UCSF

This dissertation examines the historical context of nineteenth- and twentieth-century neurophysiological ideas and experiments. It uses archival records and correspondence, primary scientific literature, and secondary materials to explain and interpret the origins of contemporary neuroscience and, concurrently, explains and interprets modern ideas of the self. It analyzes nineteenth-century investigations into the nature of the nervous impulse via the examination of the laws of electrical activity as part of new formulations of natural law and the natural order. It demonstrates how nineteenth-century neurophysiological findings and interpretations were shaped by discoveries in electromagnetism and thermodynamics and must be understood through philosophical and evolutionary discourse. Twentieth-century neurophysiologists made the electroconductive model of nervous system functionality axiomatic through the methods and tools of reductive experimentation and analysis which depended on instrumentation developed for industrial and military purposes. Psychologists, cyberneticists, and modelers of neural computation engaged with neurophysiological research and concepts to create new theories and frameworks of functionality which took for granted the notion of the nervous system as continuously active, temporally dynamic, finely regulated, and incessantly adapting. A neuropsychological theory from the mid-twentieth century conceived of human behavior and cognition as the integration of neural activity which preserved permanency yet allowed for generalization through neurophysiological processes of learning and remembering. Neural modelers mechanized the notion of human cognition as distributed across networks of neurons that are continuously changing into themselves. By investigating neurophysiological research and concepts from the mid-nineteenth to the late twentieth centuries, this dissertation reveals the fundamental ideas, experimental approaches, and physical tools that continue to shape how we make sense of ourselves.