The phenomenon of continuous partial attention - the inability to concentrate on any given thing for a long period of time - has received it's few seconds of attention recently. Nick Carr has written a few cogent entries in his blog concerning this. Today, for instance:
The more we suck in information from the blogosphere or the web in general, the more we tune our minds to brief bursts of input. It becomes harder to muster the concentration required to read books or lengthy articles - or to follow the flow of dense or complex arguments in general.