 In the late 1990s, researchers began to turn their attention towards grapheme-color synesthesia, one of the most common and easily studied forms of synesthesia.In 2006, the journal Cortex published a special issue on synesthesia, composed of 26 articles from individual case reports to functional neuroimaging studies of the neural basis of synesthesia.Synesthesia has been the topic of several recent scientific books and novels and a recent short film has even included characters who experience synesthesia (for more information, see the main synesthesia page).