The Open Loop Problem: Why Your Brain Needs a GTD Inbox

You know the feeling. You’re deep in focused work when a thought surfaces: Did I reply to that email? You push it aside. Minutes later: I need to schedule that dentist appointment. You push again. Then: What was that thing Sarah mentioned in the meeting?

Each thought pulls you out of flow. Each one you suppress comes back. By afternoon, you’re not tired from working – you’re tired from remembering.

This is the open loop problem. And it’s why David Allen made capture the first step of Getting Things Done.

For the complete GTD methodology – all five steps from capture to engage – see our Getting Things Done Guide. This article goes deep on the psychology of capture: why it works, why it fails, and how to build the habit.

What’s an Open Loop?

In GTD terminology, an “open loop” is anything that has your attention but hasn’t been captured, clarified, or resolved. It could be a task, a commitment, an idea, or just a vague sense that you need to do something.

Open loops aren’t inherently bad. They’re how your brain flags things that matter. The problem is how your brain handles them.

The Zeigarnik Effect

In the 1920s, psychologist Kurt Lewin noticed something odd at a café: waiters could remember complex unpaid orders perfectly – but once the bill was settled, the details vanished. His student, Bluma Zeigarnik, decided to test this in the lab.

Her 1927 research confirmed the pattern: incomplete tasks occupy mental bandwidth that completed tasks don’t¹. Participants remembered interrupted tasks nearly twice as well as completed ones. The explanation? Your brain maintains a background process for each unfinished commitment, constantly checking whether it needs attention.

This is useful when you have one or two things to track. It’s catastrophic when you have dozens.

(Note: While subsequent replication studies have shown mixed results, the core insight – that unfinished commitments demand mental attention – aligns with modern research on cognitive load and goal pursuit.)

The Cognitive Cost

Modern knowledge workers juggle far more commitments than working memory can handle. Estimates suggest working memory holds roughly four items at once². Meanwhile, the average professional manages dozens of projects with hundreds of individual tasks.

The math doesn’t work. Your brain tries anyway.

The result is what David Allen calls “psychic RAM”–mental energy consumed by open loops that should be stored externally. Every uncaptured thought burns a small amount of cognitive fuel. Multiply that by dozens of loops, and you get:

• Decision fatigue: Too many open loops competing makes even simple choices hard
• Ambient anxiety: The nagging feeling that you’re forgetting something important
• Reduced focus: Background processes interrupt foreground work
• Sleep disruption: Open loops don’t clock out when you do

Why Capture Works

Here’s the counterintuitive finding: you don’t have to complete a task to close the loop. You just have to make a plan for it.

In 2011, researchers Masicampo and Baumeister tested whether the Zeigarnik Effect could be neutralized without actually finishing tasks. Their answer: yes. Simply making a concrete plan for when and how you’ll address a task reduces its cognitive burden³.

This is the science behind GTD capture. When you write something in a trusted inbox, you’re not just organizing – you’re telling your brain: I’ve got this. You can let go.

The key word is “trusted.”

Trust Is Everything

Capture only works if you believe your system will surface the item at the right time. If you’ve ever written something down and then kept thinking about it anyway, you’ve experienced a trust failure.

Trust failures happen when:

• Your inbox becomes a graveyard of items you never process
• You use multiple capture points and lose track of what’s where
• You capture vaguely (“marketing stuff”) instead of concretely
• You don’t review your inbox regularly

When trust breaks down, your brain stops offloading. It keeps the loops open, keeps burning cognitive fuel, keeps interrupting your focus. The inbox becomes decoration rather than relief.

The Capture-Trust Loop

This creates a feedback cycle:

1. High trust → You capture everything → Your inbox works → Trust increases
2. Low trust → You hesitate to capture → Items stay in your head → You forget things → Trust decreases further

Breaking into the positive cycle requires two things: reliable capture and reliable processing. Capture without processing builds an inbox you dread opening. Processing without capture means there’s nothing useful to process.

The GTD Weekly Review is what maintains trust over time. Capture is what builds it in the first place.

Capture vs. Clarify

One of the most common capture mistakes is trying to do too much at once. You have a thought, you write it down, and then you immediately start organizing: Which project does this belong to? What’s the priority? When should I do it?

Stop. That’s not capture – that’s clarify. And mixing them breaks both.

Why Separation Matters

Capture should be frictionless and fast. The moment you start making decisions about an item, you’ve added friction. That friction compounds:

• You hesitate before capturing because you know decisions await
• You capture less because each capture requires mental effort
• Open loops stay open longer because capture feels like work

The inbox is a waystation, not a filing cabinet. Its job is to hold items temporarily until you’re ready to process them. When you capture, your only question is: “Do I need to think about this again?” If yes, it goes in the inbox. Full stop.

The Two-Minute Guideline

There’s one exception. If something takes less than two minutes to complete, do it immediately rather than capturing it. The overhead of tracking it exceeds the cost of just doing it.

