左右手利者對情緒詞處理之差異

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(1)國立臺灣師範大學英語學系碩士論文 Master's Thesis Department of English National Taiwan Normal University. 左右手利者對情緒詞處理之差異 Hemispheric Lateralization of Emotion Word Processing in Right- and Left-handers. 指導教授：詹曉蕙博士 Advisor: Dr. Shiao-hui Chan 研究生：吳岳錚 Student: Yueh-Cheng Wu. 中華民國一零五年八月 August, 2016.

(2) 摘要文獻上指出，左撇子(左利)，以及家族性左利都是影響語言側化的因素。軀體特異性假設(body-specificity hypothesis) (Casasanto, 2009) 指出，人們較易將慣用手側與正向概念聯結在一起。本研究旨在探討情緒詞處理是否也能在此軀體特異性假設上得到驗證。實驗採用分視野實驗典範，實驗刺激為中文雙字詞，有三個水準：正向情緒詞、中性詞，及負向情緒詞。受試者則招募了左手慣用者、有家族左撇的右手慣用者以及無家族左撇的右手慣用者，每組受試者約三十人。本實驗假設，當正面詞彙呈現在與慣用手同側的視野時，受試者反應速度較快。實驗結果沒有支持軀體特異性假設，但是三組受試者於作答精確度以及反應速度上皆呈現了字詞辨識文獻中常觀察到的右視野優勢。實驗結果也觀察到顯著的效價效果（valence effect），亦即受試者對於正面詞作答反應最快，負面詞次之，中性詞速度最慢。此外，比較左右視野的情緒詞作答精確度，發現只有左視野 /右腦的情緒詞（正面詞或負面詞）對比中性詞有顯著精確度差異，右視野/左腦則無此情緒效果，此結果呼應了常現於情緒處理文獻的左視野/右腦優勢。最後，比較三組受試者，我們觀察到左撇子組別的詞彙表徵較為雙側化，此發現也與現存的左利與語言半腦優勢文獻不謀而合。. 關鍵詞：情緒詞處理、左利、語言側化、視野. i.

(3) Abstract Left-handedness, as well as familial sinistrality (FS), has been shown to influence the language lateralization. According to the body-specificity hypothesis, people tend to associate their dominant side of space with positive ideas than the contrary sides. The current study aimed to investigate whether the body-specificity hypothesis extended to emotion word processing. A divided visual field paradigm was employed, and the experimental materials were bisyllabic Chinese words manipulated by valence at three levels (positive, neutral, negative). Participants were also specifically recruited, with roughly 30 individuals in the left-handed group, FS+ group and FS- group respectively. It was hypothesized that shorter RTs might be observed when the positive words were presented to the visual field ipsilateral to one’s dominant hand. The results of the current study did not support the body-specificity hypothesis. However, our data showed a robust RVF advantage on both accuracy rates and RTs in all three subject groups commonly reported in studies on word recognition. The data also revealed significant valence effect, with positive stimuli being most swiftly responded to, negative stimuli longer RTs, and neutral words longest RTs. Moreover, it was found when comparing the two visual fields that only LVF/RH, but no RVF/LH, exhibited accuracy contrasts between valenced words and neutral words, which echoed the LVF/RH advantage commonly reported in emotion processing studies. Last but not least, with the comparisons between visual fields across three groups, we also observed a somewhat bilateral lexical ii.

(4) representation in the left-handed group, which joins the existing literature on the investigation of handedness and language dominance.. Keywords: emotion word processing, sinistrality, language lateralization, visual field. iii.

(5) 謝辭 Acknowledgement 這個碩士學位，唸了好多年。期間曾經出國交換、曾經休學工作，人生在意想不到之處，轉了好多個彎。一路走來有很多很多的人伸出援手，其實真心覺得文字也無法表達我的感動與感激，但是，還是想藉由這篇謝辭（非常長一篇）回顧一下這個歷程，也算是為這段時光留下點珍貴的紀錄吧！要感謝的人實在太多了，若稍嫌混亂或太多流水帳（與其說是謝辭，不如說是時光紀錄）就當作是整篇論文中的難得任性吧！. 簡述. 一下，內文會先感謝家人，再來是實驗室成員，再來是各界好友以及「我不認識你但我謝謝你」的眾多受試者們，最後是口試委員，跟最最重要的指導教授。首先想要謝謝我的家人，我的碩士學位拖了很久還沒有完成，爸媽想必比誰都擔心，但是真的很謝謝他們願意放手讓我走走停停，探索我的人生，不管是出國交換、或者休學去工作，他們其實本來都是比較希望我可以先把學位完成的。但是他們表達完想法之後，即使我最後的決定並非如他們期待，他們還是尊重，真的很謝謝他們！尤其是媽媽，在我寫論文的期間，想要為我加油，卻又不知道該說什麼，所以常常傳 LINE 貼圖給我，真是太可愛了，哈哈。另外，我的哥哥跟姊姊，知道我懶散成性、尚有許多不足，卻總是在人生的路上不吝於肯定我、支持我，當我在叉路徬徨猶豫的時候，總鼓勵我儘管放心前行，他們做我的後援。我總是感動於心。謝謝哥哥特地從新竹來台北當我的受試者，也謝謝姊姊在月子中心還接我電話聽我心慌意亂崩潰哭泣。由衷感謝我的家人做我最大的後盾！. iv.

(6) 當初雖然是滿懷著壯志將酬的心態休學去工作的（一種 I will be back! 的概念），然而工作結束之後，曾經一度陷入蠻長的低潮期，到後期完全否定自己，覺得自己做不到，日子拖著拖著一天天過去其實很快，絕望地覺得時間根本來不及、自己一定會肄業，甚至認為自己就這樣一輩子委靡不振等等，非常黑暗的想法總是盤踞不散。謝謝一路上朋友們俐馨、美瑜、佳雯、懷彤、建超、博智的關心，也謝謝遠茜親筆寫了一封好幾頁的書信，跟我分享她的心路歷程，學業的、人生的心路分享。此舉無疑為我心中注入很大一道暖流，真的很謝謝她。也非常感激祖婗某天晚上的私訊。人在低潮的時候想不起來曾經熱愛的事物，多虧祖婗私訊我聊了好多，說我當年交換學生時在前往 Wissembourg 的火車上，跟她分享了好多神經語言學領域的德文詞彙。我自己都不記得了，反而是旁人提醒了我以往的熱情。因為她的鼓勵，我決定再試試看。也衷心感謝 Vivi，好幾次只要一覺得心慌，就打電話給她。因為心中一直是否定自己的，好需要一些過來人的鼓勵，而 Vivi 總是完美扮演了此角色。那天跟祖婗聊完，撥了電話給 Vivi，對話中寫下了她鼓勵我的話，貼在書桌前，而那張紙條在我整個寫論文期間，都是很重要的精神支柱！我想，沒有祖婗跟 Vivi，我今天是不可能坐在筆電前敲鍵盤寫著謝辭的，真的很謝謝她們！於是我在長長一段的委靡之後，重啟了跟老師討論題目的信件往來，我永遠都記得老師那時候回我的信中寫著「Welcome back!」。老師總是像太陽般一貫地溫暖和煦，像這樣信末的小打氣總會讓我感動的淚流在心裡。《牧羊少年奇幻之旅》裡有一句話，說「當你真心渴望某種東西時，整個宇宙都會聯合起來幫助你完成」。有沒有全宇宙我 v.

