How the Brain Distinguishes Reality from Imagination

Imagine an apple, any apple. If you do not suffer from aphantasia, this idea activates your brain in a way similar to when you see a real apple. But the question remains: how does our brain differentiate between reality and imagination?

The Neural Mechanism of Differentiating Reality from Imagination

Neuroscientists have begun to understand the neural circuits involved in distinguishing reality from imagination. In a recent study, researchers identified a brain region that generates what is known as the “reality signal.” This signal is evaluated by another region, and when it functions abnormally, it is associated with disorders such as schizophrenia.

Research suggests that understanding the mechanism of reality monitoring can aid in comprehending and treating schizophrenia and other disorders that affect the ability to distinguish between reality and imagination.

How the Brain Processes Visual Information

We tend to believe that we perceive reality as it is, but the information that travels from the eye to the brain becomes more abstract and subjective. In the early stages of visual processing, lines and colors are transformed into concepts and meanings as they reach higher cortical networks.

This process is called “bottom-up processing,” where information flows from the eye to the brain. However, there is also “top-down processing,” where higher cognition influences sensory perception. This processing can lead to visual or auditory illusions, such as the “Yanny-Laurel” audio clip.

Experimental Understanding of Reality and Imagination Distinction

Researchers conducted an experiment where participants were shown difficult-to-see patterns while inside a brain scanner. Participants were asked to imagine a certain pattern and identify it if it was actually present. The results showed that participants were more likely to consider the pattern present if they were imagining the same pattern.

Functional MRI scans revealed that a region called the fusiform gyrus is activated when seeing or imagining something. These activities indicate whether a person believes something is real, even if it is imagined.

The Importance of the Reality Signal in the Brain

The reality signal in the fusiform gyrus is the sum of activity from both imagination and perception. Researchers believe this signal is evaluated in another region called the anterior insular cortex, which decides whether the activity above a certain threshold is real or not.

This system usually works well because perception generates stronger activity than imagination, allowing it to surpass the minimum threshold for the reality signal, while imagination typically does not.

Conclusion

Research indicates that the brain relies on a reality signal to determine whether information is real or imagined. This understanding may help develop new treatments for mental disorders like schizophrenia, where an imbalance in this mechanism can lead to hallucinations. By targeting these neural circuits, individuals’ ability to distinguish between reality and imagination can be improved.