THE MIND'S PAST

Adding to a growing genre that purports to say how mind arises from brain, a study that is short and witty but not entirely convincing. Dartmouth cognitive neuroscientist Gazzaniga (Nature’s Mind, 1992) argues that human brains are composed of distinct, automatic devices that evolved through natural selection and are already present in a child at birth. A person’s sense that a unified “self” is in charge of these devices is an illusion created by one of them, a left-brain gadget he calls the “interpreter.” It manufactures the fictional self by weaving a narrative in which the self gets credit for issuing orders already executed (moving an arm, writing a sentence). The author supports his thesis with accounts of perception and memory experiments, and anecdotes about brain-damaged patients. Much of this information is entertainingly conveyed, such as Gazzaniga’s critique of the popular notion that reading to babies helps wire their brains. Some elements of his argument are dry, others overly familiar, but the book’s biggest flaws are polemical and logical. Too often Gazzaniga argues by setting up straw men, representing a caricature of theories about centralized brain functions. He tries to banish questions by denying them—“no doubt about it” he says about a typically dubious assertion. Most frustratingly, he insists that the left-brain interpreter is a “spin doctor” without explaining for whose benefit the spinning takes place. Who is the little voter inside the head? Why should the brain construct an illusory self to persuade the illusory self that it is in control? Maybe Gazzaniga has an answer; if so, he should reveal it. On the other hand, this kind of argument may ultimately be a dead end—a figment of the late 20th century scientist’s need to explain the mind entirely as a product of the physical brain. An intriguing theory, assertively stated, but often Gazzaniga’s arguments seem too reductive or dogmatic to be convincing. (12 b&w illustrations, not seen)