What are the Types of Synesthesia?

The term synesthesia comes from the Greek words syn meaning together and aisthesis meaning sensation. Synesthesia is a perception where stimulating a sensory or cognitive pathway causes experiences in another sense or cognitive pathway. In other words, a meaning or concept is linked to a different meaning or concept, such as smelling colors or tasting a word. The link between paths is involuntary, consistent over time rather than being made consciously or arbitrarily. That is, a person experiencing synesthesia does not think about connection and always establishes exactly the same relationship between the two feelings or thoughts. Synesthesia is an atypical way of perception, not a medical condition or a neurological abnormality. A person who experiences synthesis for a lifetime is called synesthesia.

Types of Synesthesia

There are many different types of synesthesia; It is divided into two groups as relational synesthesia and projective synesthesia. When an employee feels a connection between a stimulus and a sensation, they see, hear, feel, smell or taste a stimulus. For example, while this may strongly associate blue with the color of a violin when hearing a violin sound, a stimulus can hear a violin and see the color blue reflected in space as a physical object. There are at least 80 known types of synesthesia, but some are more common than others:

• Chromesthesia: Sounds and colors are interrelated in this common form of synesthesia. For example, the musical note “D” can correspond to seeing the color green.

• Grapheme-color synesthesia: This type is a common form of synesthesia characterized by seeing graphics (letters or numbers) shaded with a color. Synesthetes do not associate the same colors with each other for a grapheme, but the letter A appears red to many. People with grapheme-color synesthesia sometimes report seeing impossible colors when red and green or blue and yellow graphs appear side by side as a word or number.

• Number format: Number format is a mental figure or number map resulting from seeing or thinking about numbers.

• Lexical-gustatory synesthesia: This is a rare type of synesthesia where hearing a word results in tasting a taste. For example, a person’s name may taste like chocolate.

• Mirror-touch synesthesia: Although rare, mirror-touch synesthesia is remarkable because it can disrupt the life of a synesthesia. In this form of synesthesia, a person feels the same as another person in response to a stimulus. For example, seeing a person hit their shoulder causes the synesthesia to feel a hit on the shoulder as well.

Many other forms of synesthesia occur, including the type of scent, moon taste, sound-emotion, sound-touch, daytime color, bitter color, and personality color (auras).

How Does Synesthesia Work?

Scientists have yet to make a definitive determination of the synesthesia mechanism. It may be due to increased conversation between specialized regions of the brain. Another possible mechanism is that inhibition of a neural pathway decreases in synesthesia and allows for multisensory processing of the stimulus. Some researchers believe that synesthesia is based on the way the brain receives and assigns the meaning of a stimulus.

Who Has Synesthesia?

Julia Simner, a psychologist working on synesthesia at the University of Edinburgh, estimates that at least 4% of the population has synesthesia and more than 1% of people have grapheme color synesthesia (colored numbers and letters). More people in women than men have synesthesia. Some studies suggest that the incidence of synesthesia may be higher in people with autism and left-handed people. Whether the person has synesthesia or not there is a genetic component to develop this form of perception is hotly debated.

Who Can Develop Synesthesia?

There are cases of non-synesthesia that develop synesthesia. Specifically, head injury, stroke, brain tumors, and temporal lobe epilepsy can produce synesthesia. Transient synesthesia can result from exposure to mescaline or LSD, psychedelic drugs, sensory deprivation, or meditation.

It is possible for non-synesthetists to develop relationships between different senses through conscious application. One potential advantage of this is the improved memory and response time. For example, a person may react to sound faster than sight or remember a set of colors better than a set of numbers. Some people with chromasthesis have perfect pitch as they can describe notes as specific colors. Synesthesia is associated with enhanced creativity and unusual cognitive abilities. For example, synesthesia Daniel Tammet broke a European record that specifies 22,514 digits of pi from memory using his ability to see numbers as colors and shapes.

How Are the Types of Synesthesia Different?

Someone with synesthesia is known as synesthesia, and there are over 80 combinations of ways in which the senses of a synesthesia can be linked. For example, some synestheses perceive words as a taste, while others may associate different personality traits with each of the 26 letters of the alphabet. Moreover, while synesthesia is most commonly seen as a link between the two senses, there are forms of synesthesia involving three or more senses. Also, there is at least one case where a synesthesia exhibits a connection between all five senses. This is also known as intermodal perception and is related to how people experience multiple sensory modalities.

Another distinction between synestheses is that their synesthesia can be divided into two main groups. First, there is projective synesthesia in which synesthesia senses, sees, feels, smells or tastes the second sensation triggered by the first stimulus. An example of this is an apple-smelling synesthesia when they hear a guitar playing a particular note. The smell of apples is as real as the sound they hear for synesthesia.

The second main category is relational synesthesia. Synestheses that fall into this group feel a connection between a stimulus and a sensation that is normally not perceived. In the above example, while a synesthesia with associative synesthesia will not smell apples, they will feel a strong correlation between the guitar’s music and the smell of apples. Of course, there is some gray area between these two types of synesthesia, as there are synestheses that describe their experiences in a way both predicted and correlated, both independently and with mixed or simultaneous occurring forms.

It should be made clear that synesthesia is not a selectively occurring or typically closable reaction, synesthesia cannot choose when to be synesthetic. Nor is it simply a sensory exchange or replacement of one sense for another. In addition, in the types of synesthesia that include reflected colors, these colors do not interfere with the colors in the environment, on the contrary, both are perceived separately and differently.

For example, someone who perceives individual numbers as a color will still see the numbers no matter what color they are shown. However, they will also experience a very strong association of the figure with a particular color in each case, or they will very clearly see the color reflected in a region in space, like the associated color shining around the number.

While many of the examples given above will include the five basic senses, it should also be emphasized that there are forms of synesthesia where secondary perception is in the form of internal feelings or emotions. For example, some synestheses perceive numbers and letters with personality traits, such as the number 5 being optimistic or the letter C being generous. There are other criteria that allow differentiation in synesthesia types. These include research findings that support the theory that synesthesia is more prevalent among women than men, but there are other studies showing that there is no distinction between the prevalence of synesthesia between the sexes. For those who argue that women are more likely to have synesthetic experiences, they generally conclude that the degree of prevalence is much less than previously thought.

Some studies have shown that synesthesia has a genetic link and runs in families. In fact, more than 40% of synestheses also have a parent, sibling or child with synesthesia. For this reason, there may be people with more than one synesthesia in their family. However, a distinction emerges when recent research shows that sensory perception is, apart from congenital synesthesia, certain forms of synesthesia that can be chemically induced by psychoactive stimulants or developed through experiences, follow a learned or traumatic experience and alter the responsible cognitive pathway. An example of the latter is the link shown between post-traumatic stress disorder (PTSD) and Grapheme-color Synesthesia.