An illustrator suddenly lost his ability to imagine or dream. It could be a post-COVID side effect called aphantasia.

• After Luke McKay got COVID-19, he stopped being able to see images in his mind.
• He said he's "never needed to use reference images so much to do my job as an artist as I do now."

Luke McKay had done everything possible to avoid a COVID-19 infection. In May, he decided to finally take a trip to Scotland that he'd been delaying for over two years. Despite masking in public throughout his travels, he tested positive for the virus on the day he was scheduled to fly home. McKay hunkered down in a hotel room, isolating for two weeks as he waited for his fever and other symptoms to subside.

That hotel stay put an unexpected strain on McKay's finances. Upon returning to the United States, he had to get back to work before he felt he had recovered. But when he sat down to draw, McKay, an illustrator in Seattle, noticed a curious new symptom: "I couldn't visualize images."

McKay also said that around this time he noticed that his inner monologue — the private voice that narrates the thoughts we have throughout the day — was gone. Additionally, though he could normally recall having vivid dreams throughout the night, he realized he could no longer remember having had any dreams at all.

Three months after he was cleared to come home, McKay's cognitive symptoms persist. "Where normally I could draw a car from a mental image, now I need to have a picture of a car on the screen next to me for reference as I draw," McKay says. "I have never needed to use reference images so much to do my job as an artist as I do now."

Before his career as an artist, McKay worked as a nurse for 10 years. It's from his experience in this field that he knew of a medical term to describe what he was feeling: aphantasia, a lack of mental imagery.

His condition is part of a growing list of cognitive symptoms and neurological disorders associated with COVID-19. A case study published in 2021 described a 59-year-old woman with mild COVID-19 symptoms who experienced aphantasia after the infection cleared. These case notes are part of a body of evidence suggesting the coronavirus can directly attack the central nervous system and lead to neurological complications.

An analysis involving over 1.2 million people published in August in The Lancet Psychiatry indicated that the risk of "cognitive deficit" (commonly called "brain fog"), dementia, epilepsy, and seizures was elevated even two years after a COVID-19 infection. Case studies have linked aphantasia to brain trauma.

What is aphantasia?

The term aphantasia can be used to describe anyone with a literal lack of imagination. It can also be used to describe a neurological limitation.

People who have clinically defined aphantasia aren't able to form mental pictures in their mind's eye. The condition is sometimes also called dysikonesia or anauralia, though some neurologists have recently pushed to make "aphantasia" the standard terminology.

It's hard to know how prevalent aphantasia is, because most people aren't on the lookout for it. Even some doctors haven't heard of aphantasia.

"If your hand doesn't work, or if you're numb, that's a significant disability. But if you have problems visualizing as you're speaking, you might not perceive this as a disability, or you might not even perceive it as odd," said Dr. Amit Sachdev, a board-certified neurologist and the director of the division of neuromuscular medicine at Michigan State University.

McKay's case is a notable one because he relies on his mind's eye for rendering when he does graphic design, draws comics, and produces video-game art.

What are the causes and symptoms of aphantasia?

Some people are born with varying degrees of aphantasia. Others may develop it after a stroke or another trauma.

McKay said he worried that a blood clot could have affected his brain when he had COVID-19. Research suggests that acquired aphantasia is usually secondary to a brain injury.

A trip to the doctor ruled out a left-hemisphere stroke, and McKay left with a referral for a neurologist. He said he hadn't used that referral yet because his health insurance "isn't amazing" and he can't afford another financial hit after his unexpected quarantine in Scotland.

While Sachdev hasn't treated McKay, he said his first recommended course of action for someone with symptoms of aphantasia would be to schedule imaging tests to rule out a stroke. Beyond that, he said, there isn't much of a treatment strategy available.

That's partially because it's hard to nail down a standard set of symptoms for aphantasia. It's a condition defined by a lack of something that may or may not have been present before — but that thing isn't a sense, like hearing or sight, but an intangible inner sense of imagination. That can make it hard to explain to other people, or even to detect at all.

McKay's aphantasia may be an example of how COVID-19 can affect a creative and image-based person. While a person who doesn't engage often with their imagination might describe their experience as brain fog, a person with a vivid inner world who has aphantasia might feel a sharper discoloration between what they normally see and what they're currently experiencing.

Sachdev says that "it's absolutely true" that the brain in general can slow down during an active COVID-19 infection or after it's cleared. "We know that because the general complaint of brain fog happens with many patients who have had COVID," he said.

How long does aphantasia last?

Sachdev said that for people like McKay with no visible trauma detectable in a diagnostic image, he'd expect the brain to return to its natural state in time. But there's no treatment to make that happen faster and no studies to help estimate how long it could take.

McKay said he'd experienced some symptoms of long COVID "here and there," including intense fatigue that can be hard to power through. But it's not all bad news. McKay said that after about a month of being home, he could start to see shadows of his former daydreams cropping up; sometimes he'll notice himself having a conversation with himself in the shower. He says he's also started having dreams again, though nothing as vivid as he would typically have had. If his symptoms persist, he says, he's planning on seeing that neurologist.