Science + Technology

Don’t Talk to a Friend While Reading This; Multi-Tasking Adversely Affects the Brain’s Learning Systems, UCLA Scientists Report


Multi-tasking affects the brain's learning systems, and as aresult, we do not learn as well when we are distracted, UCLA psychologistsreport this week in the online edition of Proceedings of the National Academyof Sciences.

"Multi-tasking adversely affects how you learn," said Russell Poldrack, UCLA associate professor ofpsychology and co-author of the study. "Even if you learnwhile multi-tasking, that learning is less flexible and more specialized, soyou cannot retrieve the information as easily. Our study shows that to thedegree you can learn while multi-tasking, you will use different brain systems.

"The best thing you can do to improve your memory is to payattention to the things you want to remember," Poldrack added. "Our data supportthat. When distractions force you to pay less attention to what you are doing,you don't learn as well as if you had paid full attention."

Tasks thatrequire more attention, such as learning calculus or reading Shakespeare, willbe particularly adversely affected by multi-tasking, Poldracksaid.

The researchers used functional magnetic resonance imaging (fMRI) to examine brain activity and function, a techniquethat uses magnetic fields to spot active brain areas by telltale increases inblood oxygen.

Participants in the study, who were in their 20s,learned a simple classificationtask by trial-and-error. They were asked to make predictions after receiving a set ofcues concerning cards that displayed various shapes, and divided thecards into two categories. With one set of cards, they learned without anydistractions. With a second set of cards, they performed a simultaneous task:listening to high and low beeps through headphones and keeping a mental countof the high-pitch beeps. While the distraction of the beeps did not reduce theaccuracy of the predictions — people could learn the task either way — it didreduce the participants' subsequent knowledge about the task during a follow-upsession.

When the subjects were asked questions about the cardsafterward, they did much better on the task they learned without thedistraction. On the task they learned with the distraction, they could notextrapolate; in scientific terms, their knowledge was much less "flexible."

This result demonstrates a reduced capacity to recall memories whenplaced in a different context, Poldrack said.

"Ourresults suggest that learning facts and concepts will be worse if you learnthem while you're distracted," Poldrack said.

Different forms of memory are processed by separate systems in thebrain, he noted. When you recallwhat you did last weekend or try to remember someone's name or your driver'slicense number, you are using a type of memory retrieval called declarativememory. (Patients with Alzheimer disease have damage in these brain areas.) Whenyou remember how to ride a bicycle or how to play tennis, you are using what iscalled procedural memory; this requires a different set of brain areas thanthose used for learning facts and concepts, which rely on the declarative memorysystem. The beeps in the study disrupted declarative memory, said Poldrack, who also studies how the typesof memory are related.

The brain's hippocampus — asea-horse-shaped structure that plays critical roles in processing, storing andrecalling information — is necessary for declarative memory, Poldrack said. For thetask learned without distraction, the hippocampus was involved. However, forthe task learned with the distraction of the beeps, the hippocampus was notinvolved; but the striatum was, which is the brain systemthat underlies our ability to learn new skills.

The striatum is the brain system damaged in patients with Parkinsondisease, Poldrack noted. Patients withParkinson's have trouble learning new motor skills but do not have troubleremembering the past.

"Wehave shown that multi-tasking makes it more likely you will rely on thestriatum to learn," Poldrack said. "Our study indicates that multi-tasking changes the way peoplelearn."

The researchers noted that they are not saying never to multi-task, just don't multi-taskwhile you are trying to learn something new that you hope to remember. Listeningto music can energize peopleand increase alertness. Listening to music while performing certain tasks, suchas exercising, can be helpful. But tasks that distract you while you try tolearn something new are likely to adversely affect your learning, Poldrack said.

"Concentrate while you're studying," he said.

The research isfederally funded by the National Science Foundation ( and the Whitehall Foundation (

Poldrack noted that other research shows that talking on the phonebadly impairs the ability to drive a car.

Co-authors are Karin Foerde, a UCLA graduatestudent in psychology, and Barbara Knowlton, UCLA associate professorof psychology.

About UCLA


California'slargest university, UCLA enrolls approximately 38,000 students per year andoffers degrees from the UCLA College of Letters and Science and 11 professionalschools in dozens of varied disciplines. UCLA consistently ranks among the topfive universities and colleges nationally in total research-and-developmentspending, receiving more than $820 million a year in competitively awardedfederal and state grants and contracts. For every $1 state taxpayers invest inUCLA, the university generates almost $9 in economic activity, resulting in anannual $6 billion economic impact on the Greater Los Angeles region. Theuniversity's health care network treats 450,000 patients per year. UCLA employsmore than 27,000 faculty and staff, has more than 350,000 living alumni and hasbeen home to five Nobel Prize recipients.



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