The transparent and automatic feat of reading comprehension disguises an intricate biological effort, ably analyzed in this fascinating study. Drawing on scads of brain-imaging studies, case histories of stroke victims and ingenious cognitive psychology experiments, cognitive neuroscientist Dehaene (The Number Sense
) diagrams the neural machinery that translates marks on paper into language, sound and meaning. It's a complex and surprising circuitry, both specific, in that it is housed in parts of the cortex that perform specific processing tasks, and puzzlingly abstract. (The brain, Dehaene hypothesizes, registers words mainly as collections of pairs of letters.) The author proposes reading as an example of “neuronal recycling”—the recruitment of previously evolved neural circuits to accomplish cultural innovations—and uses this idea to explore how ancient scribes shaped writing systems around the brain's potential and limitations. (He likewise attacks modern “whole language” reading pedagogy as an unnatural imposition on a brain attuned to learning by phonics.) This lively, lucid treatise proves once again that Dehaene is one of our most gifted expositors of science; he makes the workings of the mind less mysterious, but no less miraculous. Illus. (Nov. 16)
