Morphed images of basic emotional expressions: ratings on Russell's bipolar field.

An object may be gradually changed into another object by a technique called "morphing" as in the current study. Although in some studies, such as by Coren and Russell, subjects were asked to rate psychologically synthesized facial images seen in a stereoscope, there do not seem to be any studies in which facial images were physically synthesized as morphed images. Our question then was how subjects would rate them. Multidimensional scaling indicated that ratings of facial images, physically synthesized by morphing, showed essentially the same configuration as those of psychologically synthesized faces and that our results conformed to the well-known dimensions of emotional space. In contrast, ratings of fear might not conform to the dimensional emotional space, suggesting cultural differences in emotion between Japan and the United States.