In today’s always-connected world we feel proud of our ability to do several things at once, and many adults are even more amazed as they watch their children managing multiple tasks at the same time.
It turns out, however, that we may need to rearrange the way we work, reconsider our understanding of multi-tasking, and rethink how we supervise children when they are attending to learning activities. According to Professor John Medina, a respected molecular biologist and author of the 2008 book, Brain Rules, the brain cannot multitask efficiently. Multi-tasking during homework times may decrease a 21st Century student’s ability to learn efficiently.
Medina’s book, an entertaining read, discusses 12 important brain rules and devotes one chapter to multitasking. Addressing the widely accepted view that in the digital age we all multi-task effectively, Dr. Medina explains why the brain has trouble with multi-tasking and why this practice can cause difficulty for learners, workers, and especially for pre-teens and adolescents. Many entertaining video explanations of the 12 brain rules are posted on his website.
When a student does homework while chat, a DVD, Facebook, texting, and other media are all active and constantly interrupting, no task, especially the homework, can be accomplished efficiently.
Dr. Medina explains that the brain goes through a series of four steps each time a change in focus occurs. When a person changes from one activity to another — from math to Facebook, for instance — the brain proceeds through the four steps. First, it is distracted, and then it disengages, re-engages, and starts the new task. The brain is not multi-tasking, but rather using up valuable time switching from one thing to another and then back again. Thus people, but especially young learners, lose a significant amount of concentrated working time if these four steps occur over and over during an evening of study.
Visit Professor Medina’s BrainRules.net web site and also watch him explain what happens when a person switches between activities. An amazing graph (click on small reproduction at above right, used with permission), comparing the number of errors made by people who are multi-tasking with those who do not, provides further evidence that a media-filled, multi-tasking environment may actually be hurting our children when they do homework.
Click on the video to watch Dr. Medina presenting a lecture about Brain Rules in the Authors@Google series.
Media! Tech! Parenting! 
Very helpful!