Key takeaway number 1 : Your nervous system is more than your brain

Your nervous system is composed of your brain and spinal corde but also the connections between them and the organs of the body.

Everything humans think, remember, feel and imagine is governed by the nervous system and especially the communication between the nervous systems and the organs.

Key takeaway number 2 : Sensations are an integral part of your Human experience

Sensation is a non-negotiable element of the nervous system. And given that the nervous system shapes everything about Human experience, it's a non-negotiable part of Human experience.

The saying "Mind over the body" is bullshit. Understanding and manipulating sensations is a strong mecanism to influence the nervous system and is an important part of the toolbox to improve Human performance through the nervous system.

Key takeaway number 3 : You control your perceptions

Perception is one's ability to postprocess sensations. Perceptions are sensations that one pays attention to.

Sensation is not negotiable but perception is. One can direct its spotlight of attention to a specific sensation if desired. And, as with any spotlight, it's possible to focus it on a particular area or make it more diffuse.

Understanding that principle is one of the basis for understanding tools to improve one's performance.

Attention mechanism is something that is used in Artificial Intelligence.

Key takeaway number 4 : Improving one's self requires effort and energy

The nervous system tries to make most things reflexive i.e. automatic and enters in a process which is also called bottom-up i.e. one feels something (sensations) and the brain reacts to it through its internal model. Functionning that way requires less energy which is efficient from the nervous system's perspective.

But that's not always desired. One may want to change something about its "automatic behavior".

When one wants to deliberately focus on something (learning a new skill, changing a behaviour, …), it will inevitably requires a higher energy demand and feel difficult, trigger some sort of agitation and provoke some mental friction. One then enters in a top-bottom process.

Key takeaway number 5 : Chemicals control our emotions and our behaviour

Neuromodulators such as dopamine, serotonin, acetylcholine, epinepherine are neuromodulators.

They bias which neurons are likely to be active and which ones are likely to be inactive.

Dopamine, famously known as the chemical of joy, is involved in reward and triggers action. Serotonin tends to make us feel good with what we have and therefore promotes stillness.

Key takeaway number 6 : Your nervous system is geared to make you act on your environment

A significant part of our nervous system is devoted to converting sensations, perceptions, feelings, and thoughts into actions. It's designed to either impact our behavior or not.

Huberman thinks of actions in terms of Duration Path Outcome (DPO).

Key takeaway number 7 : Neuroplasticity (i.e. learning) requires agitation

When we decide we want to learn something, or do something or not do something, we have to engage in top down restriction, and it feels like agitation because it's accompanied by the release of norepinephrine (=adrenaline),

Therefore, modifying something is gonna feel challenging because the chemicals in the body that are released in association with that effort are designed to make us feel agitated.

Key takeaway number 8 : Plasticity is "free" until about age 25

Kids learn passively. Adults will need to engage deliberately in learning bouts.

The young brain is incredibly plastic. children can learn three languages without an accent reflexively. Whereas adults, it's very challenging. It takes a lot more effort and strain a lot more of that duration, path outcome kind of thinking in order to achieve those plastic changes.

Key takeaway number 9 : Plasticity is controlled by neuromodulators

Dopamine, adrenaline, serotonin, and in particular acetylcholine are what open up plasticity. They allow brief periods of time in which whatever information can literally be mapped in the brain.

Adrenaline makes us feel alert and agitated which increases learning. Acetylcholine focuses the "light" on neurons which are active during the learning task. It marks up the neurons.

Key takeaway number 10 : Traumatic events also induce plasticity unfortunately

The Dark Side of plasticity is it's actually very easy to get neuroplasticity as an adult through traumatic or terrible or challenging experiences.

The reason is because when something very bad happens, there's the release of epinephrine and acetylcholine which are involved in the plasticity process.

Key takeaway number 11 : Plasticity occurs during sleep and non-sleep deep rest

The actual rewiring of the nervous system occurs during periods of sleep and non sleep deep rest.

Doing something very hard and very intense and then taking 20 minutes immediately afterward to deliberately turn off the intentional focused thinking and engagement accelerates neural plasticity.

Key takeaway number 12 : External cues can optimize learning

Hearing a tone playing in the background periodically during learning (e.g. like a bell) and playing that same tone during sleep or non-sleep deep rest increases the learning rate. It's a sort of a Pavlovian cue

Key takeaway number 13 : Memories can't be erased. The attached emotional load can

Unfortunately, bad memories can't be erased. But tools exist to erase the emotional loads attached to it.

In other words, one will always remember a traumatic event. But one can learn to not feel bad about it.

Key takeaway number 14 : The autonomic nervous system is the pillar of plasticity

The autonomic nervous system is composed of the sympathetic and parasympathetic nervous system.

The autonomic nervous system has internal clocks. Every 24 hours,there are phases of our day that are optimal for thinking, focusing and learning. And others that are optimal for resting.

To master neural plasticity, one has to master the transition between wakefulness and sleep.

Key takeaway number 15 : Most important ultradian cycles last 90 minutes

Circadian cycles last 24 hours. Ultradian cycles occur within this 24 hours timeframe.

And the most important ultradian cycle last 90 minutes. Sleep is broken into 90 minutes cycle. And focused states shall last about 90 minutes also.

Sleepiness and wakefullness alternate following those ultradian cycles and are governed by the autonomic nervous system.

Therefore, mastering tools to influence the autonomic nervous sysystem will help one's to optimize its Human performance for learning or any other desired outcome.