中文分類詞對名物分類知覺之調節: 神經語言學研究

Abstract

語言相對論（linguistic relativity），又稱為薩丕爾-沃夫假說（Sapir-Whorf hypothesis），主張語言可以影響人們如何感知世界。雖然相關行為研究支持語言能夠影響思維的說法，但仍有學者對此提出質疑（如Pinker，2007 [1994]），認為儘管實驗中使用非語言的刺激，實驗中仍可能有潛在的語言干擾。因此，Thierry（2016）建議，語言相對論的議題可透過認知神經領域的研究方式，去探測基於無意識感知處理的自發大腦活動。本研究旨在藉由兩個事件相關腦電位（event-related potentials，ERP）實驗檢視中文分類詞在前語言層面（pre-linguistic level）及語言層面（linguistic level）對於中文母語者的名物知覺的影響。在實驗一中，我們參考胡世強（2019）的實驗設計，並做些微調整，共計招募三十位中文母語者及七位英文母語者。我們採用特異刺激典範（oddball paradigm），而受試者的任務則是在看到目標刺激時按鍵。實驗刺激分為標準刺激（使用相同分類詞的圖片，出現機率80%）、特異刺激（使用和標準刺激不同分類詞的圖片，包含維度內違反特異刺激（within-dimension deviant）及維度間違反特異刺激（between-dimension deviant），出現機率15%）與目標刺激（圖片為一隻貓，出現機率5%）。中文母語者的維度內及維度間違反特異刺激在175-250毫秒間誘發顯著的P2效應，而英文母語者只有維度間違反特異刺激誘發P2效應。我們推測在英語母語者中發現的P2效應，可能是由刺激材料中的物體外觀所誘發，而非語言的影響。在實驗二中，中文母語者同實驗一中的受試者，實驗二亦採用特異刺激典範，但是刺激材料為中文字詞。字詞刺激分為標準刺激（出現機率80%）、維度內及維度間違反特異刺激（出現機率15%）與目標刺激（為字詞「老鼠」，出現機率5%）。雖然在標準刺激和特異刺激並無觀察到顯著P2效應，但我們發現維度內違反特異刺激在250-350毫秒間，於大腦前方的位置誘發較早的N400。綜合兩個實驗的結果，在中文母語者中所發現的P2及N400效應，顯示出無論在前語言層面或語言層面，中文分類詞皆可能影響中文母語者對於名物的知覺。本研究也支持語言相對論的論點—語言中的某些因素可以影響人們對於世界的感知，且不同語言的使用者也可能有不同的認知處理方式。Linguistic relativity, also called Sapir-Whorf hypothesis, refers to the proposal that the language people speak can influence the way they perceive the real world. Although previous behavioral research has suggested that language can affect thoughts, it could not convince the opposing side due to possible verbal interference even in experiments adopting a nonverbal design (e.g. Pinker, 2007 [1994]). Thierry (2016) thus suggested that researchers should test linguistic relativity by investigating mental processes, especially automatic and unconscious ones, with cognitive neuroscience approaches.The current study aimed to examine the effect of Mandarin Chinese classifiers on Mandarin Chinese speakers' perception of the real-world objects at both the pre-linguistic and linguistic levels with two ERP experiments. In Experiment 1, we replicated the experiment design in Hu (2019), but with substantial modifications. Thirty Mandarin Chinese speakers and 7 English speakers were recruited, and they were shown pictorial stimuli to perform a target detection task in an oddball paradigm. The standard stimuli (probability 80%) were photos of objects sharing the same classifier, the deviants (probability 15%) which were photos of objects either dimensionally congruent with the standard classifiers (within-dimension deviants) or dimensionally incongruent with the standard classifiers (between-dimension deviants), and the targets (probability 5%) were photos of a cat. For the Mandarin Chinese group, both within- and between-dimension deviants evoked a significant P2 effect (175-250 ms), but for the English group, a P2 effect was found only in the condition of between-dimension stimuli vs. standards. The P2 effect we found in the English group in Experiment 1 might be related to the appearance of the stimuli instead of the effect of language. In Experiment 2, the participants were the same Mandarin Chinese speakers in Experiment 1, and they were shown word stimuli to perform a target detection task in an oddball paradigm. The word stimuli were also divided into the standards (probability 80%), the within- and between-dimension deviants (probability 15%), and the target (which was laoshu 老鼠'rat', probability 5%). Although a P2 deviancy effect was not found, we found an early anterior N400 (250-350 ms) in the comparisons of within-dimension deviants vs. standards. The P2 and N400 effects found in the Mandarin Chinese group in the present study reveal that the Mandarin Chinese classifiers can affect Mandarin Chinese speakers' perception of the real-world objects pre-linguistically and linguistically, supporting linguistic relativity that certain language factors can affect people'sperception of the world, and that different language speakers may process things differently.