Dissociating voluntary mental imagery and mental simulation: Evidence from aphantasia

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Speed, L. J., Geraerds, E. M. E., & McRae, K. (2025). Dissociating voluntary mental imagery and mental simulation: evidence from aphantasia. Memory & Cognition. doi:10.3758/s13421-025-01731-y

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.

Authors

Laura J. Speed4
Emma M. E. Geraerds1
Ken McRae2

What This Study Is About

Researchers investigated whether people with aphantasia—the inability to visualize things in the mind—still use "mental simulation" to understand language. They wanted to know if the brain automatically processes the physical properties of objects (like their shape or size) even when a person cannot consciously "see" those objects in their mind.

How They Studied It

The study compared a group of people with aphantasia to a "control" group of typical visualizers. Participants performed a "property verification task" where they had to quickly decide if a specific part belonged to an object (for example, "Does a blender have a blade?").

The researchers looked at two things:

1. Linguistic Association: How often the two words appear together in language (like "blender" and "blade").

2. Perceptual Simulation: How much people usually rely on mental pictures to verify that specific part.

By measuring how fast participants reacted, the researchers could tell if they were relying on word habits or internal "mental simulations" of the objects.

What They Found

Surprisingly, people with aphantasia were just as fast and accurate as typical visualizers when the task relied on physical properties. Even though they couldn't consciously see the objects, their reaction times were influenced by the physical characteristics of the items, just like the control group. This suggests that their brains were still performing a "mental simulation" of the objects behind the scenes, even without a conscious mental image.

What This Might Mean

This study suggests that aphantasia might be a disconnect between the brain's "data processing" and our conscious awareness. It indicates that "mental simulation"—the automatic way our brains grasp the meaning of words by simulating the objects they represent—can happen independently of the ability to voluntarily "picture" something. However, the study is limited to simple word pairs; more complex tasks, like reading a long novel, might still show differences in how people with aphantasia experience language.

One Interesting Detail

The researchers found that people with aphantasia actually relied more on "linguistic shortcuts" (how often words are used together) than the control group did. This suggests that while they can simulate objects, they might also develop clever verbal strategies to compensate for their lack of conscious imagery.

Dissociating voluntary mental imagery and mental simulation: Evidence from aphantasia

Abstract

Authors

Dissociating voluntary mental imagery and mental simulation: Evidence from aphantasia

Abstract

Authors

Dissociating voluntary mental imagery and mental simulation: Evidence from aphantasia

Abstract

Authors

Dissociating voluntary mental imagery and mental simulation: Evidence from aphantasia

Abstract

Authors

What This Study Is About

How They Studied It

What They Found

What This Might Mean

One Interesting Detail

What This Study Is About

How They Studied It

What They Found

What This Might Mean

One Interesting Detail

Joel Pearson

Merlin Monzel

Adam Zeman

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