(7) 不清楚，但是絕對有「全實驗室」！真的真的很感謝實驗室的每一位成員，雖然身在遠方，但總不忘為我打氣的 Gracie，以及也在遠方但是三不五時會傳 LINE 為我加油的 Elvis，說著自己也在生論文，就於遠方一起加油吧之類的話語，每每提醒了我的不孤單。Elvis, thank you! 也謝謝第一時間舉手報名我實驗受試者的 Terry！謝謝 Lilian，除了熱心地來當我實驗受試者之外，睜著她的水汪汪大眼，非常肯定地告訴我：一定會在這過程中湧出連自己都沒有想像過的潛力！也感謝讓我隨時以 LINE 詢問論文相關問題的 Matt，尤其是後來又臨時再度更換題目之後，參考的是 Matt 碩論的實驗素材，所以閱讀了 Matt（以及也是做情緒詞的 Lilian）的碩論文獻，Matt 跟 Lilian 的文獻讓我得以在短時間內迅速找到跟我碩論相關的核心文獻，大大感謝！另外，Matt 不厭其煩地回答我很多小問題，包括大綱通過之後，設計實驗 e-prime 檔案時的寫碼問題，到後來的結果統計也問了 Matt，真的很謝謝他。也要大大感謝戰友：一起在實驗室打拚、一起回顧文獻一篇又一篇的 Lin！論文趕工期間，自己大概都是實驗室最晚離開的，而貼心的 Lin 總會捎來問候，說著「你一個人在實驗室嗎？那我等等帶晚餐過去跟你一起吃～」或者是夜深時刻，正巧感到孤單或疲累時收到訊息：「你還在實驗室嗎？要不要吃宵夜？我去幫你買豆花～」每次收到這樣的訊息，總是感動地一塌糊塗覺得想哭。說到食物，在短時間內無暝無日趕工忙到都沒時間好好吃飯卻又發福的研究生，可能只有我了吧！這一切都多虧了實驗室的「餵食模式」，除此之外還有專職小秘書照顧我的飲食，容我隆重介紹 -- Lucy 小秘書！大大感謝露西一手包辦我的午餐晚餐，餐餐 vi.

(8) 有變化，天氣熱吃涼麵，天氣涼吃熱粥，這頓吃飯隔餐吃麵，讓我心無旁騖飯來張口，其餘時間全心衝刺論文。小秘書不只照顧「食」，「育」跟「樂」也一手包辦。「育」方面，在我實驗設計期間，視覺刺激的呈現位置因為跟實驗操弄息息相關，我花了很多時間微調字詞位置，調到後來自己都錯亂，精明的 Lucy 總在此時提醒我剛剛試過的最佳位置是第幾個組合等等。「樂」方面，Lucy 則是眾所皆知的我的好坑友，跟我一起在鋼筆坑、沾水筆坑內失心瘋，在這段論文期間，最佳的身心調劑，感謝她！放鬆如果過了頭，就交給 Ken 來拉回！「耿伯」、「役男」、「實驗室地縛靈」、「破壞王」有著眾多外號的阿耿，是我最佳的時間規劃員。他總會跟我一起開心地寫鋼筆字，時間到了就像鬧鐘般響起：「好囉！Julia 你只能再休息五分鐘！」或者是「Julia 你大概這週完成 blahblah 進度，下個禮拜三把 blahblah 做完，月底前弄到 blahblahblah 就 OK 了！」哀鳳的 Siri 都沒有他優秀！沒有他，懶散如我可能天天都躺在自家床上翻滾過一天吧！阿耿的時程規劃彷彿定心丸，在這樣緊迫的時程裡，讓我不至於被焦慮打敗。阿耿，謝謝！如果說 Ken 是我的 Siri，Helen 就是我的 Google。關於論文內容的一切總是可以問 Helen，實驗素材的問卷評分、受試者報名表的內容、受試者的資格審查、實驗流程、實驗日程規劃、實驗結果統計，幾乎沒有我沒有問過的，謝謝 Helen 總是耐心地一起跟我討論、一起找答案。Helen 也總是在聽我練習 presentation 時，給很多建議。論文的部分內容，也麻煩了 Helen 幫我看，她總是鉅細靡遺地跟我討論論文的邏輯與流暢度，給了很多寶貴的修改建議，譬如她提到利用英文的主句副句的調換，讓句子的重點從不足 vii.

(9) (limitation) 轉到了貢獻(contribution) ，她跟曉蕙老師一樣，總是鼓勵著我，雖然沒有做到那點，但是有做到了這點，而我應該驕傲地呈現我花了心力得到的結果，而不是自我跛足地窘陷在缺失中。除了學術小幫手，Helen 也是我慌亂時的浮木。永遠都記得正式實驗開始前的那天晚上，我再做最後一次的實驗檔案檢查時，發現實驗檔案的換頁出現問題，第二頁會顯示第一頁的內容，但是之前檢查都沒有這樣的情形，而檔案應該都沒有問題才對，可能的原因是電腦不知怎麼了。晚上十點半多，一通電話撥過去，Helen 冷靜地跟我一起找解決的方式。那天晚上，如果沒有聯絡到她，我可能會崩潰，由衷謝謝她當我的浮木。謝謝里克不遠千里地從中南部趕回台北參與我的答辯口試，謝謝實驗室的大家在我答辯口試那天的慶祝會，那是我生平第一次當被拉炮！也好喜歡你們為我設計的對聯！其實邊打字邊浮出更多更多說不完的回憶，譬如有次在實驗室裡我看文獻讀到一直笑，因為覺得那研究太有趣了！Lin 默默地轉頭跟我說羨慕我如此投入，哈哈。我想，那也是因為有她的陪伴，使得留到那麼晚讀文獻這件事顯得不辛苦了。譬如某天我趕工趕到了半夜已經頭昏眼花，Matt 借我安全帽讓 Ken 載我回家，而 Matt 自己搭捷運回家，在最累最累的時候有你們的照顧，真好（淚光閃閃）。譬如大綱口試前夕 Lin, Helen 跟阿耿留到了很晚，只為了幫我聽模擬報告。譬如大綱口考完，走回實驗室就開始掉淚，很多的情緒是覺得很抱歉讓大家為我辛苦了，也有部分情緒是覺得很不可思議，就在一陣子前我還悲觀地覺得要失敗一輩子了，哈哈。譬如 Vivi 下班後特地買我最愛吃的那家饅頭店來實驗室要給我驚喜，卻在說出口味後看到我笑容凍結的表情，讓她一直懊悔怎 viii.

(10) 麼沒有記住我最愛的口味是芋頭。嗚嗚嗚，不管什麼口味我都感動到不行啦！譬如放颱風假的前一天，Helen 與 Ken 傍晚離開時都再三叮嚀我不可以留太晚，颱風晚上要登陸了。意外地 Matt 從歐洲研討會回來，帶來了荷蘭煎餅，我跟 Lucy 跟 Matt 聊了聊他的都柏林/荷蘭行，而 Lilian 在台大忙完，買了復興南路有名的烤肉飯便當來實驗室，我跟 Lucy 還有 Lilian 就看著窗外漸強的風勢，聊著天，吃著究極美味的晚餐（Matt 趕著回家吃晚餐先走了）。有時候這種很平凡的時刻，回憶起來卻是千金不換的幸福。謝謝你們，真的。除了實驗室的大家之外，我也想要感謝我的研究所同學和大學同學。謝謝研究所同學（唱名一下：Alison, Carol, Joy, Debbie, Becky, Jeccie, Jocelyn, Irene, Felix, Eric, Matt, Andres, Horace）的不斷加油與打氣，與你們相遇可說是研究所時期最幸福的事情之一，謝謝你們不遺餘力地幫我填寫及轉發實驗問卷或者參與我的實驗。我永遠都記得 Becky 跟我說過的那句話「碩論不難，但是它需要你專心地把一段時間獻給它，一步一步地完成它。」這句話在我開始悲觀認為自己完成不了的時候，常常迴盪在我心頭。也謝謝不斷為我打氣的大學摯友們：Daniel, Peggy, 小咪、毓玲、小璞，還有我的室友 Starmay。 Daniel 跟我一樣這學期得趕著完成論文，而我們總是每隔一陣子就通一下電話，互相報告一下自己的進度，也互相激勵對方。謝謝 Daniel 的鼓勵，覺得有個人也跟自己一樣在努力的感覺，很溫暖。小咪也是，彷彿心電感應般，從大學到現在，總是在最需要的時刻，彼此打氣，這次論文期間，最後寫「結果」與「討論」那兩章節時，寫到頭昏眼花覺得沒有力量再撐下去的那種時刻，總每每收到小咪的打氣訊息，完美無瑕的時機點， ix.

