Rethinking Consciousness: A Scientific Theory of Subjective Experience

Graziano (The Spaces Between Us), a Princeton psychology and neuroscience professor, lays out a “promising theory of consciousness... that can apply equally to biological brains and artificial machines” in an educating and entertaining treatise aimed squarely at general readers. He posits what he terms the “attention schema theory” as the explanation for the rise of consciousness. At its core is the distinction between “overt” and “covert” attention. The former is what all animals do—pay attention to the world around them—while the latter, present only in conscious organisms, entails the ability to focus on ideas rather than simply on sensory input. Graziano provides an evolutionary context for the origin of covert attention and offers meaningful comparison with other hypotheses advanced to explain the basis of consciousness. Covert attention, as he describes it, serves as the “foundation for social cognition,” which, in turn, is responsible for human interaction. While still intriguing, Graziano is at his weakest in his final chapter, where he discusses the possibility, likely far in the future, of uploading human minds into machines. Nonetheless, he has produced an exciting example of how to present complex scientific topics for the general public. (Sept.)