Bottom-Up vs. Top-Down Processing: Why the World Feels Different.

Have you ever walked into a crowded store and immediately felt overwhelmed, your brain scrambling to process the bright lights, the hum of conversations, and the shifting movement of people around and close to you? Or maybe someone asks, “How was your day?” Instead of summarizing, you replay every little detail, struggling to filter out what matters.

If that sounds familiar, you’re likely experiencing bottom-up processing, which is how many of us with ADHD and Autism naturally engage with the world. It’s the opposite of top-down processing, which is more common in neurotypical brains. Understanding this difference can explain why certain environments, tasks, and social interactions feel easier or harder for different people.

What’s the Difference?

• Bottom-Up Processing (Common in ADHDers & Autistic Folx)

Think of it like piecing pieces of a jigsaw puzzle together. Your brain takes in raw information first, every sight, sound, smell, and texture, before deciding what it all means. This makes you hyper-aware of details, but it can also be overwhelming because your brain doesn’t automatically filter out “unimportant” information.

• Top-Down Processing (Common in Neurotypicals)

This works more like a director guiding a movie. The brain starts with an expectation or framework, like knowing they’re in a grocery store, so they focus only on their shopping list. They don’t need to process every flickering light or distant conversation because their brain already “knows” those details don’t matter.

Both ways of processing have strengths and challenges. Still, in a world designed for top-down thinkers, bottom-up processing can feel like a disadvantage, especially when it comes to sensory overload, decision-making, and social interactions.

Real-Life Examples of Bottom-Up vs. Top-Down Thinking

1. Sensory Overload in a Grocery Store

• Bottom-Up Thinker (ADHD/Autistic Experience): You walk into the store and immediately feel bombarded. Your brain registers the buzz of fluorescent lights, the beeping checkout scanners, the smell of freshly baked bread, and the cart squeaking behind you all at once. So, focusing on your list requires extra effort because your brain doesn’t filter out the background noise.

• Top-Down Thinker (Neurotypical Experience): They walk in, and their brain instantly prioritizes: “I need milk, bread, and eggs.” Their mind automatically tunes out most of the sensory environment, so they don’t notice the buzzing lights, level of noise, or strong smells unless something unusual happens.

2. Decision-Making and Task Paralysis

• Bottom-Up Thinker: You’re cleaning your room but get stuck. You notice an old notebook, start flipping through it, get lost in memories, and then suddenly spot a pile of laundry and start sorting socks. Before you know it, an hour has passed, and your room is still messy, but now you’ve gone down three different mental rabbit holes.

• Top-Down Thinker: They approach cleaning with a clear mental roadmap: “First, pick up laundry, then dust, then vacuum.” They can stick to the plan because their brain isn’t constantly being pulled in new directions by tiny details.

3. Conversations and Social Interactions

• Bottom-Up Thinker: Someone asks, “How was your weekend?” Your brain replays everything, including what you ate, the movie you watched, and your weird conversation with your neighbour. You struggle to find the “right” summary because all the details feel equally important.

• Top-Down Thinker: They instinctively know the expected socially acceptable answer is “Good! I went to the beach.” Their brain doesn’t get caught up in every detail because it already understands the social script.

Why This Matters

As ADHDers and Autistic people, many of us are told that we “overthink” things, “get distracted too easily,” or “miss the big picture” (depending on the situation). But this is not a flaw; it’s just a different way of experiencing the world. Bottom-up processing means you often notice details others miss, make connections in unique ways and experience life with rich sensory awareness.

The challenge is that the world is built for top-down thinkers. Schools, workplaces, and social norms all assume that people will automatically filter out distractions, follow established scripts, and focus on “big picture” goals. When you don’t, you’re often labelled as inattentive, anxious, or slow when, really, you’re just processing information differently.

Strategies to Work with Bottom-Up Processing

1. Use External Filters: Noise-canceling headphones, tinted glasses, or background music can help limit sensory input so your brain isn’t constantly overwhelmed.

2. Break Down Decision-Making: Instead of “clean the house,” try breaking tasks down into visual steps like “put all the dishes in the sink” first. This helps prevent task paralysis.

3. Practice “Big Picture” Thinking: Before starting a conversation, mentally ask yourself, “What’s the main point I want to share?” This can help with summarizing thoughts.

4. Give Yourself More Time: Bottom-up processing often takes longer, especially in new environments. Building in buffer time can reduce stress.

5. Advocate for Your Needs: Whether asking for written instructions instead of verbal ones or requesting a quieter workspace, knowing how your brain works can help you communicate your needs more effectively.

Final Thoughts

Neither way of processing is “better” than the other; they’re just different. But when you understand how your brain works, you can find ways to work with it instead of against it.

If you struggle with sensory overload, decision paralysis, or social interactions, know this: You’re not broken. Your brain is just wired to process the world in a very perceptive, detail-oriented, and unique way. And that’s a strength, even if the world doesn’t always recognize it yet.