汉字正字法家族效应的ERP研究

摘要： 以汉字为实验材料，自变量为汉字正字法笔画家族大小，采用延迟反应的同一字判断任务，记录并研究大学生被试对刺激字的脑电(EEG)。本文对笔画家族的定义是，通过改变1~5笔笔画得到刺激字的正字法家族成员，改变的笔画不构成部件。脑电结果显示：大家族刺激字比小家族刺激字诱发更负的N400 和N250成分、更低的P200，其中N400的结果与交互激活模型侧抑制的预期一致。
Abstract: There is a major concern highlighted in the literature that previous findings in alphabetical language studies regarding the N400 effect of neighborhood size may be confounded by phonological neighborhood size. A major purpose of this study is to resolve this concern. The stroke-based neighborhood size of a Chinese character is defined in this study as the number of characters that can be formed by replacing strokes of the root character. Event-related brain potentials (ERPs) elicited by target characters were recorded while participants completed a character-matching task where in a probe character was matched on each trial with its preceding target character. The task was performed to avoid potential P300 contaminations related to immediate responses and/or decisions to the stimuli. Using the delayed character-matching task, we manipulated the number of stroke-based neighbors of the target characters to study Chinese character orthographic neighborhood effects and to explore whether ERPs are influenced by cognitive processing during Chinese character recognition. In this study, characters of the highest frequency in their neighborhood were used as stimuli in order to eliminate the influence of the higher-frequency neighbors. The orthographic neighbors of Chinese characters were defined at stroke level. The neighbors of the characters were created by replacing 1 to 5 random strokes of the root characters depending on the total number of their strokes while keeping their structure and the orientations of their remaining strokes relatively constant. Actual neighbors of each target (selected) character determined by extra group of participants, who received a paper-pencil task in which they wrote the neighbors according to this definition and instructions provided. A total of 140 stimulus characters were then selected from the root characters to form 2 types of stimuli: characters with a large and characters with a small number of stroke-based neighbors which were each identified by at least 2 of the participants during the task. Character frequencies, stroke counts and radical counts were balanced across these types. The results revealed a greater N400-like deflection, a higher N250 and a lower P200 elicited by characters with a large number of neighbors compared with similar characters with a small number, while revealing no significant difference in