Synesthesia: Blending of the Senses

Have you ever felt the bitter taste while seeing a vibrant green colour? or saw a purple colour house, experiencing the taste of cakes? Why does Hearing some singers’ voices, make you see splashes of colours?, and seeing the number 7 make you cheerful and friendly?

Feeling and enjoying the visuals of clouds might remind you of the sweetness of cotton candy. If you’re experiencing these, you have to know, that this is called synesthesia. Let’s dive into what is it. 

What is Synesthesia?

When one sense is stimulated, an involuntary sensation in another is produced, a condition known as synesthesia. To be clear, synesthesia is a neurological phenomenon where perceiving one sense automatically triggers sensations in another. For instance, thinking about the numbers or days of the week might bring out specific colours in mind.  

This phenomenon can occur in conditions like psychosis, brain trauma, or under the influence of psychedelics, but it also partially affects nearly everyone in everyday situations. Francis Galton, a cousin of Charles Darwin, introduced the term “synesthesia” and started documenting various cases, though it is an ancient phenomenon in human psychology. The word, rooted in Greek, means “perceived together.”

Scientific Orientation of Synesthesia: 

For over 200 years, scientists have been trying to study the reason behind synesthesia. Still, why some people mix sensory experiences such as associating words with tastes or sounds with textures has remained unclear. Today, there is a general agreement that certain types of synesthesia,  especially letter-colour synesthesia (For example, visualizing the colour red to the letter A), are closely related to learning.  

Research indicates that synesthesia might provide a unique sensory advantage. For instance, some scientists believe that synesthetes might excel at differentiating between smells and colours. Additionally, synesthesia can boost cognitive skills like creativity and memory, making it easier to connect concepts. 

Recent advancements in neuroscience have provided insights into how synesthesia works. Using techniques like functional magnetic resonance imaging (fMRI), researchers have identified unique brain activity patterns in synesthetes compared to those without synesthesia. These findings suggest that synesthesia involves enhanced connectivity and heightened communication between the brain regions linked to various sensory functions, facilitating the simultaneous activation of different sensory pathways. While severe synesthesia can lead to challenges and limitations, milder forms are found among artistic individuals, and certain variations are experienced by many people. 

Researchers remain uncertain about the prevalence of synesthesia. A study from 2006 suggested that it occurs in approximately 2 to 4 per cent of the population. In the past two decades, several studies have indicated that the condition is more prevalent among women, with up to six times as many female synesthetes compared to males. 

Is Synesthesia a Disorder?

Synesthesia is not a disorder and does not cause any harm to your health or daily activities. It won’t affect your routine or cause any distress in your work, social, or personal life. Some studies suggest that synesthesia can enhance memory and improve performance on intelligence tests compared to individuals without synesthesia. 

Read More: Theories of Intelligence in Psychology

Although synesthesia is linked with psychiatric disorders, it is not listed in the latest Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Instead, it is classified as a “neurological condition” that tends to be more prevalent among women and left-handed individuals. Additionally, it can also develop in people with typical neurological functioning. 

Causes of Synesthesia: 

Experts cannot able to find out the exact causes behind this condition but they believe the  following might be the factors: 

1. Brain Structure: Individuals with synesthesia frequently show increased connectivity between various regions of the brain. This increased connectivity may account for why multiple areas of the brain activate in response to a single type of sensory input. The connectivity might also explain why synesthesia occurs in people with Autism Spectrum Disorder (ASD) at a rate at least three times higher than in those without ASD.
2. Genetics: Synesthesia appears to be hereditary, though the specific form can differ among family members. This indicates that synesthesia is not merely a learned trait passed down through family members.
3. Brain Development: Some research suggests that synesthesia is a common early developmental stage in the brain.  If this is true, it means that synesthesia diminishes in most individuals as they grow older,  which is why only a small percentage of adults retain it. 
4. Non-medical drugs: Non-medical drugs can affect your mental state. Some drugs, such as hallucinogens like Dimethyltryptamine (DMT), lysergic acid diethylamide (LSD), peyote (which contains mescaline), and psilocybin (found in psychedelic mushrooms), can significantly alter your mental state.

Traits of Synesthesia: 

People with synesthesia typically experience involuntary sensory perceptions that blend across senses, like tasting colours and shapes. They have consistent triggers that reliably connect senses, such as associating the letter “A” with the colour red. Additionally, they can describe these distinctive experiences to others. Characteristics of synesthesia differ according to the types. We will discuss it later.  

How does it work? 

