Emotional Metaphors for Emotion Recognition in Chinese Text

Transcription

1 Emotonal Metaphors for Emoton Recognton n Chnese Text Xaox Huang 1, Yun Yang 2 and Changle Zhou 1,2 1 College of Computer Scence, Zhejang Unversty, , P.R. Chna tshere@zju.edu.cn 2 Insttute of Artfcal Intellgence, Xamen Unversty, , P.R. Chna onenaom@163.com, dozero@xmu.edu.cn Abstract. The affectons of a person can be expressed by non-verbal methods such as facal expressons, gestures, postures and expressons from eyes. Whle mplct language lke emotonal metaphor s also an mportant way to express one s affectons. Dfferent knds of emotonal metaphors n Chnese and ther characterstcs are proposed, ncludng happness, sadness, anger, fear and surprse. Experment result shows the characterstcs of Chnese emotonal metaphors are reasonable. The mportance of emotonal metaphors n emoton recognton s also dscussed. 1 Introducton The latest scentfc fndngs have ndcated that emotons lead an mportant role n human ntellgence, such as decson-makng, nter-communcaton and more. As Marvn Mnsky sad n hs the socety of mnd [1], The queston s not whether ntellgent machnes can have any emotons, but whether machnes can be ntellgent wthout any emotons, f we want computers to be vvdly ntellgent and to nteract wth us more naturally and socally, we should let the computers have the abltes to recognze, understand, and even to express emotons[2]. To date, much of the work studyng affectve computng has concentrated on facal expressons, gestures, postures, and propertes of speech. Although much emotonal expresson s conveyed n physologcal features or speech s acoustc realzatons, t s equally mportant to trace nto how t s conveyed n the lngustc content[3]. In wrtten language, the nterpretaton of emotonal states s more complex. It can be referred to drectly, for nstance, I am angry, but usually t s not explct and the reader or hearer must nfer t. The cues for nferrng t can come from grammatcal structures, vocabulary forms and verbal nflectons, etc. Metaphor s useful for abstract concepts, and the functon of a metaphor s to express, clarfy or explan some concept through a better understood, and generally concrete, concept. For example, n metaphor Tme s money, the concept tme s an abstract concept, whle money s a concrete concept. Snce emotons are abstract concepts, t s natural that metaphor s an effectve method for expressng emoton. In fact, one of the major functons of metaphor s to express emoton[4, 5]. Through metaphor, an emoton can be related to some other concept, whch tends to make t more concrete.

2 In ths paper, the dfferent emotonal metaphors and the characterstcs of Chnese emotonal metaphor are dscussed. We thnk that emotonal metaphor plays an mportant role n emoton recognton for text. Takng emotonal metaphor nto account wll make up the nsuffcency of merely focusng on emoton keywords. The rest of the paper s organzed as follows: Secton 2 descrbes some backgrounds about metaphors and emotonal metaphor. Secton 3 dscusses the dfferent knds of emotonal metaphor accordng to the source doman. And then, the characterstcs of fve prmary emotons of happness, sadness, anger, fear and surprse are proposed n secton 4. Related works are ntroduced n secton 5. At last, the conclusons and future work are gven n secton 6. 2 Metaphors and Emotonal Metaphor The study for metaphor can trace back to the era of Arstotle. Snce then, the tradtonal vew to metaphor s that metaphorcal language s decoratve and secondary, whle lteral language s the prmary. However, along wth the development of metaphor research, researchers have realzed that metaphor s prevalent n natural language, and s the center of language and human thnkng[6]. Lakoff and Johnson proposed that metaphor s a means of understandng one doman of experence, called the source doman, n terms of the conceptual structure of another doman, called the target doman. Ther study ndcates that the cogntve system of human tself s a metaphorcal system. Metaphor s not merely decoraton of language, but also an mportant method of human thnkng and cognton[6]. Many lngusts have researched about emotonal metaphor n Englsh. The results ndcate that the emotons of human are generally expressed through metaphors about body perceptons n a way[6-8]. Some researchers have compared the emotonal metaphors between Chnese and Englsh[7, 8]. Yu Nng[8] dscussed the metaphorcal expressons about Chnese emotonal concept 愤怒 (anger) and 喜悦 (happy). He demonstrates that the metaphorcal schemas of emotons n Chnese s the same to those n Englsh, whch are ANGER IS HEAT and HAPPY IS UP. There are two derved conceptual metaphor for ths schema, namely, anger s fre and anger s a hot flud/gas n a contaner. Here, based on the research result on emotonal metaphors from lngusts, through analyzng dfferent knd of emotonal metaphors, we dvde emotonal metaphors nto followng knds n secton 3. 3 Knds of Emotonal Metaphor In ths secton, we wll dscuss 3 types of emotonal metaphors, namely, orentatonal metaphors, body metaphors and nature metaphors. The man standard s the source doman of emotonal metaphors.

