Bits: Study Shows Multitasking’s Toll on Memory

A growing body of research shows that juggling many tasks, as so many people do in this technological era, can divide attention and hurt learning and performance. Does it also hinder short-term memory?

That’s the implication of a study being published on Monday in Proceedings of the National Academy of Sciences, a respected journal. The research shows that multitasking takes a significantly greater toll on the working memory of older people.

Researchers said the key finding of the new study is that people between the ages of 60 and 80 have significantly more trouble remembering tasks after experiencing a brief interruption than do people in their 20s and 30s.

During the study, subjects were asked to look at a scene, then were interrupted for several seconds by an image of a person’s face. They were asked to identify the person’s gender and approximate age, and then returned to answer questions about the earlier scene. Older subjects found it much harder to disengage from the interruption and reestablish contact with the scene, the researchers found.

Even though the study did not revolve around interruptions from cellphones or other gadgets, one researcher said the results provide a “clear extrapolation” to the impact of a stream of incoming rings and buzzes.

“Technology provides so much more of an interference than what we did here,” said the researcher, Dr. Adam Gazzaley, a neurologist at the University of California at San Francisco. Indeed, the paper argues that studies like this are becoming increasingly important as aging adults spend more time in a work force with heavy multitasking demands.

“This issue is growing in scope and societal relevance as multitasking is being fed by a dramatic increase in the accessibility and variety of electronic media,” Dr. Gazzaley said.

The test, in addition to observing and measuring subjects’ behavior, also entailed observing their brains using real-time imaging to understand the neurological mechanisms at play. The images showed differences in the brains of younger people and older people following an interruption; in the younger subjects, the brain areas that had been engaged during interruption ceased to be engaged more quickly, but in the older subjects, those areas continued to remain stimulated.

Dr. Gazzaley said the researchers initially hypothesized that the reason older subjects remained engaged with the “interruption” was because they simply became more focused on the face. But what he said the research shows instead is a “diminished ability” to reactivate the networks involved in the initial task.

Gary Small, director for the Center on Aging at the University of California at Los Angeles, said the research was consistent with existing studies — and with many peoples’ everyday experiences. “You say, I’ve got to go to the market to get eggs, but then you get home and you’ve got 20 other things and you forgot the eggs,” said Dr. Small, a psychiatrist and the author of “iBrain: Surviving the Technological Alteration of the Modern Mind.” He added: “As your brain ages, it’s harder to get back to the task at hand after an interruption.”

Dr. Gazzaley’s study looked at a type of memory called working memory, which is considered a precious and finite resource that people tap into when they are engaged in a task, like doing a work project or having a conversation. The study did not look at the effects of multitasking on long-term memory. However, Dr. Gazzaley said there was a relationship between people’s ability to develop long-term memories and the amount of time they spend focused on a particular experience. In other words, if interruptions make it difficult for older people to remember what they were doing in the short run, it also could hurt their ability to record those experiences over the long run, he said.

But Dr. Gazzaley said the study sheds more light on the reasons that short-term memories seem suddenly to go empty, as when someone stands in front the refrigerator, forgetting what it is he went to get.

“Events such as these increase in frequency as we get older — the classic senior moment. We now understand that this is not necessarily a memory problem per se, but often the result of an interaction between attention and memory,” he said. “For example, a phone call or text that interrupts us on the way to the refrigerator will negatively impact our ability to remember what we were going to the refrigerator to get in the first place.”

Article source: http://feeds.nytimes.com/click.phdo?i=55e6a06a93ddeb6fb7ae878460860ad5