In the seventeenth century, the philosopher Spinoza examined the role emotion played in human survival and culture. Yet hundreds of years and many significant scientific advances later, the neurobiological roots of joy and sorrow rema...

Since Descartes famously proclaimed, 'I think, therefore I am,' science has often overlooked emotions as the source of a person's true being. Even modern neuroscience has tended, until recently, to concentrate on the cognitive aspec...