Barbara Fredrickson who is a psychology researcher working at the University of North Carolina. To test the influence of different positive emotions and feelings on the human brain, she invited some participants and divided them into five groups. The first and second groups were shown different clips showing positive emotions. The first group saw clips containing joy while the second one saw clips based on contentment. The third group was labeled as the ‘control’ group and was shown neutral images. The fourth group saw images based on fear, while the fifth one saw images based on anger.
