I have asked hundreds of people (no exaggeration), What is the most annoying thing that PowerPoint presenters do to you? What is it that most makes you wish you had something to throw?
Here's the answer: "Reading out every word I can read perfectly well for myself."
From long before the days of the sabre tooth tiger, we have been programmed to put our visual senses on high alert when something moves. That hasn't changed. Advertisers know it and ruthlessly exploit it - it's hard to find a TV ad that doesn't have something moving or changing all the time.
Here's the point for PowerPoint presenters.