The Influence of Expressive Images for Computer Interaction
Authors: Xu Zhe , John David , Boucouvalas Anthony C. 
Published: May 2011

The soul is divided into an immortal part, located in the head, and a mortal part, distributed over the body. Philosophical and intellectual loves of beauty are located in the immortal soul. Other “regular” emotions are located in the mortal soul. (Plato as cited in Koolhaas, 2001) Emotion is one of the lovely gifts from nature. It is present not only in humans, but most species present sorts of emotions and expressions in daily behaviors. However, only human beings ask for explanations. Research into the mystery of emotion can be traced back to Heraclitus (500 BC), who claimed that “the emotional state is characterized by a mixture of body parameters such as temperature (hot/cold) and sweat amount (wet/dry)” (as cited in Koolhaas, 2001). In the 21st century, technology has achieved a standard that Plato never dreamed about, but emotion is still an unsolved question. Although science needs more time to work out the mechanism, it does not keep emotion out of human communication. With the commercial success of the Internet, more people spend their time with their box: the computer. Designing an attractive user interface is not only the objective of every software developer but also is crucial to the success of the product. Methods and guidelines (Newman & Lamming, 1995) have been published to design a “vivid” user interface. One of the most important methods is to add expressive images in the display (Marcus, 2003). For example, when a user finishes some operation, an emotional icon or emoticon (an industry term introduced in the 1980s by Meira Blattner) will pop up to communicate “well done” to the user. Two widely accepted methods exist for displaying emotional feelings in software interfaces. One is the use of emotion-oriented icons; the other is using complex images, for example, a cartoon or a facial image (Boucouvalas, Xu, & John, 2003; Ekman, 1982). Emotion icons cannot communicate complex feelings, and they are not usually customized. As the industry matures, perhaps emoticons will be replaced by expressive images as sophisticated as the computer-generated Golem of The Lord of the Rings movie fame. Expressive images present emotional feelings to users. What internal factors (e.g., image intensity or people’s mood) may influence the perceived emotional feelings? Will external factors (e.g., display duration) influence the perceived emotional feelings as well? In this article, we are particularly interested in discussing the factors that may influence the perceived emotional feelings. Our conclusions are based on the findings from a series of experiments that demonstrate an empirical link between the level of expressive-image intensities and the perceived feelings. The detected factors include the following: • Expression intensity • Wear-down effect (display duration effect) The test results demonstrate that increasing the expressive-image intensity can improve the perceived emotional feeling. However, when the intensity is increased to an extreme level, the perceived emotional feelings fall. The experiment results also indicate that the perceived emotional feelings are not affected by the length of time that users are exposed to the expressive images.