Almost all presentations (PowerPoint or otherwise) entail a presenter talking while displaying slides full of words. The idea is that the words on the screen support the words being spoken, thereby increasing both comprehension and retention.

There's only one problem: presentations decrease comprehension and retention, because the human brain is really bad at any multitasking that involves using the same part of the brain. Psychologist Marc Coutanche from the University of Pittsburgh explains in Popular Mechanics:

Your [brain's] language regions are processing the sounds, the words, the meaning of the sentences. Imagine a circuit where you've got multiple inputs and multiple outputs, but they share the same wires.

In other words, when your brain hears words and sees different words, either it simply short-circuits (in which case you zone out) or it toggles between the two set of words, garbling both. This is why virtually all PowerPoint presentations are boring and forgettable.

Your brain can, however, multitask when multitasking puts demands on different parts of your brain. That's why you can drive a car safely while listening to a podcast .

A large number of high successful entrepreneurs, such as Jeff Bezos and Elon Musk, have intuitively concluded what science has since suggested and are reportedly no longer willing to sit through PowerPoints.

Fortunately, there are effective alternatives to slide/bullet presentations. I provided those alternatives in a previous column, but here's a quick summary:

  • If you need to discuss and decide, use a briefing document. This is a short (three-page maximum) document that everyone in attendance reads at the beginning of a meeting. Important: Don't assign the document as pre-meeting homework, because almost nobody will read it.
  • If you're teaching and training, create interactive experiences. This means workbooks, group exercises, and especially note-taking -- always with a pencil or pen and never with a computer. Note-taking on paper vastly increases retention because it draws on multiple parts of your brain -- the PowerPoint effect in reverse.
  • If you want to entertain or inspire, give a speech. With a group too large to participate in interactive exercises, think TED Talk rather than college lecture. If there's an image that's crucial to understanding your speech, display it, but never, ever display bullet lists. Think: Have you ever seen a bullet list on a TED Talk?