Datensatz

Zusammenfassung

The brain activity of orthographic neighborhood size (N size) effect in Chinese character naming has been studied in adults, meanwhile behavioral studies have revealed a developmental trend of Chinese N-size effect in developing readers. However, it is unclear whether and how the neural mechanism of N-size effect changes in Chinese children along with development. Here we address this issue using functional magnetic resonance imaging. Forty-four students from the 3rd, 5th, and 7th grades were scanned during silent naming of Chinese characters. After scanning, all participants took part in an overt naming test outside the scanner, and results of the naming task showed that the 3rd graders named characters from large neighborhoods faster than those from small neighborhoods, revealing a facilitatory N-size effect; the 5th graders showed null N-size effect while the 7th graders showed an inhibitory N-size effect. Neuroimaging results revealed that only the 3rd graders exhibited a significant N-size effect in the left middle occipital activity, with greater activation for large N-size characters. Results of 5th and 7th graders showed significant N-size effects in the left middle frontal gyrus, in which 5th graders induced greater activation in large N-size condition than in small N-size condition, while 7th graders exhibited an opposite effect which was similar to the adult pattern reported in a previous study. The current findings suggested the transition from broadly tuned to finely tuned orthographic representation with reading development, and the inhibition from neighbors' phonology for higher graders.