But be honest about what “two minutes” means. If you’re using the two-minute rule to avoid capturing, you’re not saving time – you’re leaking tasks.

Building the Capture Habit

Knowing why capture works doesn’t make it automatic. Habits form through repetition, and capture needs to become reflexive – something you do without deciding to do it.

Reduce Friction to Zero

Every barrier between thought and capture is a reason to skip it. If you have to:

• Open an app
• Navigate to the right list
• Choose a project
• Set a due date

…you’ll only capture when the thought feels “important enough.” The mundane stuff – which often matters just as much – leaks through.

In Super Productivity: Use the global keyboard shortcut to open the inbox instantly. Type your thought. Hit enter. Done. The whole interaction should take under five seconds.

Capture Everything (At First)

When building the habit, err on the side of capturing too much. You can delete items during processing. You can’t recover thoughts you never captured.

Common categories people forget to capture:

• Ideas that pop up during other tasks
• Commitments made in conversation (“I’ll send you that link”)
• Things you notice that need fixing
• Questions you want to research later
• Someday/maybe daydreams

If it’s occupying mental space, it belongs in the inbox.

The Capture Reflex

With practice, capture becomes automatic. You’ll notice the moment a thought creates cognitive load and immediately externalize it. The gap between “thought” and “captured” shrinks to seconds.

This reflex is the foundation of GTD. Without it, the rest of the system – clarify, organize, reflect, engage – has nothing to work with. With it, you’ve built the first link in a chain that leads to “mind like water.”

One Inbox or Many?

GTD purists argue for a single inbox. Everything goes to one place, which you process regularly.

In practice, most people have multiple capture points:

• A digital inbox (task manager, notes app)
• Email inbox
• Physical inbox (papers, mail)
• Voice memos or quick notes on their phone
• A notebook for meetings

Multiple inboxes aren’t inherently wrong. The danger is forgetting one of them. If you capture something in a notebook and never review that notebook, the loop stays open.

The Consolidation Rule

However many capture points you use, establish a regular consolidation routine. During your daily review or weekly review, check all capture points and move items to your primary system.

In Super Productivity: You can paste plain text directly into the inbox – each line becomes a separate task. This makes consolidation fast: copy your scattered notes, paste them in, process from one place.

When Capture Fails

Even with the right tools and habits, capture can break down. Here are the common failure modes:

The Overflowing Inbox

Your inbox has 200 items. Opening it feels overwhelming. So you don’t. New items pile on top of old ones. The inbox becomes a monument to procrastination.

Fix: Schedule a “capture bankruptcy” session. Process everything ruthlessly – most items can be deleted, deferred to Someday/Maybe, or converted to two-minute actions. Then commit to processing inbox to zero during every Weekly Review.

The Vague Capture

“Marketing” isn’t a capture – it’s a category. “Call vendor about pricing” is a capture. Vague captures require re-thinking when you process them, which adds friction and often leads to deferral.

Fix: Capture the specific thought you had, even if it’s incomplete. “Marketing – that idea about the newsletter thing” is better than “Marketing” because it gives your future self a hook.

The Distrust Spiral

You’ve tried capture before. It didn’t stick. Now you don’t believe it will work, so you don’t fully commit, which guarantees it won’t work.

Fix: Start small. Commit to one week of capturing everything and processing to zero daily. Don’t judge the system until you’ve actually used it. Trust builds through experience, not intention.

Capture in Super Productivity

Here’s how to implement capture effectively:

Quick Capture Setup

1. Learn the keyboard shortcut – Opens the inbox from anywhere in the app
2. Keep the inbox visible – Don’t bury it in navigation
3. Use quick syntax – Add time estimates inline: Call dentist 5m or Review proposal 30m

Processing the Inbox

During processing (daily or as part of your Weekly Review):

1. Take each item one at a time
2. Ask: Is this actionable?
   • No → Delete, file as reference, or move to Someday/Maybe
   • Yes → Define the next action, assign to a project, add context tags
3. Apply the two-minute rule: if it’s fast, just do it
4. Goal: inbox zero, every time

Multi-Device Capture

If you capture thoughts on your phone, in meetings, or away from your computer, establish a consolidation routine. During your review, pull items from all capture points into Super Productivity so everything lives in one trusted system.

The Payoff

When capture becomes habitual, something shifts. The background noise quiets. The nagging feeling fades. You stop spending mental energy on remembering and start spending it on doing.

This is the first taste of what David Allen calls “mind like water”–a state where you respond to what’s in front of you without the drag of unprocessed commitments. It doesn’t come from completing everything. It comes from knowing that everything is captured, clarified, and waiting in a system you trust.

Your next step: capture everything for one week. Don’t judge, don’t organize, don’t filter. Just capture. Then process to zero daily. Notice how it feels by day seven.

The open loops will close. Your brain will thank you.

Ready for the full GTD system? Learn all five steps – capture, clarify, organize, reflect, engage – in our complete Getting Things Done Guide.