With over 50 forms of synesthesia, this condition represents one of the richest perceptual conditions known to science. Rather than a deficit, synesthesia describes an augmentation of a very particular sensory experience. For synesthetes with colored-sequence synesthesia (CSS), the letter ‘K’ is actually ‘K’, Saturday means something very different than just Saturday, and  pops into their [...]
Synesthesia is a perceptual condition where individuals make unusual sensory associations. There are over 50 different forms of synesthesia, but the most common form is called colored-sequence synesthesia (CSS). People with CSS associate colors with over-learned sequences including numbers, letters, weekdays, and months.