Behavioral and Neural Signatures of Visual Imagery Vividness Extremes: Aphantasia versus Hyperphantasia
Milton, F., Fulford, J., Dance, C., Gaddum, J., Heuerman-Williamson, B., Jones, K., Knight, K. F., MacKisack, M., Winlove, C., & Zeman, A. (2021). Behavioral and neural signatures of visual imagery vividness extremes: aphantasia versus hyperphantasia. Cerebral Cortex Communications, 2(2). doi:10.1093/texcom/tgab035
Visual Imagination: Why Some People See Vivid Mental Images and Others See Nothing at All
Imagine being asked to picture your childhood home in your mind's eye. For most people, this is effortless—a rich tapestry of colors, textures, and details floods their consciousness. But for others, the request triggers nothing but darkness. This stark difference in how people experience visual imagery has long puzzled scientists, yet until recently, nobody had systematically studied these extremes. A 2021 study published in *Cerebral Cortex Communications* finally tackled this puzzle, revealing that the vividness of our mental imagery isn't just a quirk—it's a measurable trait with profound differences in how our brains are wired.
The researchers focused on two extreme groups: people with aphantasia, who cannot voluntarily create visual images in their minds, and those with hyperphantasia, who experience exceptionally vivid, almost photorealistic mental imagery. By comparing these groups to people with typical imagery abilities, scientists could map out exactly how visual imagination varies across the population and what happens in the brain to cause these differences.
The team, led by researchers at the University of Exeter, conducted a thorough investigation combining behavioral tests and advanced brain imaging. They assessed participants' memory, ability to imagine future events, performance on spatial reasoning tasks, and personality traits. They also scanned participants' brains using multiple imaging techniques to look for structural and functional differences. What they discovered was striking: visual imagery vividness appears to be one of the most significant ways human minds differ from one another.
What the research revealed:
The study found clear behavioral differences between the groups. People with aphantasia scored significantly lower on tests asking them to imagine detailed scenarios—whether remembering the past or envisioning the future. When asked to imagine a future event and describe it in detail, they struggled more than others to construct narratives rich in sensory information. Interestingly, those with aphantasia also reported more difficulty recognizing faces, suggesting their mental imagery challenges extend beyond just imagining scenes. Meanwhile, people with hyperphantasia showed the opposite pattern: they excelled at these imagination tasks and rated their mental images as intensely present and vivid.
The personality differences were equally revealing. People with aphantasia tended to be more introverted and showed elevated autism spectrum traits—not autism itself, but higher scores on measures associated with autism. Those with hyperphantasia, by contrast, scored higher on "openness to experience," a personality dimension reflecting curiosity, broad interests, and a rich inner life. This connection between personality and mental imagery suggests our ability to visualize shapes not just memory and imagination, but perhaps our whole relationship with experience.
Brain imaging exposed structural differences that help explain these behavioral patterns. The researchers used resting-state functional MRI to measure how different brain regions communicate when a person isn't actively performing tasks. They discovered reduced connectivity between distant brain regions in people with aphantasia—their brains showed weaker communication networks compared to controls. This reduced "long-range connectivity" aligns with similar patterns seen in autism spectrum conditions, possibly explaining the personality overlaps they observed.
The research also touched on something remarkable: the relationship between visual imagery and autobiographical memory. When the brain struggles to generate visual imagery, memory for personal experiences appears to suffer. This suggests that visualization isn't merely entertainment for the mind—it's deeply woven into how we remember our lives and imagine our futures. For someone with aphantasia, this could mean their life memories feel less vivid, less emotionally resonant, or harder to access.
Why this matters beyond the laboratory
This study validates something many people with aphantasia have long reported: that their condition is real, neurological, and not simply a failure of effort or attention. These aren't people being stubborn or lacking imagination in the abstract sense—their brains are genuinely configured differently. Understanding this has real implications. It could help clinicians better support people with aphantasia, explain why some individuals struggle with memory or face recognition, and even inform how we approach education and therapy for people with these traits.
Perhaps equally important, the research demonstrates that the human mind varies far more than we often recognize. Our subjective experience—what's actually happening in our consciousness—reflects genuine differences in brain structure and function. The next time someone tells you they can't visualize things, you'll know it's not stubbornness or a metaphor. It's neurology. And that simple fact opens doors to understanding human diversity in profound new ways.