Abstract
Intentional visual imagery is a component of numerous aspects of cognition. Related to visual imagery, mental simulation plays a role in language comprehension: modality-specific regions of the brain are activated as an implicit part of people understanding language. The degree of overlap between the processes underlying conscious, voluntary visual imagery versus less conscious, more automatic mental simulation is unclear. We investigated this issue by having aphantasics (people who are unable to experience conscious voluntary visual imagery) and control participants perform a property verification task in which they were asked whether a property is a physical part of an object (e.g., is mane a physical part of a lion ?). We manipulated the false trials so that the two words either were associated (semantically related) but did not form an object–part combination ( monkey – banana ), or were not associated ( apple – cloud ). Solomon and Barsalou ( Memory & Cognition, 32 , 244–259, 2004) demonstrated that word association influenced responses when the words in the false trials were not associated, whereas when they were associated, perceptual measures most strongly influenced the results, indicating mental simulation. In the present study, control participants and aphantasics demonstrated similar evidence of the use of both mental simulation and word association when verifying whether the words formed an object–part combination. These results suggest that visual imagery and mental simulation are at least somewhat separable cognitive processes.
What This Study Is About
Researchers wanted to know if people with aphantasia—the inability to "see" images in their mind—still use the visual parts of their brain automatically when they process language. They were testing if "picturing something on purpose" is a different process than the brain "simulating" an image behind the scenes to understand a word.
How They Studied It
The team worked with 59 participants: 30 with aphantasia and 29 "typical imagers" (people who can easily see mental pictures). Participants performed a "property verification task." They were shown pairs of words and had to quickly decide if one was a physical part of the other—for example, "Does a lion have a mane?" or "Does a house have a chimney?" The researchers measured how fast and accurately they answered.
What They Found
Surprisingly, people with aphantasia performed almost exactly like the control group! Even though they couldn't "see" the lion or the mane in their mind's eye, they were just as fast and accurate at confirming the parts.
In science, we call the ability to picture things on purpose mental imagery. The automatic, background process of the brain "prepping" visual info is called mental simulation. This study found that even without the "mental pictures," the aphantasic group’s brains were still using that background simulation to understand the words.
What This Might Mean
This suggests that aphantasia might only affect the "conscious" part of the brain—the part that lets you enjoy a mental movie. The "unconscious" part that helps you understand language seems to work just fine.
Think of it like a computer: aphantasia might be like having the monitor turned off. You can't see the image, but the processor inside is still running the code perfectly. However, we should be careful; this was a small study of 59 people and relied on the VVIQ (a questionnaire where people rate their own imagery), which is subjective. We need more brain-scan data to be 100% sure.
One Interesting Detail
The researchers found that visual details actually influenced the reaction times of people with aphantasia *more* than the control group. It’s as if their brains were leaning even harder on that "hidden" visual data to get the job done!