The Problem with Complex Things
Is it's Someone Else's Problem
If you are new here, welcome!
I write on topics in neuroscience, consciousness, and AI.
Usually, I write in-depth essays at the intersection of these topics, but I thought I’d start the year with something a little different — a series of shorter essays.
Six questions have been rattling around in my head. This mini-series of mini-essays will introduce those questions. Throughout 2025, I’ll return to these questions and explore them in more depth.
This is Question 3
In this essay, I want to explore a question that comes up a lot in brain science:
What’s the best way to study something as complex as the brain? Should we look at the big picture or zoom in on the tiny details?
I’m using the brain as my main example here because… well… this is When Life Gives You a Brain… But the principles we’ll explore in this essay apply to many complex systems — which is why I’ll sometimes talk about other examples that help illustrate these ideas.
Often, complex things we want to understand — like life, the universe, and the brain — can be studied on different levels — from the microscopic to the macroscopic.
Consider water: we could study it at different levels. We could zoom way in and look at individual Hâ‚‚O molecules. We could zoom out a bit and study how water flows and freezes. Or we could zoom way out and look at how rivers shape valleys over thousands of years.
Understanding what exists in our world requires some understanding of the different levels of reality. I covered the idea of different levels of reality in May of 2024, and it’s an idea that will keep popping up in the essays I’m planning for 2025.
When we study how our brain works, different scientists look at different levels:
At a high level, we might look at the influence of societies and culture
Psychologists might study how individuals think and behave
Going deeper, system neuroscientists look at how brain circuits correlate with our experiences and behaviours
Going even deeper, others study individual brain cells
At the lower levels, scientists study the molecular machinery that makes brain cells work.
And some study the quantum level
We might think that understanding how we perceive and interact with the world requires looking at the higher levels. After all, things like perception, sensation, and even consciousness seem like big-picture phenomena, right? Maybe we can ignore all those tiny molecular details.
This perspective is surprisingly common, even among brain researchers. We might treat lower-level ideas and findings as almost irrelevant details — lower-level questions are matters for others to figure out later.
There’s a certain appeal to this approach. For practical reasons, focusing on one level of abstraction might be necessary. Different levels may be better suited to addressing different questions.
Take consciousness, for instance. It’s common to approach it as a ‘big-picture’ problem, focusing on brain-wide networks or global states of activity. For many, it feels intuitive to think that understanding consciousness will come from studying these higher levels.
This is a reasonable approach to take.
But what about those lower levels? What if those so-called ‘irrelevant details’ aren’t so irrelevant after all? Could ignoring them mean we are missing out on insights we didn’t even realise we were missing?
For example, consider the details of how neurons get energy, respond to stress, and maintain themselves. These seemingly minor processes can have big effects on how the entire system functions.
Take how neurons use energy, for example. Neurons rely on sugar, and even a tiny drop in how efficiently they process it — say, just 5% less — can make them more sensitive during critical developmental stages. That extra sensitivity can end up rewiring the brain in subtle but lasting ways, eventually shaping how it works. Something as basic as how a neuron powers itself can ripple upward, influencing the behaviour of entire neural networks.
This reminds me of something we explored last week: how simple rules, like Rule 110, can generate complex and unpredictable patterns. A similar principle may apply to our brains. Seemingly simple molecular mechanisms interact in ways that produce complexity, making it impossible to predict higher-level behaviour even when we know the details of the lower levels.
This idea has me thinking…
Many of us who are interested in human behaviour, thought, and consciousness turn to psychology and neuroscience, hoping that understanding the brain’s structure and function at a higher level will reveal how it works.
Perhaps focusing on the higher levels is a necessary simplification. Even brain research is divided into specialised areas of study, each approaching the brain from a different level. But I wonder if this division into levels of abstraction, while practical, comes with significant downsides.
The brain is not just a static collection of parts; it’s a system where molecules, cells, circuits, and behaviours are constantly influencing one another. While dividing research into levels makes studying the details easier, do we risk missing how these levels come together to create complexity?
So, here’s the third question on my list for 2025:
As we try to understand complex phenomena — like how brains work, how to build intelligent systems, or even how consciousness happens —
It is important to distinguish between studying the function of a device and studying its elements. Studying the design of an internal combustion engine is not studying the functions of a car - the engine can be electric. Studying a transistor is not studying how a computer works - instead of a transistor, you can use a relay, a vacuum tube, and even purely mechanical elements. Studying neurons is not studying intelligence - it can be implemented on a computer.
My take is that until we can build a system that is able to reliably convince us it's conscious, or has human level intelligence, or even common animal level intelligence, we should explore at all levels of abstraction. Let a thousand flowers bloom.
There is a danger in the people looking at one level not talking with those working on other levels, or insisting that all the answers are at their particular layer. I'm not sure what needs to happen in academia to protect against that. But it's probably worth remembering that the answer to an intractable problem might be in another layer.
Interesting, as always Suzi!