Here’s a surprising fact about your brain: roughly 99% of the energy it uses has nothing to do with what you’re actually doing at any given moment. Reading, thinking, watching TV — all of that accounts for barely 1% of its energy consumption. The rest is the brain talking to itself, neurons firing in constant, restless patterns whether you’re concentrating hard or staring blankly at a wall.
A new theory from neuroscientists suggests this relentless background hum isn’t just noise. It may be the very raw material from which imagination is made.
The Old View: Imagination as Vision in Reverse
The long-held understanding of imagination went something like this: when you see something, light enters your eyes and triggers a cascade of signals moving through the visual system, from simple edges and lines all the way up to recognisable faces and scenes.
Imagination, under this model, was simply that process running backwards — starting from a concept or memory and working downward through the visual system to reconstruct an image in the mind’s eye.
It’s a tidy explanation. But it turns out it’s probably not quite right.
A New Idea: Carving, Not Building
The new theory, published in a leading psychology journal, proposes something more counterintuitive. Rather than constructing images from scratch, imagination works by suppressing brain activity — selectively quieting neurons that would otherwise pull the brain’s spontaneous patterns in a different direction.
Think of it like a signal emerging from static. Even behind closed eyes, your visual brain areas are alive with shifting patterns of activity — fragments of every face, scene, and object you’ve ever encountered drifting through at low volume. When you try to picture a friend’s face, your brain doesn’t generate that face fresh. It’s already there, scattered and unresolved in the background noise. What imagination does is hold it still — dampening the competing neural chatter until the image settles into focus.
In this sense, imagination may have more to do with what the brain silences than what it creates.
The Evidence
Several lines of research point in the same direction. In experiments where people were asked to imagine objects, the neural signatures their brains produced matched patterns of suppression rather than activation. Other research groups have independently found the same pattern.
Perhaps most striking is what this explains about aphantasia — a condition affecting roughly one in a hundred people, in which a person is completely unable to form mental images. People with weaker mental imagery, it turns out, tend to have more excitable early visual areas, where neurons fire more readily on their own. A visual system that’s harder to hold steady, in other words, is one where imagination struggles to carve anything out of the noise. At the opposite end, people with hyperphantasia — where mental images are almost as vivid as real perception — may simply have visual systems that are easier to shape and hold.
Why Imagination Feels Weaker Than Sight
This theory also neatly explains something we all intuitively know: imagined images feel thinner, more fragile, than actually seeing something. That’s because real vision arrives as a powerful, consistent signal from the outside world, strong enough to override the brain’s internal patterns. Imagination, by contrast, is working with those patterns — gently reshaping what’s already there rather than overwhelming it. The result is something we can almost see, but not quite.
It also explains why we rarely confuse imagination with reality. The brain’s own internal activity simply doesn’t have the strength or regularity of genuine visual input. We know the difference because we feel the difference.
What This Changes
This isn’t just a technical tweak to an existing model — it reframes imagination as fundamentally a subtractive process rather than a generative one. The brain isn’t a blank canvas on which the mind paints pictures. It’s a constantly churning sea of activity, and imagination is the act of stilling part of it into something coherent.
It’s a strangely beautiful idea: that every image you’ve ever conjured in your mind was already there, waiting in the noise, and all your brain had to do was learn to listen for it.