Summary:
Linden, a professor of neuroscience, has written a book for a general audience on the subject of touch. A synthetic thinker, he combines insights from science, anatomy, neurophysiology, psychology, and social behavior. He argues that touch pervades much of human experience: “From consumer choice to sexual intercourse, from tool use to chronic pain to the process of healing, the genes, cells, and neural circuits involved in the sense of touch have been crucial to creating our unique human experience” (p. 5). Case studies of medical oddities enliven his account.
Chapter One, “The Skin is a Social Organ,” draws on a wide range of examples, from NBA players to vampire bats. Touch is especially important to the development of human newborns. Lab experiments have shown that the attitude of the toucher can influence the experience of the touched. English and American cultures are touch aversive.
Chapter Two discusses the neurophysiology of touch, the sensory nerves and the neurons that link to the spinal cord or to the brain. Lively examples include string players, 1900-era women with “underwear-shaped numbness,” and the Braille writing system for the blind.
In Chapter Three, “The Anatomy of a Caress,” Linden explores further the tactile fibers that relay touch. “A caress communicates that you are safe,” he writes, and the C-tactile system is the main route from skin to the brain.
Chapter Four, “Sexual Touch,” moves beyond caress all the way to orgasm, detailing the roles of touch receptors and brain activity as well as the wide variety of personal and social contexts.
Chapter Five looks at nerve endings of human skin that detect chili peppers as hot and mint as cool. Vampire bats have another version that detect heat, useful for locating blood vessels on “donors.”
Chapter Six, “Pain and Emotion,” opens with Pakistani children who do not feel pain; they have a genetic mutation that influences a sodium channel in neurons. Pain itself varies with people’s emotions, experience, and expectations. Some mindfulness practices (yoga, Tai Chi, meditation) can lessen chronic pain.
Chapter Seven, “The Itchy and Scratchy Show,” discusses river blindness and shingles, among other topics.
Chapter Eight, “Illusion and Transcendence,” provides a helpful overview of sensory nerves and their connection to various parts of the brain. Some stimuli activate the “emotional-affective-cognitive portions,” while others activate “sensory-discriminative centers.” Touch, in general, often has strong social meanings but does not, for Linden, imply any supernatural dimensions.
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