What is Synesthesia?
Synesthesia is a condition in which one sense (for example, hearing) is simultaneously perceived as if by one or more additional senses such as sight. Another form of synesthesia joins objects such as letters, shapes, numbers or people’s names with a sensory perception such as smell, color or flavor. The word synesthesia comes from two Greek words, syn (together) and aisthesis (perception). Therefore, synesthesia literally means “joined perception.”
Synesthesia can involve any of the senses. The most common form, colored letters and numbers, occurs when someone always sees a certain color in response to a certain letter of the alphabet or number. For example, a synesthete (a person with synesthesia) might see the word “plane” as mint green or the number “4” as dark brown. There are also synesthetes who hear sounds in response to smell, who smell in response to touch, or who feel something in response to sight. Just about any combination of the senses is possible. There are some people who possess synesthesia involving three or even more senses, but this is extremely rare.
Synesthetic perceptions are specific to each person. Different people with synesthesia almost always disagree on their perceptions. In other words, if one synesthete thinks that the letter “q” is colored blue, another synesthete might see “q” as orange.
Synesthesia (https://synesthesia.com/blog/index.php/synesthesia/) has a variety of resources on the science behind synesthesia, blog articles, diagnostic tools, and more.
Synesthesia Battery (https://www.synesthete.org/) From their website: This battery of tests provides a standard battery of questions, tests and scoring. This test is available to the whole community of researchers and “synesthetes” for their use in making scientific progress. Your data will be kept entirely private, for use only by yourself, and by a researcher if you provide a valid email address for one.
American Psychological Association (http://www.apa.org/monitor/mar01/synesthesia.aspx) APA is the leading scientific and professional organization representing psychology in the United States, with more than 115,700 researchers, educators, clinicians, consultants and students as its members.