Can you develop synesthesia? Synesthesia explained

Have you ever wondered what it might be like to see sounds or taste words? For many synesthetes, these cross-sensory experiences can be part of everyday life. Many artists, musicians, and other creatives consider synesthesia to be integral to their process, and for many, synesthesia is central to their identity. Synesthetes may not remember a time without synesthesia, nor be able to imagine life without it. Those who are neurotypical may hear of its fascinating effects and wonder whether it’s possible to develop synesthesia. In some cases, such as traumatic brain injuries, psychedelic substance use, and sensory deprivation, it may be possible to develop or experience synesthesia. For professional insight and support in addressing mental health challenges related to or co-occurring with synesthesia, consider connecting with a therapist in your local area or through an online therapy platform.

Understanding synesthesia

Synesthesia can be defined as a neurological condition in which the stimulation of one sense triggers an experience in another sensory pathway. For example, a person with synesthesia may perceive colors when listening to music, associate specific colors with letters, or taste flavors in different words.

There can be many different types of synesthesia, and most synesthetes tend to have only one kind. A person with synesthesia may find that their synesthetic associations change slightly as they age; however, synesthesia tends to remain relatively consistent over time.

For example, someone with grapheme-color synesthesia may always perceive the letter “A” as being red in their mind’s eye. As that person gets older, they may notice fewer bright colors and more dull or achromatic hues in their synesthetic experiences. Synesthesia is generally considered a neurodivergent trait. As such, it is typically not treatable, nor may it subside on its own.

How does synesthesia develop?

Synesthesia tends to occur more frequently among close relatives of individuals with synesthesia compared to the general population, suggesting it could have a genetic component. However, unlike eye color, synesthesia does not usually follow a simple inheritance pattern and may occur due to any number of genetic combinations.

Synesthesia tends to develop in early childhood when new sensory pathways in the brain are still forming. However, the exact causes for its development are currently not well understood by scientists. Some suggest that the genes responsible for the formation of the brain’s cerebral cortex may cause structural differences that lead to synesthesia. Other research explores the link between synesthesia and concepts learned in early childhood, such as letters, numbers, colors, and musical notes.

While updated research may be needed, there is some evidence that excess serotonin may play a role in the development of synesthesia. This may explain why it often co-occurs with autism, another neurodivergence often associated with atypical serotonin levels. Excess serotonin may also play a role in synesthetic experiences caused by psychedelic substances, which can flood the brain with serotonin. Likewise, traumatic brain injuries can cause a rush of serotonin and have been observed to trigger sudden-onset synesthesia.

Can synesthesia be learned?

Some research suggests that it may be possible to acquire synesthetic associations through certain kinds of training tasks. In one study, researchers gave non-synesthetes books in which the letters were printed in different ink colors. Participants were tested before and after reading the books, and researchers found that the process resulted in significant synesthetic associations. 

This supports the idea that it may be possible to “learn” grapheme-color synesthesia. However, while it might be possible to train your brain to make certain associations, there is generally little evidence to suggest that other types of synesthesia can be learned, or that learned associations are irreversible or permanent. 

Can you develop synesthesia later in life?

It may be possible to develop synesthesia suddenly or later in life, although such cases tend to be rare compared to those who have synesthesia from early childhood. There have been documented instances of acquired synesthesia resulting from various factors at different stages of life.

Synesthesia after a traumatic brain injury

One known trigger for the development of synesthesia may be a brain injury or trauma. In some cases, damage to certain areas of the brain can lead to the emergence of synesthetic experiences. 

For example, one man who sustained a brain injury began having synesthetic perceptions of fractal patterns in organic shapes like tree branches. In addition to synesthesia, his aptitude for mathematics and physics underwent a remarkable improvement, and he developed an extraordinary ability to visualize and accurately depict intricate geometric shapes that he perceived in his surroundings.

