"The brain's design made reading possible, and reading's design changed the brain in multiple, critical, still evolving ways. The reciprocal dynamics shine through the birth of writing in the species and through the acquisition of reading in the child."
In part one Wolf presents a brief history of early writing systems — Sumerian, Akkadian, ancient Egyptian, and Chinese — and touches on how reading must have co-opted existing brain structures. She goes on to describe the origin of the Greek alphabet and differences in the way the brain handles alphabetic (or syllabic) writing systems, evaluating claims that they make acquisition of reading faster and more efficient and contribute to "novel thought" and "enhanced awareness of speech". A countering viewpoint is Socrates' opposition to writing, as inflexible, destructive of memory and uncontrollable.
Part two turns to development and how children (normally) learn how to read, exploring how the brain supports reading and how reading in turn changes the brain. Wolf covers topics such as the importance of family backgrounds, word play and "word poverty", ear infections, bilingual environments, the different stages of reading, and when children should learn reading. This includes some "folksy" anecdotes about children, but Wolf also presents a detailed look at what happens in the brain of an expert reader. Reading continues to drive learning even in adults, in an ongoing process that is never complete.
Wolf's own area of study is dyslexia, which she covers in part three. Dyslexia can take a whole range of different forms, which she classifies into three broad classes: flaws in one of the older brain subsystems used for reading, failures to achieve automaticity and speed, and impediments to the connections between different brain structures. There is also a group of dyslexic readers who use different circuits for reading — with more activity in right-hemisphere regions, including the occipital-temporal regions, and less in the left posterior regions, especially the angular gyrus. Wolf also offers some practical recommendations for parents and teachers, touches on genetic studies, and considers links between some kinds of dyslexia and creativity.
Wolf observes that "learning to read released the species from many of the former limitations of human memory", but her approach is "more biological and cognitive than cultural-historical" and she doesn't attempt anything like a cultural or social history of literacy. And, though her account is informed by evolutionary ideas, she avoids sociobiology or speculation about the broad trajectory of human evolution.
In several places Wolf expresses concerns about the effects of digital communications, and concomitant changes to reading, on forthcoming generations. Here, unfortunately, she repeats the obvious speculative possibilities rather than attempting evaluation of the evidence — a contrast with her approach elsewhere.
Proust and the Squid doesn't get bogged down, but does provide substance in its treatment. There are detailed scientific references for those who want them; these are not marked in the text at all, but are in endnotes identified by a page number and a short quote. Proust and the Squid is an easy and entertaining read, recommended to anyone curious about reading and the brain as well as to those dealing with dyslexia or the teaching of reading.