It's the brain they're talking about and this is neuroscience, as Omni editors Hooper and Teresi see it. The style is the magazine's mod tone of interviews in the office or home, replete with details of the landscape, the furnishing, the clothes; it's breezy, sometimes intrusive, but often produces a vivid image or catchy aside. Pondering the prospect of having no memories, for example, the pair declare, ""Without them you'd be about as individual as the lobby of a Ramada Inn."" As to content, the authors span the spectrum of the neurosciences: anatomy, physiology, theories of learning, perception, memory, causes of disease. They consider the role of emotions and will; the putative pathways and centers for the roster of mental activities. They touch base with most of the Big Names--Eric Kandel on learning in sea mails; Solomon Snyder on endorphins and other neurotransmitters; Louis Sokoloff on brain scans which show which parts of the brain are active under given test conditions. And they dig sufficiently far back to resurrect Karl Lashley and his search for the (memory) engram and to recall Wilder Penfield's tappings into the brains of neurosurgery patients and hearing them report long-ago memories. Indeed, if the book has a central theme it could be defined as the age-old metaphysical question of the relationship between mind and brain, invoking Plato, Descartes, Berkeley, Hume, et al. Many an interviewee is queried on whether he or she is a reductionist, a dualist, a ghost-in-the-machine believer, an ""emergent property"" theorist or what. Some readers will find this laboring beside the point--like asking a molecular biologist when life begins. When the authors do stick to the subject at hand, be it brain waves or behavioral drugs, they are often very good at short sharp state-of-the-art summaries and are becomingly unbiased, presenting opposing theories or counterevidence with equanimity. This is a big book that catches the mood of a field that is undergoing explosive growth and that in itself is an achievement. However, the authors devote a major hunk of their finale to alternate states of consciousness: hallucinations, near-death experiences, more Berkeley-Hume ponderings laced with Jung and Eastern philosophy. For the most part, however, these sections are a rehash of believers and debunkers' theories and a departure from mainstream neuroscience. Pick and choose then, appreciating that there is much of value in this OMNIgatherium.