br Methods br Results br Discussion We found

Methods
Results
Discussion We found that Chinese characters induced the bilateral N170 component in the occipital-temporal purchase KPT-185 in preschool children before training, consistent with previous findings for alphabetic scripts (Maurer et al., 2005b, 2006; Brem et al., 2010). Importantly, our data, for the first time, showed that the word-related N170 expertise emerged very quickly in very young preliterate Chinese children (4 to 5 years old) after short-term word learning (about 100min), especially in visual identification groups. Although the N170 amplitude for characters was larger than that of tools before training, we still observed a training effect reflected by larger amplitude of characters in the right hemisphere. Furthermore, such changes in the character N170 amplitude at the neural level were coordinated with the behavioral performance changes in the character-matching test, which reflects a fast character-processing ability enhanced after training sessions. Thus, combined with the findings in children who learn to read alphabetic script (Brem et al., 2010), our findings indicate that the fast emergence of visual word N170 expertise after learning to read is independent of the type of script young children learn. It is worth mentioning that the pronunciation and semantic meaning of the specific characters were provided to children when we visually presented the characters at the beginning of each training session in both groups. Such a learning method is similar to that in Brem et al. (2010)’s study, which asked children to learn letter-sound correspondences (Brem et al., 2010). Thus, the enhanced N170 effect for visual words by short-term training suggests that visual-speech correspondences (character-syllable correspondence in Chinese) are essential for the emergence of N170 word expertise processing regardless of the differences in visual and linguistic features that make up different scripts. Our other interesting finding is the different training effects of visual identification and writing learning on the visual word N170 expertise processing. The visual identification task made the neural activities of character processing change differently in both hemispheres. The N170 amplitudes to characters did not change significantly after training in the left hemisphere, whereas the N170 amplitudes of characters enhanced remarkably in the right hemisphere. Regarding the free writing group, we did not observe very strong learning effects on N170 character amplitudes compared with that in the visual identification group. However, although writing training did not produce significant increases in N170 character amplitude, in the right hemisphere, the amplitude difference between characters and faces disappeared (Fig. 6B and D). Since the pattern of N170 amplitudes of the three categories was similar in both groups before training, different learning effects may reflect different impacts of different literacy inputs on the N170 word expertise processing. The current study did not show that writing experience produces significant improvements of reading ability either in terms of the behavioral performance in the character recognition tests, or the N170 amplitude for characters in Chinese preschool children. We did not find any significant correlations between the character recognition score after 4 weeks training and the N170 amplitude of characters before or after training (all p-values >0.10) as well. These results appear to be inconsistent with the results obtained with children learning to read English letters (James, 2010). For example, James (2010) trained 4–5 years old children with limited letter knowledge (7.5 letters) to copy English letters. During learning sessions, words that contained letters highlighted in the story text were learned. The experimenter read the story and then children copied the highlighted letters and words. After four 30-min writing practice sessions (2h in total), they found an enhanced fusiform gyrus response to the letters in both hemispheres while the response to pseudoletters and shapes remained unchanged. However, Suppressor (extragenic) should be noted that in the study of James (2010), children in visual learning groups were offered the pronunciations of the whole words which consisted of the letters to be learned. In other words, the children in that study were presented with the whole word in learning sessions but tested with the recognition of letters instead of words after training. This procedure might lead less effective visual learning since the grapheme-phoneme correspondences would be less likely to be encoded (Morrison et al., 1995).