Monday, April 19, 2010
A recent rigorous study of this matter evaluated a group of study participants, divided into those that were heavy multi-taskers and those that multi-tasked only infrequently. All participants were probably at the higher end of general mental capabilities, given that they were Stanford college students. Each participant was tested in a series of thinking tests to check for any difference in the way the two types of people processed information and disciplined their attentiveness.
Heavy multi-taskers were less able to sustain focus in the presence of distractions. The researchers concluded that light multi-taskers "find it easier to attentionally focus on a single task in the face of distractions."
The study did not directly examine ability to memorize, but there surely must be a significant difference, given that memory formation is enhanced by sustained attentiveness and focus. There may be some undiscovered benefits of multi-tasking, but memorizing cannot be one of them.
Nor is intelligent thought likely to benefit from multi-tasking. Several studies that I have summarized elsewhere show that intelligence correlates with working memory capacity, which under the best of circumstances is limited and easily over-loaded by multiple simultaneous informational input.
The study did not test whether distractibility is a cause or a consequence of multi-tasking behavior. But the data clearly support the notion that people whose work or study requires concentration should not multi-task.
There is also the potential problem that frequent multi-tasking could be teaching the brain to become more distractible.
Ophir, E., Nass, C., and Wagner, A. D. 2009. Cognitive control in media multitaskers. Proceedings National Academy of Science. 106 (37): 15583-15587. doi/10.1073/pnas.0903620106