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Is aphantasia a neurological deficit? An event-related potentials entropy study on perception and mental imagery interaction

Wymark, D., Jani, V., Sheculski, M., & D'Angiulli, A. (2025). Is aphantasia a neurological deficit? an event-related potentials entropy study on perception and mental imagery interaction. Journal of the Neurological Sciences, 480, 125361. doi:10.1016/j.jns.2025.125361

Abstract

Mental imagery, or recreating sensory experiences without external stimuli, is crucial for memory, problem-solving, and creativity. Research reveals significant cognitive variability in conditions like aphantasia (inability to form mental images) and hyperaphantasia (extremely vivid imagery). While aphantasia is considered a deficit, recent studies suggest it reflects a different cognitive processing mode. Neuroimaging indicates reduced activity in the visual cortex in aphantasics, while hyperaphantasiacs show heightened activation in these areas. These differences suggest variations in neural processing without dysfunction. We aimed to explore how varying levels of mental imagery impact brain activity and cognitive performance.

What This Study Is About

Researchers investigated whether aphantasia—the inability to form mental images—should be viewed as a medical "deficit" or simply a different way of processing information. They looked at how varying levels of imagery vividness, from aphantasia to hyperphantasia (extremely vivid imagery), affect brain activity and performance on tasks.

How They Studied It

The study used EEG (electroencephalogram) to record the electrical activity of the brain. Researchers compared three groups: people with aphantasia, people with average imagery, and people with hyperphantasia. Participants performed tasks designed to test the "Perky effect"—a phenomenon where mental imagery can interfere with or be mistaken for actual visual perception. The team also used "entropy analysis" to measure how organized or complex the brain's electrical signals were during these tasks.

What They Found

The results showed that people with aphantasia actually performed slightly better (2.5% higher accuracy) on certain tasks when imagery was involved compared to those with high vividness, who saw a decrease in accuracy. The brain scans revealed different patterns of activity:

Aphantasia group: Showed higher "entropy" (more complex or varied activity) in the frontal and temporal lobes, which are areas often associated with high-level processing and memory.

Hyperphantasia group: Showed higher entropy in the vision-processing areas at the back of the brain (occipital lobes).

Perky Effect: The tendency for imagery to interfere with real-world seeing increased as imagery became more vivid.

What This Might Mean

These findings suggest that aphantasia is not a neurological "brokenness" or deficit. Instead, it represents a different cognitive strategy. While people with vivid imagery rely heavily on the brain's visual centers, people with aphantasia may use different networks, particularly in the front of the brain, to process information. This supports the idea of "neurodiversity"—that there are many valid ways for a human brain to function.

One Interesting Detail

While people with hyperphantasia have the "superpower" of vivid imagery, it can sometimes get in the way; they were nearly 10% less accurate on certain perception tasks because their intense mental images likely interfered with what they were actually seeing.

Is aphantasia a neurological deficit? An event-related potentials entropy study on perception and mental imagery interaction

Abstract

Authors

Is aphantasia a neurological deficit? An event-related potentials entropy study on perception and mental imagery interaction

Abstract

Authors

Is aphantasia a neurological deficit? An event-related potentials entropy study on perception and mental imagery interaction

Abstract

Authors

What This Study Is About

How They Studied It

What They Found

What This Might Mean

One Interesting Detail

Is aphantasia a neurological deficit? An event-related potentials entropy study on perception and mental imagery interaction

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

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

Rebecca Keogh

Martin Reuter

Juha Silvanto

Paolo Bartolomeo

Carla Dance

Jianghao Liu

Fraser Milton

Joel Pearson

Merlin Monzel

Adam Zeman

Rebecca Keogh

Martin Reuter

Juha Silvanto

Paolo Bartolomeo

Carla Dance

Jianghao Liu

Fraser Milton