Wolfgang Schultz, a professor of neuroscience at the University of Cambridge, set up experiments to investigate cravings through learning. He was using monkeys who would receive a reward, blackberry juice, when they completed a simple task. Throughout the experiment Schultz was monitoring brain activity.
What developed was interesting. In the initial stages of the experiment brain activity spiked when the monkey received the reward. As Schultz noted that the behaviours being elicited were becoming habitual e also noticed that things started to change in the brain activity patterns.
“The monkeys brain began anticipating the blackberry juice. Schultz probes started recording the ‘I got a reward!’ brain activity pattern the instant the monkey saw the cue on the computer screen, before the juice had arrived. In other words the shapes on the monitor had become a cue not just for pulling the lever, but also for a pleasure response inside the monkeys brain.” From; The Power Of Habits, Charles Duhigg.
As our training progresses we can easily get trapped by this pattern of learning. If we stick with the same behaviour without any change for too long the learner begins to anticipate the reinforcer. What we want to create instead is a learner who craves the training as a reward itself.