(11) 小咪真是儼然天使來著。也想要謝謝毓玲和斐瑱，遠在恆春跟地球另一端都還不忘傳訊息為我加油打氣。另外，當我抱怨碩論很困難的時候，小璞一句「快點畢業吧！畢業後，還有更困難的人生等著你。」是啊！若我沒有克服目前的難關，要怎麼面對未來更困難的人生呢？這句話莫名地為我帶來很大的力量呢。小璞也說寫論文是自己跟自己的對話，發現自己的不足面，不逃避、接受它，再繼續努力。Peggy 也說過：「最後論文這段路，再累也要把它完成。也許再不斷挑戰自己的過程中，我也能慢慢貼近，那個更勇敢更好的自己。」我得其有幸生活中有這些朋友，在他們不經意的言語間，滿滿都是我的能量來. 源，真心感謝。謝謝 David 學長，雖然好久沒見到，但是某天早上的巧遇，他給了我很多過來人的心得，與學長聊完，更是增加了信心，覺得應該可以有能力好好地完成碩士研究。感謝我的高中好友以及眾多各界好友們。謝謝柏聿跟盈臻還有念恩，體諒我因為要趕大綱而臨時延期了很早之前就說好的兩天一夜小旅行，打亂了她們原本的計畫，她們卻完全體諒，我真的是淚流在心底，也謝謝盈臻跟念恩來幫我做實驗。也感謝其他高中好友（包括地瓜團的你們！）、國中好友昭佑與鈺欣、國小好友佳鈺、鋼筆群的朋友幫忙填寫及轉發問卷，甚至不遠千里來實驗室做實驗。有一位受試者，因為電腦當機，在重開機空檔我與對方搭聊：「你怎麼知道這個實驗的呢？」對方答：「因為我的姊姊的朋友的妹妹是做實驗的。」我腦袋轉了幾秒：「那你不就是我姊的朋友的妹妹！你姊是誰？」諸如此類的情形大家一個一個逗相報，讓我的老鼠會作戰十分成功，在短短十天內（實際實測日九天）就收齊一百出頭位受試者，真的很感恩參與的各位受試者，不論是線上填 x.

(12) 寫問卷或者是到現場參與實驗，也無敵感激大家踴躍幫我轉知資訊給朋友。放上第一份問卷到臉書上時，隔一陣子就看見十幾次分享，真的很感激。標準吃貨如我，要另外感謝餵食過我的各界好心人，Vivi 的麵煎餅跟芋頭饅頭、表弟書平的珠寶盒檸檬塔、雪影與傑克的水果塔、嚼嚼的蘋果牛奶，餵食過我的人我是不會忘記感謝的，哈哈！接下來想要對師長表達我的感激之情。首先是張妙霞老師，捎信問候我關心我論文進度，恰巧正逢我如火如荼趕工論文期間，我簡短地回了信之後，收到老師鼓勵的暖心話語。或許是我太不夠有自信，總是覺得自己不值那些誇讚，除了感動的同時，也更加有動力期許自己能夠做到老師口中的我的那般好。再來，想要以九十度鞠躬禮感謝這次的口試委員，李佳霖老師及謝舒凱老師。記得我當初一直想要等實驗設計都有了個底之後再寄信詢問老師擔任口委意願（當初打算在信中可以簡單介紹自己要做的研究主題跟實驗設計），但這般的堅持在緊迫的時程下其實對老師們是很不方便的！無限感激佳霖老師在收到我的信後即應允擔任我的口試委員，即便後來我又再後著臉皮通知老師我更換後的題目，甚至大綱文稿跟答辯文稿都很晚才給老師，老師仍對我以溫柔的笑容，並在大綱口試時於受試者控制部分及其他提了很多見地，真的很感謝佳霖老師！謝舒凱老師也是鼎力支持，從很多年前認識謝老師到現在，老師總是不遺餘力地提攜後進，即使後進才小志小如我。記得幾年前跟老師說自己打算先休學去工作時，老師也是用一貫溫暖如冬陽的眼神及語調輕輕地說：「我相信你們不管去做什麼，都會有很好的發展的。」這次的碩論請謝老師擔任口委的邀請信其實是躊躇再三才寄出的，部分 xi.

(13) 是因為自己原地繞圈太久，不好意思面對老師，更大部分是擔心老師會因為是舊識而有人情壓力不得不來，雖然最後還是硬著頭皮寄信了，哈！真的很感謝老師在非常短的時間內仍然抽空擔任口委，老師在構詞方面提了很多想法，在大綱口考跟答辯口試的過程中，也都提供了一些我從沒有想過的角度跟思考，真的很受用！非常謝謝謝老師。最後想感謝的，是最重要的指導教授詹曉蕙老師。太多太深的感謝其實怕自己說不清晰。從最最一開始第一次跟老師討論題目時（剛從德國回台灣時），我拋出的想法老師總是很鼓勵，但不知為何我自己又會想了想，就覺得行不通，就又再換個題目，再問老師。一直在題目間跳躍，而沒有關聯性系統性地縮小題目範圍，久而久之又挫折又對自己很惱火。逃避了一陣子，決心振作時，又來了個工作機會。跟老師討論，聽了老師分析的利與弊，最後卻是做了暫時放下學術的決定。工作結束後回到學校，對文獻生疏許多，再上手花了好大一番力氣與掙扎，同時也陷入了低潮，身體跟心靈都沒有把自己照顧好。個性或許太容易自我責備或是自我放逐，漸漸地覺得以前那個努力向上的自己不是自己，覺得現在這個懶散無能的狀態才是真樣貌，把自己縮在繭裡，不跟老師聯絡。還好終究在時間的壓力及朋友的鼓勵下，重啓了跟老師來回信。一開始還是半出繭半繭內的狀態，但是謝謝老師真的很鼓勵我，沒有放棄我。因為自己把時間拖著拖著的關係，一直以來想做的 EEG 實驗也無法做了，這時候我的慣性就是先責備自己，但是曉蕙老師分析了我的現況，講了很多行為實驗的好話，包括行為實驗比較容易解釋，未來若工作面試時被問到，比較能夠清楚簡易說明等等，於是我開開心心地做了行為實驗。曉蕙老師就是這樣，先學生一步為學生的未來著想，由衷感謝她。 xii.

(14) 從開始有題目、確定題目到大綱口考這段陣子非常地趕，每天可能睡不到四個小時，我還來不及把我的低潮拋下，只是忙到無暇顧及。大綱口考那天，被通知「通過」之後，走回去實驗室灑了幾滴眼淚。回到會議室，跟老師討論了接下來的實驗內容要多注意的事項之後，老師問了我的情形，知悉了我的低潮，說了很多鼓勵我的話語。我永遠都會記住老師說的：「心魔每個人都有，沒關係，但是如果它影響到了你的生活，你就要努力別輸給它，拿回掌控權。」這句話，以及老師當天講的其他話，都被我寫下來貼在書桌前。我想，不只是這段期間限定的論文生活適用，往後的人生都要這樣記得、這樣努力。想要感謝老師，除了在論文上的大力幫忙、盡心指導外，更是在我自己的心態上、人生上的一個調適幫了很大的忙。最感謝老師的，是老師說：「別讓過去這一兩年的失敗定義了你這個人。」我因為這句話而相信或許我再努力一點就或許可以找回以前那個因為努力而表現不錯的自己。論文指導上，也百分之兩千慶幸自己找了曉蕙老師，老師的思緒清晰，用詞簡潔，很多時候看著老師改過了的自己的文稿，都覺得「嗯！這樣變得好清楚！」尤其是文獻回顧的部分，梳整了好久，試過了好多種分章節的方式，都還是覺得說不上來哪裡不對勁，覺得已經試過所有排列組合覺得山窮水盡了的時候，老師改過的文稿讓我覺得 Okay, she cut the Gordian knot，簡潔明瞭，老師完全是在另一個層次上了！哈哈。真的很謝謝老師的論文指導，讓我在學術的思考上，或者是一般邏輯事物的思考上，都見習到了很多，真的很感謝老師。. xiii.

(15) 最後的最後，想把這本論文獻給在我這段論文生活中離開的兩個人。一位是我的國小老師。因為我自小被教導要尊師重道，所以求學生涯中，較難跟老師親近（因為太尊重了，無法沒大沒小。這個情形到大學唸英語系才比較改變），國小五六年級的老師是唯一的例外。老師就像朋友一樣，會跟我們約去看午夜場電影，會一起討論看了什麼小說或漫畫，每年過年也都要去老師家坐坐聊聊。本來以為這樣就會到老。某天接到電話說老師轉安寧病房無疑是晴天霹靂，知道老師頻繁進出醫院，只是從不知道是這麼嚴重的病......親愛的老師，妳曾說過國小老師就像跑龍套的，很容易被學生忘記。並沒有喔！我還是很時常想起老師妳呢。另一位是我爸媽的朋友 -- 賈媽媽，對我來說像乾媽一樣的存在。賈媽媽走得突然，爸媽擔心我在趕工論文，沒有主動通知我，我是從姊姊那邊得知的。得知的瞬間淚崩，也謝謝那天阿耿跟魯盧的安慰，謝謝阿耿跟魯盧分享的一些關於死亡的詩句，很安慰人心。賈媽媽，謝謝妳從小到大的照顧，我會非常非常想念妳的。這本論文，也獻給在天堂的妳們。. xiv.

