 "brain illusion")
Do you remember the viral blue-and-black versus white-and-gold dress debate that broke the internet a few years ago? People swore they were seeing completely different colours, yet they were all looking at the same photo. The mystery sparked arguments, memes, and scientific studies.
Now, a new study published in Nature Neuroscience, titled Recurrent pattern completion drives the neocortical representation of sensory inference, finally explains why your brain does not just see the world, it guesses it.
Researchers found that a special set of neurons in the primary visual cortex can trick you into seeing shapes and patterns that are not even there, because your brain constantly fills in the blanks to create its own version of reality.
According to the researchers, this is not a bug in your brain, it is a feature designed by evolution to keep you alive.
What does the study reveal about how we see the world?
The researchers found that the brain does not passively record reality like a camera. Instead, it infers reality by combining sensory data with past experiences and expectations. That means your brain makes its best guess about what you are seeing, especially when information is incomplete.
Also Read
 "Cancer cells")
 "cough syrup, medicine, cold")
 "role of protein in the body")
 "Cough syrup")
 "Calcium")
This ability, known as sensory inference, helps you make quick survival decisions. Imagine spotting movement in the bushes, your brain fills in the missing details and tells you it might be a predator. It is better to be wrong and safe than to take too long to process.
Scientists identified a subset of neurons in V1, the brain’s first visual processing layer, that respond to illusions known as illusory contours (ICs). For example, in the Kanizsa triangle illusion, you “see” a bright white triangle that does not actually exist.
When these neurons were artificially activated with lasers, the brain responded as though it were seeing the illusion, even when no visual input was present. These neurons do not just respond to raw data; they broadcast the brain’s best guess of reality.
Why does the brain rely on illusions at all?
At first glance, illusions seem like mistakes. But scientists argue they are rational errors. The brain is wired to fill in the blanks because much of what we see in daily life is incomplete or obscured, such as objects behind a tree or words half-covered on a page.
In this sense, illusion is survival. By quickly completing the missing picture, the brain allows you to act without hesitation
How did scientists prove this?
Researchers used advanced neuroimaging and stimulation techniques such as:
- Two-photon calcium imaging to track activity in thousands of neurons
- Neuropixels probes to record brain activity with ultra-high resolution
- Holographic optogenetics to activate specific neurons and trigger illusions
The results showed that stimulating just the IC-encoder neurons caused the brain to “fill in” the missing shapes, essentially manufacturing perception from scratch.
Does this mean reality is just an illusion?
The researchers emphasised that while perception is a form of inference, it is not the same as hallucination. Our brains generally agree on what we see because we all run on the same biological “software.”
But the study underlines a startling truth that your perception of reality is not reality itself, it is your brain’s version of it.
For more health updates, follow #HealthWithBS
This content is for informational purposes only and is not a substitute for professional medical advice.
 "Doctors, prescriptions")
 "hair dye")
 "cyberbullying and parents roles")
 "cocoa")
 "active lifestyle")
