Spherical model of discrimination of emotional expressions of a schematic human face

The four-dimensional spherical emotional space was constructed by multidimensional scaling of visually perceived differences between emotional expressions of schematic faces. In this spherical model Euclidean distances between the points representing the schematic faces are directly proportional to perceived differences of emotional expressions. Three angles of the four-dimensional sphere correspond to specific characteristics of emotions, such as emotional modality (joy, fear, anger? etc.), intensity of emotions, and emotional fullness (saturation). At the same time Cartesian coordinates represent excitations in the neuronal channels encoding line orientatios. It was shown that the structure of the emotional space is similar to the structure of color space, i.e., emotional modality corresponds to color hue, emotional intensity to brightness, and emotional tullness to color saturation. The obtained evidence suggests the common mechanisms of information coding in the visual system.