A slightly dated (Dec., 2013), but timeless article about the multiple roles of dopamine (or lack thereof) with a focus on that of motivation. It may be of interest to those of us who occasionally have a tough time getting out of bed in the morning or off the sofa in the middle of the day. It presents the idea that a shortage of dopamine can be compensated for by incorporating a few habits or a routine that may begin by setting a couple modest goals and culminate by the realization of those goals (the 'reward' factor):
"The brain can be trained to feed off of bursts of dopamine sparked by rewarding experiences. You create the dopamine environment, and the brain does the rest.
"One way to achieve this is by setting incremental goals, according to neurologist Judy Willis. In essence, what you are doing is rewiring the brain to attach a dopamine response to the task you want as a reward. Allow yourself to experience frequent positive feedback as you progress through a series of goals. Dopamine will flow as a result of your brain’s positive reinforcement every time you complete a step and meet a challenge.
"Dopamine engages a vast set of reactions in the body [motivation, memory, behavior and cognition, attentiveness, sleep, mood, learning, pleasure]. Dopamine is involved in both ends of the motivation spectrum, both in lighting a fire to persevere and in waving the white flag.
"Through this lens, motivation becomes less about increasing dopamine, and more about digging deep and being diligent."