(16) Table of Contents 摘要 -----------------------------------------------------------------------------------------------------i Abstract ------------------------------------------------------------------------------------------------ ii Acknowledgements --------------------------------------------------------------------------------- iv Table of Contents ---------------------------------------------------------------------------------- xv List of Tables ---------------------------------------------------------------------------------------xvi List of Figures ------------------------------------------------------------------------------------- xvii Chapter 1. Introduction ------------------------------------------------------------------------ 1. 1.1 Motivation -------------------------------------------------------------------------------- 1 1.2 Research Questions ---------------------------------------------------------------------- 3 Chapter 2. Literature Review ------------------------------------------------------------------ 4. 2.1 Handedness and Hemispheric Lateralization ---------------------------------------- 4 2.2 Handedness and the Body-Specificity Hypothesis ---------------------------------- 6 2.3 Emotion Word Processing ------------------------------------------------------------ 11 2.4 Summary -------------------------------------------------------------------------------- 13 Chapter 3. Methods --------------------------------------------------------------------------- 15. 3.1 Participants ----------------------------------------------------------------------------- 15 3.2 Materials -------------------------------------------------------------------------------- 17 3.3 Procedure ------------------------------------------------------------------------------- 20 3.4 Data Acquisition and Analysis ------------------------------------------------------- 21 Chapter 4. Results ----------------------------------------------------------------------------- 23. 4.1 Accuracy Rates ------------------------------------------------------------------------- 23 4.2 Reaction Times ------------------------------------------------------------------------- 25 4.3 Analysis of the Headedness of the Materials -------------------------------------- 27 Chapter 5. Discussion ------------------------------------------------------------------------- 29. Chapter 6. Conclusion ------------------------------------------------------------------------ 35. References ------------------------------------------------------------------------------------------ 37 Appendix A: Oldfield Handedness Inventory (Chinese version) --------------------------- 42 Appendix B: Beck Depression Inventory-second edition (BDI-II, Chinese version) ---- 43 Appendix C: Interpersonal Reactivity Index --------------------------------------------------- 49 Appendix D: The complete wordlists of the experimental materials ----------------------- 51. xv.

(17) List of Tables Table 1. Example words of the experimental materials. ------------------------------------------17 Table 2. Summary of the valence and arousal rating means and SDs (in parenthesis) for the positive, neutral and negative conditions of the experimental materials. -----------------------19 Table 3. Summary of the statistical results for valence and arousal ratings among the positive, neutral and negative conditions of the experimental materials. ----------------------------------19 Table 4. Summary of the accuracy rates (Mean and SD) in each experimental condition across groups. -------------------------------------------------------------------------------------------------- 24 Table 5. The summary of the follow-up paired t-tests on accuracy rates after a valence x visual field interaction. -----------------------------------------------------------------------------------------25 Table 6. Summary of the mean RTs and SDs (ms) in each experimental condition across groups. --------------------------------------------------------------------------------------------------------------26 Table 7. Summary of the mean RTs and SDs(ms) collapsed by valence or visual field. -----27 Table 8. The distribution of headedness among the three valence categories. -----------------27. xvi.

(18) List of Figures Figure 1. The experimental materials adapted from Casasanto (2009). -------------------------- 7 Figure 2. Procedure of stimulus presentation. -------------------------------------------------------21. xvii.

(19) Chapter One. Introduction. 1.1 Motivation When most people prefer to use their right hands to open a jar or brush the teeth, a group of people tend to act with their left hands. Left-handed people have accounted for roughly 10 percent of the whole population (Rife, 1940; Perelle & Ehrman, 1983; Corballis, 1991; Gilbert & Wysocki, 1992). With the dominant hand difference, individuals interact with the physical world differently. For example, when the left-handers write a horizontal line, they tend to write from right to left, opposite to right-handers’ direction (i.e., from left to right) because it is more natural to write a horizontal line toward the palm of the pen-holding hand (Franks et al., 1985; Suitner et al., 2016). Would this subtle but prevalent difference among the right- and left-handers lead to correspondingly different mental representations? Abundant literature on brain lateralization has indicated that right- and left-handed population employ different cerebral areas or strategies on a range of events, including language processing (Hancock & Bever, 2013) and face reception (Willems, Peelen & Hagoort, 2010). Though the sinistrals are often excluded from the majority of psychological or neurological studies for the reduction of variance in the data, the inclusion or even targeted recruitment of left-handers can help clarify issues including hemispheric functional lateralization and genetic influence on hemispheric asymmetry. In fact, aside from explicit sinistrality, the familial sinistrality (henceforth FS) factor also plays a role in individual language processing. Studies indicate that FS can modulate the cerebral dominance for language processing, with the language dominance lateralized to the left hemisphere. 1.

(20) (henceforth LH) in FS- group, but somewhat bilateral representation was observed in FS+ group (Andrews, 1977; McKeever & VanDeventer, 1977; McKeever et al. 1983). Therefore, a closer look at how left-handers, FS+ right-handers and FS- right-handers differ in terms of their language lateralization may help us re-examine previous empirical findings about brain laterality. Emotion words, for example, have been used to investigate the issue of hemispheric lateralization. Literature has pointed out that the right hemisphere (henceforth RH) has shown not only greater involvement but also advantages on emotion word processing (Graves et al., 1981; Atchley et al., 2003; Landis, 2006). But such processing advantage is shown in research in which all subjects were right-handed. The emotion word processing by lefthanded population remains a less clear picture. In fact, according to the body-specificity hypothesis, the personal preference of right- or leftward space is under the influence of handedness (Casasanto, 2009). Specifically, right-handers tend to interpret the rightward object with positive concepts and left-handers show a contrary pattern with the preference toward the left side of space. It would thus be very interesting to further examine if right- and left-handers extend the space preference to affective content of language. In sum, the current study examined whether there exists a lateralization difference in emotion word processing between right- (both FS+ and FS-) and left-handed population. To our knowledge, no studies have investigated a possible interaction of handedness and emotionality in word processing. This study hoped to shed some light on the hemispheric difference between dextrality and sinistrality in emotion word processing.. 2.

(21) 1.2 Research Questions This study aimed to examine the hemispheric lateralization of emotion word processing by left-handers, FS+ and FS- right-handers. To be more specific, this study investigated whether the handedness factor influences one’s processing of emotion word in a divided visual field paradigm. Accordingly, the research questions of the current study are shown as follows: 1. Will the positive words shown in the visual field ipsilateral to the dominant hand be preferred and processed faster? 2. Will handedness (left-handers, FS+ and FS- right-handers) be an influential factor on such processing?. 3.

(22) Chapter Two. Literature Review. This chapter reviews the literature pertaining to the current study. First, hemispheric lateralization studies with the factor of handedness are discussed in Section 2.1, including the explicit sinistrality (i.e., left-handedness) and implicit sinistrality (i.e., familial sinistrality). Section 2.2 introduces the body-specificity hypothesis. Section 2.3 addresses the emotion word processing.. 2.1 Handedness and Hemispheric Lateralization It is well established that in most right-handed adults the major capacity for language is located in the LH, either from clinical evidence (Sperry and Gazzaniga, 1967; Luria, 1970; Rasmussen & Milner, 1977; Bryden, Hecaen & DeAgostini, 1983) or from experiments with healthy subjects (Knecht et al, 2000, 2003; Szaflarski et al., 2002; Tzourio et al., 1998). However, the pattern of such functional specialization for left-handers is less consistent. Based on the observation of neurological patients, early studies reported that only about twothirds of the left-handed population have their language lateralized to the LH. The remainder either display a reverse lateralization (approximately 15 to 18%) or a bilateral representation pattern (about 17%) (Rasmussen & Milner, 1977; Bryden, Hecaen, & DeAgostini, 1983). But it can be argued that the patients may not be representative for the general population because they may be pathological left-handers due to the LH lesions (Rasmussen and Milner, 1977). With the help of functional transcranial Doppler sonography, Knecht et al. (2000) were able to examine the relationship between handedness and language dominance in healthy subjects.. 4.

