Jerome Bruner was one of the most famous and most cited American psychologists. He worked mainly in the fields of cognitive psychology and educational psychology.
Bruner had an experiment that he used to prove how emotion and motivation can affect perception. He gathered a group of children from different socioeconomic backgrounds and asked them to estimate the sizes of American coins. He discovered there was a strong tendency for children from poorer backgrounds to overestimate the sizes of coins, when compared to richer kids.
Another possible example is how, during your graduation from middle school or high school, you look back on the years you spent there and think of them as full of wonderful experiences, even though you might had had a different opinion just the day before. This is because your perception is affected by the emotion of saying goodbye to your friends and your school.
