國小三年級、六年級兒童及大學生字彙處理歷程中語意部件扮演角色之發展變化

Developmental Changes in the Role of Semantic Radicals in Lexical Processing in Third Graders, Sixth Graders, and College Students

過去中文字彙辨認歷程之發展研究中，關於單字語意部件的語料特性，鮮少進行細緻的操弄與探討。語意部件的處理，反映了兩種可能的內在歷程，其一為語意部件出現在單字內的次字彙歷程，其二為含有這個語意部件的單字字群間的相互影響歷程。本研究分別以國小三年級、六年級兒童及大學生為參與者，同時進行了操弄單字字頻與語意部件組字數二因子設計的實驗，觀察字彙判斷作業的表現，以探討語意部件處理在兒童識字發展歷程中所扮演的角色。首先，於不同年齡層，皆穩定地觀察到目標字頻變項之促進效果，顯示本研究字彙作業於各發展階段皆能夠敏感反映字彙觸接之歷程。進一步探討語意部件組字數變項，結果顯示語意部件組字數對於國小三年級兒童字彙判斷之作業表現有促進的效果。然而在國小六年級兒童與大學生，均顯示語意部件之操弄無顯著影響效果。本研究據此推論，國小三年級兒童字彙處理歷程中，仍會倚賴單字內的語意部件協助識字的歷程。這種辨識歷程，可以採用雙向激發模式，解釋次字彙與字彙訊息所產生的交互激發。但國小六年級兒童及大學生在進行認字過程裡，已觀察不到語意部件能扮演的次字彙角色。本研究最後提出兒童相對於成人在部件處理差異的原因及規劃未來的方向。

The role of the semantic radical is important to understand the cognitive mechanisms of lexical processing. However, it is still unclear about the cognitive accounts of developmental changes of the semantic radical on lexical processing, including the sublexical and the neighborhood size account. In the present study, we address this issue by recruiting 60 third graders, 54 sixth graders and 28 college students. Participants were tested using the lexical decision task. They had to decide whether a visual symbol was a real Chinese character. Frequency (high, low) and radical combinability (high, low) were independently varied to study lexical processing. There were two main results. First, a significant frequency effect was found across three age groups during the lexical decision task, suggesting that lexical access was involved in the task for participants. Second, for the third graders there was a significant effect on radical combinability effect, with better sensitivity performance on characters with high combinability. This finding suggests that third graders may rely more on the knowledge of the sub-lexical component (i.e., semantic radical) within a character to facilitate their lexical decision judgments. This result can be explained by the bi-directional activation model, using the interactive activation of sublexical and lexical information during lexical processing. In contrast, there was no significant effect on radical combinability in both the sixth graders and college students. We will present several views and future directions to explain the differences in radical processing between children and adults.