(23) They discovered that the incidence of RH language dominance was found to increase linearly with the degree of sinistrality, from 4% in strong right-handers (number in accordance with the study by Rasmussen & Milner, 1977) to 15% in ambidextrous individuals and 27% in strong left-handers. The results clearly demonstrated that there is a relationship between handedness and language dominance and that this relationship is not an artifact of cerebral pathology. Since handedness is determined in the gene, it is natural to wonder if the factor of FS influences the linguistic lateralization among the right-handed population. As early as 1970, Luria and colleagues noted that the right-handed aphasic patients who had left-handed family members (FS+) recovered faster from LH aphasia and showed a higher incidence of RH aphasia than those without familial left-handers (FS-) (Luria, 1970). They speculated that the FS+ right-handed population has a genetic disposition towards bilateral representation for language, which can be manifested as explicit left-handedness in their family members. Later language researchers incorporated the FS factor into their studies. At an early stage, FS was discussed within syllable or single word processing (Andrews, 1977; McKeever & VanDeventer, 1977; McKeever et al. 1983). Andrews (1977) observed a tendency of right visual field (RVF) lateralization for meaningful words, nonsense syllables, and consonant strings but not vowel strings (all trigrams) and that this lateralization was modulated by FS. McKeever & VanDeventer (1977) also noted a RVF recognition superiority in FS+ left-handers. McKeever et al. (1983) employed an object naming task and reported a sex-FS interaction in the spatial visualization ability, that is FS- females and FS+ males performed better than FS- males and FS+ females. Though the approaches of the experiments were variant, the studies all confirmed FS’s modulation on the cerebral dominance for language processing.. 5.

(24) Later on, Bever et al. (1989) discovered that FS+ right-handers focused more on lexical/semantic information, whereas the FS- group relied more on syntactic information in sentence comprehension. In 2010, Hancock and Bever further looked into the FS effect via probe word recognition with subordinate clause fragments, and they observed that FS+ individuals exhibited greater RH involvement during early lexical processing of isolated words. Recently, Lee and Federmeier (2015) combined event-related potential (ERP) measures with divided visual field paradigm to invoke lateralized processing differences (Banich, 2003). They used “to” and “the” to create the syntactic expectancy of the lexical category of the following word (either a noun or verb). It was found that the RH sensitivity to the syntactic word violation was modulated by the FS factor. In sum, the FS factor exhibited a modulation effect not only on the lexical but also on the syntactic level. Overall, the literature suggested that manifest handedness and the familial handedness have an influence on hemispheric asymmetry when individuals process language.. 2.2 Handedness and the Body-Specificity Hypothesis In addition to its relationship with language representation, handedness is also found to be associated with conceptual representation. Casasanto (2009) investigated the links between handedness and mental representation of abstract concepts with positive or negative valence (e.g. intelligence, sadness, bravery). He observed that right-handers tend to associate rightward space with positive ideas while the left-handers with the leftward space. The author argued that people who interact with the physical environments in systematically different ways should form different mental representations accordingly, which he named “the bodyspecificity hypothesis” (Casasanto, 2009). In one of his experiments, the participants received a piece of paper with a cartoon figure at the center and two boxes at each side of the figure,. 6.

(25) either horizontally or vertically arranged (vertical array being the control) (See Figure 1 adapted from Casasanto, 2009). Participants were instructed that the cartoon figure liked zebras and hated pandas (counterbalanced) and they were to draw the zebra in the box that best represented good things like seeing zebras and the panda in the box representing bad things (or vice versa). Results demonstrated that participants had a tendency to draw the good animal in the box at their dominant side. The results were replicated with Dutch speakers and with oral response instead of hand-drawing, which indicates that this preference was not due to the native language of the subjects or the fact that the hand drawing of the animal was the dominant hand.. Figure 1. The experimental materials adapted from Casasanto (2009). Another experiment in the series examined whether the left-right position of the stimuli would have an implicit influence on left- and right-handers’ judgements towards positive/negative traits. Participants received a piece of paper with 12 pairs of created alien creatures. The creatures were arranged in two columns, one on each side of a list of questions printed in a center column. The task was to circle one of the creatures in the pair that best fit the question, to indicate a judgement about one of the four personal characteristics (i.e., intelligence, attractiveness, honesty, happiness). Results showed that participants’ directional. 7.

(26) preference was influenced by the right-left location of the creature, even though spatial location was irrelevant to the judgements. In fact, research has demonstrated that positive emotion (pleasantness) reflects the “approach motivation” while negative emotion links to the “avoidance motivation” (Cacioppo & Berntson, 1994; Lang & Bradley, 2010). For example, food and drink provoke one’s motivation to approach, which is a natural instinct for survival and progeny, whereas punishment or danger motivates one to avoid. Approach motivation is thus associated with positive emotion while avoidance motivation with negative valence. Literature also pointed out that the LH is specialized for approach and the RH for avoidance motivation (Davidson & Fox, 1982; for a review, see Harmon--Jones, Gable & Peterson, 2010). Interestingly, Brookshire and Casasanto (2012) have found that the cerebral lateralization of approach motivation is to the same hemisphere that controls the dominant hand: the hemispheric correlate of approach motivation is lateralized to the LH for the right-handers, but to the RH for the left-handers. In addition to representation of abstract concepts, the body-specificity hypothesis is also exhibited in the interaction between language and action. An fMRI study by Willems, Hagoort & Casasanto (2010) investigated whether the meanings of manual action verbs are grounded in how the particular language users perform the actions. The researchers compared the premotor activation in right- and left-handers during a lexicaldecision task on manual-action verbs (e.g. grasp, throw) and non-manual-action verbs (e.g. kneel, giggle). In the first task, participants viewed the manual-action verbs, nonmanualaction verbs, pseudowords, and fillers in an fMRI machine. The presentation of a pseudoword or filler stimulus was followed by the screen showing a question of whether the stimulus was an extant word, and the participants should press the key for response as fast as possible. After the critical stimuli (i.e., manual-action verbs and nonmanual-action verbs) no responses were solicited. In the second task, participants were instructed to mentally imagine. 8.

(27) themselves performing the action denoted by the verb. By comparing the first and the second task, the researchers were able to determine the cerebral activation of viewing the manualaction verbs was not due to the participants’ mental visualization of the verbs. After careful exclusion of the potential confounding factor -- mental imagery, they observed that each group, right- or left-handed, preferentially activated premotor areas in the hemisphere contralateral to their dominant hands, which suggested the body specificity of the motor component in action verb semantics. In summary, people have implicit preference to their dominant side and that the approach motivation, which is associated with positive emotion, is lateralized to the dominant hemisphere. And since body-specificity has been exhibited in both conceptual representation of positive/negative characteristics and language, it would be informative to see if we can combine the two and explore whether this hypothesis can also be true for emotion word processing. However, before we move on to the literature about emotion word processing, it is important to note that positive/negative valence has not always been associated with left-right distinction. In fact, in many languages such as English and Chinese, metaphorical expressions tend to associate positive and negative valence with the top and bottom of a vertical spatial continuum (Lakoff & Johnson, 1980, 1999). A happy individual has “high” spirit, but a sad person feels “down.” In Chinese, a smart person has “high” IQ (“高”智商), but a foolish person is “an idiot” (“低”能兒 (literal translation: low ability)). An object of great quality is of “top” class (“頂”級). This High Is Good mapping associates the source domain of physical space with abstract target domain that is of positive valence. These mental metaphors import the inferential structure of source domains like space into target domains, which allows language users to envision, measure and compare the height of excitement or the depth of sadness. (Boroditsky, 2000; Casasanto, 2008; Pinker, 1997) 9.

(28) It is still under debate as to whether mental metaphors arise from correlations (1) in linguistic experience or (2) in bodily experience. On the first account, it is proposed that mental metaphors are established through experience by using linguistic metaphors. Using spatial words in both literal and metaphorical contexts (e.g., a high shelf, a high standard) in daily life could induce a transfer effect of the structural elements from the concrete source domain to the abstract target domain representations in mind via analogical processes that are not necessarily “embodied” (Boroditsky, 2000; Gentner et al., 2001). For example, in the experiment by Meier & Robinson (2004), participants were faster to judge words like polite and rude as having positive or negative valence when positive words were presented at the top and negative words at the bottom of a computer screen. Linguistic conventions associating valence with vertical space are reinforced by other non-linguistic cultural conventions, such as the “thumbs up” and “thumbs down” gestures signaling approval and disapproval. This account believes that once these linguistic and non-linguistic conventions are part of a culture, they can serve as the basis for metaphorical mappings in the minds of individual learners, diminishing the role of direct bodily experience (Casasanto, 2009). On the second account, it is said that mental metaphors like Positive Is Up and Negative Is Down could be established as people implicitly learn associations between physical experiences and emotional states that typically co-occur. For instance, people stand tall and raise the chin when feeling proud, slouching and dropping the head when feeling frustrated (Lakoff & Johnson, 1999). Linguistic metaphors later encode the pre-existing mental metaphors developed on the basis of these relationships between different types of bodily experiences. In one experiment, participants assuming an upright posture persisted longer in a puzzle-solving task, as compared to a slouching posture (Riskind & Gotay, 1982), and in another study participants expressed more pride in their test performance after sitting upright during the critical phase of the experiment than after slouching (Stepper & Strack,. 10.

