RESUMO
This event-related functional MRI study examined the neural correlates for Chinese writing, by comparing the writing of logographic characters and that of pinyin, a phonetic notation system for Chinese characters. The temporal profile of the activations indicated that the middle frontal gyrus, superior parietal lobule, and posterior inferior temporal gyrus reflected more central processes for writing. Although pinyin writing elicited greater activity overall than character writing, the critical finding is that the two types of symbols recruited essentially the same brain regions. The results were compared with studies in Japanese showing dissociation between logographic kanji and phonetic kana writing and frequency of use was suggested to be an important factor in accounting for result differences across the two writing systems.
Assuntos
Encéfalo/fisiologia , Escrita Manual , Adolescente , Adulto , Córtex Cerebral/fisiologia , China , Sinais (Psicologia) , Interpretação Estatística de Dados , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Idioma , Imageamento por Ressonância Magnética , Masculino , Oxigênio/sangue , Fonética , Desempenho Psicomotor/fisiologia , Lobo Temporal/fisiologiaRESUMO
BACKGROUND: Functional magnetic resonance imaging (fMRI) has become a powerful tool for tracking human brain activity in vivo. This technique is mainly based on blood oxygenation level dependence (BOLD) contrast. In the present study, we employed this newly developed technique to characterize the neural representations of human portraits and natural sceneries in the human brain. METHODS: Nine subjects were scanned with a 1.5 T magnetic resonance imaging (MRI) scanner using gradient-recalled echo and echo-planar imaging (GRE-EPI) pulse sequence while they were visually presented with 3 types of white-black photographs: natural scenery, human portraits, and scrambled nonsense pictures. Multiple linear regression was used to identify brain regions responding preferentially to each type of stimulus and common regions for both human portraits and natural scenery. The relative contributions of each type of stimulus to activation in these regions were examined using linear combinations of a general linear test. RESULTS: Multiple linear regression analysis revealed two distinct but adjacent regions in both sides of the ventral temporal cortex. The medial region preferentially responded to natural scenery, whereas the lateral one preferentially responded to the human portraits. The general linear test further revealed a distribution gradient such that a change from portraits to scenes shifted areas of activation from lateral to medial. CONCLUSIONS: The boundary between portrait-associated and scenery-associated areas is not as clear as previously demonstrated. The representations of portraits and scenes in ventral temporal cortex appear to be continuous and overlap.