Article talks about "electronic devices", but the study compared paper with reading on smartphone screens. My feeling is that reading on an e-reader should be

Article talks about "electronic devices", but the study compared paper with reading on smartphone screens. My feeling is that reading on an e-reader should be quite similar to paper, because of the different kind of screen and different use pattern of the device (your brain is probably half distracted just by knowing that it's using a smartphone...), but that wasn't included.