The Mind and the Brain Read Online Free PDF

Alcmaeon of Croton, an associate of the Pythagorean school of philosophy who is regarded as the founder of empirical psychology, proposed that conscious experience originates in the stuff of the brain. A renowned medical and physiological researcher (he practiced systematic dissection), Alcmaeon further theorized that all sensory awareness is coordinated by the brain. Fifty years later, Hippocrates adopted this notion of the brain as the seat of sensation, writing in his treatise on seizures: “I consider that the brain has the most power for man…. The eyes and ears and tongue and hands and feet do whatsoever the brain determines…it is the brain that is the messenger to the understanding [and] the brain that interprets the understanding.” Although Aristotle and the Stoics rejected this finding (seating thought in the heart instead), today scientists know, as much as they know anything, that all of mental life springs from neuronal processes in the brain. This belief has dominated studies of mind-brain relations since the early nineteenth century, when phrenologists attempted to correlate the various knobs and bumps on the skull with one or another facet of personality or mental ability. Today, of course, those correlations are a bit more precise, as scientists, going beyond the phrenologists’ conclusion that thirty-seven mental faculties are represented on the surface of the skull, do their mapping with brain imaging technologies such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), which pinpoint which brain neighborhoods are active during any given mental activity.
    This has been one of the greatest triumphs of modern neuroscience, this mapping of whole worlds of conscious experience—from recognizing faces to feeling joy, from fingering a violin string tosmelling a flower—onto a particular cluster of neurons in the brain. It began in the 1950s, when Wilder Penfield, a pioneer in the neurosurgery of epilepsy, electrically stimulated tiny spots on the surface of patients’ brains (a painless procedure, since neurons have no feeling). The patients were flooded with long-forgotten memories of their grandmother or heard a tune so vividly that they asked the good doctor why a phonograph was playing in the operating theater. But it is not merely the precision of the mental maps that has increased with the introduction of electrodes—and later noninvasive brain imaging—to replace the skull-bump cartography beloved of phrenologists. So has neuroscientists’ certainty that tracing different mental abilities to specific regions in the brain—verbal working memory to a spot beneath the left temple, just beside the region that encodes the unpleasantness of pain and just behind the spot that performs exact mathematical calculations—is a worthy end in itself. So powerful and enduring has been Alcmaeon’s hypothesis about the seat of mental life, and his intellectual descendants’ equating of brain and mind, that most neuroscientists today take for granted that once you have correlated activity in a cluster of neurons with a cognitive or emotional function—or, more generally, with any mental state—you have solved the problem of the origin of mental events. When you trace depression to activity in a circuit involving the frontal cortex and amygdala, you have—on the whole—explained it. When you link the formation of memories to electrochemical activities in the hippocampus, you have learned everything worth knowing about it. True, there are still plenty of details to work out. But the most deeply puzzling question—whether that vast panoply of phenomena encompassed by the word mind can actually arise from nothing but the brain—is not, in the view of most researchers, a legitimate subject for scientific inquiry. Call it the triumph of materialism.
    To the mainstream materialist way of thinking, only the physical is real. Anything nonphysical is at best an artifact, at