Since the 1980s a debate has raged about what is better for the human brain: to read on a screen or to read ink on paper. More than a hundred studies have been devoted to the topic, and the results are mixed.

Some studies have shown that the emission of light from computers, tablets, and phones makes reading more difficult on the eyes. That’s why Amazon lit the Kindle the way it did: to mimic the way light hits a printed page.

Other studies have talked about how babies and toddlers learn better through kinesthetic or hands-on learning. The more interaction a child has with an object, the better he or she learns. This is why the first apps and iPad books created for children were so interactive (and why children love scratch and sniff and activity-based board books). As Ferris Jabr wrote in a 2013 article for Scientific American, “Babies touch everything…they will jab at an illustration they like; heck, they will even taste the corner of a book.”

E-readers, computers, and touch screens fail – no matter how hard they try – to imitate the tactile experience of holding a book in one’s hand and cracking its binding for the first time. But beyond the tactile experience, how else do traditional books and e-books differ?

Neuroscience has shown that reading on screen uses a different part of our brain, shifting our brains toward “non-linear reading” and may affect our deep reading skills. Deep reading is a term coined by Sven Birkerts in “The Gutenberg Elegies and it means to read in a thoughtful and deliberate manner that filters out distractions and becomes a form of deep thinking.

Author of the book “Paper to Digital: Documents in the Information Age Ziming Liu, a professor at San Jose State University, found that when we read on screen we spend more time browsing, scanning, and performing non-linear reading. When we hold a physical book in our hands, our attention is more often captured by it.

Little boy reading book.

Maryanne Wolf, director of the Center for Reading at Language Research at Tufts, and author of “Proust and the Squid: The Story and Science of the Reading Brain,” has been researching deep reading versus reduced reading because of her concern of how it affects young novice readers or “those who are learning how to read in a way that helps them to comprehend and expand upon the information given.”

Wolf provides this basic explanation of how reading and the brain works (viewable through modern imaging technology): “Whenever we learn something new, the brain forms a new circuit that connects some of the brain’s original structures. In the case of learning to read, the brain builds connections between and among the visual, language, and conceptual areas that are part of our genetic heritage, but that were never woven together in this way before.”

Wolf argues that with its “sound bites, text bites, and mind bites” digital reading may not help children develop deep reading skills nor deep thought.

In two separate 2013 and 2014 studies, one of school children and one of adults, Anne Mangenand her colleagues at the University of Stavanger in Norway gave groups of people with similar reading abilities texts to read, with half reading electronic and half reading text on paper. Afterward, the readers completed a test to gauge reading comprehension. In both cases, the people who read the texts electronically did worse than their paper reading counterparts.

For the student study, Mangen thinks this is due to the students having a more difficult time finding specific information in the electronic texts. Printed documents are easier to navigate. “The ease with which you can find out the beginning, end, and everything in between and the constant connection to your path, your progress in the text, might be some way of making it less taxing cognitively, so you have more free capacity for comprehension,” Mangen said.

For the adult study, Mangen thought the readers might have different emotional reactions to the Elizabeth George short story, based on their interaction with it, but this was not the case. The Kindle readers did significantly worse on the 14-point plot reconstruction than the paperback readers did. The professor speculates that the physical act of turning pages helps readers orient themselves within the plot sequence. Physical pages also make it easier to turn back to something recently read. Similar experiments have been conducted by Kate Garland at the University of Leicester and others with similar results

Researchers also say there’s something emotionally satisfying about knowing where you are in a book, how much you’ve read, and how far you have to go before the end of the book or the end of the chapter (something that doesn’t resonate as much when seeing the “x percentage read” or the “hours left” countdown of e-readers). And anyone who has read the same book ad nauseam to a small child knows that feeling of relief as you near the end of the story for the umpteenth time.

All of that said, both types of literature, print and electronic, help kids develop a lifelong love and habit of reading. Fabr said, “Today’s so-called digital natives still interact with a mix of paper magazines and books, as well as tablets, smartphones, and e-readers; using one kind of technology does not preclude them from understanding another.”

But let’s face it: a plastic coated board book is much friendlier to a teething infant than an electronic version of “The Very Hungry Caterpillar” any day, even if the content is the same.