Human emotion is a subjective experience, which is short
and strong. It helps people to choose appropriate actions to deal
with different situations, enhancing people’s auto adaptive
capacity to deal with stimuli in the external environment. The
nature of emotion is ambiguous and plays an important part in
a human being’s self-protection. Currently, scientists have
generally agreed on the following aspects regarding the major
functions of emotion [5]: Emotion controls people’s cognitive
procedure; Emotion is the bridge which connects the external
environment with people’s internal experience; Emotion
functions on people’s behavior by way of stimulus and
reinforcement. Also the fundamental features of emotion are
listed below: