.png)
2 months ago
19
Imagine having a conversation with someone and seeing each word they use appear before your eyes like subtitles in a film, or even as speech bubbles near the speaker’s mouth. Now, picture trying to read a book on a crowded train, only to have the sentences spoken around you intrude on your vision, as if they were printed right in front of your eyes. Or, even more intriguing, seeing your own thoughts written out in your mind’s eye. This is the everyday experience of those living with ticker-tape synaesthesia.
“When you and I talk, everything you say appears as written words in my mind,” says François Le Chevalier, 73, over Zoom. “It’s just like when I am reading – sometimes the words appear handwritten, other times typewritten, and occasionally even in bold.”
Synaesthesia refers to the blending of the senses. In the most common form, sounds are seen as colours. Ticker-tape synaesthesia – named after 19th-century machines that printed news and stock prices on thin paper strips, or “tickers” – describes a different manifestation of this trait.
The experience can vary widely. “Classically it would be a visualisation, where people see subtitles in their mind’s eye, but there is a lot of variation in how this appears,” says Mark Price, a professor in psychology at the University of Bergen who works as part of the Bergen Laboratory for the Study of Decision, Intuition, Consciousness, and Emotion.
He explains that in some, less common instances, the mind may project the subtitles as if they were appearing in the external world. The experience can differ in whether the subtitles are static or moving, whether full words or just parts of them appear, or only certain key words are highlighted. For some, it might feel as though their mind is mimicking the physical act of writing the word, a phenomenon known as motor imagery. “Some might notice typing words on a phone or a computer keyboard,” says Price.
after newsletter promotion
And it’s not just spoken words that may appear as written, but pseudowords too, according to Fabien Hauw, a neurologist and cognitive neuroscientist at the Paris Brain Institute. “Pseudowords, which although not real words are phonologically correct, can also be visualised by people experiencing ticker-tape synaesthesia,” he says. “Subtitled speech can appear for noises that can be translated in a phonological way. For example, when someone is laughing, some may see it appear written as ‘hahaha’. For others, if they hear a cat meowing, they may see the word ‘meow’ written.”
Ten years ago, when François Le Chevalier began learning Chinese, he found that whenever he was pronouncing words, their phonetic spelling would appear in his mind’s eye, interfering with the actual characters. When Le Chevalier, who subsequently became one of Hauw’s study participants, opened up about it to a friend, her surprise made him realise that not everyone perceives the world as he does. For him it’s an automatic process, which he describes as being similar to dictation: he constantly sees spoken words in his mind, and even some of his own thoughts appear written, specifically when he is thinking of what to say next. When I ask whether he sometimes feels overstimulated by it, he likens the experience to the “cocktail party effect”, where people have to tune out background conversations to be able to focus on a single one. Watching films with subtitles can be disorienting for him at times, as his brain “writes” the spoken language while also processing the on-screen text.
Laurent Cohen, a neurologist and cognitive neuroscientist at the Paris Brain Institute and Hauw’s former PhD adviser, first encountered ticker-tape synaesthesia two decades ago, when a man wrote to him describing his mother’s experience. As a schoolgirl, she confided in friends that she could see words written near people’s mouths as they spoke. Laughed at, she kept the secret for decades, only revealing it to her son when she was 90.
This prompted Cohen to look into what may be contributing to people experiencing the world in this way. In a recent paper, Cohen, Hauw and their team used fMRIs to show that when people who experience ticker-tape synaesthesia listen to speech, they have overactivation of two brain areas: the left perisylvian region, which is involved in processing speech, and the visual word form area (VWFA), which plays a key role in reading. “When people are listening to speech there is a larger increase in connectivity between those two regions in synaesthetes,” says Cohen. “We know that there are links between the visual cortex, which supports orthographic representation, and phonological regions.”
Orthographic representation refers to the way written words or letters are visually encoded and processed in the brain. It involves recognising the shapes of letters and words, as well as understanding how these visual symbols correspond to specific sounds and meanings. Essentially, it’s how we mentally store and recall the spelling and structure of written language. This process primarily engages the visual cortex, as it relates to how we visually perceive and interpret text.
Anyone who is literate will experience activations in this part of the visual cortex when they hear speech, but with ticker-tape synaesthetes it seems that this activation is increased, which may account in part for their experiences.
Interestingly, the brain regions overactive in ticker-tape synaesthesia overlap with regions that are underactive in dyslexia. “There is certainly an overlap between the two conditions in the cerebral reading system,” says Cohen. However, he emphasises how they must not be seen as being on opposite ends of a spectrum. “They are both highly multidimensional. There are many varieties of dyslexia and probably many varieties of ticker-tape synaesthesia. So putting everything on a single line is wrong.”
This increased connectivity between different sensory areas in the brain, as seen in those experiencing ticker-tape synaesthesia, seems to be supported by other research carried out about synaesthesia in general. As children develop, it is thought that unused neural connections are “pruned away”, which some believe may be a way of improving brain efficiency. In synaesthetes, some of these connections may remain, enhancing communication between different sensory areas. Another theory suggests that synaesthesia may result from reduced inhibition between these regions, allowing them to communicate more freely. When it comes to whether genes play a role, “there are no genes identified as eliciting synesthesia,” says Hauw, “but some research papers point to the idea of genetic influences. If you have synaesthesia in your family, it seems that you may be more susceptible to developing it yourself. In Le Chevalier’s case, none of his siblings experience it but his daughter and niece do.
As research continues to uncover the neural mechanisms behind this phenomenon, it opens the door to broader questions about how we all process and experience reality. Ultimately, ticker-tape synaesthesia is a reminder that the mind’s eye, for some, holds a vivid and fascinating narrative of its own – one where words are not just heard but also seen. Or in the words of Le Chevalier: “In our minds there are many things happening that we are not conscious of at all, but which are important.”
