Brain Training Can Teach Synesthesia-Like Perception

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Lisa Winter

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59 Brain Training Can Teach Synesthesia-Like Perception
Martin Abegglen via Flickr, CC BY-SA 2.0

For 95.6% of the people reading this, every word in this article (excluding hyperlinks) will appear black. The remaining 4.4% will have a different experience altogether. Perhaps the M's will appear orange, while the A's take on a violet hue. These individuals have a condition known as synesthesia, which is a tangling of sensory input. While interpreting letters or numbers as color is the most common manifestation of this phenomenon, certain people may believe that reading certain words “tastes” a certain way, while others “hear” music when eating certain foods. For example, the word “pen” might taste like chocolate, while eating toast could sound like piano music.

A new study from researchers at the University of Sussex have found that performing daily brain exercises can actually train people to have perception of different colors when reading words in black font. Though the results are temporary, this type of training could eventually have clinical implications for those with sensory processing disorders, a common comorbid condition with autism, ADHD, and other neurological disorders. The study was co-led by Daniel Bor and Nicolas Rothen, and the paper was published in Scientific Reports. For thirty minutes per day over a nine week period, a group of fourteen participants trained to associate 13 letters with particular colors. Not only were they able to begin to see letters as certain colors, but many also began to associate emotions with certain letters. Some reported that the letter X felt boring, while W felt calm.


One unexpected result of the study was that the group that performed the daily training experienced an average jump of 12 IQ points between the beginning and ending of the study, compared to the untrained control group. However, it is likely that the scores jumped because of the training, not because of the synesthesia-like experience gleaned from that training. 

Intelligence quotient tests are largely based on pattern recognition and memory; cornerstones of the synesthesia training. It was not measured if these participants gained advantages in something tangible, like reading comprehension or math skills. Further study could find a practical use for this training, and the team may introduce an online training platform in the future.

"The main implication of our study is that radically new ways of experiencing the world can be brought about simply through extensive perceptual training,” Bor said in a press release. "The cognitive boost, although provisional, may eventually lead to clinical cognitive training tools to support mental function in vulnerable groups, such as children with Attention Deficit Hyperactivity Disorder (ADHD), or adults starting to suffer from dementia.”

While a person with normal sensory perception views black text like the box on the left, individuals with synesthesia can associate colors with certain numbers or letters, making the the text appear like the box on the right. Credit: Ranveig via Wikipedia

The cause of synesthesia is not known. While some believe it may have a genetic component, others argue that it is learned in childhood through brightly colored letters on toys and sensory play. While the current method of training from this study can generate a similar experience, it doesn’t actually cause synesthesia. When training ends and participants only read black text, the ability fades.


"It should be emphasized that we are not claiming to have trained non-synesthetes to become genuine synesthetes,” Rothen explained. “When we retested our participants three months after training, they had largely lost the experience of 'seeing' colors when thinking about the letters. But it does show that synesthesia is likely to have a major developmental component, starting for many people in childhood.”

The diminished ability to see letters as colors could be connected to the fact that the participants are inundated with reading English in black text. In future studies, the team will try synesthesia training in a language that the participants rarely come across and that uses a different alphabet, such as Hebrew, in order to see if the effect will last longer. 

[Image: Martin Abegglen via Flickr, CC BY-SA 2.0]


  • tag
  • Synesthesia,

  • sensory perception