The Mind’s Eye

Previously, I viewed sight and imagination as distinct processes, yet research indicates that the brain generates mental images by essentially reversing its perceptual functions.

When light enters our eyes, it transforms into neural signals directed to the brain's visual cortex, which processes the information. This data is then relayed to the semantic and memory regions at the brain's front, enabling us to identify objects — be it a book or a sandwich.

Nadine Dijkstra, a postdoctoral researcher at University College London focusing on perception, explained to Yasemin Saplakoglu of Quanta Magazine:

> “During imagination, we basically do the opposite.”

According to Dijkstra, the imagination process begins with a desire to visualize something, such as a whimsical treehouse. Information flows from the semantic and memory areas to the visual cortex, where the mental image is constructed. However, the exact workings of visual imagination remain largely enigmatic.

Nonetheless, some individuals, including myself, find it difficult to "see" anything in our mind's eye; a subset cannot visualize at all.

Aphantasia

Much of my cognitive activity manifests as swirling sensations that take time to interpret. Additionally, I have a rich inner dialogue filled with numerous distinct voices, each serving a purpose. Generally positive and verbose, my inner voices can be muted when necessary. Like many, I assumed that everyone experienced thoughts in this manner.

However, my ability to visualize is almost nonexistent. I can only recall images I have previously seen, and even those are often fragmented and static. It's akin to peering through a foggy window. I initially believed that expressions like "picture it in your mind's eye" were figurative until I realized they were meant literally.

Sir Francis Galton of the University of Cambridge documented experiences similar to mine in 1880, but the term "aphantasia" was only coined in 2015.

Aphantasia describes individuals who lack a visual imagination and cannot create mental images. While I can somewhat recall what I've seen, many with aphantasia cannot visualize anything at all. It's important to note that aphantasia is not classified as a disorder, but rather one of many cognitive variations among humans.

Research into aphantasia is still in its early stages, with estimates suggesting that around 1% to 4% of the population may experience it. However, these figures could evolve as studies progress. The challenge lies in the fact that scientific methodologies often focus on observable phenomena, while aphantasia pertains to subjective internal experiences.

Researchers primarily depend on self-reported experiences to gain insights, utilizing tools like the Vividness of Visual Imagery Questionnaire from 1973 to assess mental imagery strength. The reliance on introspective reports has led some neuroscientists to question the existence of aphantasia altogether.

Dijkstra noted the potential for language barriers in describing mental imagery. She stated:

> “We think we know what we mean when we talk about what mental imagery is, but then when you really dig into it, everybody experiences something wildly different.”

For those with mental imagery, imagining life without it can be perplexing. Bence Nanay, a professor of philosophical psychology at the University of Antwerp, remarked:

> “You might think that aphantasia is this terrible thing … a very impoverished mental life, [but] I really think that if you have aphantasia, you actually have something to be happy about.”

Research links mental imagery to mental health, suggesting that individuals with aphantasia may be less prone to vivid mental health issues, while the opposite may apply for those with heightened imagery.

Mental imagery exists on a spectrum. Full aphantasia, characterized by an inability to visualize, contrasts with hyperphantasia, where individuals experience vivid mental imagery akin to reality.

Hyperphantasics perceive images as real and can engage all five senses, though they do not hallucinate. They recognize that their mental "sight" is not reality; however, hyperphantasia might be associated with conditions like schizophrenia and Parkinson's disease.

Aphantasia in the Brain

Neuroscientists are keen to understand how the brains of those with aphantasia differ from those who experience mental imagery.

Initial studies indicated that the ability to form mental images may relate to the connections between brain areas responsible for decision-making, memory, and vision. Some individuals with aphantasia can still recognize objects and faces and dream in images, suggesting their minds retain visual information, though they struggle to access or recreate it voluntarily.

However, this theory is just one of several possibilities. Subjective experiences are diverse, implying that various neural mechanisms may operate across the aphantasia spectrum. Fortunately, advancements in technology now allow scientists to observe the brain activity of those with aphantasia.

2003–2010

In 2003, neurologist Adam Zeman encountered a 60-year-old man named Jim Campbell, whose case would transform visual imagery research.

Campbell reported losing his ability to create mental images following cardiac surgery. Previously, he could visualize scenes from novels and remember where he placed objects. Post-surgery, he could no longer visualize anything.

In the early 2000s, evidence was accumulating that the visual cortex activates during imagination, prompting Zeman to investigate whether Campbell's visual cortex had become inactive.

To explore this, Zeman placed Campbell in a functional magnetic resonance imaging (fMRI) machine to monitor blood flow in his brain while showing him images of famous individuals. As Campbell imagined the celebrities, scans revealed that his visual cortex activated only when he viewed the photos, not during imagination. Zeman described Campbell's condition as a "blind imagination."

Zeman's case study could have faded into obscurity, but journalist Carl Zimmer highlighted it in Discover magazine, drawing attention to the phenomenon. Consequently, Zeman was contacted by over twenty individuals who identified with Campbell, noting they had never been able to visualize.

