Acetylcholine: the chemical of focus & precision

The human brain is built to wander.

Left to its own devices—in traffic, on a trail, in the shower—attention quickly drifts.

(Try counting ten slow breaths without losing track; it’s surprisingly hard!)

Deep, single-task focus forces that nomadic mind to plant its flag, which is why it’s such hard work (and why most of us are pretty crap at it!)

But the fact that it’s hard doesn’t mean there’s something wrong with our brain. It’s doing exactly what its designed to do.

So for me, Huberman’s post is a blunt but important reminder:

Stop searching for a pill or waiting for the perfect conditions.

Instead, train the skill.

Yes, it’s hard, but it’s worth it.

However! Before we attempt a 3-hour deep-work marathon, we need the neural equivalent of marathon prep: steady mileage, smart fuel, the right gear.

That means understanding and optimising the key neurochemicals involved in focus.

We’ve already covered dopamine and epinephrine.

Today we’re zooming in on the third player: acetylcholine.

Acetylcholine: what do we need to know?

Neuroscientists describe focus as a combination of three neurochemicals working together. I like this analogy to bring this to life visually:

• Dopamine is the propeller that drives the arrow forward, providing the motivation and drive to start and sustain your effort.

• Epinephrine is the arrow’s shaft, providing the energy and alertness. (No focus is possible if you’re feeling drowsy!)

• Acetylcholine (ACh) is like the arrowhead. It precisely directs your attention, spotlighting the neurons and neurocircuits that need to be involved.

You need all 3 for deep, sustained focus.

Concretely, here’s what ACh does for you:

1. Sets the scene → selective attention

   When you focus, ACh floods the exact neural circuits you need for the task at hand and dims those you don’t, carving a crisp channel through the mental chatter. That “locked-in” feeling during a flow state? That’s ACh doing its thing.

2. Marks the moment → learning and memory

   When you’re learning something new or trying to remember a skill, ACh is the signal that tags the active synapses with a biochemical message saying, “This is important. Let’s remember this.” Then during sleep, those tagged circuits get rewired and strengthened.

3. Keeps the tempo → one task only
   Every time you glance at your phone or try to multi-task, ACh has to yank its spotlight to a new target. Repeated toggling drains the supply, which shows up as mental fog and slower recall. Single-tasking is therefore so so so important!

If your ACh is too low, you feel scattered, forgetful, or stuck in a fog. When it’s balanced, you can focus deeply, learn faster, and remember more.

So now, let’s look at a series of simple tools and habits to manage your ACh levels:

• 📈 Baseline: Maintain healthy ACh levels for consistent focus

• 🧰 Directed: Boost ACh in the moment

• 👩‍💻 Task-Oriented: Set up your schedule and workspace to support deep work

📈 Baseline: Maintain healthy ACh levels for consistent focus

Ahh, we have all the usual suspects here: nutrition, sleep, friction and movement.

Eat choline-rich foods

ACh is made from choline, a nutrient found in foods like:

• Eggs (one of the best sources)

• Chicken, fish, beef liver

• Soybeans, beans, and seeds

Your body can make a little bit of choline on its own, but not enough for optimal brain function. So getting it from food is essential.

Prioritize quality sleep 

Sleep is when your brain balances and replenishes its focus chemicals. If you skimp on sleep, you’ll likely feel unfocused and sluggish because the ACh (and other neuromodulator) systems haven’t had a chance to do their maintenance.

During REM sleep (dreaming stage), your brain’s ACh levels peak. This is when your brain consolidates memories and “locks in” what you’ve learned.

Aim for 7-8 hours, and keep a consistent sleep schedule.

Stay mentally engaged

Your ACh system thrives on curiosity and challenge.

• Read challenging books

• Learn an instrument

• Write essays

The more you engage your brain, the stronger your ACh system becomes.

(Scrolling and mindless consuming is the worst we can do. Zero challenge. Zero friction. Zero skill.)

Regular exercise 

Physical activity is a natural booster of ACh, especially in areas of your brain tied to learning and memory.

Doesn’t matter what you do. The key is to get your blood flowing most days of the week. Even 20-30 minutes of brisk walking makes a difference!

