When facing a difficult project, we might tell ourselves, "Use your head." But as Annie Murphy Paul argues, we need to think outside the brain. A host of "extra-neural" resources—the feelings and movements of our bodies, the spaces in which we work, and the minds of those around us—can help us focus more intently, comprehend more deeply, and create more imaginatively. Paul also discusses how such figures as Jackson Pollock, Jonas Salk, and Robert Caro have used mental extensions to solve problems, make discoveries, and create new works.