(29) 1993). This account proposes that mental metaphors are developed by the implicit reinforcement of the repeated co-occurrence of bodily experience and emotional states. In sum, although testing the left vs. right preference (i.e. the body-specificity hypothesis) on emotion word processing is the focus of the current study, it is important to note that up vs. down preference might be another interesting topic to pursue to complement the current study.. 2.3 Emotion Word Processing Emotion words are different from non-emotion words. The strong effect of emotional connotation in word reading and writing was confirmed by several studies (Borod, 1992; Borod et al., 1992; Cicero et al., 1999; Landis, 2006). For example, Landis et al. (1982) reported that aphasic patients, when shown an emotion or non-emotion word, pronounced the emotion word relatively easily. This clearly demonstrated the importance of emotion in language. Abundant literature has shown greater RH involvement in processing affective words (e.g. Atchley et al., 2003; Graves et al., 1981; Landis, 2006). Atchley et al. (2003) investigated hemispheric lateralization of emotion processing by comparing the performance of clinically depressed, previously depressed, and control individuals on a divided visual field task. The researchers used person-descriptive adjectives (of positive/negative valence) to form a prime-target pair. The pair was either matching for valence, termed related (e.g. SMART-BRAVE, both positive valence), or not, termed unrelated (e.g. SMART-DIRTY). All words were presented as white lettering on a black background. A trial consisted of a fixation cross presented for 500 ms, followed by a centrally presented prime displayed for 300ms. A flash mask followed prime presentation. The unilateral targets were then presented. 11.

(30) for 185ms. Specifically, the word presented at the right side of the screen would be in the subject’s right visual field (RVF) and projected to the LH, while the left side of the screen was in the subject’s LVF and words appeared in the LVF would project to the RH. After 185ms the targets were then also masked. Following the presentation of the targets, participants made valence judgement by pressing the key as soon as possible. Results showed no difference between groups in the RVF/LH. However, both the past-depressed and currentdepressed groups showed shorter response time (RT) and higher accuracy on negative words presented in the LVF/RH, whereas the non-depressed controls exhibited shorter RT and higher accuracy on positive words in the LVF/RH. In a study similar to the above, Walsh et al. (2010) also recruited previouslydepressed and never-depressed individuals, all right-handed. The depressed subjects were subdivided into Selective Serotonin Reuptake Inhibitors (SSRIs) respondents and SSRIs nonrespondents. Participants were instructed to fixate their gaze at the center cross while a mixture of positively and negatively valenced words of high and low arousal appeared one after another on the right or left side to the central cross. The central cross was presented for 1000ms and the target word appeared for 185ms. Then it was followed by a pattern mask (########). The degree of visual angle to the inner edge of the lateralized stimuli was 2°. After the target onset, the participants had 2500ms to press the key to indicate whether the stimulus was positive or negative. Upon receiving the response from the subject, the experiment automatically moved onto the next trial. The participants were instructed to respond as fast as they could. Any response exceeding 2500ms was deemed incorrect. They found that positive words showed a RVF/LH advantage. Critically the results indicated that the SSRIs non-respondents showed a strong bias toward negative evaluation of words presented to the LVF/RH.. 12.

(31) These two studies confirmed greater RH involvement in processing emotion words, which echoes to previous studies (Graves et al, 1981; Landis, 2006). However, the converging evidence of RH involvement on emotion word processing all came from righthanded participants. Since left-handers represent a population with different cerebral lateralization, it would be illuminating to look into the difference of emotion word processing between right- and left-handers. Therefore, this study adopted the divided visual field paradigm and similar experimental procedure of the above two experiments but included both right-handed and left-handed populations.. 2.4 Summary This chapter first discussed some studies on handedness and its interaction with hemispheric lateralization and then introduced the body-specificity hypothesis before reviewing literature on emotion word processing. To begin with, Section 2.1 discussed manifest handedness as well as familial handedness and their interaction with cerebral lateralization of language. In other words, studies reviewed in this section confirmed the modulation effect of handedness when individuals process language. Section 2.2 introduced the body-specificity hypothesis (Casasanto, 2009), which proposed that individuals with different dominant hands might form different mental representations in that they interact with the physical environment consistently in a different fashion. Specifically, the studies indicated that individuals not only preferred the objects shown at their dominant side of space but also associated positive ideas with their dominant side of space. Aside from the left-right space preference, this section also discussed the top-down associations with positive and negative valence common in the metaphorical expressions (Lakoff & Johnson, 1980, 1999). Finally Section 2.3 reviewed research on emotion word processing, which exhibited a RH. 13.

(32) advantage in right-handed subjects and also reported different behavioral results with depressed and non-depressed participants.. 14.

(33) Chapter Three. Methods. This chapter illustrates the methods of the current experiment. First of all, the characteristics of the target participants and how they were divided into groups are described in Section 3.1. Experimental materials are introduced in Section 3.2. Then Section 3.3 illustrates how the experiment proceeded. Lastly, how the data were analyzed is depicted in Section 3.4.. 3.1 Participants This study recruited 37 left-handed and 68 right-handed participants, aged 20 to 40 (mean age = 27, 32 males). All of them were native speakers of Mandarin Chinese. All participants were required to have normal or corrected-to-normal vision for the experiment. Participants with neurological or psychiatric disorders were not considered. All of the subjects were verified by the Edinburgh handedness inventory (Oldfield, 1971, see Appendix A). Right-handers were further divided into either having familial sinistrals (FS+) or not (FS-) based on whether any of their blood relatives (including parents, siblings, grandparents, uncles, aunts or cousins) was left-handed: the participants who had at least one left-handed family member were categorized as the FS+ group, and the participants who reported no known left-handed family members were in the FS- group. Aside from the Edinburgh handedness inventory (Oldfield, 1971), the participants also completed the Beck Depression Inventory-second edition in Chinese (BDI-II, see. 15.

(34) Appendix B) to measure the level of depression in the participants since previous research has shown that people who suffered from depression responded to the negative verbal stimuli in the LVF differently from people without depression (Atchley et al, 2003; Walsh et al, 2010). BDI-II is a self-report questionnaire based on Beck et al. (1961). It has 21 questions of 4-point Likert scale (0 to 3), with the total score between 0 to 13 indicating minimal depression, 14 to 19 indicating mild depression, 20 to 28 indicating moderate depression, and 29 to 63 implying a severe depression. The questionnaire has the test-retest reliability at 0.93 (Beck et al., 1961). Its internal reliability (Cronbach’s alpha) for clinical patients is 0.92 and 0.93 for college students, which suggests good reliability and validity in patient samples as well as in college students. Participants also filled out the adopted Chinese version (Zan, 1986) of Interpersonal Reactivity Index (IRI, see Appendix C) to measure both their cognitive and emotional components of empathy. This is because empathy, by its definition, is sharing the emotion of others. It is proposed in the previous studies that emotion embodiment occurs when one reads an emotional word. There has also been literature indicating the correlation of emotion and reading speed. Thus for better subject control, a questionnaire on empathy was also included in the study. IRI is a questionnaire designed by Davis (1980, 1983). It has 28 items on a 5point Likert scale ranging from “Describes me very well” to “Not describing me at all.” IRI has good intra-scale and test-retest reliability, and convergent validity is indicated by correlations with other established empathy scales (Davis, 1980). All subjects signed the consent forms prior to the experiment, and they were paid for the participation after the completion of the experiment.. 16.

