How Interoception and the Insula Shape Mental Imagery and Aphantasia
Silvanto, J., & Nagai, Y. (2025). How interoception and the insula shape mental imagery and aphantasia. Brain Topography, 38(2). doi:10.1007/s10548-025-01101-6
Abstract
A major question in cognitive neuroscience is understanding the neural basis of mental imagery, particularly in cases of its absence, known as aphantasia.
Authors
- Juha Silvanto10
- Yoko Nagai3
What This Study Is About
Researchers wanted to know if aphantasia—the inability to "see" pictures in your mind—is caused by how the brain connects our internal body feelings (like a heartbeat) to our thoughts. They propose that mental imagery isn't just a "movie" in your head, but a full-body experience that requires a strong connection to your physical self.
How They Studied It
This wasn't a lab experiment with new volunteers. Instead, it was a "review paper" where scientists analyzed years of existing research. They looked at brain scans, psychological tests, and data from both aphantasics and people with typical imagery to see how the insula (a brain region that acts like a "hub" for body signals) behaves.
What They Found
The researchers found that creating a mental image is like a team sport. One part of the brain handles the "picture," but another part—the insula—adds the "feeling." This process is called interoception (your brain’s ability to sense what’s happening inside your body, like your pulse or breathing).
The study suggests that in people with aphantasia, the insula might not be "plugged in" correctly to the visual parts of the brain. Without those internal body signals to "anchor" the image, the brain struggles to create a vivid, stable picture that you can control.
What This Might Mean
This suggests that aphantasia isn't just a "vision" problem; it’s a "connection" problem. It explains why some people with aphantasia also find it harder to remember personal memories or recognize emotions—both of which require the brain to link facts with physical feelings.
However, because this is a theoretical paper based on previous studies, we can't say for sure yet. It "suggests" a new map for future researchers to follow, but we still need more direct brain-scan experiments to prove the insula is the main culprit.
One Interesting Detail
The researchers pointed out that people with aphantasia are more likely to have dyspraxia (a condition that makes physical coordination difficult). This supports their theory: if your brain struggles to integrate body signals with your "mental map," it affects both your imagination and your movement!
This summary was generated by AI and may contain errors. Always refer to the original paper for accuracy.