David Linden

Sponsors: ROKA & Levels; Huberman Lab Survey

Sensory Touch & Genitals, Krause Corpuscles

Sexual Experiences & Sensation

Human Individuality & Variation; Senses & Odor Detection

Sponsor: AG1

Visual Individuality; Heat Tolerance; Early Life Experiences & Variation

Auditory Variability, Perfect Pitch

Heritability & Human Individuality: Cognitive & Physical Traits

Heritability, Environment, Personality; Twin Studies

Sponsor: InsideTracker

Development, Chance; Transgenerational Epigenetic Inheritance

Single Generation Epigenetic Inheritance & Stress; Autism

Sleep Paralysis; Cerebellum, Prediction

Nature vs. Nature, Experience; Linden Hypothesis

Mind-Body Interaction; Chemical Signals

Inflammation & Depression

Neuroplasticity, Inflammation & Mental Disorders; Microglial Cells, Exercise

Fads & Science

Mind-Body Communication; Cancer

Mind-Body, Mediation, Breathwork

Atrial Fibrillation, Synovial Sarcoma, Heart

Gratitude & Anger; Chemotherapy, Curiosity & Time Perception

Death, Brain & Future Prediction, Religion & Afterlife

Life Advice; Time Perception & Gratitude

Zero-Cost Support, YouTube Feedback, Spotify & Apple Reviews, Sponsors, Momentous, Social Media, Neural Network Newsletter

- Dr. David Linden discusses neuroplasticity and the cerebellum in the podcast episode.
- Topics covered include touch, perception, nature versus nurture, and the mind-body connection.
- Dr. Linden shares his personal experience with cancer and its influence on his life.
- The podcast aims to provide free science-related information to the general public.
- The podcast is sponsored by Roka and Levels, and there is a feedback survey.
- Krauss corpuscles raise questions about sexual preferences and aging.
- Individual variation is explored in olfactory and visual perception, as well as heat tolerance.
- Heritability and environmental factors are discussed in relation to perfect pitch, height, and IQ.
- The Minnesota Study of Twins Reared Apart found little correlation between family and personality traits.
- InsideTracker is a personalized nutrition platform that analyzes blood and DNA data.
- Genetic mutation, early life experiences, and stochastic development contribute to individual traits.
- Transgenerational epigenetic inheritance and stress during pregnancy are mentioned.
- Immune signaling molecules can disrupt brain development and lead to autism-like behaviors.
- The effects of immune insults during pregnancy on neuroimmune interactions and child development are unknown.
- The cerebellum is involved in more than just balance and has connections to other brain regions.
- The cerebellum predicts the immediate future, plays a role in motor coordination and social interactions.
- The "nature versus nurture" concept should be replaced with "experience" for a broader understanding.
- The mind-body connection is being studied and is important in biology and scientific hypotheses.
- Inflammation may be linked to depression, and microglial cells may be involved.
- Psilocybin shows promise in treating depression, while exercise improves mental function and reduces inflammation.
- Glial cells, specifically microglia, have gained attention in research.
- Mind-body communication involves neural signals and the release of hormones, neurotransmitters, and cytokines.
- Mental processes can influence biology, chronic stress is detrimental, and short-term stress can be beneficial.
- The nervous system includes components outside the skull and spinal cord.
- The speaker shares their personal experience with a heart cancer diagnosis and reflects on gratitude and agency.
- The brain's inability to imagine a world without oneself may explain afterlife beliefs.
- Knowledge of impending death can shift attention and perception of time.
- The podcast asks for support and offers discounts, a newsletter, and social media content.

- Dr. David Linden is a professor of neuroscience at Johns Hopkins School of Medicine, specializing in neuroplasticity and the cerebellum.
- The cerebellum is responsible for motor behavior, balance, learning new motor behaviors, and sense of timing.
- The discussion with Dr. Linden covers topics such as the sense of touch, individual perception, nature versus nurture, mind-body connection, and Dr. Linden's personal experience with cancer.

- The podcast is separate from the speaker's teaching and research roles at Stanford, and aims to provide free science-related information to the public.
- The podcast is sponsored by Roka, a company that makes high-quality eyeglasses and sunglasses designed for sports performance.
- The podcast is also sponsored by Levels, a program that uses a continuous glucose monitor to provide real-time feedback on how different foods and behaviors affect health.

