The lucius prism array described in the paper is a four-centimeter square, yet the researchers estimate the size could be enlarged to that of a smartphone screen or even a video monitor.

For example, this group was composed of all "avid" readers, given short stories by Ernest Hemingway to read on four platforms; the Kindle 2, an iPad, a PC monitor, and paper.

You might do this on the computer or on paper, and you can even try it with your eyes shut or the monitor off, which encourages speed and freedom of thought.