Does Your Brain Really Not Know the Difference Between Reality and Imagination? 🧠
The Neuroscience Behind Perception, Memory, and the Power of Your Mind (8min Read)
TL;DR Summary
Your brain does distinguish between reality and imagination—but it's not foolproof.
Imagined and real experiences activate many of the same neural circuits, which can sometimes lead to confusion.
A "reality threshold" mechanism helps the brain filter strong sensory signals as "real" and weaker ones as "imagined."
Biases, stress, and vivid mental imagery can distort this process, sometimes causing false memories or misperceptions.
Evolutionarily, this ability to imagine and simulate reality helped us plan, survive, and innovate—but it also made us prone to cognitive distortions.
Understanding this mechanism has practical applications in therapy, stress management, virtual reality, and cognitive training.
The Brain’s Reality Filter: Does It Actually Work?
You’ve probably heard the claim: “Your brain doesn’t know the difference between reality and imagination.”
But is that really true?
If it were, we'd all be hallucinating our worst fears or living in a fantasy world with no concept of what’s real.
While it’s true that imagining an experience and actually living it engage similar brain regions, the brain does have systems in place to distinguish between the two—though these systems aren’t perfect.
So, where does this myth come from? And why does the brain sometimes struggle to separate reality from imagination?
Great questions, let’s find out!
Where Did the Myth Come From?
The idea that "your brain doesn’t know the difference between reality and imagination" stems from a mix of psychological studies, neuroscience findings, and, as always, oversimplified self-help claims.
While imagination and reality activate overlapping brain regions, the brain still has reality-checking mechanisms—though they aren’t foolproof.
More on that in a moment, before we get there, let's hit on the origins of this myth!
It all started with the Perky Effect in 1910.
A study by Mary Cheves West Perky showed that people sometimes mistook real faint images for their own imagination.
This suggested that imagination can influence perception—but not that the brain can’t tell the difference.
More recent neuroscience research has revealed that imagining an action (like moving your hand) activates the same brain areas as actually doing it.
This fueled the idea that the brain processes imagination as reality, ignoring the fact that other systems monitor what’s real.
Then, books on manifestation, the Law of Attraction, and motivational psychology popularized the claim that "your brain believes what you tell it."
While mental rehearsal can enhance performance, the idea that "thoughts alone create reality" is a distortion of neuroscience.
It is so much more complex than that it’s laughable…
Your brain is a prediction machine—it blends memory, imagination, and sensory input to construct reality.
While thoughts influence perception, the brain still distinguishes between imagined and real experiences—unless stress, bias, or altered states interfere.
Let’s explore how the brain does this, and when it goes awry!
Neural Overlap: Why Imagining & Experiencing Feel Similar
Neuroimaging studies have shown that real and imagined experiences activate overlapping brain regions!
Places like:
The sensory cortices (visual, auditory, etc.) – Imagining a sound or a face activates sensory areas similar to actually perceiving them.
The hippocampus – Which plays a role in memory retrieval, whether recalling something real or mentally constructing an imagined scenario.
The prefrontal cortex is responsible for planning, predicting, and evaluating reality vs. fiction.
The motor cortex – When you visualize moving your hand, this area lights up as if you were physically moving it.
This overlap explains why mental imagery, mental rehearsal, and memory recall can feel vivid—and why sometimes, your brain does mistake imagination for reality.
I’m sure you’ve heard of the famous experiment, where people who simply imagined playing the piano showed activation in their motor cortex similar to those who physically played it.
Even more fascinating? Those who visualized it showed improved performance when they later played for real.
This experiment is at the center of a ton of the myths we’re debunking today!
The Reality-Checking System: How the Brain Differentiates
Even though imagination and reality share neural pathways, your brain doesn’t just blindly accept everything it imagines as real.
It uses multiple mechanisms to monitor reality.
In fact, each of us has a "Reality Threshold" that it’s always looking out for.
This means that your brain assesses the strength of all the sensory signals hitting it.
If the sensory input is vivid and has strong sensory feedback, it gets labeled as "real."
If it’s weak or internally generated, it gets filed as "imagined."
What is Sensory Feedback?
You’re probably wondering what the hell this “sensory feedback” thing is!
This is the brain's ability to use real-time sensory information (touch, sight, sound, proprioception, etc.) to verify whether something is actually happening.
A really easy example of this system at work is phantom phone vibrations.
I’m sure you’ve experienced this.
You’re sitting in a quiet room, and you suddenly think you feel your phone vibrate in your pocket.
You reach for it, but… nothing. There was no actual notification.
So, what happened?
Your tactile sensory cortex briefly fired as if your phone vibrated.
However, when you checked your phone, your sensory feedback loop (confirming with touch and sight) did not match the expectation of a real vibration.
Your brain quickly adjusted and categorized it as "imagined" rather than real.
If the vibration had been real, your reality threshold would have been crossed because the sensory input was strong and it was confirmed by multiple senses (touch and sight).
So, your brain would have accepted it as real rather than an imagined sensation.
Wild, right?
Source Monitoring & Error Detection
This isn’t the only way your brain distinguishes reality from imagination though.
There’s another mechanism called “source monitoring.”
The concept is covered in the name!
Your prefrontal cortex and hippocampus work together to track where information came from: Did you see this happen, or did you just think about it?
And then the anterior cingulate cortex helps catch errors in perception vs. imagination, preventing mix-ups.
Another very common example of your reality threshold failing you is your dreams!
Ever had a dream that felt so real you questioned it when you woke up?
That’s your reality threshold failing temporarily—until you check the evidence and realize it was just a dream.
