I've been watching some of the younger ones in our family. TV and computers have a definite negative impact on their thinking and behavior. These kids are addicted to their DS and Wii games and movies. They don't listen, can't focus, whine and complain if you make them do something else, are constantly bored if they don't have electronic stimulation, and are becoming quite anti-social. So, when they are at my house, TV and electronic entertainment devices are restricted. I make them go outside to play or work inside on non-electronic games or crafts. And you know what? They are becoming social again, they are listening better, they don't whine and complain near as much (but two sisters are always going to fight, it seems).
You MUST do something about this NOW. If you wait until trouble strikes, you will be dealing with children who will not follow your instructions, who will drive you insane with their noise, and who will not be able to cope with the earth changes. The children in my life get absolutely depressed when deprived of their electronic stimuli. Then add on the depression and other psychological stresses of troubled times and they could easily just go psychotic on you. Imagine bugging out with 2 or 3 or 4 psychotic children. Your chances of survival will be seriously impacted. Or else you will have to leave your children behind. Could you do that?
I couldn't. So the solution is that you just HAVE to start interacting with your children NOW. Turn off the electronics. Involve the kids in games and social activities. Teach them to listen and follow your orders. Teach them they don't know it all (not a good thing in life and death situations).
And do it NOW! It will take time to bring them back from the brink.