(35) 3.2 Materials The materials were 180 two-character Chinese emotion words varied with valence: either positive, neutral or negative, with each valence category containing 60 words. Some examples are provided in Table 1 below. No fillers were added because of the employment of neutral words, which served as a cushion against fatigue effect from viewing all the emotion words.. Table 1. Example words of the experimental materials Valence. Example Word. Negative. 貪心、邪惡、骯髒、世仇、小偷. Neutral. 翻閱、遷徙、列舉、電池、人民. Positive. 漂亮、激勵、珍藏、冠軍、恩惠. The wordlist of the present study was created by the following steps. First, 160 words of each valence condition (i.e., positive, neutral, negative) were chosen (480 in total) from the 750-word list of a former study on Chinese emotion word processing by Ku and Chan (2014). In their study, the materials were selected from the research by Zhuo et al. (2013) as well as from the Chinese Linguistic Inquiry and Word Count Dictionary by Huang et al. (2012). Based on these two resources, Ku and Chan (2014) preliminarily had 1040 words. After screening for repetition, word frequency, lexical categories, the frequency distribution of their lexical categories and also orthographic neighborhood sizes based on Chinese Word Sketch Engine1, the words were then manually inspected of homographs, in order to delete word candidates with multiple senses. Subsequent to the deletion of homographs, the remaining 750 words were rated online against their valence, arousal and imageability.. 1. Chinese Word Sketch Engine (http://wordsketch.ling.sinica.edu.tw/) is a Corpus Query System incorporating concordance, word sketches, grammatical relations, and a distributional thesaurus based on Chinese Gigaword Corpus and Sinica Corpus 5.0 and maintained by Lexical Computing Ltd. in Academia Sinica.. 17.

(36) Based on the rating data, the present study selected 480 words with the following two criteria: (1) Valence rating (on a scale of -3 to 3): high ratings of positive valence for positive words; ratings between -1 to 1 for neutral words; high negative ratings for negative words, and (2) Arousal rating: high arousal for positive and negative words, low arousal for neutral words. The first criterion was to maximize the valence difference between positive, neutral, and negative words. The second criterion was to control the arousal level among positive and negative words, so that the arousal of words would not be a confounding factor for the participants to interpret the valence of emotion words. After the 480 words were selected, the second step of the creation of the wordlist was to control the valence and arousal differences among the three conditions. To achieve this, the words underwent an online rating with a 7-point Likert scale on two variables -- valence (-3 to 3 from negative to positive) and arousal (0 to 7 from low to high arousing). Four questionnaires were created, each containing 240 words (80 words on each valence condition). Two questionnaires asked the raters to evaluate the words by valence, the other two questionnaires, by arousal. The four questionnaires were respectively rated by 85, 39, 35, 37 native speakers of Chinese, aged 20 to 40, who did not participate in the formal experiment. The subject number of the first questionnaire was much larger than the latter three because the 240 words in the first questionnaire did not serve as a pool large enough for word selection. Thus one more questionnaire with 240 new words was then provided. To control the arousal levels of the experimental materials, two more questionnaires were also added online for arousal ratings. Finally, 180 words (118 verbs, 62 nouns) were selected as the experimental materials. To be more specific, 60 words rated higher than 1.5 (from -3 to 3) were chosen for the positive words, 60 words rated between -0.4 to 0.4 for the neutral words, and 60 words rated lower than -1.5 for the negative words. The arousal levels of the words were also carefully. 18.

(37) matched during the word selection process. A three-way repeated measures ANOVA ensured the difference of the valence ratings between all the three valence conditions, F(2,118)=65307.285, p<.001 (mean score: 1.84 for positive words, 0.03 for neutral words, 1.79 for negative words). As for the arousal levels, statistical results of a three-way repeated measures ANOVA showed significant main effect of arousal ratings, F(2,118)=238.555, p<.001 (mean score: 4.22 for positive words, 2.59 for neutral words, 4.26 for negative words). Follow-up pairwise comparisons further revealed that the arousal level of the neutral word category was significantly lower than the other two categories (p’s<.001) while the positive and negative categories did not differ significantly (p=.124). Table 2 summarizes the rating results of the experimental materials. Table 3 summarizes their statistical results, while a complete list of the words is detailed in Appendix D.. Table 2. Summary of the valence and arousal rating means and SDs (in parenthesis) for the positive, neutral and negative conditions of the experimental materials Positive Words. Neutral Words. Negative Words. Valence (from -3 to 3). 1.84 (0.03). 0.03 (0.02). -1.79 (0.02). Arousal (from 0 to 7). 4.22 (0.31). 2.59 (0.74). 4.26 (0.41). Table 3. Summary of the statistical results for valence and arousal ratings among the positive, neutral and negative conditions of the experimental materials Variable. Pair. t value. Pairwise p value. Valence. Positive, Neutral. t(59)= -172.53. .000**. Positive, Negative. t(59)= -348.194. .000**. Neutral, Negative. t(59)= -198.91. .000**. Positive, Neutral. t(59)= -1.43. .000**. Positive, Negative. t(59)= .531. 1.79. Neutral, Negative. t(59)= 15.93. .000**. Arousal. Note: p-values were Bonferroni-corrected.. **= <.001. 19.

(38) 3.3 Procedure The experiment was carried out in a sound attenuated room in the Neurolinguistics Lab at National Taiwan Normal University. After signing the written informed consent, participants were seated in a chair facing a computer screen. They were instructed to rest their chin on a chinrest positioned 68 cm from the computer screen, so the distance to the screen was maintained throughout the experiment. To familiarize themselves with the procedure, the participants were required to experience 24 practice trials before they started the 180 target trials. When the experiment started, a white fixation cross (a plus sign “+”) appeared in the center of the screen with black background. The subjects were instructed to fixate their eye gaze on the central cross throughout the experiment. After 1000ms, a target two-character word appeared in either the LVF or the RVF for 185ms. The degree of visual angle to the inner edge of the laterally displayed stimulus was 2°. After 185ms, the target word was replaced by three pound signs (###) at the same location to mask the word to prevent the participant from moving his/her eyes away from the fixation point, while at the same time the participants had to make a response. They were asked to indicate whether the valence of the word was positive, neutral, or negative by key-pressing on the response box. The participants were instructed to put his/her index finger, middle finger and ring finger of the right/left hand on the respective buttons of the response box (fingers and hands counterbalanced across participants and groups). Response buttons were also counterbalanced: the index finger and the ring finger were switched for indicating “positive” or “negative”. Participants were required to respond within 2500 ms after target onset. If there was no response within the time frame, the trial was recorded as incorrect, and the screen automatically moved onto the next trial. The participants were instructed to respond as quickly and accurately as possible. Please see Figure 2 for the experimental procedure of stimulus presentation. The total time 20.

(39) for the experiment lasted 10 to 15 minutes with two short breaks in between.. Figure 2. Procedure of stimulus presentation Each trial began with a central fixation (+) and the subjects were randomly presented with a two-character word either in the RVF or LVF. The stimulus was presented for 185ms then covered by a pattern of three pound signs (###). Participants pressed the key to indicate if they thought the word was positive, neutral or negative within 2500ms (from stimulus onset).. 3.4 Data Acquisition and Analysis The E-Prime 2.0 software from Psychology Software Tools, Inc. was used in the Windows 7 environment on a PC to present the stimuli and to record the behavioral data of the participants (i.e., reaction time and response accuracy). The SPSS software version 21 (IBM Corporation) was used to analyze the collected data. Data with accuracy rate lower than two standard deviations were excluded, and only trials with correct responses were analyzed. The collected RTs and accuracy rates were respectively analyzed with a three-way repeated measures ANOVA with three independent 21.

(40) variables: group (left-handed, FS+, FS-), valence (positive, neutral, negative), and visual field (LVF, RVF). Post-hoc pairwise comparisons were carried out and Bonferroni corrected when needed. In addition, the p-values were adjusted with the Greenhouse-Geisser correction (Greenhouse & Geisser, 1959) when the Mauchly's test of Sphericity was violated. Importantly, planned comparisons, including paired t-tests on valence under two visual field conditions and paired t-tests on visual field under three valence conditions for each of the subject groups, were carried out to test the body-specificity hypothesis.. 22.

