Essentials: How Your Brain Works & Changes

Introduction to Huberman Lab Essentials & the Nervous System (0s)

• Huberman Lab Essentials is a series that revisits past episodes to provide the most potent and actionable science-based tools for mental health, physical health, and performance (0s).
• Andrew Huberman is a professor of neurobiology and ophthalmology at Stanford School of Medicine (11s).
• The nervous system is composed of the brain, spinal cord, and connections between the brain, spinal cord, and organs of the body, as well as connections between organs back to the spinal cord and brain (57s).
• The nervous system functions as a continuous loop of communication between the brain, spinal cord, and body, and cannot be separated into distinct parts (1m31s).
• The way the nervous system works can be compared to playing keys on a piano in a particular order, with experiences and memories being created by the specific sequence and intensity of neural activity (1m37s).
• The brain is a map of an individual's experiences, with a bias towards learning particular kinds of things from birth, and is ready to receive and learn information (2m1s).
• The brain's function is closely tied to an individual's experiences, and understanding the brain and nervous system can provide insight into how a person works and how to apply that knowledge (39s).

Understanding Sensation & Perception (2m15s)

• The nervous system performs several key functions, including sensation, which is a non-negotiable element that involves neurons perceiving various stimuli such as colors, light, touch, and sounds through sensory receptors (2m23s).
• Sensory receptors in the eyes, skin, and ears perceive specific types of stimuli, and the entire experience of life is filtered through these receptors (2m28s).
• Perception is the ability to focus on and make sense of the sensations being perceived, and it is under the control of attention, which can be thought of as a spotlight that can be directed at specific stimuli (2m53s).
• There are actually two attentional spotlights, allowing for multitasking, and attention can be split between two locations or brought to a single location (3m15s).
• Attention can also be dilated or concentrated, and it is something that is under an individual's control, making it an important aspect to understand when considering tools to improve the nervous system (3m59s).
• The nervous system can operate in either a reflexive or deliberate mode, with deliberate thoughts requiring effort and focus, while reflexive actions feel easy and require minimal metabolic demand (4m19s).
• When attempting to do something specific, mental friction can be felt, making it challenging, and this highlights the distinction between sensations, perceptions, and feelings/emotions (4m48s).

The Complex World of Emotions (5m2s)

• Emotions and feelings are products of the nervous system, involving the activity of neurons, which are electrically active and release chemicals, including a category called neuromodulators that have a profound influence on emotional states (5m12s).
• Neuromodulators, such as dopamine, serotonin, acetylcholine, and epinephrine, bias which neurons are likely to be active and which ones are likely to be inactive, similar to playlists that play particular categories of music (5m33s).
• Dopamine is often discussed as the molecule of reward or joy, involved in reward, and creates an upbeat mood when released in appropriate amounts in the brain by making certain neurons and neural circuits more active and others less active (6m2s).
• Serotonin is a molecule that when released tends to make individuals feel good with what they have, their internal landscape, and the resources they have, whereas dopamine is more a molecule of motivation toward things outside and that individuals want to pursue (6m26s).
• Healthy conditions or situations, such as being in pursuit of a goal, can release dopamine and increase motivation, while extreme examples like mania can result from relentless pursuit of external things (6m47s).
• Emotions are generally felt as not being under control, somewhat reflexive, and experienced in a passive, reflexive way, without deliberate thought to be happy or sad (7m18s).
• Thoughts are like perceptions, drawing on the present, past, and future, and can be both reflexive, occurring all the time, or deliberate, allowing individuals to decide to have a thought (7m42s).
• Thought patterns and the neural circuits that underlie thoughts can actually be controlled in a deliberate way, and actions are also influenced by these processes (8m14s).

The Role of Thoughts & Actions (8m24s)

• Actions or behaviors are the most important aspect of the nervous system because they create a fossil record of existence, as the nervous system deteriorates after death, but the skeleton and actions taken during a lifetime remain (8m24s).
• The sensations, perceptions, thoughts, and feelings experienced during a lifetime are not carried forward, except those converted into actions such as writing, words, or engineering new things (9m8s).
• The fossil record of a species and individual is through action, which is why a significant part of the nervous system is devoted to converting sensations, perceptions, feelings, and thoughts into actions (9m21s).
• The central nervous system, including the brain and spinal cord, connects heavily to the body because most experiences, including thoughts and feelings, were designed to impact behavior or not (9m39s).
• Thoughts allow individuals to reach into the past and anticipate the future, enabling behaviors that are not just for the moment but based on past knowledge and future desires (9m56s).
• The nervous system's capacity for creating movement occurs through simple pathways, including the reflexive pathway with central pattern generators in the brainstem (10m21s).
• Central pattern generators generate automatic movements, such as walking, when an individual already knows how to perform the action (10m27s).
• Deliberate movements require top-down processing, engaging areas of the brain for controlled movement, such as hiking on rocks, which involves the forebrain working with central pattern generators (10m39s).
• Movement can be either reflexive or deliberate, depending on the level of attention and control required (11m7s).

