From the bestselling author of Gratitude and Musicophilia , a collection of essays that displays Oliver Sacks's passionate engagement with the most compelling ideas of human endeavor: evolution, creativity, memory, time, consciousness, and experience. Oliver Sacks, scientist and storyteller, is beloved by readers for the extraordinary neurological case histories ( Awakenings , An Anthropologist on Mars ) in which he explored many now-familiar disorders--autism, Tourette syndrome, face blindness. He was also a memoirist who wrote with honesty and humor about the remarkable experiences that shaped him ( Uncle Tungsten , On the Move , Gratitude ). In the pieces that comprise The River of Consciousness (many first published in The New York Review of Books , among other places), Dr. Sacks takes on evolution, botany, chemistry, medicine, neuroscience, and the arts, and calls upon his great scientific and creative heroes--above all, Darwin, Freud, and William James. For Sacks, these thinkers were constant companions from an early age. The questions they explored--the meaning of evolution, the roots of creativity, and the nature of consciousness--lie at the heart of science and of this book. The River of Consciousness demonstrates Sacks's unparalleled ability to make unexpected connections, his sheer joy in knowledge, and his unceasing, timeless endeavor to understand what makes us human.

A proposal by two eminent biological scientists for a mechanism whereby mind becomes manifest from the operations of brain tissue. This significant contribution to neuroscience consists of two papers, the first by Mountcastle an, the second by Edelman. Between them, they examine from different but complementary directions the relationships that connect the higher brain—memory, learning, perception, thinking—with what goes on at the most basic levels of neural activity, with particular stress on the role of local neuronal circuits.Edelman's major hypothesis is that "the conscious state results from phasic reentrant signaling occurring in parallel processes that involve associations between stored patterns and current sensory or internal input." This selective process occurs by the polling of degenerate primary repertoires of neuronal groups that are formed during embryogenesis and development. Edelman's theory extrapolates to the brain the selectionistic immunological theories for which he was awarded the 1972 Nobel Prize in Physiology or Medicine. Mountcastle's paper reviews what is known about the actual structure of various parts of the neo cortex. He relates the large entities of the neocortex to their component modules—the local neuronal circuits—and shows how the complex interrelationships of such a distributed system can yield dynamic distributed functioning. There are strong conceptual parallels between Mountcastle's idea of cortical columns and their functional subunits and Edelman's concept of populations of neurons functioning as processors in a brain system based on selectional rather than instructional principles. These parallels are traced and put into perspective in Francis Schmitt's Introduction.