Aphantasia

The phenomenon was first described by Francis Galton in 1880 in a statistical study about mental imagery.[2] Galton found it was a common phenomenon among his peers. He wrote:

To my astonishment, I found that the great majority of the men of science to whom I first applied, protested that mental imagery was unknown to them, and they looked on me as fanciful and fantastic in supposing that the words 'mental imagery' really expressed what I believed everybody supposed them to mean. They had no more notion of its true nature than a colour-blind man who has not discerned his defect has of the nature of colour.[2]

In 1897, Théodule-Armand Ribot reported a kind of "typographic visual type" imagination, consisting in mentally seeing ideas in the form of corresponding printed words.[9] As paraphrased by Jacques Hadamard,

The first discovery of this by Ribot was the case of a man whom he mentions as a well-known physiologist. For that man, even the words "dog, animal" (while he was living among dogs and experimenting on them daily) were not accompanied by any image, but were seen by him as being printed. Similarly, when he heard the name of an intimate friend, he saw it printed and had to make an effort to see the image of this friend... Moreover, according to Ribot, men belonging to the typographic-visual type cannot conceive how other people's thought can proceed differently.[10]

The phenomenon remained largely unstudied until 2005, when Professor Adam Zeman of the University of Exeter was approached by a man who seemed to have lost the ability to visualize after undergoing minor surgery.[11] Following the publication of this patient's case in 2010,[12] a number of people approached Zeman reporting a lifelong inability to visualize. In 2015, Zeman's team published a paper on what they termed "congenital aphantasia",[3] sparking renewed interest in the phenomenon.[4]

Zeman's 2015 paper used the Vividness of Visual Imagery Questionnaire (VVIQ), developed by David Marks in 1973, to evaluate the quality of the mental image of 21 self-diagnosed and self-selected participants. He identified that aphantasics lack voluntary visualizations only; they are still able to have involuntary visualizations such as dreams.[3]

In 2017, a paper published by Rebecca Keogh and Joel Pearson, researchers at University of New South Wales, measured the sensory capacity of mental imagery using binocular-rivalry (BR) and imagery-based priming and found that when asked to imagine a stimulus, the self-reported aphantasics experienced almost no perceptual priming, compared to those who reported higher imagery scores where perceptual priming had an effect.[13] In 2020, Keogh and Pearson published another paper illustrating measurable differences correlated with visual imagery, this time by indirectly measuring cortical excitability in the primary visual cortex (V1).[14]

A 2020 study concluded that those who experience aphantasia also experience reduced imagery in other senses, and have less vivid autobiographical memories.[15]

In 2021, a study that measured the perspiration (via skin conductance levels) of participants in response to reading a frightening story and then viewing fear-inducing images found that participants with aphantasia, but not the general population, experienced a flat-line physiological response during the reading experiment, but found no difference in physiological responses between the groups when participants viewed fear-inducing images. The study concluded the evidence supported the emotional amplification theory of visual imagery.[16]

In addition to congenital aphantasia, there have been cases reported of acquired aphantasia, due either to brain injury or psychological causes.[17][18]

A 2022 study estimated the prevalence of aphantasia among the general population by screening undergraduate students and people from an online crowdsourcing marketplace through the Vividness of Visual Imagery Questionnaire. They found that 0.8% of the population was unable to form visual mental images, and 3.9% of the population was either unable to form mental images or had dim or vague mental imagery.[19]

• Ed Catmull, co-founder of Pixar and former president of Walt Disney Animation Studios. Catmull surveyed 540 colleagues from Pixar about their mental visualization and found that the production managers tended to have stronger visualizations than the artists.[20]
• James Harkin, British podcaster and television writer[21]
• Richard Herring, British comedian and podcaster[22]
• Glen Keane, animator, author, and illustrator[23]
• Lynne Kelly, an expert and prolific writer on mnemonics and memory techniques has reported that she has aphantasia, but notes that she still uses personal memory methods, such as the memory palace, which are typically thought to rely on visual memory.[24]
• Mark Lawrence, fantasy author[25]
• Yoon Ha Lee, science fiction author[26]
• Derek Parfit, British philosopher. His aphantasia may have influenced his longtime interest in photography.[27][28]
• Blake Ross, co-creator of the web browser Mozilla Firefox.[29] In April 2016, Ross published an essay describing his own aphantasia and his realization that not everyone experiences it.[30][31] The essay gained wide circulation on social media and in a variety of news sources.[32][33]
• Michelle Sagara, fantasy author[34]

• Creative visualization
• Engineering and the Mind's Eye
• Number form – Mental map of numbers
• Prefrontal synthesis – Conscious process of synthesizing mental images
• Prosopagnosia – Cognitive disorder of face perception

• "Aphantasia: When the Mental Image Is Missing". Quirks and Quarks. Episode Part 1. CBC Radio. 2016-06-25.
• Aflalo P (2019-09-14). "Can you picture things in your head? Well, this guy can't". The Doc Project. Episode Part 1. CBC Radio.
• "Aphantasia: The People Without a Mind's Eye - 'Out of Mind'". YouTube. Wired UK. Retrieved 20 September 2021.
• Media related to Aphantasia at Wikimedia Commons