 (Athletic Greens)

Andrew discusses the benefits of Athletic Greens, a vitamin, mineral, and probiotic drink that covers all of your foundational nutritional needs. He explains how it helps with gut health and provides adaptogens, vitamins, and minerals. Listeners can try Athletic Greens by going to for five free travel packs and a year's supply of vitamin D, three K two.+

10. Understanding Seizures

Andrew and Eddie discuss different types of seizures, including absence and temporal lobe seizures. They also talk about the timing of seizures, including nocturnal seizures that occur during specific stages of sleep.+

11. Brain and Language

Speech Organization:Eddie discusses the textbook version of how speech and language are organized in the brain, and how his laboratory is discovering that much of what we know from the textbooks could be wrong. He shares his fascination with trying to figure out how the brain creates words and sentences and how it poses a serious challenge to what we've learned.+
Language and Neuroscience:Eddie Chang explains the history of neuroscience and how it began with the discovery of language. He discusses the debunking of phrenology and the observation by Pierre Broca of a patient who could only say the word "tan". Broca discovered that the patient's inability to speak was due to a part of the brain in the left frontal lobe.+
Language and the Brain:Eddie and Andrew discuss the history of language processing in the brain and how recent research has challenged traditional ideas about Broca's area and its role in speech production. They highlight the importance of the pre central gyrus and motor cortex in language processing and the need to update textbooks to reflect these new findings.+
Brain Complexity:Eddie and Andrew discuss the complexity of the brain, specifically in regards to language and the accuracy of information taught in medical school. Eddie estimates about 50% of what is taught about the brain is accurate, while the other 50% is an oversimplification of what is actually going on. They also touch on the importance of technical advances and the evolving understanding of the brain.+

12. Language Lateralization Insights

Lateralization of Language:Andrew and Eddie discuss the lateralization of language in the brain, with Andrew explaining that language is heavily lateralized and Eddie adding that this is mostly true, but complicated. They explore the equivalent brain area on the right side and its function, with Eddie noting that it looks very similar to the left side.+
Handedness and Language:Eddie explains that handedness is strongly genetic and that the areas of the brain that control the hand are close to the areas responsible for the vocal tract. He also discusses how the machinery for language likely exists on both sides of the brain but we strongly bias one side for everyday use.+

13. Bilingual Brain

Eddie and Andrew discuss the shared circusry and machinery in the brain that allows us to process both languages and how the brain activity patterns occur when bilinguals hear one language versus the other.+

14. Brain Mapping Insights

Brain Mapping:Andrew discusses brain mapping and representation in the context of visual recognition and language processing, exploring what exactly is represented in different areas of the brain and how they build up from basic elements to create coherent representations.+
Understanding Language:Eddie Chang explains the difference between language and speech, and how the ear translates sounds into different frequencies to process speech.+
Auditory Perception:Andrew and Eddie discuss the precision of our auditory perception, including how sound is broken down into frequencies and how the cortex is responsible for converting sounds into language. Our brains are able to detect millisecond differences in sound to determine direction, and the cortex specifically looks for the sounds of human language.+
Speech Processing Insights:Eddie and Andrew discuss their research on brain mapping and speech processing. They explain how they use electrodes to record neural activity and identify areas important for speech and language. They also delve into the complexity of speech, including how certain parts of the brain are tuned to specific features of consonants.+

15. Vocalization and Language

Eddie explains the difference between vocalization and language, and how they are produced by different areas of the brain. He also discusses the role of the larynx in shaping breath and creating the energy of the voice.+

16. Mapping Language in the Brain

Eddie Chang shares insights on how language is represented in the brain. The primary auditory cortex has a map of different sound frequencies, and there is a salt and pepper map of the different features in speech. The speech cortex has its own pathway to process speech.+

17. Language Complexity

Sounds and Consonants:Eddie and Andrew discuss the science behind plosive and fricative sounds, how they are created, and the difficulty of pronouncing certain words that combine the two types of sounds.+
Language Complexity:Eddie and Andrew discuss the complexity of different languages, with some having more consonant clusters than others. They also touch upon the best time to learn multiple languages and the importance of real human interactions in language acquisition.+

18. Mapping Speech

Andrew and Eddie discuss how the brain maps speech sounds to motor structures and how the twelve fundamental elements of speech generate all possible meanings.+

19. Brain and Reading

The Brain and Reading:Eddie Chang explains how reading and writing are human inventions that have mapped to functions the brain already has. He discusses how the brain processes speech sounds and the importance of mapping reading signals to the part of the brain that makes sense of sounds. This has relevance to how we learn to write and can explain some cases of dyslexia.+
Understanding Dyslexia:Eddie explains that dyslexia can be caused by a problem of phonological awareness and that the modern treatments for dyslexia involve changing things from the speech side. He also talks about how skilled readers usually need to map the vision to the sound in order to get that foundation.+

20. Evolution of Language

Eddie and Andrew discuss how language and speech change over time and how it is completely normal. They talk about dialects, the evolution of language, and the brain's sensitivity to sound changes.+