Cases like the one discussed above may suggest that physical changes to the brain can cause the onset of synesthesia. Scientists believe this phenomenon may be due to a sudden spike in serotonin after injury. When brain cells die suddenly, serotonin and glutamate typically flood the area and overexcite receptors. Though they may eventually return to normal as the brain heals, the event may be enough to permanently alter sensory function.

Synesthesia and psychedelic substances

Hallucinogens, such as LSD and psilocybin, can temporarily induce synesthesia-like experiences. Users commonly report experiencing hallucinations that align with certain types of synesthesia, such as chromesthesia and auditory-tactile synesthesia. 

As psychedelic drugs usually affect the brain’s serotonin levels, serotonin is thought to be one of the neurotransmitters responsible for drug-induced synesthetic experiences. However, psychedelics are not typically known to cause permanent or irreversible synesthesia. 

Synesthesia in sensory deprivation

Researchers have often been able to induce synesthetic experiences in non-synesthetes using visual sensory deprivation. A recent study found that after just five minutes of being in a dark room, sounds could trigger synesthesia-like experiences in about half of people who don't have synesthesia. These experiences generally included seeing vivid colors and specific patterns and tended to be consistent with chromesthesia.

Synesthesia and PTSD

Synesthesia has been identified as a risk factor for post-traumatic stress disorder (PTSD). Synesthetes are usually more likely than neurotypical individuals to re-experience sensory details when recalling memories, and their memories may be more vivid and inflexible. This may make synesthetes more prone to flashbacks. 

Those with PTSD may be more likely to experience certain types of synesthesia, such as grapheme-color synesthesia, though there may not be a causal relationship. 

Additionally, individuals with PTSD may also be susceptible to a disorder called misophonia, which some experts believe may be a form of synesthesia.

Can synesthesia be treated?

In general, synesthesia is considered a neurodivergent trait rather than a disorder, meaning it is considered a normal variation of human perception. Thus, there is generally no treatment for synesthesia. 

In rare cases, substances that act upon the brain’s serotonin receptors may temporarily stop synesthetic experiences. However, medication is not typically prescribed for those with synesthesia, as it is not considered to be a disorder, nor a cause for concern.

Therapy for sensory concerns

There may be situations in which synesthesia interferes with a person’s ability to function. For example, loud or chaotic environments may be overwhelming for someone with synesthesia. Synesthesia may also make it challenging to concentrate on tasks that require focus. In such cases, these individuals may benefit from the intervention of a mental health professional. 

A therapist can help individuals learn valuable coping skills and self-soothing techniques for managing difficult situations. They may also be able to treat mental health disorders that sometimes co-occur with synesthesia, such as PTSD and anxiety. 

Benefits of online therapy

Online therapy platforms like BetterHelp can offer a convenient, cost-effective way to connect with a licensed therapist who understands the unique needs of those experiencing synesthesia. Since online therapy normally allows people to meet with therapists from the comfort of their homes, it may be the right option for individuals prone to sensory overload.

Effectiveness of online therapy

While synesthesia isn’t usually seen as a disorder, it can lead some people to experience low self-esteem if they don’t fit in with or feel different from their peers. Online therapy can be an effective way to improve self-esteem, with one study finding that a web-based CBT intervention usually increased feelings of self-esteem, self-compassion, and quality of life while also reducing symptoms of depression and anxiety. CBT usually works by helping individuals identify unhelpful ways of thinking and shifting those thoughts to promote behavioral changes.

Takeaway

While the overwhelming majority of synesthetes develop the condition in early childhood, there have been rare cases in which individuals have developed synesthesia due to a traumatic brain injury. Synesthetic experiences can also be induced through psychedelic substance use, sensory deprivation, and mental training tasks, though these experiences tend not to be permanent. As synesthesia is not usually considered a disorder, it generally cannot be treated or cured. However, synesthesia may sometimes be associated with treatable mental health conditions like PTSD and anxiety. Those experiencing difficulties related to synesthesia may benefit from connecting with a therapist online or in person.