Happy? Mad? Afraid? Scientists have now developed the first computer model of brain activity that can be used to identify people's emotions, according to a new study.
The technique was developed using 10 actors who were asked to randomly and repeatedly go into nine emotional states -- anger, disgust, fear, happiness, lust, pride, envy, sadness and shame -- while their brains were monitored by functional MRI.
To identify the emotions within the brain, the researchers used the participants' neural activation patterns in early scans to identify the emotions experienced in later scans.
Research on emotions has been difficult due to the lack of reliable methods to evaluate them, mostly because people tend to be reluctant to honestly divulge their feelings. Attempts are further complicated by the fact that people may not be conscious of many of their emotional responses, according to the team at Carnegie Mellon University.
"This research introduces a new method with potential to identify emotions without relying on people's ability to self-report," study lead author Karim Kassam, an assistant professor of social and decision sciences, said in a university news release.
"It could be used to assess an individual's emotional response to almost any kind of stimulus; for example, a flag, a brand name or a political candidate," Kassam explained.
The study appears in the June 19 issue of the journal PLoS One.
Study co-author Amanda Markey, a graduate student in the department of social and decision sciences, said "Despite manifest differences between people's psychology, different people tend to neurally encode emotions in remarkably similar ways."
The researchers plan to use the new computer model to tackle a number of challenging problems in emotion research, including identifying feelings that people are actively trying to suppress and multiple emotions experienced at the same time, like the blend of joy and envy you might feel when you hear about a friend's good fortune.
The research was funded by the U.S. National Institute of Mental Health.