Firstly, the senses detect events in the surroundings. For example, using your eyes to observe the things around you and using your ears to hear the sounds around you. Secondly, signalling happens, and sensory information travels to your brain, detailing what you are experiencing. For example, you convey details about colours and shapes, while you transmit ear transmits information about sound volume, pitch, etc. and your brain finally receives these signals and directs them to specific processing areas.

These areas interpret the information, helping you recognize objects like a stop sign based on shape and colour, or identify sounds as music or speech. However, people with synesthesia have a unique way of processing sensory information where their brains simultaneously engage multiple areas when interpreting the same input. 

Types of Synesthesia: 

Researchers classify different types of synesthesia based on how different sensory or cognitive functions overlap. Research suggests that synesthesia can exist in more than 70 different forms. A  few major of them are given below: 

1. Auditory-tactile Synesthesia: This type causes individuals to feel tactile sensations like temperature changes or pressure in response to certain sounds. For example, somebody can feel when listening to a particular  song, and they kind of feel warmth around their body. 
2. Day-colour Synesthesia: Some people associate specific colours with days of the week, a common form of synesthesia. For instance, synesthetes might associate some colour for some particular day like blue for Tuesday.
3. Hearing-Motion Synesthesia: People with this type of experience hear sounds triggered by visual motion, for example, synesthetes hear sounds like a “swish” or a “whoosh” when cars pass them so fast. 
4. Grapheme-Colour Synesthesia: Individuals who are experiencing this type see colours that correspond to letters, numbers, or symbols. For example, as already we discussed visualizing the color red to the letter A. 
5. Sound-colour synesthesia: This form involves seeing colours in response to specific sounds or music, often reported by musicians and artists. For example, synesthetes may perceive vivid blue hues or other colours in addition to hearing certain musical notes.
6. Time-space synesthesia: Those with this type visualize time sequences or numerical patterns in specific, often detailed and vivid ways, resembling the mental mapping of calendars or numbers. For example, they could see the days of the week in linear positions and with equal amounts of space. 
7. Color-Taste Synesthesia: The taste sensation occurs when the individual perceives colour visually, although often simply thinking about the colour or hearing its name can also trigger this experience. For instance, a green colour may trigger a harsh taste. 
8. Taste-Emotions Synesthesia: The tastes are experienced based on the synesthete’s emotions, closely intertwined with the colours they perceive or associate with those emotions. For example, happiness might trigger sweetness. 
9. Olfactory-Auditory Synesthesia: It is a rare type, that involves perceiving sounds triggered by different smells. These sounds can range from general noises to musical elements such as tones, chords, and hums. A  complex smell may evoke a blend of two or more sounds, potentially creating a musical melody. 
10. Auditory-kinesthetic Synesthesia: If specific involuntary body movements are consistent, idiosyncratic, automatic, and triggered by auditory stimuli other than rhythm, they could potentially be classified as a type of synesthesia. However, activities like dancing or foot-tapping, though automatic, would not fall under this category.

Treatment: 

Developmental and acquired synesthesia typically do not require treatment. In rare instances, individuals may experience unwanted effects, but they can often learn to manage or reduce these effects. And some people may experience loneliness when they try to explain their sensory experience to others. In that case, they can seek help from supportive groups and mental health professionals. Drug-induced synesthesia may arise from elevated doses of specific drugs, possibly necessitating intervention to manage an overdose. Treatment approaches vary depending on the specific drug involved but generally focus on supportive care to alleviate more serious symptoms like seizures or agitation. 

In conclusion, we uncover the interesting phenomenon called synesthesia, which is a condition where stimulating one sense leads to an automatic experience in another. We also discussed the scientific insights into this condition, its traits and types of this condition.  Synesthesia also discovers different and unique ways of an individual’s perception. There is a need to explore this phenomenon with scientific approaches because the causes and other contexts remain unclear. And to all synesthetes embrace the unique perceiving qualities. 

FAQs 

1. What is Synesthesia? 

Synesthesia is a neurological phenomenon where perceiving one sense automatically triggers sensations in another. For instance, thinking about the numbers or days of the week might bring the specific colours. 

2. Is synesthesia a disorder? 

No, it is not considered a disorder because it won’t cause any series illness to the individual who experiencing synesthesia. Also, the DSM did not give any diagnostic criteria to consider it as a disorder. 

3. Who are synesthetes? 

Individuals who all have synesthesia are synesthetes. People have this condition by birth.

4. How common Synesthesia is? 

Researchers remain uncertain about the prevalence of synesthesia. A study from 2006  suggested that it occurs in approximately 2 to 4 per cent of the population.