Synaesthesia

What is it?

It is...

• A phenomenon in which two or more of the senses are linked
• Involuntary
• Genetically inherited
• Idiopathic or non-idiopathic
• Not a disease
• Fairly common
• Not just good memory, it is an actual phenomenon in the brain
• Increased nerve fibers (connections) between brain regions

Who has it?

Synesthetes...

• make up 1% of the population ( up to 1 in 23 people)
• Are often women
• Are often left handed
• Are of normal or higher than average intelligence
• Are usually in the same family of another synesthete

What causes it?

Idiopathic Synesthesia

• Seizure- in the core of the limbic system it causes strong synesthesia, but restricted to the hippocampus results in a weakened version
• Drug Induced- mostly hallucinogenic drugs such as mescalin, peyote, or LSD
• Neuron Degeneration- sensory deprivation such as blindness or deafness can cause synesthesia
• Brain Damage- Most common form of Idiopathic Synesthesia, induced by the stimulus of bimodal neurons in the brain
• Spine Injuries- A touch above or below a lesion (tumor) sometimes causes a sensation in that area and a seemingly unrelated area of the body
• Concussion Induced- In 2% of concussions, a temporary synesthesia occurs where light or sound causes pain in certain areas

Non-Idiopathic Synesthesia

• Uninhibited Natural State- There is little evidence for this point of view, which is that everyone is synesthetic, and that most people just aren't aware of it
• Neonatal- Babies are bimodal, and after a time, a pruning gene comes and removes extra connections, but a mutation or malfunction in the gene causes the bonds to remain, even grow

What are synesthetes like?

Synesthetes are...

• Not mentally ill- In fact, they score higher on several memory and intelligence tests
• Often poets, novelists, and artists
• Likely to be more creative and artistic
• Just normal people

Pros and cons

Pros

• Synesthetes can discern similar colors
• It can allow for easier memorization
• Leads to unique job opportunities
• Can enhance creativity
• Most synesthetes consider it a gift that they wouldn't want to live without

cons

• Seeing words printed in the wrong color can be confusing
• For some types, certain names might taste bad, or certain sounds might inspire negative emotions
• It can be embarrassing describing synesthesia, thinking everyone experiences it, only to find you stand out a bit

Types of synesthesia

TYPES...

• Chromesthesia- Sound inspires color or shapes in the eyes of these synesthetes
• Lexical Gustatory- Words have a taste that can be good or bad
• Mirror Touch- If these synesthetes see someone else being touched they physically feel it
• Misophonia- Sound inspires negative emotions such as anger or frustration
• Personification- Sequences such as days of the week or months will have personalities- Ex. Monday is laid back
• Number Color- Numbers are color coded
• Number Form- Numbers appear in a map, but not in our order
• In number color or letter color synesthesia, if one number or letter is blue, than that number or letter will always be blue

Color Number Synesthesia

One of these shapes is called kiki, and one is bouba. Which shape do you think is bouba?

Chromesthesia

WHO STUDIES IT ?

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• Francis Galton was the first to describe synesthesia
• He discovered that ut runs in families
• Dr. Vilayanur Ramachandran is a major researcher of synesthesia currently

GLOSSARY

• Limbic- Referring to the limbic system, an evolutionarily older section of the brain that is associated with emotion, learning, and memory
• Bimodal- Dealing with two modalities
• Neocortex- The most evolutionarily advanced part of the brain, found only in mammals and largest in humans; also called the cortex; associated with higher levels of processing information