- InsideTracker is a personalized nutrition platform that analyzes blood and DNA data to help understand the body and meet health goals.
- Regular blood work is important for understanding factors that impact immediate and long-term health.
- InsideTracker provides a personalized platform to easily understand blood test results and offers protocols to adjust numbers for optimal health.

- Genetic variation is at the heart of individuality and is driven by mutations, which provide adaptive traits.
- There is limited evidence for transgenerational epigenetic inheritance in mammals, with most claims based on poor statistical comparisons.
- While there is transgenerational inheritance of parenting and upbringing, the evidence for the modification of stress-related genes during trauma in grandparents or great-grandparents is weak.

- During the 1918 pandemic flu, pregnant women who got the flu had children who were on average a millimeter or two shorter and had a higher incidence of schizophrenia and autism.
- Stress during pregnancy, possibly related to the hypothalamic-pituitary-adrenal axis or an immune-neural interaction, may impact brain development and increase the risk of schizophrenia and autism.
- A mouse model study showed that immune signaling molecules passed from the mother to the fetus during a specific stage of development can cause disordered brain development similar to autism.

- The cerebellum is a complex structure that is involved in more than just balance, including timing, cognition, and learning.
- It is connected to the thalamus and frontal cortex, suggesting its involvement in planning, decision-making, and personality.
- The cerebellum's main function is to predict the immediate future, which is important for motor control and social interactions.

- The term "nature versus nurture" is misleading and should be replaced with "heritability interacting with experience filtered through the randomness of development" (the Linden hypothesis).
- Experience, including social, environmental, and biological factors, plays a significant role in shaping an individual's traits and abilities.
- Genes and experience interact in complex ways, sometimes opposing and sometimes reinforcing each other.

- Neuroscience used to focus mainly on the brain, but now there is a growing understanding of the mind-body connection and the influence of bodily organs on mental states.
- The mind-body interaction is being explored in scientific research, including practices like meditation and breathing exercises.
- There are two ways that signals from the body reach the mind: through neurons that monitor the body's internal state (introception) and through diffusible immune signals, such as cytokines, that can activate neurons in the brain.

- Inflammation in the body, particularly in the gut, may be linked to depression through inflammation-sensing neurons or immune signaling cytokine molecules.
- Depression is a complex disorder, and only a subset of cases are helped by antidepressant drugs.
- There are links between inflammation and depression, but the relationship is still not fully understood. However, there is some indication that anti-inflammatory drugs may help those who do not respond to antidepressants.

- Psilocybin therapy shows promising results for the treatment of depression, with 65-80% of people experiencing relief.
- SSRIs are less effective, helping only a third of people, and have side effects.
- Neuroplasticity, rewiring of neural circuits, may be the key to treating depression, and inflammation could be a barrier to neuroplasticity. Exercise also has positive effects on mental function and reduces inflammation.

- Glia, specifically microglia, have gained attention in research in the past 10 years.
- The technique of single cell expression profiling is currently popular but may be overused.
- When starting a PhD or postdoc, it is advised to choose a research topic that is not currently a fad to avoid competition and have a more pleasant experience.

- Mind-body communication involves various domains such as respiration, thought patterns, touch-based communication, and deep relaxation.
- Neurons and hormones are two potential pathways for conveying signals from the brain to the body.
- Neurons that innervate melanoma tumors can release a signaling molecule that affects immune patrolling, potentially influencing tumor growth and spread. This suggests that mental processes, such as meditative practice, could potentially impact cancer progression.

- Recent research has identified the nerve endings responsible for sexual sensation in the genitals, known as Krauss corpuscles.
- These nerve endings are mechanical sensors and can be activated or inactivated artificially.
- Further research is needed to understand the individual variations in Krauss corpuscle structure and the impact of aging on sexual sensation.

- The transcript discusses the idea that how we think influences our biology, specifically in relation to stress and mental processes.
- The speaker believes that biomedical researchers need to reclaim this idea from the realm of nonsense and conduct rigorous scientific tests to understand and optimize the true effects of mental processes on the body.
- The example of breathwork is mentioned as a potential way to consciously modulate breathing and have manifold effects on neural function.

- The speaker initially experienced shortness of breath and thought it was due to COVID, but it turned out to be atrial fibrillation.
- A mass was discovered near the heart, initially thought to be an atrial hernia but later diagnosed as synovial sarcoma, a rare cancer.
- The oncologist estimated the speaker had 6 to 18 months to live, but the speaker has exceeded that estimate.

- The speaker initially felt furious and angry upon learning about their heart cancer diagnosis, but also felt a deep sense of gratitude for their life and loved ones.
- They realized that they could simultaneously feel grateful and angry, and that being curious and nerdy about their own mental processes helped them maintain a sense of agency during their cancer treatment.
- The speaker also reflected on the malleability of perception, particularly in relation to time, and how their perspective on the amount of time they had left changed after their diagnosis.

- The speaker struggles to engage with the idea of their own death, despite being able to handle practical matters like updating their will.
- The brain is constantly trying to predict the future, which may explain why humans have a hard time imagining a world without themselves.
- The prevalence of religious beliefs about an afterlife may be a result of the brain's tendency to always anticipate the future.

- The speaker's advisors who died early experienced a heightened sense of gratitude and noticed the little things before their deaths.
- The knowledge of impending death shifts attention and perception of time, leading to a sense of slowing down and increased gratitude.
- The speaker's perception of time is slower due to action-packed experiences since being diagnosed, and their gratitude is for the big things in life.

- Support the podcast by subscribing to the YouTube channel, leaving a review on Spotify and Apple, and checking out the sponsors mentioned.
- Momentous Supplements are discussed on previous episodes, and listeners can access them with a 20% discount at livemomentous.com/huberman.
- Sign up for the Neural Network newsletter at HubermanLab.com for free monthly summaries of podcast episodes and protocols. Follow HubermanLab on social media for science-related content.

- Peripheral nerves are involved in sexual touch, and they have the ability to regenerate and remodel themselves more extensively than neurons in the brain and spinal cord.
- It is unknown if the patterns of innervation within the genitals change based on sexual stimulation, as monitoring this in people is not possible.
- Chronic masturbation in males can lead to desensitization and changes in sexual sensation, possibly due to a physical or functional change in the cross corpuscles.

- The book "Unique" explores the concept of human individuality, which is often overlooked in neuroscience.
- Experiments on mice in labs focus on genetic similarity and limited experiences, neglecting the importance of individual variation.
- The olfactory system is highly variable among individuals, with differences in odor receptors and perception, influenced by genetics and cultural context.

- AG1 is a vitamin mineral probiotic drink that provides foundational nutrition and adaptogens to help with stress.
- The speaker has been taking AG1 daily since 2012 and feels better with increased focus, energy, and improved sleep.
- Listeners can try AG1 at drinkag1.com/Huberman and receive five free travel packs and a year supply of vitamin D3K2.

- Visual perception can vary among individuals, with some seeing certain colors in front of others and some seeing all colors in the same plane.
- Early life experiences, such as exposure to light, can affect visual traits like myopia.
- Traits that are dependent on early life experiences can provide advantages that cannot be achieved through evolution. Examples include heat tolerance in Japanese soldiers and fur density in field mice.

- Perfect pitch is the ability to identify a note by hearing it, and it is a rare trait.
- Among highly trained musicians, the incidence of perfect pitch is higher than in the general population, but still only about one in ten musicians have it.
- Twin studies suggest that perfect pitch has a heritable component, but it only accounts for about 30-40% of the variability in perfect pitch.

- Human traits vary in their heritability, with some being 100% heritable (e.g., wet or dry earwax) and others being 0% heritable (e.g., speech accent).
- Most traits fall in between, with one example being height, which is about 85% heritable in the United States.
- Heritability can vary depending on factors such as nutrition, access to healthcare, and education, with disadvantaged populations having lower heritability for traits like height and IQ.

- The correlation in IQ between identical twins raised separately can be predicted to about 66% based on genetic makeup alone.
- Good schools are correlated with other beneficial factors such as good medical care, safer neighborhoods, and access to books, which can impact IQ test performance.
- Personality traits, on average, tend to be about 50% heritable, with family having little influence, and the remaining variation is attributed to the random nature of body and neural development.

Dr. David Linden: Life, Death & the Neuroscience of Your Unique Experience | Huberman Lab Podcast