Deliberate Processing & Neuroplasticity (11m10s)

• When the nervous system does something deliberately, it involves paying attention and analyzing three things: duration, path, and outcome, referred to as DPO, which stands for duration, path, outcome, type of deliberate function in the brain and nervous system (11m31s).
• Deliberate processing is not typically used for automatic tasks such as walking down the street, eating, or talking reflexively, but rather for tasks that require top-down processing and control (11m51s).
• An example of deliberate processing is when someone says something triggering, and you actively suppress your behavior through top-down processing, preventing yourself from responding impulsively (12m1s).
• This suppression of behavior can feel like agitation and stress because the forebrain is actively preventing a circuit from being completed (12m12s).
• Young children do not have the forebrain circuitry to engage in top-down processing until they reach age 22 or 25, which is why they often act impulsively (12m38s).
• People with damage to certain areas of the frontal lobes may also lack top-down control, leading to impulsivity and a lack of restriction in their behavior (13m1s).
• The motor system is designed to work reflexively, but when we want to learn something new or change our behavior, we need to engage in top-down restriction, which can feel like agitation due to the release of norepinephrine, also known as adrenaline (13m14s).
• The feeling of agitation and strain is a necessary part of neuroplasticity, which requires top-down processing and deliberate effort to change behavior and thinking (13m59s).
• Neuroplasticity is the ability to change the nervous system, and understanding how to shape behavior, thinking, and performance requires understanding the role of top-down processing and deliberate effort (14m2s).

The Mechanisms of Neuroplasticity (14m29s)

• Neuroplasticity is the ability of connections in the brain and body to change in response to experience, and humans have the unique ability to direct their own neural changes (14m29s).
• For a long time, it was thought that neuroplasticity was limited to young animals and humans, but it is now known that the adult brain can also change in response to experience (15m15s).
• Children's brains are highly plastic, allowing them to learn multiple languages without an accent, whereas adults require more effort and strain to achieve similar plastic changes (14m57s).
• Plasticity in the adult human nervous system is controlled by neuromodulators such as dopamine, serotonin, and acetylcholine, which open up brief periods of time for neural changes to occur (15m48s).
• Acetylcholine plays a crucial role in neuroplasticity by highlighting and mapping information in the brain, making it easier to experience and feel certain things in the future (15m59s).
• Traumatic or challenging experiences can lead to neuroplasticity in adults due to the release of epinephrine and acetylcholine, which create a state of heightened alertness and focused attention (16m43s).
• Epinephrine creates alertness and increased attention, while acetylcholine highlights and marks neurons that are active during this period, making them more likely to be strengthened and active in the future (17m38s).
• When trying to learn new skills or become more motivated, the release of epinephrine is necessary to create alertness and focus, which is required for directing plastic changes in the nervous system (18m48s).
• Understanding the role of neuromodulators in neuroplasticity has immense implications for developing tools and strategies to induce neural changes and improve focus and motivation (19m4s).

The Importance of Sleep & Rest (19m24s)

• Neuroplasticity, the process of strengthening synapses and adding new nerve cells or connections between nerve cells, does not occur during the actual learning or event, but rather during sleep and non-sleep deep rest (19m24s).
• The process of neuroplasticity requires attention, focus, and a feeling of strain or agitation to be triggered, but the actual rewiring of the brain occurs during periods of sleep and non-sleep deep rest (20m29s).
• A study found that 20 minutes of deep rest after intense mental effort can accelerate neuroplasticity, and another study showed that hearing a tone during deep sleep can cue the nervous system to prioritize learning and retention (20m37s).
• The tone acts as a Pavlovian cue, reminding the sleeping brain to remember what was learned during the waking phase, resulting in significantly higher learning rates and retention (21m46s).
• Sleep and focus are key components of the learning process, with sleep allowing for the consolidation of changes between nerve cells and the transition from deliberate to easy and reflexive learning (22m12s).
• Non-sleep deep rest, characterized by a lack of analysis and a drifting attention, is also important for the consolidation of learning and the prevention of bad circumstances from becoming permanently ingrained in the nervous system (22m33s).
• Different approaches to preventing traumas from becoming permanent, including interfering with the consolidation process, are being explored by modern clinicians (23m12s).
• The brain has the ability to change its states and move away from negative experiences, and this process can occur over time, from the next day to the next year (23m17s).
• Neuroplasticity is not only about adding new things to the nervous system, but also about getting rid of unwanted things, such as bad experiences, emotional contingencies, and phobias (23m33s).
• The goal of neuroplasticity can be to reduce the emotional load of memories, rather than erasing the memories themselves, which is not possible (23m59s).
• Reducing the emotional load of memories can happen in various ways, all of which require neuroplasticity (24m6s).
• Neuroplasticity is a two-phase process, and understanding this process is crucial (24m18s).
• The autonomic nervous system, which includes the sympathetic and parasympathetic nervous systems, governs the transition between alert and focused states, and deep rest and deep sleep states (24m20s).
• The sympathetic nervous system is associated with alertness, while the parasympathetic nervous system is associated with calmness, but these names can be misleading (24m42s).
• To avoid confusion, the sympathetic nervous system can be referred to as the "alertness system" and the parasympathetic nervous system as the "calmness system" (25m2s).

