The findings have implications for today's universities and workplaces, where multi-tasking has become the norm, said Dr. John Lucas, a clinical assistant professor of psychiatry at Weill-Cornell Medical College.
"There is no free lunch in switching from one task to another," Lucas said. "People multi-task without an awareness that transitioning from one set of responsibilities to another involves some lag time, and when they do switch, the cognitive skills are not going to be as sharp."
While computers are well-equipped to switch rapidly from one task to another, the human brain struggles with such demands. "The human brain is not a hard disc that can switch from one part of the drive to the other," Lucas said. "The average person is going to have difficulty performing two tasks as well as he or she would have performed one task and being focused on it over time."
The Kaiser Family Foundation has more on youth and media multi-tasking.
SOURCES: Eyal Ophir, M.S., researcher, Stanford University's Communication Between Humans and Interactive Media Lab, Palo Alto, Calif.; John J. Lucas, M.D., clinical assistant professor, psychiatry, Weill-Cornell Medical College, New York City; Aug. 24-28, 2009, Proceedings of the National Academy of Sciences