As a frequent sigher I found most amusing the part about measuring the number of sighs. I had to dwelve deep in the article to find why it's significant: "Prev

As a frequent sigher I found most amusing the part about measuring the number of sighs. I had to dwelve deep in the article to find why it's significant: "Previous studies have indicated that the number of sighs increased with increased cognitive load[14,21]. In our study, the number of sighs increased during cognitive reading activity on a paper medium and decreased when reading on a smartphone." My anecdotal experience is that I sigh when tired, so the research passes my tests. Also, I love physical books. I love holding them, opening them, and of course, reading. If possible with a pencil in my hand.