Many of the tasks essential to successful PhD completion do not have immediate rewards. Completing pages of a chapter, for example, or learning the software for data analysis, will often come with delayed or absent rewards. Many dissertation tasks generate difficult and frustrating feedback.   

It’s helpful to self-motivate toward long-term anticipated rewards by linking immediate, tangible, satisfying rewards to the work you are doing. Pick rewards that encourage you step-by-step through the many small steps needed to conduct your research and finish your dissertation.

Even though you know “what’s good for you,” your brain will often overvalue an immediate reward and undervalue a delayed reward. The immediate and easily obtained reward of food or entertainment triumphs over the challenging and sometimes punishing dissertation tasks. 

Your brain will always look for rewards anywhere it can. However, most likely those immediate and satisfying rewards (eat, play game, exercise surf the web) won’t help your dissertation unless you connect them with your dissertation efforts.