Blue Cats and Chartreuse Kittens: How Synthesthetes Color Their World (By Patricia Lynne Duffy, W.H. Freeman/Times Books/Henry Holt & Co., 185 pages, paperback, $14) Synesthesia is the blending of two or more sense perceptions where the person experiences music or letters as having color, for example, or taste as having shapes. Several researchers have noted that synesthesia is far more common in children than in adults, with between one third to one half of children reporting such perceptions. Is your child synesthetic? In Blue Cats and Chartreuse Kittens, journalist and synesthete Patricia Duffy offers a rare and entertaining glance into the minds of the individuals who experience this condition. She touches on the following factors: Why researchers believe all infants are born synesthetic; theories as to why many of us lose synesthetic abilities as we age; what to do if your child is synesthetic; and the link between synesthesia and language skills as well as how to help your child take advantage of this gift.