• Learning tennis is best done between the ages of 8 and 15.  The longer you delay, the harder it will be, and your ability to play will suffer.  This principle applies to all sorts of skills, both physical and mental, including the ability to concentrate, direct your focus at will, manage your time.  Kids also need to work at developing the capacity for the concentrated, sustained attention required to succeed in many endeavors.
• The young can get away with IM’ing while playing a computer game, but there’s a risk.  If you grow up assuming that you can pay attention to several things at once, you may not realize that the way you process such things is superficial at best.  When you’re finally forced to confront intellectually demanding situations in high school or college, you may find you’ve traded depth of knowledge for breadth, and stunted your capacity for serious thought.
• Studies show that through practice, you can expand your capacity to focus.
• Where big breakthroughs are concerned, getting to “That’s it!!” requires not only the intense focus and explicit learning …but also plenty of (non-conscious) incubation, mind wandering, and implicit learning.
• Science has determined that multitasking, for most practical purposes, is a myth.  Focusing on 2 demanding activities simultaneously is a skill that requires months of drilling to acquire, and, even then, is confined to just those two tasks!
• You may think you’re multitasking, but what you’re really doing is switching back and forth between two activities.  The extra effort involved actually makes you less productive.  Your overall performance will be inefficient, error prone, and more time consuming than if you had done one thing at a time.  If your train of thought is interrupted even for a second, you have to go back and say “Where was I?”  There are startup costs each time as you reload everything into memory, and people aren’t as good at is as they think they are.
• When you focus on a demanding task, your brain’s hippocampus, which is important to memory, is in charge.  However, if you try to work while distracted by instant messaging, or the like, the Striatum, which is involved in rote activities takes over.  As a result, even if you get the job done, your recollection of it will be more fragmented, less adaptable, and harder to retrieve than it would be had you given it your undivided attention.

• Poor retention:  “…when forced to multitask, the overloaded brain shifts its processing from the hippocampus (responsible for memory) to the striatum (responsible for rote tasks), making it hard to learn a task or even recall what you’ve been doing once you’re done.”
• He sees our distraction as a full-blown epidemic—a cognitive plague that has the potential to wipe out an entire generation of focused and productive thought. He compares it, in fact, to smoking. “People aren’t aware what’s happening to their mental processes,” he says, “in the same way that people years ago couldn’t look into their lungs and see the residual deposits.”
• If John Lennon had a BlackBerry, do you think he would have done everything he did with the Beatles in less than ten years?”

To Deal With Obsession, Some Defriend Facebook

Computers at Home:  Educational Hope vs. Teenage Reality

The Duke paper reports that the negative effect on test scores was not universal, but was largely confined to lower-income households, in which, the authors hypothesized, parental supervision might be spottier, giving students greater opportunity to use the computer for entertainment unrelated to homework and reducing the amount of time spent studying.