3/7/2022:
I was listening to a Huberman Labs podcast and the host, Andrew Huberman, made a comment that you retain more information from a physical book than an electronic device, like a cellphone. It had to do with the size of the image and that looking at such a small area to read in interferes with breathing and blood flow to the brain. He cites an article in Nature (https://www.nature.com/articles/s41598-022-05605-0). The article states “If the negative effects of smartphones are true, it may be beneficial to take deep breaths while reading since sighs, whether voluntary or involuntary, regulate disordered breathing.” The study in the article compared physical books to cell phones. When I compare the reading area of most physical books with my tablet and 24″ computer monitor, reading area is greater in the electronic devices. Nevertheless, I have found myself breathing more deeply while reading. It cannot hurt to increase blood flow to the brain.
Another question to consider is whether I truly own any of the books in my Kindle library. I really like reading the Kindle versions, either on my computer or tablet. Both contain a multitude of books and are always available to read when I want. Highlighting and note-taking are very easy and retrieving the highlights and notes later is also very easy. But what if Amazon decides to stop selling Kindle versions or disabling the software or deciding I should not have in my library a book I bought from them. I think that happened with 1984 a few years back. I have tried to find some open source programs to read the Kindle content, but have not yet found any that work.