In Human, Dr. Michael S. Gazzaniga provides us with a detailed (almost to a fault at times) examination of the human brain. Although I wouldn't recommend it for anyone without at least rudimentary knowledge of brain anatomy and function, it provides an enlightening and humbling look at just what exists inside our heads that makes us so dramatically different from every other species on Earth.



My tendency to devour science fiction books while pretty much ignoring the world of non-fiction had me apprehensive about reading such a lengthy and in depth work of legitimate science, but I found myself pleasantly surprised (and at times enthralled) by the many facets of this book and how well they blend together. Gazzaniga has mastered the art of keeping lengthy anatomical dissertations interesting by linking them with thought-provoking experiments and case-studies, all the while inserting chuckle-inducing one-liners and quips.



The book is laid out in four parts, with each part being around 100 pages long and consisting of two to three chapters apiece. Within the chapters are titled subsections that help keep the countless ideas and transitions neatly organized. Footnotes and citations abound throughout the book, and the last fifty or so pages consist of bibliographical notes and an index.



The first of the four parts is called The Basics of Human Life, which begins with Chapter 1: Are Human Brains Unique? In this chapter, Gazzaniga begins with a discussion of the basic anatomy of the brain, including size, regions and structures. He explains lateralization and cortical columns in a fair amount of detail, and begins showing how the human brain is physically different from the brains of other primates. This chapter may seem boring for readers, but it provides a good introduction to the human brain which is necessary for understanding the later observations of the book.



The next chapter begs the question of whether a chimp would be a good date, and it begins to delve deeper into the mental capacity and characteristics exhibited by humans and other primates. Gazzaniga immediately discusses the tendency of humans to personify other animals, and cautions against using that tendency to interpret the actions of chimpanzees and other animals in lieu of a purely scientific approach. He briefly touches on the genomic differences between humans and chimps before beginning a discussion on the physical similarities and differences between the two species, and how each species came to evolve these characteristics. The discussion soon leads to mental differences, including the use of language and theory of mind. Gazzaniga describes the areas of the brain responsible for these characteristics, and how the relative size of these regions differs greatly between the two species. Gazzaniga concludes that "a day spent with [a chimpanzee] would be very interesting," but he would "prefer more culture" (75).



Part 2 - Navigating the Social World - begins with a chapter called Big Brains and Expanding Social Relationships. In this chapter, Gazzaniga discusses the evolutionary origins and positive selection of social groups. The discussions regarding the evolutionary benefits and origins of gossip and intentional lying were particularly interesting and humorous.

The next chapter highlights the presence of morals in human culture and how our brain incorporates both moral inclinations and rational thought into the decision making process. An in depth illustration of the evolutionary development and advantages of the five "moral modules" - reciprocity, suffering, hierarchy, coalition, and purity - explains that all human virtues originated from one or more of these five modules (132). The chapter closes by mentioning that the rational and emotional parts of our minds often conflict with one another, but unconscious mental processes influence our decisions also.



The fifth chapter, called I Feel Your Pain, illustrates many examples of subconscious imitation and mimicry between humans, such as wincing when seeing another human in pain. Discussions of mirror neurons and their involvement in unconscious empathetic responses were very illuminating. The chapter continues on to mention conscious displays or suppression of emotion, and ends by touching on self-awareness and its importance in filtering automatic empathetic responses to distinguish between experienced and observed harm.



Part three (The Glory of Being Human) begins with the sixth chapter, entitled What's Up with the Arts. This chapter details the evolutionary roots and fitness benefits of art and music, which I found to be quite interesting. In addition to art and music, aesthetics and human ideals of beauty are shown to have fitness benefits that are purely biological, including sexual preferences for symmetry, which subconsciously suggests physical fitness.



Chapter seven examines the tendency of humans to emphasize the belief of duality of mind and body. This section struck me as unnecessarily lengthy and philosophical, though not without a few interesting points, such as the power of human intuition with regards to physics and the benefits and fallacies humans owe to their theory of mind.



The eight chapter, Is Anybody There, discusses in depth the specific regions and characteristics of the brain that allow humans to experience consciousness and self awareness. This chapter has a great deal of information about people whose brains have been injured and the effects of such injuries on their personalities or mental/physical functioning. Gazzaniga concludes with the statement that "consciousness is an emergent property and not a process in and of itself" (320).



As a fanatical science fiction reader and biomedical engineer, the last chapter (Who Needs Flesh) was the most interesting in the book. It describes the advances being made in neuroscience and what we have to look forward to from the future. Discussions of brain-computer interfacing, AI development, genetic modification, and medical device implantation were very in-depth and interesting. Detailed explanations of recent scientific advances should leave any reader anticipating the near future with optimism and excitement.



All in all, I'd say that Human is a very enlightening read for anyone interested in neuroscience or human evolution. It has definitely given me a new respect for the human brain, and maybe even an idea or two for a new science fiction story.