Exercise also indirectly boosts focus by improving sleep quality and reducing stress

🧰 Directed: Boost ACh when you need it

Healthy baseline, check.

But sometimes you need an extra boost, like right before an important work session or when you notice your focus is drifting.

Visual focus drill

You can directly tap into your brain’s attentional circuits by narrowing your visual field on purpose.

• Pick a point in front of you

• Stare at it intently for 30–60 seconds, keeping it in the center of your vision

• Don’t move your head or your eyes

• This triggers ACh release in the brain’s attention centers—like a warm-up for your focus muscle

Give it a try. You’ll notice how difficult this is to stay visually focused even for 30 seconds. That friction you feel? That’s the ACh working.

(I write more about how to use your visual system for focus and relaxation here and here.)

Short burst of intense exercise

One of the quickest ways to kick your brain into a focused state is to get your heart rate up briefly.

• 5–10 minutes of brisk movement (jumping jacks, stairs, shadow boxing) before a big task

• This stimulates a burst of ACh (and dopamine and epinephrine), sharpening your focus and making you alert

(Have you noticed how short bursts of movement have been a key tool in every chemical deep-dive so far? If at the end of this series, you’re not convinced of the importance of constant movement, even for a few mins… I’ve not done my job well!)

👩‍💻 Task-Oriented: Set up your schedule and workspace to support deep focus

Beyond physiology, how you organize your work and environment can greatly influence ACh’s effectiveness.

Monotask (stop multitasking!)

If there’s just one thing you take away from this deep-dive, let it be this:

Focus is fragile. Protect it fiercely by designing your work sessions to be about one thing at a time.

Studies confirm that “multitasking” is really rapid task-switching, and it significantly reduces attention and overall performance. Every time you switch, there’s a cognitive cost as your ACh and other circuits have to re-engage with the new thing. Remember: ACh is like a spotlight. It works best when focused on one thing.

• Set a timer for 25–45 minutes.

• Work on one task. Close other tabs. Silence notifications.

• Resist the urge to do anything else. If other tasks or ideas pop into mind, quickly jot them down on paper to tackle later, rather than interrupting your current flow.

You’ll get tasks done faster and at higher quality.

(Bonus: as explained in the dopamine deep-dive, it helps to break down big goals into micro-milestones!)

Use ultradian rhythm blocks (90-120 minute focus)

Your brain can maintain high focus for about 90-120 minutes before it needs a break.

Any longer, and acetylcholine and dopamine levels begin to drop, making it harder to maintain the same quality of focus.

So to get the best out of your brain and work with its natural rhythm:

• Structure your work in 90-120 minute blocks dedicated to a single important task, followed by a 10-15 minute reset.

• During the break, do something to recover: stretch, look at something far away (to relax the visual system), grab a glass of water, etc. This pause allows your neuromodulators to replenish.

• Then start the next focus block fresh.

I notice a night and day difference between what I accomplish in 2 hours of truly focused work using this sprint-rest approach versus in 4 hours of trying to grind nonstop.

Optimize your workspace

If your desk is cluttered with unrelated items, your brain uses energy to block out those distractions.

A clean, organized workspace with just the materials you need for the task can help your brain relax and focus on the relevant stimuli.

• Clean, organized space = less cognitive load

• Minimal distractions = less wasted ACh

Use your breath to refocus when overwhelmed

When you’re feeling too activated or scattered to focus, a brief breathing exercise can help optimize your internal state for focus by reducing excessive adrenaline.

Try the physiological sigh.

• inhale deeply through your nose

• take a second quick inhale to fully expand your lungs

• slowly exhale through your mouth

Doing 1–3 of these sigh breaths can rapidly lower your heart rate and calm you down.

This doesn’t directly increase ACh, but it lowers the background noise of anxiety so that ACh can do its job without you feeling jittery.

Acetylcholine is your brain’s spotlight—sharpening your focus, deepening your learning, and helping you lock in what matters.

But it needs two things:

1️⃣ A healthy baseline (good sleep, food, exercise, and curiosity).

2️⃣ The right conditions (a single task, focused work blocks, minimal distractions).

When you take care of those two, you get to experience those crystal-clear, dialed-in moments whenever you need them.

Next week, we’re diving into Serotonin—the molecule of connection & contentment.

See you then!

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