This isn’t an airtight system though, as we’re about to find out.
When the Brain Gets Confused: False Memories, Bias, and Stress
Even with these safeguards, the brain isn’t perfect.
Under certain conditions, it struggles to tell reality from imagination.
The more detailed and sensory-rich an imagined event is, the more likely your brain is to file it away as a real memory.
This is why false memories can form.
Studies show that people can absolutely be convinced they experienced something that never happened just by imagining it repeatedly.
In fact, this is what’s behind most magicians and mentalists, they are masters at planting harmless false memories, sometimes weeks before a show!
Stress Makes Imagined Fears Feel Real
Considering trauma & PTSD/CPTSD are at the center of most of the work I do, I couldn’t write this blog without mentioning how these can affect the systems we’ve been talking about.
That’s because your brain reacts almost identically to real and imagined danger.
This is why worrying about a future event can cause actual stress responses—increased heart rate, sweating, and anxiety.
Our ancestors needed to anticipate threats—imagining a predator was nearly as important as seeing one.
But today, this same system makes us overreact to imagined worst-case scenarios.
That means your brain isn’t always responding to reality—it’s responding to perceived reality.
If you vividly imagine failure, embarrassment, or catastrophe, your nervous system will react as if it's happening.
So, why on earth would the brain evolve in a way that could make mixing up reality so easy?
How This Evolved: Why Would the Brain Risk Mixing Up Reality?
It’s pretty simple actually… Being able to simulate realities is the closest thing to a superpower we’ve got compared to other animals.
From an evolutionary perspective, this ability gave humans a major survival advantage!
It allowed us to plan ahead and "mentally time travel" allowing us to prepare for future threats and opportunities.
We can problem-solve and imagine solutions to puzzles before acting to help us avoid mistakes when it matters!
And, of course, social learning, imagining how others might react helps us navigate social interactions.
These things put us so far ahead of our fellow animal compadres that we’ve become the dominant species on earth!
The downside? A powerful imagination also makes us prone to overthinking, anxiety, and false memories as we’ve talked about.
How to Hack Your Brain’s Reality Filter
By now, you’re probably wondering if there are ways to hack this system, and I’m happy to inform you that, yes, you can use this knowledge to your advantage!
1. Use Mental Rehearsal & Visualization
Since your brain reacts to imagined negative experiences as if they’re real, use visualization to your benefit!
This may sound counterintuitive, but visualizing what failure would look like, sound like, feel like, etc actually doubles your likelihood of achieving the goal in mind.
Still have a positive goal in mind, but imagining how much it would suck to not accomplish it will motivate you day to day much more effectively based on how your brain processes stress!
2. Catch False Memories Before They Take Root
Be aware that repetition strengthens false memories.
If you find yourself convinced of a past event or limiting belief you can use challenge these memories!
Cross-check them with real evidence (texts, photos, or others' recollections).
Avoid "rehearsing" the memory in your mind unless you’re sure it happened.
This is the basis of Cognitive Behavioral Therapy! It was created with this exact neural process and ability in mind.
3. Counteract Anxiety by Grounding in Reality
When we’re anxious, this reality-checking system is working against us because of the way we process negatives in the brain.
This is why rumination is a thing, and why it takes such a toll on us mentally and physically!
When you’re caught in an anxious thought loop, there are a few things you can do!
First, “force” sensory reality check-ins.
Remember, one of the ways your brain distinguishes imagination from reality is sensory feedback!
This is the neuroscience behind why the now famous 5-4-3-2-1 sensory technique works so well for anxiety.
Notice 5 things you see, 4 things you can hear, 3 things you can feel, 2 things you can smell & 1 you can taste while focusing on your breath.
This centers you in reality, not the imagined scenario by activating your reality detection system!
Your Brain is More Powerful Than You Realize
Think about it—your brain has evolved to balance two incredible abilities:
It can construct entire worlds in your mind.
It can distinguish those worlds from reality (most of the time).
This means you are not just a passive observer of life.
You are a creator, an architect of your own experience.
Your brain doesn’t just record reality—it shapes it, interprets it, and, at times, bends it in ways that can either limit or empower you.
Yes, the brain sometimes gets it wrong—it can mistake imagination for reality in moments of fear, stress, or vivid memory.
But it also means that you have the power to harness this mechanism for good and bend the world to your will.
Until next time… Live Heroically 🧠
Supporting Research
Ganis, G., Thompson, W. L., & Kosslyn, S. M. (2004). Brain areas underlying visual mental imagery and visual perception: An fMRI study. Cognitive Brain Research, 20(2), 226-241. https://doi.org/10.1016/j.cogbrainres.2004.02.012
Kosslyn, S. M., Ganis, G., & Thompson, W. L. (2001). Neural foundations of imagery. Nature Reviews Neuroscience, 2(9), 635-642. https://doi.org/10.1038/35090055
Loftus, E. F. (2005). Planting misinformation in the human mind: A 30-year investigation of the malleability of memory. Learning & Memory, 12(4), 361-366. https://doi.org/10.1101/lm.94705
O’Craven, K. M., & Kanwisher, N. (2000). Mental imagery of faces and places activates corresponding stimulus-specific brain regions. Journal of Cognitive Neuroscience, 12(6), 1013-1023. https://doi.org/10.1162/08989290051137549
Schacter, D. L., Addis, D. R., & Buckner, R. L. (2007). Remembering the past to imagine the future: The prospective brain. Nature Reviews Neuroscience, 8(9), 657-661. https://doi.org/10.1038/nrn2213