3 3.1 Orentatonal Metaphors In Lakoff s conceptual metaphor theory, emotons are generally understood n terms of orentatonal metaphors, such as HAPPY IS UP, SAD IS DOWN. From these root metaphors, we can derve many emotonal metaphors as follows. (1) 他今天情绪看起来很高 / 低落. He seems n hgh/low sprts today. (2) 老师高度评价了他的成果. The teacher remarked hghly of hs achevements. (3) 战士们士气高昂 / 低落. The solders were elated/downcast. (4) 别看低他的本领. Don t look down upon hm. Example (1)-(3) uses the orentatonal concept hgh ( low ) to express one s emoton about happness (sadness). In (4), the orentatonal concept down s used to express the agent s scorn emoton. 3.2 Body Metaphors Emotons are generally expressed through the physologcal state of human body[6, 9]. Researchers have nvestgated dfferent languages such as Chnese and Englsh, and have found that many emotonal metaphors are n forms of mappng the physologcal changes nto the emoton doman[6, 7, 10]. In secton 1, we have ntroduced that most of exstng emoton recognton methods are through facal expressons, gestures, postures and physologcal features. When t comes to wrtten language, t s also a good approach to recognze emotons through the words whch descrbng the physologcal features of the agent. In body metaphors, the states of eyebrows, facal colors, hars and hearts are usually used to express dfferent emotons Eyes and Brows In Chnese, there are many methods to express emotons through eyes and brows. We can fnd these phenomena from many Chnese doms. For nstance, 眉飞色舞 (brows flyng and eyes dancng), 喜上眉梢 (joys on the brows), 舒眉展眼 (be all smles) and 眉开眼笑 (brows expandng and eyes smlng) all express the happy feelngs; both 愁眉苦脸 and 眉头紧锁 mean sadness; 横眉 and 皱眉 mean anger and worry respectvely Facal Colors Facal color s an effectve source feature reflectng agent s emoton. In wrtten language, usng facal colors to descrbe emoton s ubqutous. For examples, 脸色苍白 (pale or whte) n Chnese s generally used to express fear or frght ; 红晕 (flush) s used for shame or embarrassment ; 急红了脸 (red wth anger) and 面红耳赤 (be flushed) mean anger. Sometmes, red s also used to express happy, such as 红光满面 (n ruddy health).

