Neural Substrates of Hanja (Logogram) and Hangul (Phonogram) Character Readings by Functional Magnetic Resonance Imaging

The two basic scripts of the Korean writing system, Hanja (the logography of the traditional Korean character) and Hangul (the more newer Korean alphabet), have been used together since the 14th century. While Hanja character has its own morphemic base, Hangul being purely phonemic without morphemic base. These two, therefore, have substantially different outcomes as a language as well as different neural responses. Based on these linguistic differences between Hanja and Hangul, we have launched two studies; first was to find differences in cortical activation when it is stimulated by Hanja and Hangul reading to support the much discussed dual-route hypothesis of logographic and phonological routes in the brain by fMRI (Experiment 1). The second objective was to evaluate how Hanja and Hangul affect comprehension, therefore, recognition memory, specifically the effects of semantic transparency and morphemic clarity on memory consolidation and then related cortical activations, using functional magnetic resonance imaging (fMRI) (Experiment 2). The first fMRI experiment indicated relatively large areas of the brain are activated by Hanja reading compared to Hangul reading. The second experiment, the recognition memory study, revealed two findings, that is there is only a small difference in recognition memory for semantic transparency, while for the morphemic clarity was much larger between Hanja and Hangul. That is the morphemic clarity has significantly more effect than semantic transparency on recognition memory when studies by fMRI in correlation with behavioral study.

Dissociation of Hangul and Hanja Reading After Left Parieto-occipital Infarction: Alexia with agraphia with Hangul, but preserved in Hanja

Korean vocabularies are composed of ideograms (Hanja) and phonograms (Hangle) just like Kanji (ideogram) and Kana (Phonogram) in Japanese. Double dissociation between the phonogram and ideogram has been reported in both languages. According to those studies, the ideograms are localized in more selective brain areas than the phonograms. We report on a case of alexia with agraphia for Hangle and intact reading for Hanja after a left parieto-occipital lobe infarction.

Hanja Alexia with Agraphia After Left Posterior Inferior Temporal Lobe Infarction: A Case Study

Korean written language is composed of ideogram (Hanja) and phonogram (Hangul), as Japanese consists of Kanji (ideogram) and Kana (phonogram). Dissociation between ideogram and phonogram impairment after brain injury has been reported in Japanese, but few in Korean. We report a 64-yr-old right-handed man who showed alexia with agraphia in Hanja but preserved Hangul reading and writing after a left posterior inferior temporal lobe infarction. Interestingly, the patient was an expert in Hanja; he had been a Hanja calligrapher over 40 yr. However, when presented with 65 basic Chinese letters that are taught in elementary school, his responses were slow both in reading (6.3 sec/letter) and writing (8.8 sec/letter). The rate of correct response was 81.5% (53 out of 65 letters) both in reading and writing. The patient's performances were beyond mean-2SD of those of six age-, sex-, and education-matched controls who correctly read 64.7 out of 65 and wrote 62.5 out of 65 letters with a much shorter reaction time (1.3 sec/letter for reading and 4.0 sec/letter for writing). These findings support the notion that ideogram and phonogram can be mediated in different brain regions and Hanja alexia with agraphia in Korean patients can be associated with a left posterior inferior temporal lesion.

Neuropsychological and Neuroimaging Findings of Semantic Dementia

BACKGROUND: Semantic dementia (SD) is a temporal variant of frontotemporal lobar degeneration (FTLD), which is characterized by naming difficulty, decreased comprehension of words, prosopagnosia and object visual agnosia. We report clinical features, neuropsychological and neuroimaging findings of 4 patients with SD. METHODS: Of 55 patients diagnosed as having FTLD between Jan 1995 and May 2001 at Samsung Medical Center, four patients fulfilled the diagnostic criteria of SD proposed by consensus on FTLD diagnostic criteria. We investigated their clinical features such as presenting symptoms and abnormal behaviors, neuropsychological and neuroimaging findings. Neuropsychological tests included the Seoul Neuropsychological Screening Battery, the Korean-version of Western Aphasia Battery and Hanja reading and writing. All patients underwent brain MRI and FDG-PET. RESULTS: All of the patients showed naming difficulty as a presenting symptom. Language assessments showed severe naming and compre-hension difficulties with preserved fluency and repetition, which were compatible with transcortical sensory aphasia. Whereas Hangul reading aloud and writing were intact, three patients were impaired at Hanja reading and writing. Other neuropsychological tests were remarkable for prosopagnosia, object visual agnosia and memory loss. Brain MRI showed asymmetric temporal atrophies, mainly left antero-inferior temporal cortices. FDG-PET also showed hypome-tabolism in bilateral anterior temporal lobes, more severe on the left. CONCLUSIONS: Our SD patients had characteristic neuropsychological and neuroimaging findings, which can be differentiated from other neurodegenerative diseases. We also found Hanja alexia and agraphia in SD patients, which has not been reported yet.

Use of Korean Letter "Hangul" and Special Characters in a Chromosome Image Analyzer, QuipsTM 3.0 Operable Only in Mac OS 8.0 / 대한임상병리학회지

BACKGROUND: Nowadays, many laboratories use computer and karyotyping software in chromosome analysis on the development of computer and digital imaging technology. And some of these softwares, such as QuipsTM (Vysis, USA; QuipsTM), are those operated in Macintosh operating system (Mac OS) because it had been considered superior to IBM PC in imaging works. However, Korean users have had difficulties in use of Korean letter "Hangul" because many of these hadn't been operated in Korean Macintosh System (KH series). METHODS: We used a karyotyping software of Macintosh QuipsTM 3.0, which is inconvenient to manage patient informations such as name, department, doctor's name and etc. In order to use "Hangul" in QuipsTM 3.0, we incorporated some files (WorldScript II and ScriptSwitcher 8 along with other files such as fonts, "Imrykki" and etc.) from KH 8.0 (Elex, Co; Korean Macintosh system) to Mac OS 8.0 (Apple, Inc; English Macintosh system). RESULTS: After modifing the operating system of Mac OS 8.0, we could use not only "Hangul", but also Chinese letter "Hanja" and special characters (e.g., "alpha", "-->", and etc). CONCLUSIONS: In using "Hangul" in data management and reporting, we became to be familiar with QuipsTM and had good responses from clinicians.