Emotions studied by imaging of the human brain: The somatic and emotional motor systems

Abstract

The brain has only two goals, survival of the individual and survival of the species. One of the most important tools to accomplish these goals is the motor system, which includes the somatic or voluntary motor system and the emotional motor system (EMS). The EMS is equally or even more important than the somatic motor system. In humans, the cortex cerebri with the corticospinal tract plays the most important role in the somatic motor system, while in the EMS, the periaqueductal gray (PAG) plays a central role controlling nociception, cardiovascular changes, respiration, micturition, parturition, defecation, vocalization, vomiting, coughing, sneezing, mating behavior, pupil dilation, and defensive posture.