Seeing through the static: Reduced imagery vividness in aphantasia is associated with impaired temporal lobe signal complexity

DOI: 10.1016/j.neuropsychologia.2025.109322

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Noble, C., Taylor, N. L., Milton, F., Fulford, J., Tan, J. B., O'Callaghan, C., Zeman, A., & Shine, J. M. (2026). Seeing through the static: reduced imagery vividness in aphantasia is associated with impaired temporal lobe signal complexity. Neuropsychologia, 221, 109322. doi:10.1016/j.neuropsychologia.2025.109322

Abstract

Aphantasia is the inability to experience mental imagery during full wakefulness without any prominent perceptual deficits. Visual aphantasia is associated with differences in distributed brain networks, but its neurobiological underpinnings remain a mystery. In particular, aphantasia may arise due to impairments in the top-down control over visual imagination. We predicted that this in turn would prevent the brains of aphantasic participants from differentiating neural activity encoding the contents of imagination from the background noise of resting activity, particularly within the ventral temporal lobes. To test this hypothesis, we re-analysed functional magnetic resonance imaging (fMRI) data collected from aphantasics (n = 21), hyperphantasics (those with "photographic imagery"; n = 20), and controls (n = 17) during a simple perception and imagery task. We used two measures of informational complexity to quantify the complexity of the spatial pattern of thresholded BOLD signals in the participants' temporal lobes during visual perception and imagery. Both measures of spatial complexity showed significant correlations with imagery vividness. We then performed dynamic functional connectivity analyses on the same data revealing that the higher-order networks of aphantasics were abnormally coupled with the temporal lobes during imagery (p < 0.05). These results provide a novel perspective, reframing aphantasia as an inability of the visual system to selectively activate regions encoding object-specific visual categories above background levels of noise.

Authors

Chanelle Noble1
Natasha L. Taylor1
Fraser Milton9
Jon Fulford3
Joshua B. Tan1
Claire O'Callaghan1
Adam Zeman20
James M. Shine1

What This Study Is About

Researchers investigated why people with aphantasia—the inability to create mental images—experience a "blind mind." They specifically looked at whether the brains of aphantasic individuals struggle to filter out background "noise" to create the clear, complex neural patterns needed for vivid mental imagery.

How They Studied It

The team re-analyzed brain scan data (fMRI) from 58 participants: 21 with aphantasia, 20 with hyperphantasia (highly vivid imagery), and 17 with average imagery. While in the scanner, participants either looked at photos of famous faces and places or tried to imagine them. The researchers used a mathematical measure called "informational complexity" to see how organized or "noisy" the brain activity was in the temporal lobes—the areas responsible for recognizing objects and faces.

What They Found

The study found that people with more vivid imagery had more "complex" and organized patterns of brain activity in their temporal lobes during imagery tasks. In contrast, people with aphantasia showed less complexity, suggesting their brains were not successfully activating specific "image" signals above the background noise. Additionally, the aphantasic group showed weaker connections between the temporal lobes and the brain's "attention networks," which are responsible for focusing the mind on internal thoughts.

What This Might Mean

This suggests that aphantasia might be an "information lesion." Rather than a specific part of the brain being broken, the visual system may simply fail to "turn up the volume" on specific mental images while "turning down" background neural noise. While these findings offer a new way to map imagery strength, the study was based on a relatively small group, and more research is needed to see if these "noisy" signals are the definitive cause of aphantasia.

One Interesting Detail

The researchers used a compression algorithm—similar to how a computer shrinks a large photo file—to measure brain complexity. A brain pattern that is easy to "compress" is considered less complex and was linked to the lower imagery vividness found in aphantasia.

Seeing through the static: Reduced imagery vividness in aphantasia is associated with impaired temporal lobe signal complexity

Abstract

Authors

Seeing through the static: Reduced imagery vividness in aphantasia is associated with impaired temporal lobe signal complexity

Abstract

Authors

Seeing through the static: Reduced imagery vividness in aphantasia is associated with impaired temporal lobe signal complexity

Abstract

Authors

Seeing through the static: Reduced imagery vividness in aphantasia is associated with impaired temporal lobe signal complexity

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

Rebecca Keogh

Martin Reuter

Juha Silvanto

Paolo Bartolomeo

Carla Dance

Jianghao Liu

Fraser Milton