It seems completely natural to recall pictures of the past or to fantasize. However, not everyone is capable of this. Some people do not have visual images when they remember. Such people are called aphantists.
The case of "Monsieur X"
At the end of the 19th century, the British encyclopedic scientist Francis Galton decided to measure intelligence. One of his works dealt with mental images. He sent out questionnaires to colleagues and asked, before answering, remember how they sat at the table during breakfast this morning.
Many did not understand what they were being asked about. Then Galton questioned one hundred people of both sexes, engaged in intellectual work. And I got a lot of such answers: "I remember breakfast at the table, but I don't see it." Galton rated himself as a weak visual. But his cousin Charles Darwin remembered everything with photographic accuracy.
In 1880, Galton published an article with the results of the survey. Soon, French psychiatrist Jean-Martin Charcot described the case of "Monsieur X" who suddenly lost visual memory and picture dreams. Charcot attributed this to mental illness.
In the twentieth century they started talking about "defective visualization", "visual forgetfulness". In 1984, American neuroscientist Martha Farah collected 37 cases of "visual memory deficits" caused by brain damage. They fit well with the "visual buffer" hypothesis in which the brain places pictures from the past.
The impairment of mental vision was often accompanied by a loss of the ability to recognize faces. At the same time, some blind patients performed well on visual tests: they correctly answered questions about the shape of letters, the colors of objects, and the angles of the clock hands. All of this has helped scientists understand how the brain processes and creates visual information.
A model of the appearance of visual images in the brain. Initial impulses come from the frontal lobe (in the figure - 1). They start a cascade of processes in neurons, which includes loading pictures from memory. The temporal lobe is responsible for this - 2. Then the sensory and spatial content of the images is formed - the departments 3. If the movement of the pictures is involved, then the information goes to the temporal and parietal lobes.
Rediscovery of aphantasia
In 2005, British neurologist Adam Zeman of the University of Birmingham observed a patient who, after minor heart surgery, lost the ability to represent images. In the past, a surveyor, now a pensioner, MX had good eyesight, but when he thought about people or objects, he did not see them. At the same time, he correctly answered questions about the color of his eyes, mentally solved problems on the rotation of figures without seeing them. The fMRI scans have shown that when MX looks at faces, the regions of the brain responsible for vision are working. If he represents someone, they are inactive.
A few years later, journalist Karl Zimmer wrote a note about MX in Discover and attracted a lot of readership. People reported similar sensations. Zimmer forwarded letters to Zeman, and in 2015 he released a paper describing 21 cases of what he called aphantasia. On the scale of the brightness of the visual imagination, the aphantasts scored an average of 16 out of 80. The norm is about 58.
British neurophysiologists have confirmed that approximately 2.5% of the world's population suffers from the so-called aphantasia - the inability to imagine in your head the image of loved ones, scenes from books and even some simple things.
Many media outlets have written about aphantasia. Zeman was inundated with letters from all over the world. Scientists had to work hard, questioning a lot of people. The peculiarity of the afantasters is that they remember and correctly describe what they saw.For example, when asked which is redder, an apple or an apricot, the answer is: apple. But they cannot imagine it.
Since then, Zeman and colleagues have studied 12,000 people with aphantasia. One of the first wave volunteers created the Aphantasia Network. Famous people, for example, a geneticist, a participant in the decoding of the human genome Craig Venter, and a co-founder of Mozilla Firefox, Blake Ross, have also admitted to this peculiarity of perception.
Scientists estimate that between one and three percent of humanity are aphantastes. And some - from birth. Learning about this in adulthood, they were sincerely surprised that it could be otherwise. And there are their opposites - people with too bright inner vision, or hyper-fantastic. On the scale of brightness of visual imagination, they have 80 out of 80.
Life without inner vision
Since the time of Galton, it was believed that aphantasia is characteristic of people with developed abstract thinking. Accordingly, artistic natures have hyper-fantasy. However, recent research does not support this. Artists with visual impairments turned to Zeman. When drawing, they keep objects in front of their eyes. Among the aficionados, there are writers and architects who have developed special techniques for work.
As a rule, aphantists do not dream, but listen, understand, or feel. About a third of the respondents noted difficulties with memory for faces and details from the past. There are reports of autism spectrum disorder, and hyper-fantasy, on the contrary, coexists with synesthesia - the color vision of letters, numbers and other abstract symbols. However, there is insufficient data to generalize.
Scientists obtain objective information about the functioning of the brain of ahantists using fMRI and various clever experiments. For example, Joel Parson of the Australian University of New South Wales asked volunteers to represent the white triangle and watched their pupils. For ordinary people, they narrowed, for the Afantas, they did not change. He also measured the electrical conductivity of the skin while reading scary stories. And again, the control group showed an increase, while the Afantists did not.
As a result, it was hypothesized that the psyche of the Afantas was more stable. There is logic in this. A person cannot imagine and remember in colors the terrible scenes he witnessed. But the assumption was not confirmed. In any case, aphantasia is not a disease, but a feature of the development of the brain.