Anyone who's been a victim of "death by Powerpoint" - that glazed and distant feeling that overwhelms you when some sales droid starts their presentation - will be reassured by Aussie researchers who've discovered biological reasons for the feeling.
Humans just don't like absorbing information verbally and visually at the same time - one or the other is fine but not both simultaneously.
Researchers at the University of New South Wales in Australia found the brain is limited in the amount of information it can absorb - and presenting the same information in visual and verbal form - like reading from a typical Powerpoint slide - overloads this part of memory and makes absorbing information more difficult.
Professor Sweller said: "The use of the PowerPoint presentation has been a disaster. It should be ditched.
"It is effective to speak to a diagram, because it presents information in a different form. But it is not effective to speak the same words that are written, because it is putting too much load on the mind and decreases your ability to understand what is being presented."
The theory of "cognitive load theory" suggest the memory can deal with two or three tasks for a period of a few seconds - any more than that and information starts to get lost.
There's more from the Sydney Morning Herald here, or there's an abstract of Sweller's work (pdf) here.
Professor John Sweller is not the first to question the overarching power of Powerpoint. Edward Tufte is a professor emeritus at Yale and an information and interface design expert. His 2003 book The Cognitive Style of Powerpoint: Pitching Out Corrupts Within makes similar claims. ®
