It’s well established that we absorb less well when reading on screen. But why? And can we do something to improve it?
Reading is so commonplace that it’s hard to appreciate how much of a challenge it poses to the human brain. As you read this sentence, you’re using the visual forms of words to access their meanings and pronunciations from memory, and then using this information, and the neural systems that evolved for spoken language, to construct larger units of meaning: phrases, sentences and extended discourse. Reading is a relatively recent cultural invention; our brain did not evolve to read. Only after years of education and practice do people learn to coordinate the brain systems needed to support skilled reading. This process is inherently difficult, as evidenced by the fact that a significant proportion of people struggle to attain reading proficiency despite having normal intelligence and opportunities for education.
Now pause and think about how you’re reading this article. You are almost certainly using a digital device such as a computer, smartphone, tablet or e-reader. This simple fact is worth contemplating because it’s only in the past decade that the technology required for digital reading has become ubiquitous. This shift from reading more traditional books, magazines and newspapers to digital media has brought at least one obvious change: it has placed the wealth of information collected by our species at our immediate disposal. This has affected how people use information, with one example being that readers of digital content must exercise critical thinking to sift through the volumes of information at their fingertips.
Given these changes, one might ask if, and how, the use of digital devices has altered the nature or quality of reading. Perhaps you have noticed, for example, that it seems to be more difficult for you to concentrate when you are reading something online than when you are reading a hard-copy book. Does it actually make a difference whether you’re reading a piece of writing on a laptop or on a piece of paper? We recently conducted a review of the scientific research that bears on this subject and, based on these findings, we can offer some likely answers.
Let’s begin by considering the scripts that are used to read and write. These systems differ across cultures, as a comparison of written English and Chinese makes clear. However, despite often large differences between scripts, the mental processes that support reading appear to be remarkably similar. Perhaps the best evidence for this comes from brain-imaging experiments showing convergence in the cortical regions that support the reading of languages such as English and Chinese. This research shows that the same regions are involved in visually processing printed words and then using the meanings of those words to construct the meanings of phrases and sentences.
Based on these findings, one might predict that there wouldn’t be significant differences between the reading of paper-based and digital text. After all, if different scripts have only negligible effects on how we read, why should the manner in which text is displayed be of any consequence for how it is read and understood? But there are experimental findings suggesting otherwise.
The screen inferiority effect is larger when readers are under pressure to read rapidly
One of these findings is the screen inferiority effect. As its name suggests, this effect refers to demonstrations that – with all else being equal – a text that is read on a digital screen will be less well understood than the same text if it is read on paper. If you’re reading this article online, for example, your understanding of its content may (at least to some degree) be compromised. After reading the article, you might be able to accurately answer questions about its gist, but not necessarily be able to report the details as well as if you had read it on paper. The effect has been documented across different languages and writing systems, indicating that it is robust.
Some studies, however, have provided evidence that the size of this effect is influenced by a number of variables. One of these variables is the nature of the text: the comprehension of narrative texts (in which readers become immersed in a story) seems to be less affected by how the text is displayed, compared with the comprehension of expository texts. So, if you’re engaged in an interesting novel, as opposed to studying a textbook, your grasp of the text will likely be less influenced by whether it’s on a screen or in print form. Another important variable is the amount of time available to read, with the screen inferiority effect being larger when readers are under pressure to read rapidly. If you have to read something very quickly, you’d probably be better off reading it in print. There is some evidence that reading skill is an important variable, too, with the screen inferiority effect being more pronounced for less skilled readers.
One study in 2020 suggests that the screen inferiority effect may increase readers’ susceptibility to misinformation, making them less likely to notice important discrepancies in the content of a text that is displayed digitally. The obvious practical implication is that people might be at greater risk of being misled by false claims that they read online – which, of course, is where much (if not most) misinformation is encountered these days.
The reasons for the screen inferiority effect remain poorly understood. It might partially reflect the dry eyes and visual fatigue that sometimes result from reading on screens. But the effect could also be related to how readers control their thoughts and behaviours. According to this account, because most digital reading involves the rapid acquisition of information from social media posts, short online news articles and emails, readers fail to appreciate that the more superficial reading that is sufficient to understand the gist of these short, simple texts is insufficient to understand longer, more difficult texts.
By this account, the screen inferiority effect reflects the misapplication of one reading strategy (the skimming of short, simple texts) to another, inappropriate situation (the reading of longer, more complex texts). Readers who are skimming might, for instance, be ignoring the shorter function words (like ‘a’ and ‘the’) that mostly play grammatical roles, and instead focus their attention on the longer content words that tend to convey the most meaning. Although this skimming strategy might be sufficient to understand the gist of a short text, any information that is lost by ignoring function words would be expected to degrade understanding of longer, more complex texts, where grammatical roles are required to know ‘who did what to whom’.
It is possible that paper-like, dedicated e-readers might someday convey the benefits of digital reading without the costs
There is indeed reason to think that reading involves the use of different kinds of strategies. One compelling source of evidence comes from another common example of digital reading: the reading of subtitles in movies and television. Many of us use subtitles to watch foreign-language films or shows, and their use has become more prevalent since the beginning of the COVID-19 pandemic – particularly in education, where online instructional videos often contain subtitles. In these multimodal reading situations, people must coordinate their reading of subtitles (which are displayed for some fixed amount of time) with whatever processing is also necessary to understand the video and auditory information.
In a 2020 experiment demonstrating how people do this, researchers tracked readers’ eye movements as they read subtitles in a documentary. As the subtitle presentation rate increased from 12 to 28 characters per second, readers adapted their behaviour in response to the reduction in time available to read the subtitles. These adaptations included making longer progressive eye movements, fewer regressive eye movements back to earlier subtitle regions, and shorter looking times on the individual words in the subtitles. Simulations using a computer model of eye-movement control in reading suggest that these adaptations are a compensatory strategy, and that this strategy is used to understand the gist of subtitles by either ignoring short function words (as mentioned earlier) or allowing only some maximum amount of time to identify individual words. These demonstrations suggest that readers attempt to adapt their ‘normal’ reading behaviour to accommodate whatever additional demands might be imposed by digital reading.
What do findings such as these suggest about the future of reading in a world full of digital devices? Although it is difficult to say too much about how reading will change going forward, there is reason to be optimistic about reading technology and its likely benefits. The proliferation of such technology has increased both the opportunities to engage in reading and the breadth of materials that are available. Future definitions of what it means to be a ‘skilled’ reader may include the capacity to take advantage of different reading technologies to support different goals – eg, reading paper-based text to support deep understanding of complex subject matter, while using digital reading for entertainment, interpersonal communication or reading text that is otherwise unavailable. It is also difficult to predict future technological developments, so it is possible that paper-like, dedicated e-readers might someday convey the benefits of digital reading without the costs.
Given that many readers increasingly do most of their reading on screens, however (as you are likely doing here), it may already be worthwhile to try to deliberately adjust reading strategies based on your reading goals. This could be done by actively slowing down your reading on a screen when the goal is to understand a difficult topic, or choosing formats with fewer visual distractions, such as advertising banners, that could result in split attention. To read optimally in the digital age, you must be mindful of your aims, and then select the reading approach – including the medium – that best supports them.