4 3.2.3 Heart Heart also plays an mportant role n expressng human emoton, especally n wrtten text, when characterzng people s mental actvtes. We may use 心碎 (heart broken) and 心如刀割 (to feel as f a knfe were percng one's heart) to express the extremty of sadness or depresson, heartbroken, 心花怒放 (a flower blossoms n the heart) and 心旷神怡 (relaxed and happy, cool) are generally used to convey the happness, Whle 心惊肉跳 and 心惊胆战 are used to express fear, whch means that the heart s shakng wth fear Behavors Ordnarly, emotons can also be expressed through behavors. If someone s dancng and skppng wth joy, then he may be happy. If someone s grndng one s teeth, he may be angry. har stands on end means fear, and that weepng means sadness. (5) 孩子们拿到礼物后, 都欢蹦乱跳起来. The chldren were dancng and skppng wth joy, after they got ther presents. (6) 听了这个故事, 大家都觉得毛骨悚然. When havng heard the story, we all felt har stands on end. (7) 得知这个消息后, 她低下了头默默流泪. When heard of the message, she crouched and wept. (8) 遇到不人道的事情, 大家都咬牙切齿. We all gnash for nhumanty. 3.3 Nature Metaphors The nature s the closest thng human can feel drectly. In tradtonal culture of Chna, red s one of the symbols for happy events such as weddngs, festvals etc., and black s used to express sadness such as bereavements. In Englsh, blue represents sadness, but gray s used n Chnese for sadness, such as (9). (9) 今天的心情就像这天空一样, 是灰色的. The feelng s gray, lke the color of today s sky. Goatly[4] has ponted out that most of the language for emoton or emotonal states come from the words for weather or weather changes. (10) 她脸上带着灿烂的笑容. There are sunny smles on her face. (11) 刚才还是晴空万里, 现在就变为乌云密布, 女人的心真难琢磨. Sun shnng a moment ago has turned heavly cloudy, t s so hard to tell women s mood. (12) 老板突然来了一个晴天霹雳, 大家都沉默了. Suddenly, the boss got thunderstorm and we all kept slent. (13) 她对我大发雷霆. She blew up at me. In (10), the term sunny whch comes from weather doman s used as a modfer for smle, to express the happness of the subject. In (11) to (13), 乌云密布 (cloudy), 晴天霹雳 (a lghtnng bolt) and 雷霆 (thunder) all represent anger.

5 In Lakoff s conceptual metaphor theory, ANGER IS FIRE s a famous conceptual metaphor. In Chnese, anger s usually descrbed as gas[8]. For examples, (14) 他在发脾气 He s losng control of hmself. (15) 别惹他发火 Don t make hm get angry. 4 Characterstcs of Chnese Emotonal Metaphor In ths secton, we summarze the characterstcs of Chnese emotonal metaphor, based on secton 3. We only consder the fve prmary emotons of happness, sadness, anger, fear and surprse. The result s n table 1. The left column represents emotons, and the top row represents source domans of emotonal metaphors. The cell contents are the features of source domans used to descrbe emotons. Emoton Happy Sad Table 1. Characterstcs of Chnese emotonal metaphor for 5 prmary emotons. Orentaton Eyebrow Facal color Up Hgh Down Low Open Free Tghten Lour Angry Up Frown, Glare Flush, Cyan Fear Close Pale Body Nature Heart Behavor Color Weather Open Broken Pan Shake Tghten Dancng Sngng Flyng Jumpng Smlng Crouch, Weepng Gnash Fst Stomp Long-face Shver Breathehurry Surprse Stare Gapemouthed Black Gray Sunny Sprng Warm Rany Cloudy Autumn Dark Fre Storm Thunder Summer Thunder Lght Cold To verfy the characterstcs summarzed above, we collect 100 Chnese emotonal metaphors from a large corpus. Accordng to the characterstcs n table 1, the dstrbuton of emotons n ths collecton s 25% for happness, 25% for sadness, 25% for anger, 15% for fear, and 10% for surprse. 30 subjects who are undergraduate students from Xamen Unversty are gven the forms. Every form conssts of a sentence of Chnese emotonal metaphors; the subjects should select one and only one of the prmary emotons or other for the sentence. 24 out of the 30 subjects returned them.

