Abstract: We concluded the process of sentiment analysis, which has three main steps, acquisition and expression of sentiment, classification and estimation of sentiment, and application of sentiment analysis. The results of sentiment analysis can be classified into summarization of textual sentiment, estimation or analysis sentiment to persons or events in texts. But nobody gives any attention to the role of emotion in texts as it in cognitive. For replying to this problem, we tried to introduce sentiment analysis to cognitive science and get emotion in texts by utilizing sentiment analysis. We proposed that emotion should have two constituent parts:emotion signal and emotion element. Emotion signals are the carriers of emotion. The carriers include phenomena observed in body such as face color, heart rate, and media which expresses or pass emotion such as images,words,voices. Emotion elements are the ones which are accepted by the society,such as love, hate, delight, abashment, envy, guilt, dread, anxiety and so on, being related to consciousness. We also proposed some ideas on introducing emotion to artificial intelligence. It may be helpful for cognitive science to analyze and utilize emotion.

Key words: Sentiment analysis, Opinion mining, Cognitive science, Noctic science, Artificial intelligence