Reply to comment

I too think an alarmist approach to the brain and computer impact isn't warranted: the brain will indeed be affected by computer use, as it has been by other cultural changes in the past, but its well-nigh impossible to say what those effects will be in the long run, much less to try and evaluate them.  At the same time, I think it is indeed worth thinking more about the significance and the meaning of "downtime," of doing things "that do not require active thought."  Our inclination to spend time that way tends, irrespective of computers, to be much less than is encouraged in many more meditative cultures, both eastern and western. For more this theme in a particular clinical context, see Thinking more about depression as "adaptive." 

Interestingly, doing things "that do not require active thought" may not be quite the same thing as disconnecting from the outside world.  Mihaly Csikszentmihalyi's Flow: The Psychology of Optimal Experience argues for the desirability of a state of absorption, engagement with whatever one is doing, a state in which normal concerns/worries disappear in part because of the completeness one one's engagement with things outside oneself.   And computers may in some contexts/situations actually contribute to that.   See Life/education as a game.