It’s A Good Thing When I Don’t Know What I’m Writing About

Letting go of your expertise to tell a better story

Mark Humphries
The Spike


A writer contemplating the unknown. Credit: Pixabay.

I was stuck on the eyeball. There I was, writing a book about the brain, a manuscript that became The Spike: An Epic Journey Through the Brain in 2.1 Seconds. The big picture was clear in my mind: I wanted to tell the world about what it’s like to be a spike, the pulses of electricity that neurons send each other, the messages they use that make you do what you do — sense, think, and act.

But at the very first step in turning that picture into prose I’d run into a yawning gap between the big idea and the resources of my own brain. This then is a tale of how, inevitably, writing popular science means stretching beyond your own expertise. And of how I embrace that challenge, because it gives me the tools to take the reader deep into the science.

My book is a journey through the brain, from the light falling on the retina, bringing information about the scene in front of you, the reader, through the ascending regions of visual cortex that each process more complex parts of that scene, through to the further regions of cortex that underpin your short-term memory, decision making, and, finally, movement. That was the pitch, three journeys in one: a sight-seeing tour of regions crucial to seeing, deciding, remembering, and moving; a journey through increasingly complex ideas in neuroscience, from the elementary facts of making a spike to complex ideas of how lots of neurons work together to do stuff; and a journey through the spectacular work in systems neuroscience over the last two decades. Underpinning it all was that simple idea for the narrative backbone, a journey from eye to cortex to hand.

Therein lay the big problem: what I knew about the retina of the eye could be written on the back of a postage stamp, and still have room left over to scribble a reasonable sonnet. As a computational neuroscientist, I’ve worked on many regions of the brain, across many bits of the cortex, the hippocampus, the bundle of regions named the basal ganglia, and even three years on the medial reticular formation, a region so forbiddingly obscure most neuroscientists would have trouble accurately locating it on a map of the brain. But never on the retina. That tangled mess of cones and rods, and the layers of neurons beyond them, millions of neurons packed into a sliver of tissue that coats the back of your eyeball and turn light into messages sent to your brain. Of that, I knew nothing.

I briefly toyed with the idea of skipping it and jumping straight into the cortex, but frankly that would have been cheating, and would no doubt have left the reader feeling short-changed, by missing out the start of the journey, and never explaining exactly where the spikes began. So I steeled myself for some serious reading, and wrote a mental note in an unmissable neon pink to ask some expert on the retina to read it over.

I quickly became aware the problem was much worse than just a lack of knowledge.

The book is entirely about spikes, a book I sorely wanted to write because we neuroscientists have so much cool new knowledge to tell the wider world about how spikes operate, and someone needed to do the telling. But, oh damn: the neurons in the retina — all of the first two layers of them — do not use spikes.

Here was a nasty dilemma: how do I keep the reader onboard, the reader to whom I promised a book all about spikes, when the first tough bit of neuroscience they’ll need to read has no spikes in it at all? If they have to wade through paragraphs of how photons hitting cones in the retina get transduced into spikes over a complex circuit of neurons talking entirely in analogue, how do I stop them from dropping the book midway through Chapter 2, never to return?

The solution was to turn the dilemma into the hook, to use the absence of the key thing to explain why that thing exists.

I asked: why does the brain use spikes if they are not essential? And that triggered a whole torrent of creative thoughts, and wider reading: about the need for spikes to send messages accurately, far, and fast, reading that stretched from the deep details of the bipolar cell of the retina (two major reviews and a handful of primary research papers, all for a couple of sentences) to how fast spikes travel along the sciatic nerve of the giraffe (quickly, at over 100 metres per second, if you’re interested). Now instead of just wading through the details of the retina’s neural wiring, the reader got an answer to the deep, existential question of why the brain uses spikes.

I’d learnt this and other tricks through a few years of writing wide-ranging essays on neuroscience for my Medium publication The Spike: often I’d write about cool new work that was at the very fringes of my expertise — like breakthroughs in the neural basis of depression, or the difficulties of getting 70 teams of scientists to agree on the scientific insights from one set of fMRI data.

Those tricks are disarmingly simple. When faced with writing at the edges of your own knowledge or beyond, one trick is to take the reader on the journey of discovery with you, unpeel the work as you did, talking them through the decisions and logic of the researchers. And I’d wager this makes for more compelling prose, transmitting your own joy of discovery to the reader. Another is to frame the work in the context of broader problems or issues in science — like how the work fits into the “replication crisis” or speaks to where science funding ought to be directed. A third, used to solve my eyeball issue, is to see the problem as the thing to explain: why it exists at all. All tricks to help the “expert” writer turn stepping outside their expertise into a boost for creativity.

Writers of popular science come in two flavours: dedicated science writers, like Philip Ball, James Gleick, and Angela Saini; or subject experts reaching out to a wide audience, like me. Science writers are comfortable working beyond their innate expertise, indeed their wide-ranging books demand that they are. Us subject experts have to be comfortable with this too: Solving narrative problems in writing for a wider audience demands we move beyond what we already know well to give the reader a satisfying, informative, and entertaining journey. Sticking rigidly to what we know means a narrow, dull book, or a memoir — and I’m not even an expert on my own life, constantly struggling to remember events that others seem to recall clear as day. And if we want to write more than one book, we have to move beyond what we know, lest we end up writing the same book over and over again. Some would say it never did Richard Dawkins any harm, but few of us have his literary gifts to make restating the same points in different ways so engrossing.

The eyeball was a problem, but that problem turned out to be a wonderful source of inspiration. And another lesson learned was simple yet deep: that the key to writing a popular science book as an “expert” is to be prepared to abandon your expertise for the sake of narrative — for you are serving the reader, not yourself.

Twitter: @markdhumphries

The Spike: An Epic Journey Through the Brain in 2.1 Seconds is published by Princeton University Press, and available now from your favourite bookseller in paperback, hardback, e-book, and audiobook.

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Mark Humphries
The Spike

Theorist & neuroscientist. Writing at the intersection of neurons, data science, and AI. Author of “The Spike: An Epic Journey Through the Brain in 2.1 Seconds”