Let’s begin with a deceptively simple fact that has inspired my work on the reading brain over the past decade and move from there:

Human beings were never born to read.

The acquisition of literacy is one of the most important epigenetic achievements of Homo sapiens. To our knowledge, no other species ever acquired it. The act of learning to read added an entirely new circuit to our hominid brain’s repertoire. The long developmental process of learning to read deeply changed the very structure of that circuit’s connections, which rewired the brain, which transformed the nature of human thought.

What we read, how we read, and why we read change how we think. These changes are continuing now at a faster pace. In a span of only six millennia, reading became the transformative catalyst for intellectual development within individuals and within literate cultures. The quality of our reading is not only an index of the quality of our thought; it is our best-known route to developing whole new pathways in the cerebral evolution of our species. There is much at stake in the development of the reading brain and in the quickening changes that now characterize its current, evolving iterations.

You need only examine yourself. Perhaps you have already noticed how the quality of your attention has changed the more you read on screens and digital devices. Perhaps you have felt a pang of something subtle that is missing when you seek to immerse yourself in a once-favorite book. Like a phantom limb, you remember who you were as a reader but cannot summon that “attentive ghost” with the joy you once felt in being transported somewhere outside the self. It is more difficult still with children, whose attention is continuously distracted and flooded by stimuli that will never be consolidated in their reservoirs of knowledge. This means that the very basis of their capacity to draw analogies and inferences when they read will be less and less developed. Young reading brains are evolving without a ripple of concern from most people, even though more and more of our youths are not reading other than what is required, and often not even that: “tl; dr” (too long; didn’t read).

Will reading on digital formats impede the formation of the slower cognitive processes such as critical thinking, personal reflection, imagination, and empathy?

In our almost complete transition to a digital culture, we are changing in ways we never realized. There is as much reason for excitement, and for caution, if we turn our attention to the specific changes in the evolving reading brain that are happening now and that may happen in different ways in a few short years. This is because the transition from a literacy-based culture to a digital one differs radically from previous transitions from one form of communication to another. Unlike in the past, we possess both the science and technology to identify potential changes in how we read — and thus how we think — before such changes are fully entrenched in the population and accepted without our comprehension of the consequences.

When I was a child learning to read, I did not think about reading. Like Alice, I simply jumped down reading’s hole into Wonderland and disappeared for most of my childhood.

When I was a young woman, I did not think about reading. I simply became Elizabeth Bennet, Dorothea Brooke, and Isabel Archer at every opportunity. Sometimes I became men like Alyosha Karamazov, Hans Castorp, and Holden Caulfield. But always I was lifted to places very far from the little town of Eldorado, Illinois, and always I burned with emotions I could never otherwise have imagined. Even when I was a graduate student of literature, I did not think very much about reading. Rather, I pored over every word, every encrypted meaning in the Duino Elegies by Rilke and novels by George Eliot and John Steinbeck, and felt myself bursting with sharpened perceptions of the world and anxious to fulfill my responsibilities within it.

I failed my first round at the latter miserably and memorably. With all the enthusiasm a young, flimsily prepared teacher can have, I began a Peace Corps–like stint in rural Hawaii with a small and wonderful group of fellow would-be teachers. There I stood daily before 24 unutterably beautiful children. They looked at me with complete confidence, and we looked at each other with total, reciprocated affection. For a while, those children and I were oblivious to the fact that I could change the circumstances of their life trajectories if I could help them become literate, unlike many in their families. Then, only then, did I begin to think seriously about what reading means. It changed the direction of my life.

With sudden and complete clarity, I saw what would happen if those children could not learn the seemingly simple act of passage into a culture based on literacy. They would never fall down a hole and experience the exquisite joys of immersion in the reading life. They would never discover Dinotopia, Hogwarts, Middle Earth, or Pemberley. They would never wrestle through the night with ideas too large to fit within their smaller worlds. They would never experience the great shift that moves from reading about characters like the Lightning Thief and Matilda to believing they could become heroes and heroines themselves. And most important of all, they might never experience the infinite possibilities within their own thoughts that emerge whole cloth from each fresh encounter with worlds outside their own. I realized in a whiplash burst that those children, all mine for one year, might never reach their full potential as human beings if they never learned to read.

I revised my entire life plan and moved from the love of written words to the science beneath them. I set out to understand how human beings acquire written words and use written language to great advantage for their own intellectual development and that of future generations. I never looked back. Decades have passed since I taught the children of Waialua, now grown with children of their own. Because of them, I became a cognitive neuroscientist and a scholar of reading.

