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Memory Problems? Perhaps you are Multi-tasking

Today’s kids are into multi-tasking. This is the generation hooked on iPods, IM’ing, video games – not to mention TV! Many people in my generation think it is wonderful that kids can do all these things simultaneously and are impressed with their competence.

Well, as a teacher of such kids when they reach college, I am not impressed. College students these days have short attention spans and have trouble concentrating. They got this way in secondary school. I see this in the middle-school outreach program I help run. At this age kids are really wrapped up in multi-tasking at the expense of focus.

According to a Kaiser Family Foundation study last year, school kids in all grades beyond the second grade committed, on average, more than six hours per day to TV or videos, music, video games, and computers. Almost one-third reported that “most of the time” they did their homework while chatting on the phone, surfing the Web, sending instant messages, watching TV, or listening to music.

Kids think that this entertainment while studying helps their learning. It probably does make learning less tedious, but it clearly makes learning less efficient and less effective. Multi-tasking violates everything we know about how memory works. Now we have objective scientific evidence that multi-tasking impairs learning. A recent National Academy of Sciences study with college-age students (Reference #1 below) did an experiment where the subjects were to learn a task under two conditions, one with no distractions and the other while listening to high- and low-tone beeps, attending to the high ones. The total amount of learning was the superficially the same in both conditions, but with distractions, the learning was stereotyped and learners had difficulty in applying what they learned to other contexts and situations. The study also used functional MRI (fMRI) to assess brain activity under test conditions. The imaging data indicated that the memory task and the distraction stimuli engage different parts of the brain and that these regions probably compete with each other.

The study did not address the issue of passive distraction, such as listening to music while studying. I think that music can also be a major distraction, except for certain kinds of music played under muted conditions (see my book Thank You, Brain, For All You Remember. What You Forgot Was My Fault, pages 47, 165, and 197, Reference #2 below) .

One reason that multi-tasking interferes with memory is that the brain really does not multi-task. It just fools you into thinking so, and the way the brain does handle multiple tasks makes it hard to remember anything.

Brains Can’t Real Multi-task

Our brain works hard to fool us into thinking it can do more than one thing at a time. It can’t. Recent MRI studies at Vanderbilt (#3) prove that the brain is not built for good multi-tasking. When trying to do two things at once, the brain temporarily shuts down one task while trying to do the other. In the study, even doing something as simple as pressing a button when an image is flashed caused a delay in brain operation. MRI images showed that a central bottleneck occurred when subjects were trying to do two things at once, such as pressing the appropriate computer key in response to hearing one of eight possible sounds and uttering an appropriate verbal response when seeing images. Activity in the brain that was associated with each task was prioritized, showing up first in one brain area and then in the other  not in both areas simultaneously. In other words, the brain only worked on one task at a time, postponing the second task and deceiving the subjects into thinking they were working on both tasks simultaneously. The delay between switching functions was as long as a second. It is highly likely, though not yet studied, that the delays and confusion magnify with increases in the number of different things one tries to do simultaneously.

So what has this got to do with memory? Well, if you try to memorize the first task and the brain immediately switches to the second task, performance of the second task interferes with consolidation of the memory of the first task. In my earlier article on memory consolidation, I explained how early memory is vulnerable to interference and must be protected from distractions and new information in order for the memory to be made permanent. Likewise, there are proactive effects wherein what you learn on the first task can interfere with learning on the second. All these problems are compounded if there are three or more tasks in a “multi-tasking” experience.

Multi-tasking and School Performance

A study of 517 California high-school students found that grades were lower in those who socially interacted via MySpace, instant messaging (IM) accounts, or who used cell phones. In the study (4), students answered a questionnaire on what social networking devices they used and when they used them. The answers were paired with the grades (from the previous year and the most recent report card).

In this study, 72% of the students had a My Space account, 76% had a cell phone, and 68% had an IM address. Those who had a MySpace account had significantly lower grades than those without an account. The same was true for those that used IM, compared with those who did not. Cell phone use was also associated with lower grades and the effect was magnified if text messaging was used on cell phones. Not surprisingly, if these devices were used during homework, the grades were even lower than for students who used these technologies outside of homework. Almost half reported text messaging during class time, and their grades were lower than the students who only used IM outside of class.

These are correlational data and do not prove that using these devices causes lower grades. But it is a good bet. Multi-tasking, as when using the communication devices while trying to do homework or learn in class, can be expected to interfere with memory. Poor memory yields lower grades.

Bill KlemmW. R. (Bill) Klemm, D.V.M., Ph.D. Scientist, professor, author, speaker As a professor of Neuroscience at Texas A&M University, Bill has taught about the brain and behavior at all levels, from freshmen, to seniors, to graduate students to post-docs. His recent books include Thank You, Brain, For All You Remember. What You Forgot Was My Fault and Core Ideas in Neuroscience.



– #1 Foerde, K., Knowlton, Barbara J., and Poldrack, Russell A. 2006. Modulation of competing memory systems by distraction. Proc. Nat. Acad. Sci. 103: 11778-11783.
– #2 Klemm, W. R. 2004. Thank You Brain for All You Remember. What You Forgot Was My Fault. Benecton Press. 312 pages.
– #3 Dux, P. E., Ivanoff, J., Asplund, C. LO., and Marois, R. 2007. Isolation of a Central Bottleneck of Information Processing with Time-Resolved fMRI. Neuron. 52 (6): 1109-1120
– #4 Pierce, Tamyra, and Vaca, Roberto. 2007. Distracted: academic performance differences between teen users of MySpace and other communication technologies. Proceedings EISTA. Orlando, FL. July.

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3 Responses

  1. Thanks for submitting this post to our blog carnival. We just published the 41st edition of Brain Blogging and your article was featured!

    Thank you.


  2. Seth says:

    that seems very true when i do more then one thing i cant remember every thing i was doing

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