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Visual mental imagery in typical imagers and in aphantasia: A millimeter-scale 7-T fMRI study

Liu, J., Zhan, M., Hajhajate, D., Spagna, A., Dehaene, S., Cohen, L., & Bartolomeo, P. (2025). Visual mental imagery in typical imagers and in aphantasia: a millimeter-scale 7-t fmri study. Cortex, 185, 113–132. doi:10.1016/j.cortex.2025.01.013

Abstract

Most of us effortlessly describe visual objects, whether seen or remembered. Yet, around 4% of people report congenital aphantasia: they struggle to visualize objects despite being able to describe their visual appearance. What neural mechanisms create this disparity between subjective experience and objective performance? Aphantasia can provide novel insights into conscious processing and awareness. We used ultra-high field 7T fMRI to establish the neural circuits involved in visual mental imagery and perception, and to elucidate the neural mechanisms associated with the processing of internally generated visual information in the absence of imagery experience in congenital aphantasia. Ten typical imagers and 10 aphantasic individuals performed imagery and perceptual tasks in five domains: object shape, object color, written words, faces, and spatial relationships. In typical imagers, imagery tasks activated left-hemisphere frontoparietal areas, the relevant domain-preferring areas in the ventral temporal cortex partly overlapping with the perceptual domain-preferring areas, and a domain-general area in the left fusiform gyrus (the Fusiform Imagery Node). The results were valid for each individual participant. In aphantasic individuals, imagery activated similar visual areas, but there was reduced functional connectivity between the Fusiform Imagery Node and frontoparietal areas. Our results unveil the domain-general and domain-specific circuits of visual mental imagery, their functional disorganization in aphantasia, and support the general hypothesis that conscious visual experience - whether perceived or imagined - depends on the integrated activity of high-level visual cortex and frontoparietal networks.

Authors

  • Jianghao Liu6
  • Minye Zhan1
  • Dounia Hajhajate2
  • Alfredo Spagna2
  • Stanislas Dehaene1
  • Laurent Cohen1
  • Paolo Bartolomeo6

A Window Into the Mind's Eye: Why Some People Can't Visualize

Imagine being asked to picture your childhood home, a friend's face, or your favorite meal. For most of us, these mental images appear almost instantly in our mind's eye—vivid, detailed, and seemingly as real as if we were looking at a photograph. But for about 4% of the population, something remarkable happens: they can describe these things perfectly well, yet they experience complete blankness when trying to visualize them. They have aphantasia, a lifelong condition where the mind's eye simply doesn't work.
This paradox has puzzled neuroscientists for years. How can someone accurately describe what something looks like if they've never actually "seen" it in their mind? What's the difference in the brain between someone who can vividly imagine and someone who cannot, when both can recall the same visual information? A new study published in the journal *Cortex* finally provides some answers, using cutting-edge brain imaging technology to peek inside the brains of both typical imagers and aphantasic individuals.
Researchers led by Jianghao Liu and Paolo Bartolomeo recruited 10 people with typical visual imagery and 10 with aphantasia, then placed them inside an extraordinarily powerful MRI scanner—a 7-Tesla machine, roughly seven times more powerful than the standard hospital scanner. While lying in this machine, participants performed a series of carefully designed tasks: imagining objects of different shapes, recalling colors, visualizing written words, picturing faces, and mentally navigating spatial relationships. The researchers also had them view and hear actual images and sounds to compare how the brain responds to real perception versus imagination.
What they discovered was fascinating and precise. In people with normal imagery, a specific region in the left side of the brain called the fusiform gyrus lit up consistently during all imaginative tasks, regardless of whether participants were imagining faces, words, or objects. The researchers named this region the Fusiform Imagery Node, or FIN. This finding suggests the brain has a special hub dedicated to converting thoughts into visual experience—a kind of internal display screen for consciousness. Around this hub, the brain also activated specialized areas for each type of imagery: one region for faces, another for written words, yet another for colors.
The real insight came when the researchers examined aphantasic brains. Remarkably, these regions still activated—the brain's visual areas still "lit up" when aphantasic individuals tried to imagine things. So the problem wasn't that their visual cortex had stopped working. Instead, the crucial difference was in connectivity—the quality of communication between the brain's visual areas and the frontoparietal networks, the regions involved in conscious attention and planning. In aphantasic individuals, these communication lines were significantly weakened, like trying to watch television through static-filled cables.
This distinction matters enormously because it reveals something profound about consciousness itself. It's not enough for your brain to process visual information; that information must be integrated with your attention and awareness systems for you to actually *experience* seeing something. Without that connection, the visual machinery runs silently in the background, and you remain completely unaware of it.
The implications extend beyond understanding aphantasia alone. This research illuminates how consciousness works generally. Whether you're perceiving something in the real world or imagining it in your mind, the same high-level visual systems and attention networks must work together in concert. Damage this communication network through stroke or injury, and people lose the ability to visualize even when their basic vision remains intact. Disrupt it from birth, as happens in aphantasia, and you navigate life with perfect knowledge of how things look—stored safely in memory—but without the subjective experience of seeing them.
For the 4% of people with aphantasia, this research offers validation and explanation. They're not lacking in visual knowledge or memory; their brains simply process visual information differently. It also opens new avenues for understanding other conditions where consciousness goes awry—from certain types of brain injury to psychiatric conditions. As our brains evolved to create this rich inner world of imagination, they also created the conditions under which that ability could be disrupted. Understanding how it works in both cases helps us grasp what makes us conscious beings in the first place.
This summary was generated by AI and may contain errors. Always refer to the original paper for accuracy.