The author Esmeralda Santiago has been writing about Puerto Rico and questions of immigration and identity since the early nineties. But, in 2008, she suffered a stroke that left her unable to decipher words on a page. In the months that followed, she relied on some of the same strategies she\u2019d used to teach herself English after moving to the United States as a young teen-ager\u2014checking out children\u2019s books from the library, for example, to learn basic vocabulary. Santiago\u2019s latest book, \u201cLas Madres,\u201d includes a character named Luz who goes through a similar experience after a traumatic brain injury. \u201cThat sense stayed with me long after I was over that situation\u2014that feeling between knowledge and ignorance,\u201d she tells the staff writer Vinson Cunningham. \u201cFor me, Luz is almost representative of Puerto Rico itself. We have this very long history that we don\u2019t necessarily have access to. . . . Those of us who live outside of the island, we live the history but we don\u2019t really know it.\u201d