RESUMO
OBJECTIVE: The objective of this study was to investigate the influence of mental abacus calculation training (MACT) on subliminal cognitive processes. METHODS: Twenty children with intensive MACT (MACT group) and 20 children without MACT (non-MACT group) were selected. The two groups of children were matched in age, sex, handedness and academic grade. The participants were tested with subthreshold arithmetic priming task while their neural activities were recorded with a 32-channel electroencephalogram system. RESULTS: We found that MACT changed the subliminal cognitive mechanism of computational processing, speeding up the computation. MACT affected the computational processing mode. Specifically, in the identification stage, both groups of children adopted the visual space processing mode, while in the computing stage, the MACT group adopted a visual space processing mode, but the non-MACT group adopted a semantic processing mode. Moreover, MACT improved children's executive functions. CONCLUSION: These results yielded insights into the effect of early abacus training on children's cognitive processing, providing a theoretical basis for the development and promotion of abacus training.
Assuntos
Encéfalo , Resolução de Problemas , Criança , Eletroencefalografia , Função Executiva , Humanos , MatemáticaRESUMO
Objective: To investigate the chemical constituents from Xanthium mongolicum. Methods: The constituents were isolated and purified by silicagel,Sephadex LH-20 column chromatography. Their structures were identified on the basis of spectral data and physiochemical characteristics. Results: Ten compounds were isolated and identified as hexadecanoic acid( 1), methyl 3, 4-dihydroxybenzoate ( 2), protocatechuic aldehyde( 3), caffeic acid methyl ester( 4), vanillic acid( 5), 4-hydroxybenzoic acid( 6), caffeic acid ethyl ester( 7), chlorogenic acid( 8), caffeic acid( 9), 3, 4-di-O-caffeoylquinic acid( 10). Conclusion: Compounds 1 ~ 5,7 and 10 are isolated from this plant for the first time.
