Visual event-related potentials reveal the early lexical processing of Chinese characters

Abstract

Logographic scripts such as Chinese differ markedly from alphabetic scripts. The time-course of the lexical processing of alphabetic words was widely studied by recording event-related potentials (ERPs), and the results indicated that alphabetic words are rapidly and automatically processed. This study investigated whether there is also rapid and automatic lexical processing of Chinese characters by recording ERPs. High-frequency (HF) characters and orthographically similar low-frequency (LF) characters were pseudo-randomly presented to proficient Chinese readers. The color of half of the characters was blue and the color of the other half was black. In the color decision task, participants were asked to determine the color of each character. In the lexical recognition task, participants were asked to report whether s/he knew each character (the LF characters in this study were very rare characters which were usually not recognized by proficient Chinese readers). In both tasks, the N170 elicited by HF characters peaked earlier than the N170 elicited by LF characters in the right parieto-occipital area (PO8), and the ERPs to HF characters diverged from the ERPs to LF characters around 210–222 ms after the stimulus onset. These results reflected the rapid and automatic lexical processing of Chinese characters. Source analysis results suggested that the left and the right occipitotemporal cortices and the right visual cortex were the neural origins of the early lexical processing of Chinese characters, and the peak activation was in the right visual cortex.