[sidebar]Why does any of this matter? Apart from helping researchers create interesting graphics (like the one above), understanding how emotion and the body interact could help psychiatrists better diagnose and understand psychological disorders, Dr. Nummenmaa says. For example, depression appears to show up as a lack of feeling in the arms and legs. Knowing this—or recognizing a disconnect between the usual emotion-body sensations—could lead to more accurate diagnoses and treatments, Nummenmaa adds.More from Prevention: