How exactly does the technology we use to read change the way we read? How reading on screens differs from reading on paper is relevant not just to the youngest among us, but to just about everyone who reads—to anyone who routinely switches between working long hours in front of a computer at the office and leisurely reading paper magazines and books at home; to people who have embraced e-readers for their convenience and portability, but admit that for some reason they still prefer reading on paper; and to those who have already vowed to forgo tree pulp entirely. As digital texts and technologies become more prevalent, we gain new and more mobile ways of reading—but are we still reading as attentively and thoroughly? How do our brains respond differently to onscreen text than to words on paper? Should we be worried about dividing our attention between pixels and ink or is the validity of such concerns paper-thin?
Even so, evidence from laboratory experiments, polls and consumer reports indicates that modern screens and e-readers fail to adequately recreate certain tactile experiences of reading on paper that many people miss and, more importantly, prevent people from navigating long texts in an intuitive and satisfying way. In turn, such navigational difficulties may subtly inhibit reading comprehension. Compared with paper, screens may also drain more of our mental resources while we are reading and make it a little harder to remember what we read when we are done. A parallel line of research focuses on people's attitudes toward different kinds of media. Whether they realize it or not, many people approach computers and tablets with a state of mind less conducive to learning than the one they bring to paper.
At least a few studies suggest that by limiting the way people navigate texts, screens impair comprehension.
More at Scientific American here