To construct the maps, the researchers showed 773 participants different words, stories, movies, and expressions, and had them highlight on a human silhouette the areas of the body in which they felt decreasing or increasing activity. More activity sees the color change from black to red to yellow, while decreasing activity is represented by an increasingly bright shade of blue.
The results, published in the Proceedings of the National Academies of Sciences, tally with many of the experiences you've probably had: depression is linked with a deadening in the limbs, while shame induces bright spots on the cheeks. Sadness even features activity in the eyes, presumably representing the tears experienced by participants.
While the authors willingly admit that the results could be influenced by cultural references and stereotypes about emotions, they rightly point out that the responses are clearly culturally universal; it's worth noting that participants were drafted in from both Finland and Taiwan. Indeed, the researchers claim that such universality is likely a result of a biological basis for our response to emotions, rather than a cultural one. Not that it'll help much next time you blush your way through a date. More here.