Understanding the Autonomic Nervous System (25m11s)

• The autonomic nervous system works like a seesaw, with every 24 hours consisting of a cycle from alert to deeply calm, and then back to alert again, which affects our ability to engage in focused states and neuroplasticity (25m11s).
• This cycle includes a phase optimal for thinking, focusing, learning, and neuroplasticity, as well as a phase where we are tired and have no ability to focus (26m0s).
• Both phases are important for shaping our nervous system, and mastering the transition between wakefulness and sleep, as well as the transition between sleep and wakefulness, is crucial for engaging neuroplasticity (26m27s).
• Sleep is critically important for wound healing, learning, consolidating learning, and all aspects of our immune system, as well as our longevity (26m40s).
• During sleep, we are paralyzed to prevent acting out our dreams, and our brain is in a total idle state, allowing it to free run (27m16s).
• Mastering the transition to sleep involves more than just the amount of sleep, but also sleep quality, accessing deep states of non-duration, path, and outcome thinking, and timing of sleep (27m38s).
• The timing of sleep is important, and sleeping in a solid block of time is likely more optimal than breaking up sleep into shorter periods throughout the day (27m55s).
• The Uberman schedule, which involves taking multiple naps throughout the day, is not a recommended or sustainable sleep schedule for most people (28m17s).
• Understanding the rhythms that occur in our waking states is also important, as much of the focus has been on the value of sleep rather than the rhythms of wakefulness (28m34s).
• The brain has different states of optimization for focus, learning, and changing, and it is essential to understand these states to maximize productivity and learning (28m48s).
• Ultradian rhythms, which are shorter than circadian rhythms, occur throughout the day and play a crucial role in the brain's ability to attend and focus (29m23s).
• The most important ultradian rhythm is the 90-minute rhythm, which governs the brain's ability to attend and focus, and is also present in sleep patterns (29m32s).
• Sleep is broken up into 90-minute segments, with early night sleep consisting of lighter phase 1 and phase 2 sleep, followed by deeper phase 3 and phase 4 sleep (29m39s).
• The 90-minute ultradian rhythm continues after waking up, with the brain being optimized for focus and attention within these cycles (30m7s).
• At the beginning of a 90-minute cycle, the brain takes around 5-10 minutes to optimally tune into the task at hand, but as the cycle progresses, the ability to focus and learn increases (30m21s).
• The brain's ability to focus and learn is greater as it drops deeper into the 90-minute cycle, but eventually decreases as it reaches the end of the cycle (30m34s).
• The autonomic nervous system, which governs the seesaw of alertness to calmness, plays a crucial role in the brain's ability to focus and learn, and mastering it can help control the nervous system (30m50s).

Leveraging Ultradian Rhythms (30m57s)

• The human brain operates in 90-minute cycles, known as ultradian rhythms, which occur whether a person is asleep or awake, and understanding these cycles is crucial for learning and productivity (31m0s).
• To effectively learn new information, it is recommended to engage in focused learning sessions that last at least one 90-minute cycle, with the expectation that the early phase may be challenging (31m42s).
• The brain's ability to focus and learn can be improved by leveraging these ultradian cycles, which can lead to increased neuroplasticity and better access to flow states (32m2s).
• People's ability to learn and focus can vary throughout the day, with some individuals being more productive in the morning and others in the afternoon, and understanding these patterns can help optimize learning and productivity (32m9s).
• Paying attention to daily patterns of anxiety, focus, motivation, and sleep can provide valuable insights into how to improve productivity and well-being (32m20s).
• By understanding how different aspects of perception, sensation, feeling, thought, and action tend to be engaged or disengaged at different times of day, individuals can develop strategies to improve their ability to focus and engage in creative thinking (32m48s).
• Mastering the autonomic nervous system, which governs the transition between wakefulness and sleep, as well as the ultradian cycles, is key to accessing neuroplasticity, improving sleep, and enhancing creativity (33m13s).
• The use of specific tools, based on studies published over the last 100 years, can help individuals take control of their autonomic nervous system and get the most out of their nervous system (33m54s).