This book focuses on asymmetries in brain structure and their role in emotional functions (such as amygdala in emotional comprehension, the ventro-medial prefrontal cortex in the integration between cognition and emotion and in the control of emotional reactions, and the anterior insula in the experience of emotions).  The idea of hemispheric asymmetries in emotional comprehension and expression was first proposed about a century after the first studies showing that the left hemisphere is dominant for language, but it quickly became very popular. Initial investigations considered the right and left hemispheres as single functional units, but in the last few years several researchers have focused attention on asymmetries in brain structures playing a critical role in specific components of emotional functions.