Effects of word orthography and concreteness on cerebral hemispheric asymmetry in Korean bilinguals

The main purpose of this research was to investigate how different orthographies for representing the words of a language in writing might be associated with different patterns of hemispheric asymmetry. In the first experiment, 24 English-speaking monolinguals decided whether a series of common, high-frequency words presented to the left visual field (LVF) or to the right visual field (RVF) were concrete (e.g. milk) or abstract (e.g., fate). A significant advantage in response latency was observed for RVF presentation, indicating a left hemisphere (LH) superiority, consistent with prior findings. Concrete words were associated with somewhat smaller field asymmetry in each of the four trial blocks, although the trend did not reach significance.;Experiment 2 demonstrated that different orthographies can reverse the laterality pattern. In a within-subject design, 24 Korean-English bilinguals performed the same task as in Experiment 1 for three types of scripts. In three blocks of trials, the words were given in English, in Korean with Hangul script, or in Korean with Chinese script.;A RVF-LH advantage was found for both Hangul and English but there was a clear LVF-RH superiority for Chinese script. This striking reversal was observed both for single-character and double-character Korean words (corresponding to one and two syllables). Since Chinese script is ideographic with no phonetic cues within a word-character while Hangul and English do have within-word phonetic cues, the results support the hypothesis of LH superiority in phonological analysis, and RH superiority in visuospatial processing, within a linguistic task.;The interaction between concreteness and VHF was highly significant for Hangul and English and marginal for Chinese. In all cases, abstract words showed greater asymmetry than did concrete words. This result is in general consistent with the hypothesis that lexical information about concrete words is represented more bilaterally. The asymmetry for English words for monolingual subjects in Experiment 1 and Korean bilinguals in Experiment 2 was very similar despite tremendous differences in their language acquisition histories.