Have you ever imagined something so clearly that it felt real?
A new study from researchers at University College London (UCL) has uncovered how the brain tells the difference between what’s real and what’s imagined—and why that distinction sometimes gets blurred.
Published in the journal Neuron, the study found that a part of the brain called the fusiform gyrus, located near your temples, plays a key role in helping us decide whether something we “see” is actually in front of us or just in our minds.
To explore this, the researchers asked 26 volunteers to take part in a visual test. Participants looked at a screen where faint patterns were sometimes shown against a noisy background. But only half the time were real patterns actually displayed.
The twist?
Participants were also asked to imagine a pattern at the same time—sometimes the same pattern they were trying to spot, sometimes a different one.
The result: When people imagined the same pattern very vividly, they were more likely to say they saw something—even when nothing had actually been shown. In other words, their imagination fooled them into thinking it was reality.
Using fMRI brain scans, the team discovered that strong activity in the fusiform gyrus predicted whether someone believed what they saw was real—even if it wasn’t.
Typically, this part of the brain shows more activity when someone sees a real object and less activity during imagination. But in these cases, vivid imagination boosted activity so much that the brain misread the mental image as a real one.
Lead author Dr. Nadine Dijkstra explained, “When we imagine something very clearly, our brain activity can look a lot like when we actually see that thing. This makes it harder for the brain to tell the difference.”
The study also found that another brain region, the anterior insula, located in the front of the brain, works together with the fusiform gyrus to make decisions about what’s real. This region is known for helping us reflect on our thoughts—what scientists call “metacognition.” When both areas were active together, people were more likely to say the imagined pattern was real.
These findings could have major implications for understanding mental health conditions like schizophrenia, where people often have trouble telling reality from imagination. By learning how the brain makes these decisions, researchers hope to improve diagnosis and treatment for such conditions.
The study may also inform how virtual reality systems are developed in the future—helping us understand how the brain reacts when fake experiences feel real.
If you care about brain health, please read studies that eating apples and tea could keep dementia at bay, and Olive oil: a daily dose for better brain health.
For more health information, please see recent studies what you eat together may affect your dementia risk, and time-restricted eating: a simple way to fight aging and cancer.
