Neil Kenmuir, 39, from northwest England, discovered he was aphantasic in his early childhood when he could not visualise sheep while “counting sheep” at bedtime. An avid reader, he stays away from overly descriptive texts.

“I just find myself going through the motion of reading the words without any image coming to mind. I usually have to go back and read a passage about a visual description several times," he explains.

Tom Ebeyer, 25, from Canada, encounters the same problem and felt isolated when he could not envision things the same way his girlfriend did. When his mother died a few years ago, he also could not visualise the memories.

Both men suffer from aphantasia - once referred to as “defective revisualisation” or “visual irreminiscence” -, which is a rare phenomenon affecting about one in 50 people.

A term recently coined by scientists

Aphantasia was first recognised in the 1880s when British scientist Sir Francis Galton first spoke of the phenomenon, but since then, it has not generated much systematic research.

Adam Zeman, a professor of cognitive and behavioural neurology at the University of Exeter Medical School and his team of researchers have taken a interest in this and coined the term “aphantasia” referring to “a lack of the mind’s eye.”

"People who have contacted us say they are really delighted that this has been recognised and has been given a name, because they have been trying to explain to people for years that there is this oddity that they find hard to convey to others," he said.

In his study to evaluate the degree of this condition, Professor Zeman used the Vividness of Visual Imagery Questionnaire (VVIQ) on participants to share their experiences with him. The scores on the VVIQ can detect aphantasia; someone who has it would show a score of 16/80. Many of these people had no insight into their problem till their 20s.

As there are multiple regions within the brain at work during the visualisation process, researchers find it challenging to isolate the exact parts responsible for the missing mind’s eye. Though there were reports of people experiencing aphantasia after a brain injury, the condition tends to occur more commonly in a lifelong form.

Hyperphantasia: The flip side

On the other hand, on the opposite end of the spectrum, is hyperphantasia, whereby the individual visualises vividly. This has inspired Professor Zeman to compare the lives and experiences of the polar opposites to gain a better understanding of the conditions. As such, an interdisciplinary project has been funded by the Arts and Humanities Research Council, UK, to facilitate greater understanding of the condition.

For Ebeyer, he feels comforted that more attention is now given to aphantasia. "To have the condition researched and defined brings me great pleasure. Not only do I now have an official title to refer to the condition while discussing it with my peers, but the knowledge that professionals are recognizing its reality gives me hope that further understanding is still to come."

This condition may also impinge on learning abilities though there is no conclusive evidence yet.

A British medical consultant, Dr. Sarah Jarvis said, "It can cause some difficulties in education because these days so much learning is done visually - right up to university level. Mind maps are very common. But people who have aphantasia simply can't picture the mind maps.”

Professor Zeman sees aphantasia as “an intriguing variation in experience, rather than a problematic condition.”

"I think it makes quite an important difference to their experience of life because many of us spend our lives with imagery hovering somewhere in the mind's eye which we inspect from time to time, it's a variability of human experience," he added. MIMS

Read more:
4 reasons why doctors should use infographics
Infant amnesia: Looking into the black hole of our memories
Memory formation is a complex mix of molecular mechanisms and external influences

Sources:
http://www.medicaldaily.com/trouble-visualizing-memories-you-may-have-aphantasia-condition-impedes-visualization-350114
http://www.bbc.com/news/health-34039054
http://www.exeter.ac.uk/research/feature/aphantasia/
http://www.independent.co.uk/news/science/aphantasia-software-engineer-blake-ross-writes-mind-blowing-post-about-being-unable-to-imagine-a7000216.html