My first inklings of the high stakes involved in the reading circuit’s plasticity began more than a decade ago, when I launched forth on what I thought would be a relatively circumscribed task: a researcher’s account of reading’s contributions to human development in my book Proust and the Squid: The Story and Science of the Reading Brain. My original intention was to describe the great arc of literacy’s development and provide a new conceptualization of dyslexia that would describe the cerebral riches that are often wasted when people do not understand individuals whose brains are organized for language in a different way.

But something unexpected happened as I wrote that book: Reading itself changed. What I knew as a cognitive neuroscientist and developmental psychologist about the development of written language had begun to shift before my eyes and under my fingers and under everybody else’s, too. In the seven years it had taken me to describe how the brain had learned to read over its close to 6,000-year history, our entire literacy-based culture had begun its transformation into a very different, digitally based one.

I was gobsmacked. There was almost no research being conducted then on the formation of a digital reading brain. There were no significant studies about what was happening in the brains of children (or adults) as they learned to read while immersed in a digitally dominated medium six to seven hours a day (a figure that has since almost doubled for many of our youth). I knew how reading changes the brain and how the brain’s plasticity enables it to be shaped by external factors such as a particular writing system (for example, English versus Chinese). Now I became consumed with how the circuitry of the reading brain would be altered by the unique characteristics of the digital medium, particularly in the young.

The unnatural, cultural origin of literacy — the first deceptively simple fact about reading — means that young readers do not have a genetically based program for developing such circuits. Reading-brain circuits are shaped and developed by both natural and environmental factors, including the medium in which reading is acquired and developed. Each reading medium advantages certain cognitive processes over others. Translation: The young reader can either develop all the multiple deep-reading processes that are currently embodied in the fully elaborated, expert reading brain; or the novice reading brain can become “short-circuited” in its development; or it can acquire whole new networks in different circuits. There will be profound differences in how we read and how we think, depending on which processes dominate the formation of the young child’s reading circuit.

Will young digital readers develop a range of very different brain circuits? If so, what will be the implications of those different circuits for our society?

This leads us to the present moment and the difficult, more specific questions that arise for children raised within a digital milieu. Will new readers develop the more time-demanding cognitive processes nurtured by print-based mediums as they absorb and acquire new cognitive capacities emphasized by digital media? For example, will the combination of reading on digital formats and daily immersion in a variety of digital experiences — from social media to virtual games — impede the formation of the slower cognitive processes, such as critical thinking, personal reflection, imagination, and empathy, that are all part of deep reading? Will the mix of continuously stimulating distractions on children’s attention and immediate access to multiple sources of information give young readers less incentive either to build their own storehouses of knowledge or think critically for themselves?

In other words, through no intention on anyone’s part, will the increasing reliance of our youth on the servers of knowledge prove the greatest threat to the young brain’s building of its own foundation of knowledge, as well as to a child’s desire to think and imagine for him- or herself? Or will these new technologies provide the best, most complete bridge yet to ever more sophisticated forms of cognition and imagination that will allow our children to leap into new worlds of knowledge that we can’t even conceive of in this moment of time? Will they develop a range of very different brain circuits? If so, what will be the implications of those different circuits for our society? Will the very diversity of such circuits benefit everyone? Can an individual reader consciously acquire various circuits, much like bilingual speakers who read different scripts?

There is now emerging research from Europe, Israel, and the United States that is demonstrating worrisome differences in children and young adults when reading on print versus digital mediums. Studies on ages from elementary school students to young adults indicate that the slower, more time-demanding processes involved in comprehension and attention to details are adversely affected when reading the same content on digital mediums. Israeli researcher Tami Katzir finds these differences in comprehension in children as young as fourth grade. Norwegian researcher Anne Mangen pinpoints differences in how older students sequence the details of plot, which can go missing when reading at a more surface level. The issues that are emerging cannot be subsumed into a binary print versus digital conceptualization. Rather, they are essential to understand in order to illumine what students (and, indeed, all of us) need to know when we choose to read on any medium.

The implications of our reading brain’s plasticity are neither simple nor transient. The connections between how and what we read and what is written are critically important to today’s society. In a milieu that continuously confronts us with a glut of information, the great temptation for many is to retreat to familiar silos of easily digested, less dense, less intellectually demanding information. The illusion of being informed by a daily deluge of eye-byte-size information can trump the critical analysis of our complex realities. In my work, I confront these issues head-on and discuss how a democratic society depends on the undeterred use of these critical capacities and how quickly they can atrophy in each of us unnoticed.

Kurt Vonnegut compared the role of the artist in society to that of the canary in the mines: Both alert us to the presence of danger. The reading brain is the canary in our minds. We would be the worst of fools to ignore what it has to teach us.

From the book READER, COME HOME: The Reading Brain in a Digital World by Maryanne Wolf. Copyright © 2018 by Maryanne Wolf. Reprinted by permission of Harper, an imprint of HarperCollins Publishers.