Australian researchers have found that the human brain doesn't do a very good job of processing audio and visual information at the same time. But in pretty much every business meeting or school lecture you've been to in the last few years, you've probably found yourself struggling to listen to a speaker at the same time as bullet points flashed across a PowerPoint presentation.

Rather than driving the point home, the PowerPoint slides might be distracting you from what the speaker is saying. It's possible that the speaker is also distracting you from what's on the slides, but given the choice between paying attention to some bullet points or a human being, we're guessing you'll get more out of the lecture.