Do people read as well on screens as they do on paper? Scientists aren’t quite sure. While the type of E Ink used in the latest generation of Kindles and other tablets has been shown to be as or even more legible than printed text, other studies have indicated that — in terms of reading comprehension — the medium doesn’t much matter.

But a forthcoming paper by researchers in France and Norway suggests that there may be some cognitive drawbacks to reading even short works of literature on a screen.

A team of researchers led by Anne Mangen at the University of Stavanger in Norway and Jean-Luc Velay at Aix-Marseille Université in France divided 50 graduate students — with equivalent reading habits and experience with tablets — into two groups and had them read the same short story by Elizabeth George (in French translation). One group read the story in paperback, the other on an Amazon Kindle DX. All the while, researchers measured the students’ reading time and their “emotional response” — using a standard psychology scale — to the text. Afterward, they were tested extensively on different aspects of the story.