Understanding Synesthesia Disorder

Synesthesia is a neurological condition in which stimulation of one sense leads to involuntary experiences in another. For example, someone with synesthesia might see colors when they hear music or taste flavors when they see specific shapes.

These sensory connections are consistent for the individual and are a natural part of their experiences.

Synesthesia isn’t included in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision (DSM-5-TR). In fact, many people consider synesthesia to be a fascinating and positive trait rather than a disorder.

Here are some common traits or manifestations of synesthesia:

• Cross-sensory perceptions: Synesthetes (people with synesthesia) might see colors when they hear music, taste flavors when they touch items, or connect personalities with numbers or letters.
• Consistency: These connections are usually steady and repeatable. For example, “A” might always be seen as red, or the note C-sharp might consistently appear purple.
• Involuntary and automatic: Synesthetic experiences happen automatically and aren’t controlled by the person. They happen whenever the trigger is there.
• Vividness: Synesthetes often describe their perceptions as vivid and real, like actual sensory experiences rather than just ideas.
• Personalized associations: Each person with synesthesia has their own unique associations. For instance, two individuals with grapheme-color synesthesia may perceive different colors for the same letters or numbers.
• Enhanced memory: Some synesthetes report that their synesthetic experiences enhance memory recall or aid in learning tasks by providing additional mnemonic cues.

Synesthesia comes in various forms, each characterized by a specific type of sensory crossover or blending.

Here are some common examples of synesthesia:

• Grapheme-color synesthesia: Seeing specific letters or numbers as inherently colored. For example, the letter “A” might consistently appear as red in the synesthete’s mind.
• Sound-color synesthesia: Hearing sounds or music and perceiving accompanying colors. A certain musical note might evoke the experience of seeing the color blue.
• Number-form synesthesia: Visualizing numbers or dates as if they’re on a mental number line, where each number has its own specific place or position. It’s like having a visual map for numbers in one’s head.
• Lexical-gustatory synesthesia: Hearing or reading words that evoke specific tastes on the tongue. For instance, the word “apple” might taste sweet or tart.
• Spatial sequence synesthesia: Perceiving numerical sequences or months of the year as having a spatial layout. For example, March might be located to the left and July to the right.

Synesthesia is more common in people with autism spectrum disorder (ASD). For instance, approximately 17% to 19% of individuals diagnosed with ASD have grapheme-color synesthesia compared to nearly 1% to 2% of allistic people.

Research suggests that synesthetes show certain common traits:

• Increased intelligence: Synesthetes tended to have higher intelligence compared to non-synesthetes.
• Personality traits: Synesthetes showed increased levels of new experiences, experiencing emotions vividly, and engaging in imaginative thinking. Unexpectedly, they also exhibited increased neuroticism and decreased conscientiousness.
• Cognitive characteristics: While synesthetes did not differ from non-synesthetes in how they identify, analyze, or verbalize emotions. The study did not find significant differences in education level, handedness, age, or sex between synesthetes and non-synesthetes.

Synesthesia usually develops during childhood and has a genetic component, meaning it can run in families. It’s associated with unique structural and functional differences in the brain. People with synesthesia often show differences in memory and mental imagery compared to others.

The three primary theories of synesthesia are as follows:

• Disinhibited feedback theory: In this theory, higher-level brain areas send signals back to the primary sensory areas. Normally, these feedback signals are controlled, but they’re not properly controlled in synesthesia. This lack of control causes unusual sensory experiences because the feedback signals affect the primary senses more strongly than they should.

• Cross-activation theory: This theory suggests that there are extra connections between different sensory regions of the brain. For example, in someone with synesthesia, the area of the brain that processes letters or numbers might be directly connected to the area that processes colors. The color-processing area is also activated when they see a number, causing them to see colors with numbers.

• Practical theory: According to this theory, the brain can quickly adjust how it processes information based on context and meaning. For example, seeing a certain shape or hearing a particular sound might cause the brain to process it in a way that adds an extra sensory experience, like seeing a color or feeling a texture, based on the learned associations and context.

Synesthesia is an uncommon neurological condition in which stimulating one sense automatically triggers an experience in a different sense, like seeing colors when hearing music.

It’s not typically considered a disorder but, rather, a unique trait that can enhance memory, creativity, and emotional experiences.

Synesthesia is more commonly found in individuals with:

• autism spectrum disorder
• a high IQ
• a rich fantasy life
• a heightened openness to new experiences

This condition illustrates the intricate interplay between perception and cognition in the human brain.