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The Secret Life of the Mind

The Secret Life of the Mind: How Your Brain Thinks, Feels, and Decides

Mariano Sigman
Little, Brown
2017
288 pp.
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The human brain is one of the most complex organs known to modern science, and many things are yet to be understood about how it shapes our identity—or how our identity can shape it. In his first book, The Secret Life of the Mind, Argentinian neuroscientist Mariano Sigman positions readers to explore the fundamentals of neuroscience and psychology in the hopes of uncovering the mysterious ways our brain controls how our faculties and personalities develop.

To comprehend how the brain is formed and how it creates the “Borders of Identity,” as one of the book’s early chapters is aptly titled, one must understand how learned behavior is established in childhood. In the book’s first chapter, Sigman describes the psychology of infants from how they discern patterns in language to how and at what age they develop self-control and a moral code. Here, he elegantly explains some of the psychological experiments that have given researchers insight into the brain development of children.

In one example, Sigman describes research conducted at the University of Pennsylvania in 2012, in which the brains of children who grew up in supportive environments were compared with a comparable cohort that lacked social stability. In adolescence, not only were the subjects’ behaviors distinct, the sizes and comparative complexity of their brains were strikingly different: The nurtured children exhibited larger brain size, whereas children with minimal support showed more pronounced ventricles and even signs of atrophy in the gray matter of the brain.

The other experiments Sigman describes in this section read like an impassioned lecture in introductory psychology, supplemented with sometimes long-winded analogies and personal anecdotes. In one particularly compelling passage, Sigman recounts the vulnerability he felt after undergoing a session of transcranial magnetic stimulation (TMS).

During the treatment, faint magnetic pulses were targeted to Sigman’s frontal cortex, and he was instructed to answer a series of questions, but only after waiting for a set period of time. Despite understanding the simple instructions, Sigman found that he was incapable of waiting the requisite period of time before answering. These more personal moments of reflection add warmth and context to the sometimes black-and-white nature of scientific studies.

Sigman builds on this meandering introduction with later chapters that delve into topics such as the formation of identity, consciousness, and how the brain changes during the lifetime of an adult, especially during learning. Individual studies, and lessons derived from philosophy or history, are presented in digestible, succinct passages. The insights revealed throughout the text coalesce in the book’s final chapter, where Sigman discusses education and how we may be able to use what we know about the brain to influence how we teach.

Although often rambling, Sigman provides vivid depictions of foundational behavioral psychology experiments and poses intriguing questions about how we view the organ that presides over our thoughts. The book’s exhaustive survey of experiments is, overall, enlightening, and Sigman’s clear passion for neuroscience makes it easy to browse.

About the author

Cell and Molecular Biology Graduate Program, Michigan State University, Grand Rapids, MI 49503, USA