The Role Of Character Positional Frequency In Sentence Reading And Lexical Naming Task

Previous researches have showed that spaces between words played an important role in alphabetic writing system.Differently,there is no explicit segment cue in Chinese text,so Chinese readers should rely on some implicit cues to facilitate reading,such as word frequency and so on.Recent studies have demonstrated that the positional frequencies of word's constituent characters contributed to the process of Chinese compound word during reading.Since the morphemes in different within-word positions play different roles when processing Chinese compound words,two experiments were conducted to examine the effects of first and final character positional frequencies on compound word's identification in reading.In experiment 1,based on each character positional frequency,the first character of two-character compound word was manipulated to be at word beginning with high-or low-probability while the final character was controlled as equal to present at word ending.In experiment 2,similar manipulation was made for the final character while the first character was controlled.We found that reading time was remarkably reduced when the final character presented at word ending with high-probability compared to that with low-probability,such pattern did not present in our manipulation of first characters.It appears that only the final character within-word positional information played important role on segmenting and identifying words in Chinese reading.Another aspect of results should be noted,that child readers were less skilled to use the final character positional frequency to identify word than adults.The present findings seem to be inconsistent with most of the previous findings that the first character was more pronounced than the final character in two-character compound word's recognition.Here,one characteristic of Chinese reading should be considered,because of the lack of visual word segmentation cues in Chinese text,the right boundary of the previous word also is the left boundary of the current word.In this case,there is no need for Chinese readers to use the first character positional frequency information serving for word segmentation.In order to test this hypothesis,we adopted lexical overlapping paradigm in experiment 3 to examine whether both of the first and final character positional frequencies would be used by Chinese readers in lexical naming task.Three-character strings were constructed(eg."???",the former two-character word means "nation",and the latter two-character word means "internation".),where the former two-character word and the latter two-character word were both high-frequency words.We manipulated both the first and the final character positional frequencies as high or low level,and kept the middle character used as word beginning and word ending equally.After presenting the target character strings for 80 ms,participants were asked to orally report only one word they just saw.The results showed that when the first character was frequently used as word beginning,both children and adults tended to report the left word;similar pattern was found in the final character.It means that both the first and final character positional frequencies played important roles in lexical naming task.To summarize the findings of these three researches,the results were made as follows:(1)Chinese readers only use the final character positional frequency in sentence reading,while they use both the first and final character positional frequencies in lexical recognition.(2)The ability of adult to use character positional frequency is better than that of children.This ability is a process of development.