The neurons of the mesolimbic dopamine system originate in the midbrain and extend axons towards the limbic system of the forebrain. These neurons are associated with the reward pathways and behaviour. Stimulation of rewarding pathways makes an individual “feel good.”
Skinner proposed that the concept that behaviours can be shaped by rewards or events in the environment. He also argued that human behaviour is not under own will and free will is only an illusion.
Thus, the blank can be filled with rewards.