(41) Chapter Four. Results. The current study recruited 104 participants. Five subjects’ data were excluded due to technical problems or unexpected health issues of the participants, such as unilateral nearsightedness. Then the data of the remaining 99 participants (33 FS-, 35 FS+, 34 Left-handed) were further subjected to elimination based on the following criteria -- (1) mean accuracy rates lower than 2 SDs, (2) for the left-handed group only, the score (0-10) of the Edinburgh left-handedness inventory lower than five, and (3) the BDI-II depression score equal to or higher than 20 (indicating a moderate depression or above). After the screening, the data of 84 subjects ( 27 FS-, 30 FS+, 27 Left-handed) remained. In order to keep the number consistent across groups, three subjects’ data in the FS+ group were randomly excluded, which left 81 subjects in total, with 27 subjects in each group.. 4.1 Accuracy Rates Table 4 summarizes the mean accuracy rates under the six conditions (3 valence levels x 2 visual field levels) for each group. A three-way repeated measures ANOVA with the factors of group (FS-, FS+, Left-handed), valence (positive, neutral, negative) and visual field (LVF, RVF) was conducted. The results revealed a main effect of valence, F(1.268, 98.934) = 46.940, p<.001. Follow-up pairwise comparisons showed that neutral words had a significantly higher accuracy rate (91.79 ± 6.81%) than the other two categories of words (positive: 85.92 ± 11.04%; negative: 85.86 ± 11.83%), while the other two categories did not. 23.

(42) significantly differ from each other (p = 1.00). In addition, there was also a main effect of visual field (F(1, 78)=42.055, p<.001), with higher accuracy in the RVF. The average RVF accuracy rate was 91.33 ± 7.24%, while the LVF accuracy rate was 84.39 ± 12.00% (mean difference: 6.94%). As for the between-subject factor, the test results suggested no significant effect of group. On average, the left-handed group had a slightly higher accuracy (88.21%) than the FS- group (87.73%), and the FS- group performed slightly better than the FS+ group (87.65%), though the difference was not significant, F(2,78)=.097, p=.908.. Table 4. Summary of the accuracy rates (Mean and SD) in each experimental condition across groups Valence x Visual field Variables. Group. Negative Words. Neutral Words. Positive Words. LVF. RVF. LVF. RVF. LVF. RVF. FS-. 0.81 (0.10). 0.91 (0.10). 0.91 (0.08). 0.92 (0.05). 0.81 (0.11). 0.91 (0.08). FS+. 0.80 (0.11). 0.91 (0.06). 0.92 (0.07). 0.92 (0.09). 0.79 (0.10). 0.92 (0.04). Left-handed. 0.81 (0.16). 0.91 (0.09). 0.92 (0.06). 0.92 (0.05). 0.81 (0.15). 0.92 (0.07). Aside from the main effects, a significant valence x visual field interaction was observed, F(2,156)=21.342, p<.001. To better understand the simple effects of valence and visual field respectively, six follow-up paired t-tests were conducted to further investigate the pairwise relations, the results of which are illustrated in Table 5. As shown in Table 5, only the pair of positive/neutral stimuli and the pair of neutral/negative words in the LVF showed significant accuracy differences. Finally, except for the valence x visual field interaction, no other interactions reached significance: valence x group, F(4,156)=.140, p=.911; visual field x group, F(2, 78)=.052, p= .949; valence x visual field x group, F(4,156)=.138, p=.968. 24.

(43) Table 5. The summary of the follow-up paired t-tests on accuracy rates after a valence x visual field interaction Visual Field. Valence. t. p-value. LVF. Positive/Neutral. t(80)= -6.67. .000**. Positive/Negative. t(80)= -0.71. 2.89. Neutral/Negative. t(80)= 6.26. .000**. Positive/Neutral. t(80)= -0.34. 4.39. Positive/Negative. t(80)= 1.04. 1.80. Neutral/Negative. t(80)= 0.82. 2.49. RVF. Note: p-values were Bonferroni-corrected. **= <.001. 4.2 Reaction Times Table 6 summarizes the RTs under the six conditions (3 valence levels x 2 visual field levels) for each of the group. A three-way repeated measures ANOVA with the factors of group, valence and visual field was conducted. The results revealed a main effect of valence, F(2,156)=149.019, p<.001. Pairwise comparisons indicated that the three levels of valence all distinguished themselves from one another on a significant level (p’s <.001). To be specific, the RTs of positive words were the shortest while those of neutral words were the longest. The RTs of positive words (608.35ms) were approximately 50ms shorter than those of negative words (658.00ms), and the RTs of negative words were roughly 120ms shorter than those of the neutral words (772.17ms). Moreover, although there was no significant valence x visual field interaction, planned analyses revealed that different valence levels distinguished from each other in both visual fields (p’s <.001), with positive words soliciting shortest RTs while neutral words longest RTs. As for the visual field factor, similar to the results of the accuracy rates, a main effect of visual field was observed, F(1,78)=5.667, p<.05. Words appeared in the RVF/LH were. 25.

(44) generally processed 12ms faster than words in the LVF/RH.. Table 6. Summary of the mean RTs and SDs (ms) in each experimental condition across groups Valence x visual field. Group. Mean RT (SD). Negative Words. Neutral Words. Positive Words. LVF. RVF. LVF. RVF. LVF. RVF. FS-. 670.37 (134.88). 659.39 (135.92). 806.35 (186.16). 770.42 (189.76). 620.47 (139.15). 623.20 (147.14). 707.21 (147.89). FS+. 701.81 (145.35). 684.33 (147.69). 815.53 (157.79). 790.73 (157.73). 654.73 (134.19). 645.23 (144.36). 729.05 (144.86). Lefthanded. 646.16 (115.25). 648.76 (121.91). 765.43 (153.21). 759.20 (159.92). 595.57 (120.87). 589.06 (106.17). 678.37 (115.73). Variables. As for the between-subject factor, it was observed that the left-handed group responded faster than the FS- group, and that the FS- group had shorter RTs than the FS+ group. Although the effect of group did not reach significance, F(2,156)=.902, p=.410, this “left-handed < FS- < FS+ group” pattern could be observed across valence conditions and also across visual fields, as is shown in Tables 6 and 7. Table 7 shows the RT difference collapsed by valence or visual field. Please note that the arrangement of the groups from top to down is by the longest RTs to the shortest ones, for the ease of observation. Therefore, the FS+ group is placed at the top row and the left-handed group at the bottom row. As can be seen from Tables 6 and 7, the “left-handed < FS- < FS+ group” pattern on RTs held across every condition. Although valence x visual field interaction was significant with the accuracy data, no such interaction was observed with RTs (F(2,156)=1.226, p= .296). Also, no other interactions reached significance: valence x group, F(4,156)=.204, p= .936; visual field x group, F(2,78)=.743, p= .479; valence x visual field x group, F(4,156)=.484, p= .748.. 26.

(45) Table 7. Summary of the mean RTs and SDs(ms) collapsed by valence or visual field Valence. Group. VF. Negative. Neutral. Positive. LVF. RVF. FS+. 693.17 (144.25). 803.23 (152.41). 650.45 (135.06). 719.43 (136.12). 702.06 (142.86). FS-. 664.59 (126.90). 787.06 (182.26). 621.66 (139.77). 692.36 (140.65). 678.80 (143.23). Lefthanded. 647.15 (113.96). 762.18 (149.81). 591.78 (106.55). 661.42 (112.88). 657.60 (107.74). 4.3 Analysis of the Headedness of the Materials It is not clear if the lack of the effect of the body-specificity hypothesis was due to the difference of the headedness distribution of valence in the bisyllabic materials. In the current study, the headedness of the materials was not controlled because the employed bisyllabic words were considered a unit. It is thus not clear if the preference for the dominant side, if any, was obscured by the uncontrolled headedness of valence within the words. Therefore, we analyzed the headedness distribution of the words in the three valence conditions and the results are summarized in Table 8 below.. Table 8. The distribution of headedness among the three valence categories Valence\Headedness left-headed right-headed double-headed compositional Positive. 10 (樂觀). 15 (中獎). 23 (幸福). 12 (天堂). Neutral. 4 (發呆). 2 (打牌). 51 (填寫). 3 (傻笑). 24 (吵架) 8 (世仇) Note: Examples are provided in the parenthesis.. 26 (偷竊). 2 (自大). Negative. As can be seen from Table 8, the valence of the word could be derived from the left (e.g. 樂觀) or the right (e.g. 中獎) character of the word, which is termed left- or right-. 27.

(46) headed in the current study. Moreover, the valence could also come from both characters (e.g. 幸福), termed double-headed here. In addition, it could also be that neither of the two characters carried the word-level valence. Rather, the valence was derived from the composition of the two characters when they formed a word (e.g. 天堂). Although for both positive and negative conditions, valence was contributed by both characters in more than 20 instances, the rest of the instances showed an inconsistent pattern, with more right-headed words in the positive condition and more left-headed words in the negative one. Also, positive words exhibited a greater number of compositionality than neutral or negative words. As for neutral condition, more than two-thirds of the instances were double-headed (e.g. 巷道).. 28.