Multi-tasking May Damage the Brain

We older adults tend to be awed at how young people today can multi-task. They seem to text message on cells phones, watch TV, listen to music, play a video or computer game, carrying on a conversation, and maybe even study their school lessons all simultaneously with apparent ease. Many adults, and even teachers, encourage multi-tasking because they think it is good stimulus for the brain and that learning how to multi-task is a useful skill. But I have already identified many research reports that show multi-tasking to impair formation of memory. Multi-tasking prevents the focused attention and reduction of distractions that are necessary for good memory.

Now there is a research report suggesting that the brain itself may be damaged by multi-tasking. Investigators at Stanford University gave questionnaires to their subjects to identify how much multi-tasking each person did. Nineteen subjects were "heavy multi-taskers" and 22 were "light multi-taskers." Comparison of how these two groups in thinking control tasks revealed that heavy media multi-taskers were more susceptible to interference from irrelevant environmental stimuli and from irrelevant representations in memory.In other words, they were more distractible. Then researchers tested the subjects for ability to filter relevant information from the environment and from their memories and to switch thinking tasks. A typical filtering test, for example, required subjects to detect changes in red triangles on a screen while ignoring blue triangles in the same pictures.

The heavy multi-taskers performed worse, even though their experience and presumed skill at multi-tasking should have made them more effective at these tasks. The heavy multi-taskers believed that they were good at multi-tasking, when in fact they were bad at every task that required multi-tasking.

It is not clear how much physical deterioration has occurred in brain from chronic multi-tasking. But at a minimum, multi-tasking is likely to reduce the brain's ability to develop concentration and thinking skills. Why do I suggest diminished thinking skills? Thinking is done with an orderly progression of items in working memory. Multi-tasking bombards working memory with scrambled and unfocused information and probably keeps the brain from learning how to optimize focus and orderly sequencing of thoughts through what I call the brain's "thought engine."

Source: Ophir, E., Nass, C. and Wagner, A. D. 2009. Cognitive control in media multitaskers. Procedings of the National Academy of Science. Aug. 24. doi: 10.1073/pnas0903620106