Objective: We examined the characteristics of working memory (WM) in children with high function pervasive developmental disorders (HFPDDs), focusing on their information processing.Methods: WM tasks were administered to the HFPDDs group and the controls matched for age and IQ: other neurological disorder (OND) group and typically developing children (TD) group. To mimic a setting encountered in everyday life, specifically a classroom at school, we administered the task to groups of 4-6 children. To assess the state of WM, we used different words (both with and without meaning) written in hiragana.Results: There were no significant differences between the correct answer rate of the words with/without meaning in the HFPDDs group. Notably, the correct answer rate of the words with meaning was significantly higher than that of the words without meaning in the control groups.Conclusion: We concluded that children with HFPDDs have enhanced meaningless WM so that semantic strategy does not fully function in their information processing.

Information volume, evoked potentials and reaction time with voice were studied for reading Japanese cursive syllabary “HIRAGANAs”. Thirty-two EEGs with a filter from DC to 100 Hz were sampled at 2 kHz into 24 bits during 1000 ms after displaying HIRAGANAs. Evoked potentials were marked over the frontal and occipital areas, because of referring to scalp central areas, then the potentials were converted with the current source derivation. Reaction times for voice were 623±137 for one HIRAGANA, 819±136 for two HIRAGANAs, 993±169 ms for four HIRAGANAs. Broad central areas showed graded different potentials between reading silently and aloud, corresponding to the volume of the information, after 100 ms before 500 ms displaying HIRAGANAs.