21. Stroke & Foreign Accent Syndrome

Andrew and Eddie discuss the possibility of learning new languages throughout one's lifespan and the phenomenon of foreign accent syndrome, where individuals develop the phonology of a different language after a stroke. They debunk the myth of suddenly gaining fluency in a new language after a stroke, but acknowledge the existence of foreign accent syndrome.+

22. Auditory Memory Storage

Auditory Memory Storage:Andrew and Eddie discuss the storage of auditory memories and how the brain retrieves them. Andrew shares his personal experience with auditory memory and wonders where these memories are stored. They also explore the idea of a memory bank and how the brain retrieves information so quickly.+
Memory Distribution:Eddie explains that memory is distributed across multiple areas of the brain, and even if one area is injured, memories can still be retained. This is due to the fact that memories are built into our motor memory and are not just located in one specific area.+

23. Restoring Speech

Brain-Machine Interface:Eddie Chang discusses his lab's work on using brain-machine interface to allow paralyzed individuals to communicate by translating neural activity into speech. The lab's research has identified the electrical code of different elements of speech, which has allowed them to decode consonants and vowels of English. The team is now exploring ways to make interactions between these individuals in the real world more elaborate and real.+
Devastating Paralysis:Eddie and Andrew discuss the most severe forms of paralysis, including brain stem stroke and neurodegenerative conditions like ALS. They also touch on the heartbreaking condition of locked-in syndrome, where individuals have intact cognition but no way to express themselves.+
Restoring Speech:Eddie discusses the Bravo trial, a clinical trial aimed at intercepting signals from the brain of paralyzed individuals and translating them into words. The first participant in the trial was a man who had been paralyzed for 15 years due to a stroke in the brainstem. Despite being unable to speak or move his arms and legs, he communicated through a device that he controlled with his neck movements.+
Brain Implant Speech:Eddie describes the clinical trial where a man, Poncho, received a brain implant that allowed him to communicate through a computer by translating his brainwaves into digital signals. The surgery was a success and Poncho has been living with the implant for three years.+
Mind-Reading Technology:Eddie Chang shares the incredible experience of seeing a patient with ALS use a brainwave-reading device to communicate for the first time. Through machine learning, the device translated the patient's brainwaves into text on a screen, allowing him to communicate with others. The patient's reaction to the device was heartwarming, showing how technology can improve the quality of life for those with disabilities.+
Decoding Brain Activity:Eddie Chang discusses the use of AI to translate brain activity patterns into speech, and how autocorrect features can improve decoding accuracy. Andrew Huberman reflects on the clinical significance of the work and the rarity of such breakthroughs in neuroscience.+

24. Brain Superpowers

Brain Superpowers:Andrew and Matt discuss the potential of brain machine interface and the possibility of achieving supra human or superhuman functions through manipulating neural circuitry. They touch on the goals of Neuralink and the ethical considerations of pursuing such advancements.+
Brain Augmentation:Eddie discusses the history of brain-machine interface and how it has evolved to the point where augmentation is now possible. He raises ethical concerns about the invasive nature of some of these technologies and questions whether society is ready for them.+

25. Avatars for Communication

Facial Expressions:Eddie Chang discusses the potential of decoding speech signals from people with locked-in syndrome through facial expressions, highlighting the importance of nonverbal communication and the progress being made in the field of brain-machine interfaces.+
Avatar Communication:Eddie and Andrew discuss the potential of avatars as a form of communication, particularly for those who are disabled. They explore the benefits of avatars as a way to improve communication and how it could be used in the future, including the possibility of avatars speaking out what we would otherwise write.+

26. Stutter, Anxiety & Treatment

Understanding Stuttering:Eddie explains that stuttering is a speech condition that affects articulation and is not necessarily caused by anxiety, but anxiety can provoke or worsen it. Stuttering is a breakdown in the machinery that controls the vocal tract and can be triggered by predispositions.+
Understanding Stuttering:Eddie and Andrew discuss stuttering and how it affects speech. They explore the breakdown of coordination in the brain that causes stuttering and the importance of therapy in addressing the condition. They also touch on the role of auditory feedback and how it can affect the amount of stuttering.+

27. Brain Exploration

Mental State:Eddie Chang discusses the importance of exercise for his mental state and how being in the operating room is like a sanctuary for him. He explains how the intense focus required during surgery allows him to disconnect from the outside world and how routine tasks in the operating room can fulfill the same purpose as exercise.+
Running and Focus:Eddie and Andrew discuss the benefits of running and how it can help with focus. Eddie shares how he prefers to run without any distractions and how this translates to his work as a neurosurgeon where he needs to be completely focused on the task at hand.+
Brain Exploration:Eddie and Andrew discuss the excitement and importance of exploring the brain through neuroscience and brain surgery. Eddie shares his experiences in the operating room and the importance of applying knowledge to help patients. They both express their gratitude for the opportunity to do such intellectually important work.+

28. Neuroscience Insights

Andrew discusses the latest neuroscience research on speech and language with Dr. Eddie Chang. They cover topics such as bioengineering, epilepsy, and other brain disorders. They also mention the benefits of Momentous Supplements and the launch of the Huberman Lab Premium channel.+