FATIGUING THE CAPACITY TO DIRECT ATTENTION
Research indicates that directed attention is a scarce and finite mental resource. When placed under continual demand, our ability to direct the focus of our thoughts tires, resulting in a condition called directed attention fatigue (DAF). This condition reduces our overall mental effectiveness and makes consideration of abstract concepts and long-term goals difficult, at best.
- See more at: http://www.snre.umich.edu/eplab/demos/st0/stroopdesc.html#sthash.evqSaxPA.dpuf