So my theory is that we can still pay attention for a long time - but we want a lot more to happen per unit of time too. We want faster rewards, more action.This is (to me) an intuitively correct notion. I'm also struck by how extraordinarily bad we are at filtering our various incoming data streams. We're accessing ever larger portion's of the world's information output, without a commensurate boost in discrimination.
Why? Perhaps because there is so much stuff out there, so the alternative cost of spending a lot of time on something that does not turn out to be worthwhile is higher. In the time you have spent reading this post (and I writing it) we could have read several RSS entries and short blog posts, watched a YouTube clip, browsed Wikipedia or run a calculation in our favourite math program.
If this model is true, then we should expect the trend to continue. In the future, we are going to have far more good books, films, comics, papers and other documents instantly available.
It is rational to demand quick and reliable evidence that whatever we have in front of us is relevant or interesting. Spending a lot of time finding out if it actually is by just consuming it would mean we would often waste precious time and attention on things that are not as good.
There is of course a trade-off here, since some important things do not look inviting (since they were made before the current attention economy) and some unimportant things masquerade as important. Smart agents balance the exploration with exploitation.
This is why reliable filtering and reviewing actually are key transhuman technologies. And why training to recognize the real cost and value of what you are doing is such a key transhuman virtue.
In fact, we're so incapable of filtering that we often rely on our peers to do the job for us. Social networks are a useful but nonetheless inefficient way to sift for valuable information. Word of mouth can be hit or miss, possibly because of cognitive biases that make us believe our friends are more similar to us than they may be.
Google continues to work in the field of "attention management". Unfortunately the killer app has yet to be invented. Increasing privacy concerns may hinder Google's efforts to gather the kind of highly personalized information required for the task.
I, for one, would gladly trade away most of my privacy for an effective service to guide my attention.