Phonetic radicals, not phonological coding systems, support orthographic learning via self-teaching in Chinese.

According to the self-teaching hypothesis (Share, 1995), phonological decoding is fundamental to acquiring orthographic representations of novel written words. However, phonological decoding is not straightforward in non-alphabetic scripts such as Chinese, where words are presented as characters. Here, we present the first study investigating the role of phonological decoding in orthographic learning in Chinese. We examined two possible types of phonological decoding: the use of phonetic radicals, an internal phonological aid, andthe use of Zhuyin, an external phonological coding system. Seventy-three Grade 2 children were taught the pronunciations and meanings of twelve novel compound characters over four days. They were then exposed to the written characters in short stories, and were assessed on their reading accuracy and on their subsequent orthographic learning via orthographic choice and spelling tasks. The novel characters were assigned three different types of pronunciation in relation to its phonetic radical - (1) a pronunciation that is identical to the phonetic radical in isolation; (2) a common alternative pronunciation associated with the phonetic radical when it appears in other characters; and (3) a pronunciation that is unrelated to the phonetic radical. The presence of Zhuyin was also manipulated. The children read the novel characters more accurately when phonological cues from the phonetic radicals were available and in the presence of Zhuyin. However, only the phonetic radicals facilitated orthographic learning. The findings provide the first empirical evidence of orthographic learning via self-teaching in Chinese, and reveal how phonological decoding functions to support learning in non-alphabetic writing systems.

End-stage renal disease: in vivo diffusion-tensor imaging of silent white matter damage.

PURPOSE: To characterize and compare regional differences in anisotropy in patients with end-stage renal disease (ESRD) and in control subjects to understand the effect of ESRD and hemodialysis on the microstructures of white matter. MATERIALS AND METHODS: This study was approved by an institutional review board; written informed consent was obtained. From March 2007 to December 2007, 34 patients (16 men, 18 women; mean age, 40.0 years; range, 26-50 years) with ESRD who were undergoing dialysis and 35 control subjects (16 men, 19 women; mean age, 38.3 years; range, 25-49 years) were enrolled. There was no significant sex or age difference between the ESRD and control groups. By using a 1.5-T imager, fractional anisotropy (FA) data obtained at diffusion-tensor magnetic resonance (MR) imaging (echo-planar imaging, 33 directions; b value, 1000 sec/mm(2)) and at T2-weighted fluid-attenuated inversion recovery (FLAIR) MR imaging of the bilateral parietal, frontal, occipital, and temporal lobe white matter, as well as the genu and splenium of the corpus callosum, were compared. The Cognitive Abilities Screening Instrument (CASI) was administered to all participants at imaging. RESULTS: The ESRD group had significantly lower FA values in all regions than the control group. FA values were generally lower in older patients and in those who had been undergoing dialysis for a longer duration. Duration of dialysis was more often than age found to be correlated with differences in FA values. In areas in which there was a significant correlation between age, duration, and FA values, the regression coefficients were greater for those who had been undergoing dialysis longer than for those who were older. Patients with ESRD had significantly lower CASI scores than control subjects (P = .03). There were no significant group differences in FLAIR values (P = .25-.89). CONCLUSION: Changes in FA values may be used to follow-up white matter changes in patients with ESRD who are undergoing maintenance dialysis. SUPPLEMENTAL MATERIAL: http://radiology.rsnajnls.org/cgi/content/full/2523080484/DC1.