Synesthesia

1. Synesthesia

Synesthesia is a neurological condition in which one sense is experienced though the perception of another sense. People with synesthesia can taste colors, or see colors when they hear something. They have a unique connection between senses; for example, a person may see the number 10 as the color yellow, or may say the color purple tastes sweet.

http://www.wisegeek.com/what-is-synesthesia.htm

2. Grapheme-Color Synesthesia

Grapheme-Color Synesthesia is one type of Synesthesia where a person associates numbers and letters with colors. It is involuntary and it is one of the most common and most studied forms of synesthesia. For example, a person with grapheme-color synesthesia can see the letter P and the color purple.

http://en.wikipedia.org/wiki/Grapheme–color_synesthesia

3. Ordinal - Linguistic Personification

A type of Synesthesia where ordered sequences, like days, months and letter have a link with personalities. Scientists have paid little attention to this type of synesthesia because it is not so common. For example, the month of november can be overlapped with the feeling of happiness.

http://en.wikipedia.org/wiki/Ordinal_linguistic_personification

4. Number-Form Synesthesia

A person with number-form synesthesia have a mental number line or a mental map of numbers that appear in an involuntary way whenever they think of numbers.

http://en.wikipedia.org/wiki/Number_form

5. Sound-Color Synesthesia

People with sound-color synesthesia associate color with sound. It can be broken down into 2 categories: narrow band and broad band. In the narrow band synesthesia, music expresses different shades and brightness. In broad band synesthesia, people see colors when they hear ordinary sounds, like the ringing of the alarm clock, airplane flyings, etc. Colors change in response to different sounds.

http://undacovabear.wordpress.com/2009/02/08/sound-colour-synesthesia/

6. Lexical-Gustatory Synesthesia

This is one of the rarest forms of Synesthesia and it is when a person can taste words. Some scientists have found that lexical-gustatory synesthesia is caused by early food experiences.

http://en.wikipedia.org/wiki/Lexical-gustatory_synesthesia

pictures:

http://cytowic.net/Smithsonian/image007.jpg

http://www.elchill.com/pictures/color_number_synesthesia.jpg

http://www.apartmenttherapy.com/uimages/sf/1016_syn01.jpg

http://jlim1131.web.unc.edu/files/2010/12/800px-Galton_number_form.svg_.png

http://www.medleague.com/blog/wp-content/uploads/music-color.jpg

http://www.epworthchurch.info/abc%20soup.gif