Review

Title: The Spaces Between Us: A story of neuroscience, evolution, and human nature
Author: Michael S. A. Graziano
Publisher: New York : Oxford
Genre: Science
Year Published: c2018
Number of pages: 202
Binding: Hardback
ISBN13: 978-0-19-046101-0
Price: $24.95

Reviewed by Dennis Clark for the Association for Mormon Letters

The key to approaching this book is in the subtitle: this is a story. Like the best science writing, this story involves the people doing the science, the science being done, and the impact of the science on the lives of other people. Graziano tells us, with a personal example, why this neuroscience matters.

There’s a difference between writing science and science writing. Unless you know the jargon of the specific science, the writing of any science, its technical reports and claims of discovery, are opaque to a layman. The relationship of outsider to insider is rather like that in a cult: if you don’t know the specific technical terminology, you’re in the dark. Science writing, on the other hand, where the science takes a back seat to the writing, depends not on a specific audience, but on a general audience. This is where Graziano excels. Look at how he opens Chapter 1, “The Second Skin”:

“We all have an invisible, protective bubble around us. Personal space, margin of safety, bad breath zone, duck-and-flinch buffer — whatever you call it, we have it constantly switched on like a force field. It comes in layers, some layers close to the skin like a bodysuit, others farther away like a quarantine tent. Elaborate networks in the brain monitor those protective bubbles and keep them clear of danger by subtly, or sometimes drastically, adjusting our actions” (1).

In an earlier note on terminology, he writes “Peripersonal neurons are cells in the brain that monitor the space around the body. Their activity rises like a Geiger counter to indicate the location of objects entering a margin of safety. The neurons can detect an intruding object through vision, hearing, touch, and even by the memory of where objects are positioned in the dark” (ix). That simile “like a Geiger counter” would be unnecessary in writing science; it is at the heart of good science writing.

I have gone to such lengths to explain how Graziano writes because you really should read this book. It begins with what he acknowledges may be a disturbing series of experiments in the 1920’s studying the startle reflex in humans, involving German veterans — veterans filmed reacting to a gunshot close behind them. In that reaction, “the patient shrinks down, spine curved forward, knees bent, chin down and shoulders raised, hands pulled across the front, face contracted into a mighty squint that puckers the skin around the eyes and exposes the teeth” (6). Graziano talks about why this is a good defensive response, then notes that “the fastest and most consistent part of the reflex is the facial contraction” (6). A good part of the remainder of the book is dedicated to why that should be so, and the rest to the implications of that contraction.

Graziano’s explanation starts with a seemingly unrelated digression into the work of Heini Hediger, a Swiss biologist who directed three Swiss zoos from 1938-1973. His observations of animals in zoos and in the wild led him to the understanding that an animal’s “strongest drive was obvious: protecting the self from bodily harm” (13). Observing that animals need a territory to live in, he noted in a flight over European farmland that the fields below him were “laid out in abutting plots in a giant mosaic” (14), that people were organizing their territories as animals do.

In his book The Hidden Dimension, Edward Hall published observations in 1966 about personal space that spawned an entire psychological industry studying the subject. He “divided the space around people into four zones of different sizes: intimate distance, personal distance, social distance, and public distance” (21). In the multitude of studies following on his observations, Graziano says, “the most consistent finding … the one fundamental result, is that personal space expands with anxiety” (22). Put differently, “personal space is protective. It’s the region in which you don’t want other people” (24). This is the point at which Graziano’s story becomes personal: as the psychological research tapered off, “the neuronal underpinnings began to be discovered. At the start of my career as a scientist, in 1987, I found myself swept up in that surge of new research” (24).

You may have noticed that I am quoting Graziano a lot. That’s because he does a better job of summarizing what came before his research than I can. I can summarize the start of his career a little easier: it involved delicate experiments on the brains of monkeys. For 18 years, until about 2005, he studied the “neuronal underpinnings” of their personal space. The details of the studies are fascinating, and repellent. The animals were treated well, but the studies were invasive, and Graziano acknowledges that. This is where neuroscience was in 1987, and I am going to have to quote again, because I have no experience in this domain:

“Through a surgical port on the head, a hair-thin tungsten wire was lowered by precision machinery, micron by micron, with exquisite delicacy into the anesthetized brain. The wire was insulated with varnish except at the tip, where the tiny cone of exposed metal could pick up faint electrical signals” (29).

Those electrical signals, from a single neuron, were fed into a loudspeaker, and the work of determining what that neuron responded to was begun to the pops and clicks of that speaker. The author chose to study neurons in an obscure part of the brain, because the easiest ones to study, the ones that were involved in facial recognition, were well known by 1987. Graziano’s discussion of the scientific method in telling his story is well worth the discomfort you might feel from imagining the details of the work. The part he set out to study, the claustrum, yielded few results. What it does is still unknown. But to get to the monkeys’ claustrum, they had to go through the putamen, which is “one of the most intensely studied structures in the brain because of its involvement in Parkinson’s disease” (32).

What Graziano and his fellow experimenters found was that, if you run a weak current down that wire in the brain, you cause a twitch in some muscle in part of the body. Here, they were stimulating, rather than listening to, the neurons. They found a homunculus mapped onto that part of the brain, upside down — the further down into the putamen they went, the higher up were the twitches of the muscles, until they reached the eyes. Then they reversed the process, touching the monkey and seeing what happened in the brain: “sometimes the neurons began to respond as the Q-tip approached the face or arms, before it had touched the fur. That was spooky” (33), especially because a lot of this work was done at night, to cut down on external stimuli. Through trial and error they found that this was a visual response, in an area of the brain not known for responses to visual stimuli.

