Even though work on kindred animals has been so crucial to the development of affective neuroscience, Jaak Panskepp started his work with an interest primarily in human emotions, especially their disturbances in clinical disorders. He soon realized that deep neuroscientific understanding could not be achieved without appropriate animal models. This position has changed somewhat with the emergence of modern brain imaging, but not much if one wants to really understand the evolved functional network of the brain. It is rather difficult to have intense emotions while lying still within brain scanners that make measurements that cannot tolerate movement. (..). The primary-process emotions are all connected to movements, and the evidence now indicates that raw emotional feelings arise from the same ancient brain networks that control our instinctual emotional life.

— Archaeology of Mind by Jaak Panksepp, Lucy Biven (2%)