As you read this, take a quick look around and pick an object that catches your eye. Give it a good look. Stare at it for a while. Now close your eyes. Do you still see it? Can you picture it in your mind? How does it look? Is it as vivid as the real thing? Do the colors and lines and shapes and textures pop out at you, or does it seem fuzzy, somehow less defined, dull even? As you picture it in your mind, see how long you can hold the image. How does it change with time? Does it seem to fade away?
Now picture a random object, or a scene from your childhood, and ask yourself the same questions. How vividly can you ‘see’ it in your mind?
Some people cannot see anything. Nothing. Their mind’s eye is blank. They experience a neural phenomenon called aphantasia.
Aphantasia is a condition in which a person cannot visualize mental images. In other words, when they attempt to imagine or think about something they cannot create an internal mental image or picture. Because of this, individuals who experience aphantasia can have a hard time recalling things like past experiences and the visual details associated with those memories. They also tend to have difficulty with tasks that require visualizing or imagining physical objects and how they move and rotate in space. This can have an impact on their spatial reasoning.
Interestingly though, a recent study suggests that while individuals with aphantasia have deficits in recalling and remembering objects, their spatial memory is not affected.
It is important to appreciate however that aphantasia is not classified as a neurological or neuropsychological disorder. In general, it does not limit or impede everyday life. However, for some people who experience aphantasia, it can cause frustration and limit their ability to properly do or recall certain things. It is not entirely known what fraction of the population has aphantasia, but current estimates suggest that about 4% of the population experience it.
What does someone with aphantasia experience?
So what does an individual with aphantasia actually experience? How would they describe it?
While each experience is unique, and no two are exactly the same, the most prominent feature is the inability to “see” or imagine anything in their mind, even when they try to recall a visual scene or object or any visual imagery at all. Beyond recall, they also lack the ability, or at least have difficulty, creating mental images or pictures.
For example, a person with aphantasia may not be able to imagine or recall something they might have seen in a movie. Or they may have a very difficult time building a mental image of a description they read in a book, or from a story they hear. Or events that happened to them in the past. Remembering faces is also difficult or not possible.
What causes it?
It is not entirely understood what causes aphantasia and why some individuals simply cannot see, imagine or recall mental imagery. There is evidence that suggests that aphantasia is the result of altered activity in different parts of the brain that process and create visual imagery and imagination. A highly distributed network of brain regions, including parts of visual cortex, the temporal lobe, and the parietal lobe. These brain regions are involved in processing and integrating visual information and are thought to play a key role in the creation of mental images. There may be structural and functional changes in specific networks of neurons and other neural cells across these regions that operate differently from individuals that can produce mental imagery.
The brain takes in information from the outside world through its five senses. It then integrates that information across different brain regions and combines information between different sensory inputs to create an internal model of the physical environment. None of us has actually directly ever ‘seen’ what the physical world around us looks like, we can only interpret what it might be like from the internal model our brain and mind create. In individuals with aphantasia there is something about how the networks of neurons and other neural cells are wired up that makes it difficult for them to imagine or see visual imagery in their mind.
In one study researchers measured the brain waves of a subject with aphantasia using electroencephalography (EEG). The EEG was all within normal ranges across a battery of neuropsychological tests, except for visual imagery. When asked to imagine and see things in his mind, the parts of the brain that would normally be involved in creating the experience showed less activity, while other parts of the subject’s brain were active. Specifically, brain activity began in temporal regions instead of frontal, and there was no activity in occipital (visual) cortex or parietal areas.
There is still significant debate regarding what functional brain changes produce aphantasia, and much research is focused on attempting to synthesize and integrate the growing available information and data in order to arrive at a more comprehensive and unified understanding of how neurobiological changes lead to the observed and measured cognitive effects.
There is some evidence that aphantasia is hereditary, but the degree to which it is and the underlying genetics are not clear and remain a topic of ongoing research. While there may be a genetic component to aphantasia, the biological and cellular mechanisms that link possible genetic variants to the physiological processes that functionally and cognitively manifest as aphantasia are not understood.
Finally, it is important to note again that aphantasia is not a neurological or neuropsychological condition. While it can be frustrating and limiting under certain scenarios and for certain tasks, in general, it does not meet the criteria associated with classifying it as a mental disorder, namely, impairment in activities of daily living, violation of social norms and inappropriate behavior, and the perception of personal stress. The last criterion is statistical rarity, which it does satisfy. But on its own it is not sufficient for a clinical classification. Having said this though, it is possible that in combination with other life factors or clinical manifestations a person experiencing aphantasia may require clinical treatment or intervention, but by itself, aphantasia is not a clinical disorder. It does however, provide an intriguing window into how the brain works and the spectrum of functionality of the mind.