The world behind the world Consciousness, free will, and the limits of science

Neuroscientist Hoel (The Revelations) serves up a challenging overview of the science of consciousness, exploring how the tension between "intrinsic" and "extrinsic" perspectives has shaped debate for millennia. Defining the intrinsic perspective as "the frame we take on when discussing the events that occur only within the mansions of our minds," Hoel traces this strain of thinking from ancient Egypt, where inscriptions suggest people "lacked good language for the subtleties of the mind," to modernist novels primarily concerned with characters' feelings and thoughts. By contrast, the extrinsic perspective views the mind "as consisting of machinery, mechanisms, formal relationships," and was pioneered by Galileo in a 1623 manifesto that argued science should focus on "what can be measured and counted." Delving into current research on consciousness, the author discusses how inconclusive neuroimaging research attempting to match patterns of brain activity to specific mental states has thwarted proponents of the extrinsic view, and notes that scientists are studying whether measuring the brain's response to electromagnetic stimulation might provide a falsifiable test of consciousness. The history intrigues, but the jargon-heavy discussions of contemporary neuroscience are hard to follow ("At the macroscale, the COPY = 0 is counterfactually dependent on α = 0"). The result is a mixed bag. (July)

Investigating the mystery of the mind. Neuroscientist and fiction writer Hoel draws on history, philosophy, mathematics, and neuroscience to examine ways that consciousness has been imagined and investigated. Beginning with an overview of what ancient Egyptians, Greeks, and Romans believed about "the subtleties of the mind," he considers the distinction between intrinsic phenomena, which came to be associated with religious experience and literature, and extrinsic phenomena, which fell under the purview of science. Neuroscience should be exceptional in being "where the intrinsic and extrinsic meet," but Hoel offers a sharp critique of the field, which he finds too heavily focused on neuroimaging and mapping--on the quantitative rather than the qualitative. He points out that scientific conclusions often are based on very small samples. "It takes thousands of individuals to achieve reproducible brain-wide associations," he writes. "This is not a bar most neuroimaging studies pass." Instead, he has discovered "that findings don't replicate, that every lab uses a different methodology, that small changes in methodology lead to big changes in outcomes," and that researchers tend to make up hypotheses to fit their own data. Even research in institutes founded by Nobel laureates in biology Francis Crick and Gerald Edelman falls short, in Hoel's estimation, because they each focus on correlating brain function to conscious experience. Readers may feel daunted by the author's explanation of the complexities of integrated information theory, which he helped to develop as a graduate student but now finds inadequate as "an explanation for subjectivity." More fruitful, for Hoel, is the theory of causal emergence, which posits that "macroscales have more causal influence than their underlying microscales over the exact same events." Emergence theory, he argues, accounts for "the brain's entire evolved purpose, it's very raison d'être--maintaining a stream of consciousness" as well as offering a "scientific justification for free will." A dense inquiry that will challenge readers without a scientific background. Copyright (c) Kirkus Reviews, used with permission.