Dissociation.  It’s what I do when I run.  I focus on a far off object.  I time my breathing to my cadence (though I’ve also read that this is bad for various reasons).  I tell myself to get there, then I just pick another target.  I’m at my best when I’m aiming for something.  I don’t think about the run.  Just concentrate on my breathing, cadence, and target.  However, the second part of the article about mental expectations is also true.  If I plan on running X miles in Y time, I find myself pacing my energy for it.  Like doing what my mind expects and nothing else.  Not that I’ve run recently (being lazy these days, very very lazy).