6 Then we calculate the values of a sentence as a partcular emoton wth the followng formula: num(, k) vk (, ) = (1) S Where, vk (, ) means the value of sentence as emoton k (that s happness, sadness, anger, fear or surprse), num(, k) s the total number of subjects that vote sentence to emoton k. S s the number of subjects, here S=24. Obvously, v s range from 0 to 1. Accordng to the characterstcs descrbed n table 1, f sentence expresses emoton k s denoted as uk (, ) = 1, otherwse, uk (, ) = 0. The correlaton rk between v and u for emoton k s decded by the Pearson s correlaton as follow. r k = vk (, ) uk (, ) vkuk (, ) (, ) N 2 2 ( vk (, )) ( (, )) uk ( vkvk (, ) (, ) )( ukuk (, ) (, ) ) N N Where, N s the number of emotonal metaphor n the collecton, here N=100. The resultng correlatons are showed n table 2. Table 2. the correlaton values for emotons between decded by subjects and that by characterstcs n table 1 Emoton happness sadness anger fear surprse Correlaton value The correlaton values show that the characterstcs n table 1 are reasonable for Chnese emotonal metaphor. (2) 5 Related work Accordng to phrasal conventons of Chnese and the conclusons from lngusts, Xu & Tao[11] proposed an emoton system of Chnese, ncludng love, dsgust, happness, anger, sadness, fear and desre. Based on semantc annotaton on adjectve and verb dctonary, they further categorzed the emoton system nto mental experence based emotons and expressve force based emotons. The dctonary-based method of Xu & Tao gves a good reference for emoton classfcaton, but they haven t thought of the mportance and prevalence of metaphors. We thnk that emoton s context senstve, and metaphor s related greatly wth cultures and background knowledge. Thus, the dctonary-based method combned wth metaphorcal knowledge may gve a more effectve support for emoton classfcaton and recognton.

7 6 Conclusons and Future Work Emoton recognton from text s an mportant part of affectve computng. In ths paper, the prevalence of metaphors and emotonal metaphors are dscussed, and dfferent knds of emotonal metaphors n Chnese and ther characterstcs are proposed. Experment shows that the characterstcs descrbed n ths paper are reasonable for Chnese emotonal metaphor. Metaphor s pervasve n natural language, and emotonal metaphor s an effectve method to express emotons. To construct effcent and lfelke affectve computng system, especally Text To Speech (TTS) system, t s mportant to process emotonal metaphor. In the future work, we wll propose a computatonal model for metaphorcal mechansm. And the further relaton between characterstcs of emotonal metaphors and the emotonal keywords also need to be further nvestgated. Acknowledgements Ths work s supported partly by the Natonal Natural Scence Foundaton of Chna (no ) References 1. Mnsky, M.: The socety of mnd. New York: Smon and Schuster(1985) 2. Pcard, R.: Affectve Computng. Cambrdge: MIT Press(1997) 3. Yng, Y., Zhou, F. and Zhou. C.L.: A Research on Emoton Taggng of Chnese Understandng by Desgnng an Experment System. Journal of Chnese Informaton Processng(2002). 16(2): p Goatly, A.: The Language of Metaphors. London: Routledge(1997) 5. MacCormac, E.R.: A Cogntve Theory of Metaphor. London: MIT Press(1990) 6. Lakoff, G. and Johnson, M.: Metaphors We Lve By. Chcago: The Unversty of Chcago Press(1980) 7. Zhou, H.: Smlartes between Englsh and Chnese emoton metaphors. Journal of Schuan Internatonal Studes Unversty(2001). 17(3): p Yu, N.: The Contemporary Theory of Metaphor: A Perspectve from Chnese. Amsterdam: John Benjamns Publshng Company(1998) 9. Peng, D.L., General Psychology. 2001, Bejng: Bejng Normal Unversty Press. 10.Chen, W.C., A cogntve vew to emotonal expresson for metaphorcal concept. Journal of Nanhua Unversty(Socal Scence Edton)(2002). 3(3): p Xu, X. and Tao, J.H: Study on emoton classfcaton n Chnese emoton system. n The 1st Chnese Conference on Affectve Computng and Intellgent Interacton(ACII'03). Bejng(2003)