Our brains don’t passively record the world; they actively create it. This isn’t a philosophical idea, but a fundamental aspect of how our senses function, and why we survive. From phantom sounds like tinnitus to the way we interpret colors, what you perceive isn’t necessarily what is – it’s what your brain tells you is.
The Brain as a Constructor
Neuroscience professor Pascal Wallisch explains that everything we experience is filtered through our senses and then interpreted by the brain. This means reality isn’t objective, but deeply subjective; unique to each individual.
“Everything that you perceive is filtered for your sensory organs and then goes for your brain… If we assume that you have a unique brain – which I do – then you are bringing a lot of yourself to what you experienced.”
This isn’t just about visual illusions or auditory hallucinations. The brain fills in gaps, makes assumptions, and even creates sensations where none exist. Neuropathic itch, for example, is a purely mental sensation that feels intensely real. Even seeing shapes in clouds is your brain imposing meaning onto randomness.
The Dress That Broke the Internet
The infamous 2015 viral image of “the dress” – perceived as either black and blue or white and gold – illustrates this perfectly. Wallisch’s research showed the difference stemmed from assumptions about lighting. Night owls, accustomed to artificial light, tended to see it as white and gold, while those more familiar with natural light saw black and blue.
This demonstrates how prior experience shapes perception. The brain doesn’t wait for perfect data; it jumps to conclusions based on what it already “knows.”
Why Does the Brain Do This? Survival.
The brain isn’t designed for accuracy; it’s designed for speed. In a dangerous environment, hesitation can be fatal. Our ancestors who acted on incomplete information survived to pass on their genes.
“Your senses are not there for your viewing pleasure. They are there for survival… To be faster, you basically have to jump to conclusions.”
Imagine encountering a tiger in the forest. Waiting for absolute confirmation before reacting would mean becoming lunch. The brain prioritizes action over absolute certainty. A false alarm (getting scared for no reason) is preferable to being eaten.
The Matrix and Deeper Realities
This raises a profound question: if our brains construct reality, how reliable are our senses? Wallisch suggests they’re “very reliable… because of many redundant systems.” However, he also argues for humility: we should acknowledge the limits of our perception.
In fact, we may be living in a low-dimensional “embedding space,” unaware of a much deeper, inaccessible reality. The brain forces us to pretend that what we experience is everything, to function.
“You and I and everybody else, we are sharing a low-dimensional embedding space, but there’s a much deeper reality out there that our brains’ senses can’t see.”
Ultimately, our brains don’t show us reality; they show us a version of reality that keeps us alive. And that version might be far more limited than we think.