Eventually they discovered that “most neurons in the putamen” had a “tactile receptive field” (34) — touch the monkey in that field on the body, the neuron responds. Some “also responded to the sight of objects near the body” (35) — that spooky response. These neurons were (a) very sensitive to touch, (b) only included neurons responding to touch in the face, the arms, and the upper torso, and (c) the field of visual response corresponded to the tactile receptive field. Further testing showed that “the neurons were monitoring bubbles of space around the body” (36) — but even more interesting, they discovered a network of monitor neurons in other areas of the brain. Through many years of experimentation on both anesthetized and awake monkeys they began to understand how the monkey brain monitors what Giacomo Rizzolatti and his colleagues, working in Italy, called peripersonal neurons. And, in one of the most interesting descriptions of his work, Graziano describes how in his lab he and his colleagues developed a style of research and experimentation that he describes as “First, go fishing. Second, take out the calipers and measure the fish” (42). The book is as valuable for these descriptions of the work of science as it is for the descriptions of the results.

The major breakthrough was in finding that they could trigger the monkeys’ entire repertoire of movements by stimulating different parts of the motor cortex — that is, the monkeys’ feeding and climbing and running movements were essentially hard-wired in the brain. And this is true for some human movements as well, through the agency of transcranial magnetic stimulation. This suggests that certain human behaviors are nearly instinctual, and that they have evolved from that basic defensive startle reflex, the one demonstrated by German veterans of the First World War, and filmed in the 1920’s. It also raises the question of how, for instance, consensual mating can occur, since it involves the lowering of all one’s personal defenses, learned and evolved. Graziano discusses this in chapter 11, “Why It’s Sexy to Let a Vampire Bite Your Neck, and Other Social Consequences of Peripersonal Space.”

Then he steps back a bit, to explore in chapters 12, 13 and 14 the possible evolutionary origins of “The First Smile,” “The First Laugh” and “The First Cry.” He traces all of them to that basic cringe of the startle reflex: in that reaction, you will recall, “the patient shrinks down, spine curved forward, knees bent, chin down and shoulders raised, hands pulled across the front, face contracted into a mighty squint that puckers the skin around the eyes and exposes the teeth” (6). Elements of this reaction appear in smiling, laughing and crying, and Graziano speculates on how those instinctual reactions might have evolved from that protective neurological reflex. He is not the first to have done this — Charles Darwin explored much the same territory in his 1872 opus The Expression of the Emotions in Man and Animals — but Graziano speculates that these emotions developed as a means of social signaling in close groups of primates of one’s fitting in, evolving over millions of years. As he says in ending the chapter on smiles, “the survival advantage of a smile is the same as the survival of advantage of any social signal: it manipulates the behavior of the receiver.”

This might apply to sexual foreplay, when barriers to social interaction are gradually lowered by each party, although of course not to rape. It might explain why defining consent in such situations is so fraught with uncertainty. Consensual sex, even in a happy marriage with partners familiar with each other, is no simple negotiation. And with two people involved, the difference between giving consent and giving up may come down to that matter of manipulation.

But Graziano has an even more complicated negotiation in his final chapter, 15, “The Personal Dimension of Personal Space,” to ponder: the story of his son’s dyspraxia, which is “a gap between what you know in your head and what you can do in the physical world. It’s a difficulty with movement control, especially when learning new, complex skills” (141). And, to add to the difficulty of diagnosis and of treatment, no two cases are alike. In the case of his son, at four years old, “we realized that something was wrong. He was happy, smart, talkative, and clumsy … He had no trouble with his vision and knew the obstacles were there, but he couldn’t seem to organize his avoidance responses” (142). It got worse when he started school, and “could hold a pencil, but could barely write…. None of these tools seemed to become natural extensions of his hands” (143), as they should have, if chapter 10 is to be believed. That is, I incorporate a hand-held tool into my private space in order to use it effectively. Graziano says “I find it ironic that I studied the brain basis of personal space for decades and yet had so much trouble recognizing it up close in real life” (143-4).

What wasn’t ironic — what was tragic — was the social consequences of his trouble. His son was kicked out of school at age 6 for being different, like rocking back and forth in his seat, and having trouble with the teacher, who thought he was performing some weird sex act — and for leaning on other kids in line, among other unusual behavior. His teacher, and the principal, may have thought that they were dealing with an autistic child. He did not act like a typical autistic child, but his behavior was not what one would expect of a normal child. Graziano notes that “Dyspraxia is subtle and poorly studied, even though it affects an estimated one in fifteen or twenty children — perhaps one in every classroom” (143). That may be the worst part — he looked like a normal problem child. So the school kicked him out.

You should read that story. You should read the whole book. Having the entire story of the science as a background helps you to understand the story of the boy who could not process personal space, chapter 15. As with any well-written science book, I find myself thinking in its terms about things I see in my own life. Yesterday, my wife went to watch a granddaughter play slow-pitch softball in a recreation league, and noticed that one girl, at bat, had not been shown how to hold the bat or swing at the ball. As I thought about that, I recalled that the first time a coach told me how to hold the bat and swing at the ball, he told me to “keep your eye on the ball.” That was in elementary school. I thought about that in connection with this girl. What the coach meant was to look at the ball as it left the pitcher’s hand and reach out and touch it with the bat. Doing that, I could hit it. I could hit it because I had incorporated that bat as a tool into my personal space. I could see the ball and hit the ball as surely as I could reach out with my hand and catch it. I don’t much care for team sports, but with that ball and my tool, my bat, it was personal. I learned to hit the ball by not looking at the bat.

I don’t believe that such learned behavior could be easily made instinctual, but it can become reflexive — if incorporated as Graziano believes it can be into personal space. Such speculations as these are the most interesting part of a very interesting book. This is science writing at its best — science writing that understands its purpose as teaching, rather than reporting.