Interoception, insula, and agency: a predictive coding account of aphantasia
Silvanto, J. (2025). Interoception, insula, and agency: a predictive coding account of aphantasia. Frontiers in Psychology, 16. doi:10.3389/fpsyg.2025.1564251
Abstract
Aphantasia-the inability to consciously experience mental imagery-has emerged as one of the most intriguing phenomena in cognitive psychology and neuroscienc...
Authors
- Juha Silvanto10
What This Study Is About
Why can some people "see" a sunset in their head while others see only darkness? This paper explores a new theory: that aphantasia—the inability to create mental imagery (picturing things in your mind)—might be caused by how the brain processes signals from inside our own bodies.
How They Studied It
This wasn't a traditional lab experiment with a group of participants. Instead, it is a "theoretical paper." The researcher acted like a detective, gathering clues from many previous studies involving brain scans and psychological tests. By looking at how the brain handles internal sensations and "willpower," the author built a new model to explain why the "mind's eye" stays shut for some people.
What They Found
The researcher points to a specific brain part called the insula. Think of the insula as a "volume knob" that balances signals from the outside world (like what you see with your eyes) and signals from inside your body (like your heartbeat).
The theory suggests:
- In most people, when they want to imagine something, the brain "turns up the volume" on internal signals so the image becomes clear.
- In people with aphantasia, the brain might not "trust" these internal signals enough to turn the volume up.
- Because the volume stays low, the mental image never becomes strong enough to reach conscious awareness. It’s like a radio station that is broadcasting, but the volume is so low you can’t hear the music.
What This Might Mean
This suggests that aphantasia isn't just a "vision" problem; it’s a connection issue between our bodies and our thoughts. It helps explain a famous mystery: why many people with aphantasia still see vivid pictures in their dreams. Since dreams happen automatically (without us trying), the brain doesn't need to "turn the knob" itself.
A note of caution: This is a scientific theory, not a proven fact yet. While it fits the current evidence, we need more experiments—specifically testing how people with aphantasia perceive their own heartbeats or body signals—to see if this "volume knob" idea is 100% correct.
One Interesting Detail
The paper highlights a concept called agency—the feeling that *you* are the one in control of your thoughts. Research suggests that people with aphantasia might have a slightly different sense of "mental agency," meaning their brains don't always recognize internal thoughts as something they are actively "creating."
This summary was generated by AI and may contain errors. Always refer to the original paper for accuracy.