People with aphantasia lack the ability to create a mental image within their mind’s eye.

Although this visual handicap isn’t detrimental to daily functioning, it’s a curious medical phenomenon that significantly reconceptualizes the way visual memories are stored.

Those with aphantasia are able to recall what certain things look like (ie, a sunset, a loved one’s face), but are unable to see these things in their mind.

 

A mysterious condition

He conducted investigative queries in his book Statistics of Mental Imagery, prompting subjects to picture stimuli in their mind’s eye and score its clarity based on the following criterion: illumination, definition, and coloring.

Galton F. I.-statistics of mental imagery. OUP Academic.

 

Galton found that the vividness of these images ranged exponentially between subjects. When asked to picture a breakfast table, some could recall it with immensely high factuality, but others reported things like, “There is almost no association of memory with objective visual impressions. I recollect the breakfast table, but do not see it.”

 

Current research

Despite this unusual breakthrough, aphantasia didn’t become a talking point in mainstream research until the 21st century. In 2005, British neurologist Adam Zeman, MD, was startled to find a minor surgical procedure had taken away a patient’s visual memory.

Zimmer C. Many people have a vivid 'mind's eye,' while others have none at all. The New York Times. June 8, 2021.

 

Before the procedure, the patient could recall mental images acutely, but was only able to think of them post-operation. After hearing of the case, Zeman and neuroscientist Joel Pearson, PhD, began researching how and why this happened, studying ways changes in a brain’s wiring can disrupt its visual centerpoints.

This is not a disorder as far as I can see. It’s an intriguing variation in human experience.

He later conducted a questionnaire to better understand how aphantasia affected the mental faculties of those who believed they had it. He discovered that they had difficulty recalling events from their lives, concluding that episodic memory is more dependent upon individual experience than previously believed.

Zemen AZJ., Della Sala S, Torrens LA, et al. Loss of imagery phenomenology with intact visuo-spatial task performance: a case of  ‘blind imagination.’ Neuropsychologia. 2010;48(1):145–155.

 

Furthermore, even though they could distinguish shades of two objects sharing the same color, most participants said they were able to do so because they’d seen them enough to remember how they differed.

Now, roughly 0.7% of the world’s population have diagnosed themselves with apantasia, but since this condition currently lacks a proper way to diagnose it, this number may be higher.

 

Self-diagnosing

The lack of outward-facing symptoms make aphantasia difficult to diagnose. It’s a neurological condition that does not inhibit external vision, but rather, the capacity to visualize internally.

For this reason, a simple at-home test can be performed for those who believe they may have it. All anyone has to do is close their eyes and attempt to picture an object.

As Galton discovered, results vary exponentially. As with other visual tests, aphantasia falls on a spectrum. Some people may see an object with crisp luridity, while others may only see a hazy outline. A completely “blind mind’s eye" yields nothing but blackness.

 

Why should you care?

Thomas Ebeyer of Ontario, Canada created the Aphantasia Network to enable connection between people with the condition. A poll posted on his site revealed that its effects may go beyond one’s internal vision.

Some participants reported they couldn’t hear songs or the sounds of people’s voices in their heads. Pearson found that although these findings are valuable, the tenuous nature of self-assessment makes the results hard to conceptualize.

A 2021 survey revealed a possible link between aphantasia and autism.

Dance CJ, Jaquiery M, Eagleman DM, et al. What is the relationship between aphantasia, synaesthesia and autism? Conscious Cogn. 2021;89:103087.

The authors hypothesized that autism and aphantasia may be linked, due to both having components of weak visual imagery.

 

However, this is only one study—albeit one with promising results. For this reason, more research must be done to create a standardized scale for diagnostic purposes.