2015–2018

By 2015, Zeman had gathered sufficient data to conclude that aphantasia was relatively common, yet it lacked an official name. He invited a friend to create one, leading to the adaptation of Aristotle's term "Phantasia."

Following the introduction of "aphantasia," The New York Times published a story that significantly raised awareness. Zeman noted that prior to this, he received a few dozen inquiries about mental imagery; post-publication, inquiries surged into the tens of thousands.

Among those intrigued by the 2015 article was Rebecca Keogh, a doctoral student working under Joel Pearson, a cognitive neuroscience professor at the University of New South Wales. Keogh, now a research fellow at Macquarie University, and Pearson aimed to investigate aphantasia by designing tests to confirm its existence.

Their research assessed participants' abilities to maintain visual images in their minds, measuring pupil and sweat responses during mental imagery tasks. Keogh explained:

> “[I]t’s not just that they’re reporting a difference; there seems to be some sort of difference in their experience.”

2021

By 2021, researchers, including Zeman, sought to understand why individuals with aphantasia can dream in images despite their inability to visualize voluntarily. While they recognize mental images in dreams, aphantasics cannot access this process consciously. Zeman aimed to uncover the underlying brain mechanisms.

Using fMRI, Zeman and colleagues scanned over 100 volunteers with varying mental imagery abilities. They found that aphantasics exhibited weaker connections between higher-level control centers, like the prefrontal cortex, and lower-level perception centers, like the visual cortex, compared to hyperphantasics.

A related study by Paolo Bartolomeo at the Paris Brain Institute reinforced Zeman's findings. Bartolomeo's team observed similar brain region activations across the spectrum, but disconnections were noted in aphantasics between the prefrontal cortex and the fusiform imagery node, identified by Bartolomeo in 2020 as crucial for high-level visual processing.

2024

Cornelia McCormick, a memory researcher at the University of Bonn, questioned how individuals with aphantasia could recall their life experiences. This curiosity prompted her to conduct a study with fMRI scans of individuals recounting autobiographical memories.

The research, published in June 2024, involved 14 congenital aphantasics and 16 matched controls. The findings indicated that aphantasics displayed weaker autobiographical memories and less activity in the hippocampus, a region pivotal for information consolidation and memory retrieval. While the hippocampus was less active in aphantasics, their visual cortex exhibited heightened activity compared to those with visual imagery.

McCormick hypothesized that increased activity in the visual cortex might interfere with the retrieval of mental images. Bartolomeo echoed this sentiment, suggesting that aphantasics may access visual information but struggle to integrate it into a cohesive subjective experience.

Further research is necessary to validate these theories, yet they align with the observations that aphantasics can perceive images while dreaming and recognize faces and objects.

Normal Does Not Exist

Current research suggests differences in brain connectivity between vision centers and integrative regions in individuals with aphantasia. However, "different" does not equate to "defective."

Researchers in the field agree that neither aphantasia nor hyperphantasia constitutes a disorder. Individuals at both extremes of the spectrum navigate life successfully. Even full aphantasics can articulate descriptions effectively. Bartolomeo found that when he asked aphantasics how they describe people or objects from memory without mental images, they simply replied: “I just know.”

I can relate to this experience, though I struggle to articulate it further. More often than not, I recount information from memory without visualizing it. It feels as though it simply emerges from my subconscious.

Bartolomeo emphasized that the aphantasia spectrum represents another variation of normal brain function:

> “It’s just a variant of the normal brain. There are variants in everything human.”

This perspective is crucial. It's easy to assume everyone’s brain operates like ours, but increasing research reveals the complexity of human cognition.

Nanay noted that "everybody’s weird," suggesting that each individual occupies a unique position on the aphantasia-hyperphantasia spectrum, with varying mental imagery experiences.

Perspective Shift

During my research, I encountered a particularly intriguing statistic:

> “A small percentage of people with aphantasia only experience it with closed eyes. A little over 15% of people with aphantasia can ‘see’ mental images if they open their eyes. Why this happens is unknown.”

In my twenties, I discovered I belonged to this group. During a guided meditation, my teacher instructed us to close our eyes and visualize a scene. Oddly, my mental images were clearer with my eyes open, resembling a blank stare. My teacher reprimanded me, believing I wasn't participating, leading me to keep my eyes closed in future sessions.

This situation perplexed me, as I experienced the same phenomenon in personal visualization attempts. While my images remain incomplete, they are more vivid with my eyes open; closing them results in darkness.

It’s fascinating to live in an era where such experiences can be explored scientifically. We’ve always recognized individual uniqueness, but we are now uncovering the depth of this truth.

This article was originally published in my newsletter, Curious Adventure, which highlights the remarkable discoveries scientists make across disciplines, reminding us of our vast ignorance.

Thank you for reading. Your engagement is appreciated.