Wednesday Is Indigo Blue
Richard Cytowic
 The introduction likens the "cross-talk" occurring in the brain producing synesthetic experiences to weather patterns in coastal regions where there are no barriers and all of the elements interact. Normally communication in the brain is like weather in the Rocky Mountain regions, where weather can be isolated in one spot independent of weather systems close by. Chapter 1, "What color is Tuesday?", describes some of the early and still common resistance to the existence and study of synesthesia, and explains the fundamental characteristics necessary to "diagnose" synesthesia. The authors advocate the usefulness of introspective reports as they can later be useful in developing third-party tests for such purposes. Form constants are introduced as part of a framework to study visual synesthetic concurrents (the involuntary response in another sense). Chapter 2 builds on Chapter 1, discussing the types of synesthesia and the methods used to make a synesthesia diagnosis such as variations on stroop tests. The potential benefits of synesthesia are expanded on, including its correlation with eidetic memory and experience of a wider ranger of color. Chapter 3 discusses grapheme-color synesthesia in detail and describes the case of Solomon Shereshevsky.